diff options
| author | Jonathan Corbet <corbet@lwn.net> | 2023-03-23 14:15:28 -0600 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2023-03-30 13:00:34 -0600 |
| commit | 1a2ac6d7ecdcde74a4e16f31de64124160fc7237 (patch) | |
| tree | 3d676da9f6598204197784cbfdd1a0f32e1adac3 /Documentation/sparc | |
| parent | 87670c577041dc6d9daa1e39a3953002c6733d7f (diff) | |
| download | linux-stable-1a2ac6d7ecdcde74a4e16f31de64124160fc7237.tar.gz linux-stable-1a2ac6d7ecdcde74a4e16f31de64124160fc7237.tar.bz2 linux-stable-1a2ac6d7ecdcde74a4e16f31de64124160fc7237.zip | |
docs: move sparc documentation under Documentation/arch/
Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy. Move
Documentation/sparc into arch/ and fix all in-tree references.
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/sparc')
| -rw-r--r-- | Documentation/sparc/adi.rst | 286 | ||||
| -rw-r--r-- | Documentation/sparc/console.rst | 9 | ||||
| -rw-r--r-- | Documentation/sparc/features.rst | 3 | ||||
| -rw-r--r-- | Documentation/sparc/index.rst | 13 | ||||
| -rw-r--r-- | Documentation/sparc/oradax/dax-hv-api.txt | 1433 | ||||
| -rw-r--r-- | Documentation/sparc/oradax/oracle-dax.rst | 445 |
6 files changed, 0 insertions, 2189 deletions
diff --git a/Documentation/sparc/adi.rst b/Documentation/sparc/adi.rst deleted file mode 100644 index dbcd8b6e7bc3..000000000000 --- a/Documentation/sparc/adi.rst +++ /dev/null @@ -1,286 +0,0 @@ -================================ -Application Data Integrity (ADI) -================================ - -SPARC M7 processor adds the Application Data Integrity (ADI) feature. -ADI allows a task to set version tags on any subset of its address -space. Once ADI is enabled and version tags are set for ranges of -address space of a task, the processor will compare the tag in pointers -to memory in these ranges to the version set by the application -previously. Access to memory is granted only if the tag in given pointer -matches the tag set by the application. In case of mismatch, processor -raises an exception. - -Following steps must be taken by a task to enable ADI fully: - -1. Set the user mode PSTATE.mcde bit. This acts as master switch for - the task's entire address space to enable/disable ADI for the task. - -2. Set TTE.mcd bit on any TLB entries that correspond to the range of - addresses ADI is being enabled on. MMU checks the version tag only - on the pages that have TTE.mcd bit set. - -3. Set the version tag for virtual addresses using stxa instruction - and one of the MCD specific ASIs. Each stxa instruction sets the - given tag for one ADI block size number of bytes. This step must - be repeated for entire page to set tags for entire page. - -ADI block size for the platform is provided by the hypervisor to kernel -in machine description tables. Hypervisor also provides the number of -top bits in the virtual address that specify the version tag. Once -version tag has been set for a memory location, the tag is stored in the -physical memory and the same tag must be present in the ADI version tag -bits of the virtual address being presented to the MMU. For example on -SPARC M7 processor, MMU uses bits 63-60 for version tags and ADI block -size is same as cacheline size which is 64 bytes. A task that sets ADI -version to, say 10, on a range of memory, must access that memory using -virtual addresses that contain 0xa in bits 63-60. - -ADI is enabled on a set of pages using mprotect() with PROT_ADI flag. -When ADI is enabled on a set of pages by a task for the first time, -kernel sets the PSTATE.mcde bit for the task. Version tags for memory -addresses are set with an stxa instruction on the addresses using -ASI_MCD_PRIMARY or ASI_MCD_ST_BLKINIT_PRIMARY. ADI block size is -provided by the hypervisor to the kernel. Kernel returns the value of -ADI block size to userspace using auxiliary vector along with other ADI -info. Following auxiliary vectors are provided by the kernel: - - ============ =========================================== - AT_ADI_BLKSZ ADI block size. This is the granularity and - alignment, in bytes, of ADI versioning. - AT_ADI_NBITS Number of ADI version bits in the VA - ============ =========================================== - - -IMPORTANT NOTES -=============== - -- Version tag values of 0x0 and 0xf are reserved. These values match any - tag in virtual address and never generate a mismatch exception. - -- Version tags are set on virtual addresses from userspace even though - tags are stored in physical memory. Tags are set on a physical page - after it has been allocated to a task and a pte has been created for - it. - -- When a task frees a memory page it had set version tags on, the page - goes back to free page pool. When this page is re-allocated to a task, - kernel clears the page using block initialization ASI which clears the - version tags as well for the page. If a page allocated to a task is - freed and allocated back to the same task, old version tags set by the - task on that page will no longer be present. - -- ADI tag mismatches are not detected for non-faulting loads. - -- Kernel does not set any tags for user pages and it is entirely a - task's responsibility to set any version tags. Kernel does ensure the - version tags are preserved if a page is swapped out to the disk and - swapped back in. It also preserves that version tags if a page is - migrated. - -- ADI works for any size pages. A userspace task need not be aware of - page size when using ADI. It can simply select a virtual address - range, enable ADI on the range using mprotect() and set version tags - for the entire range. mprotect() ensures range is aligned to page size - and is a multiple of page size. - -- ADI tags can only be set on writable memory. For example, ADI tags can - not be set on read-only mappings. - - - -ADI related traps -================= - -With ADI enabled, following new traps may occur: - -Disrupting memory corruption ----------------------------- - - When a store accesses a memory location that has TTE.mcd=1, - the task is running with ADI enabled (PSTATE.mcde=1), and the ADI - tag in the address used (bits 63:60) does not match the tag set on - the corresponding cacheline, a memory corruption trap occurs. By - default, it is a disrupting trap and is sent to the hypervisor - first. Hypervisor creates a sun4v error report and sends a - resumable error (TT=0x7e) trap to the kernel. The kernel sends - a SIGSEGV to the task that resulted in this trap with the following - info:: - - siginfo.si_signo = SIGSEGV; - siginfo.errno = 0; - siginfo.si_code = SEGV_ADIDERR; - siginfo.si_addr = addr; /* PC where first mismatch occurred */ - siginfo.si_trapno = 0; - - -Precise memory corruption -------------------------- - - When a store accesses a memory location that has TTE.mcd=1, - the task is running with ADI enabled (PSTATE.mcde=1), and the ADI - tag in the address used (bits 63:60) does not match the tag set on - the corresponding cacheline, a memory corruption trap occurs. If - MCD precise exception is enabled (MCDPERR=1), a precise - exception is sent to the kernel with TT=0x1a. The kernel sends - a SIGSEGV to the task that resulted in this trap with the following - info:: - - siginfo.si_signo = SIGSEGV; - siginfo.errno = 0; - siginfo.si_code = SEGV_ADIPERR; - siginfo.si_addr = addr; /* address that caused trap */ - siginfo.si_trapno = 0; - - NOTE: - ADI tag mismatch on a load always results in precise trap. - - -MCD disabled ------------- - - When a task has not enabled ADI and attempts to set ADI version - on a memory address, processor sends an MCD disabled trap. This - trap is handled by hypervisor first and the hypervisor vectors this - trap through to the kernel as Data Access Exception trap with - fault type set to 0xa (invalid ASI). When this occurs, the kernel - sends the task SIGSEGV signal with following info:: - - siginfo.si_signo = SIGSEGV; - siginfo.errno = 0; - siginfo.si_code = SEGV_ACCADI; - siginfo.si_addr = addr; /* address that caused trap */ - siginfo.si_trapno = 0; - - -Sample program to use ADI -------------------------- - -Following sample program is meant to illustrate how to use the ADI -functionality:: - - #include <unistd.h> - #include <stdio.h> - #include <stdlib.h> - #include <elf.h> - #include <sys/ipc.h> - #include <sys/shm.h> - #include <sys/mman.h> - #include <asm/asi.h> - - #ifndef AT_ADI_BLKSZ - #define AT_ADI_BLKSZ 48 - #endif - #ifndef AT_ADI_NBITS - #define AT_ADI_NBITS 49 - #endif - - #ifndef PROT_ADI - #define PROT_ADI 0x10 - #endif - - #define BUFFER_SIZE 32*1024*1024UL - - main(int argc, char* argv[], char* envp[]) - { - unsigned long i, mcde, adi_blksz, adi_nbits; - char *shmaddr, *tmp_addr, *end, *veraddr, *clraddr; - int shmid, version; - Elf64_auxv_t *auxv; - - adi_blksz = 0; - - while(*envp++ != NULL); - for (auxv = (Elf64_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) { - switch (auxv->a_type) { - case AT_ADI_BLKSZ: - adi_blksz = auxv->a_un.a_val; - break; - case AT_ADI_NBITS: - adi_nbits = auxv->a_un.a_val; - break; - } - } - if (adi_blksz == 0) { - fprintf(stderr, "Oops! ADI is not supported\n"); - exit(1); - } - - printf("ADI capabilities:\n"); - printf("\tBlock size = %ld\n", adi_blksz); - printf("\tNumber of bits = %ld\n", adi_nbits); - - if ((shmid = shmget(2, BUFFER_SIZE, - IPC_CREAT | SHM_R | SHM_W)) < 0) { - perror("shmget failed"); - exit(1); - } - - shmaddr = shmat(shmid, NULL, 0); - if (shmaddr == (char *)-1) { - perror("shm attach failed"); - shmctl(shmid, IPC_RMID, NULL); - exit(1); - } - - if (mprotect(shmaddr, BUFFER_SIZE, PROT_READ|PROT_WRITE|PROT_ADI)) { - perror("mprotect failed"); - goto err_out; - } - - /* Set the ADI version tag on the shm segment - */ - version = 10; - tmp_addr = shmaddr; - end = shmaddr + BUFFER_SIZE; - while (tmp_addr < end) { - asm volatile( - "stxa %1, [%0]0x90\n\t" - : - : "r" (tmp_addr), "r" (version)); - tmp_addr += adi_blksz; - } - asm volatile("membar #Sync\n\t"); - - /* Create a versioned address from the normal address by placing - * version tag in the upper adi_nbits bits - */ - tmp_addr = (void *) ((unsigned long)shmaddr << adi_nbits); - tmp_addr = (void *) ((unsigned long)tmp_addr >> adi_nbits); - veraddr = (void *) (((unsigned long)version << (64-adi_nbits)) - | (unsigned long)tmp_addr); - - printf("Starting the writes:\n"); - for (i = 0; i < BUFFER_SIZE; i++) { - veraddr[i] = (char)(i); - if (!(i % (1024 * 1024))) - printf("."); - } - printf("\n"); - - printf("Verifying data..."); - fflush(stdout); - for (i = 0; i < BUFFER_SIZE; i++) - if (veraddr[i] != (char)i) - printf("\nIndex %lu mismatched\n", i); - printf("Done.\n"); - - /* Disable ADI and clean up - */ - if (mprotect(shmaddr, BUFFER_SIZE, PROT_READ|PROT_WRITE)) { - perror("mprotect failed"); - goto err_out; - } - - if (shmdt((const void *)shmaddr) != 0) - perror("Detach failure"); - shmctl(shmid, IPC_RMID, NULL); - - exit(0); - - err_out: - if (shmdt((const void *)shmaddr) != 0) - perror("Detach failure"); - shmctl(shmid, IPC_RMID, NULL); - exit(1); - } diff --git a/Documentation/sparc/console.rst b/Documentation/sparc/console.rst deleted file mode 100644 index 73132db83ece..000000000000 --- a/Documentation/sparc/console.rst +++ /dev/null @@ -1,9 +0,0 @@ -Steps for sending 'break' on sunhv console -========================================== - -On Baremetal: - 1. press Esc + 'B' - -On LDOM: - 1. press Ctrl + ']' - 2. telnet> send break diff --git a/Documentation/sparc/features.rst b/Documentation/sparc/features.rst deleted file mode 100644 index c0c92468b0fe..000000000000 --- a/Documentation/sparc/features.rst +++ /dev/null @@ -1,3 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -.. kernel-feat:: $srctree/Documentation/features sparc diff --git a/Documentation/sparc/index.rst b/Documentation/sparc/index.rst deleted file mode 100644 index ae884224eec2..000000000000 --- a/Documentation/sparc/index.rst +++ /dev/null @@ -1,13 +0,0 @@ -================== -Sparc Architecture -================== - -.. toctree:: - :maxdepth: 1 - - console - adi - - oradax/oracle-dax - - features diff --git a/Documentation/sparc/oradax/dax-hv-api.txt b/Documentation/sparc/oradax/dax-hv-api.txt deleted file mode 100644 index 7ecd0bf4957b..000000000000 --- a/Documentation/sparc/oradax/dax-hv-api.txt +++ /dev/null @@ -1,1433 +0,0 @@ -Excerpt from UltraSPARC Virtual Machine Specification -Compiled from version 3.0.20+15 -Publication date 2017-09-25 08:21 -Copyright © 2008, 2015 Oracle and/or its affiliates. All rights reserved. -Extracted via "pdftotext -f 547 -l 572 -layout sun4v_20170925.pdf" -Authors: - Charles Kunzman - Sam Glidden - Mark Cianchetti - - -Chapter 36. Coprocessor services - The following APIs provide access via the Hypervisor to hardware assisted data processing functionality. - These APIs may only be provided by certain platforms, and may not be available to all virtual machines - even on supported platforms. Restrictions on the use of these APIs may be imposed in order to support - live-migration and other system management activities. - -36.1. Data Analytics Accelerator - The Data Analytics Accelerator (DAX) functionality is a collection of hardware coprocessors that provide - high speed processoring of database-centric operations. The coprocessors may support one or more of - the following data query operations: search, extraction, compression, decompression, and translation. The - functionality offered may vary by virtual machine implementation. - - The DAX is a virtual device to sun4v guests, with supported data operations indicated by the virtual device - compatibility property. Functionality is accessed through the submission of Command Control Blocks - (CCBs) via the ccb_submit API function. The operations are processed asynchronously, with the status - of the submitted operations reported through a Completion Area linked to each CCB. Each CCB has a - separate Completion Area and, unless execution order is specifically restricted through the use of serial- - conditional flags, the execution order of submitted CCBs is arbitrary. Likewise, the time to completion - for a given CCB is never guaranteed. - - Guest software may implement a software timeout on CCB operations, and if the timeout is exceeded, the - operation may be cancelled or killed via the ccb_kill API function. It is recommended for guest software - to implement a software timeout to account for certain RAS errors which may result in lost CCBs. It is - recommended such implementation use the ccb_info API function to check the status of a CCB prior to - killing it in order to determine if the CCB is still in queue, or may have been lost due to a RAS error. - - There is no fixed limit on the number of outstanding CCBs guest software may have queued in the virtual - machine, however, internal resource limitations within the virtual machine can cause CCB submissions - to be temporarily rejected with EWOULDBLOCK. In such cases, guests should continue to attempt - submissions until they succeed; waiting for an outstanding CCB to complete is not necessary, and would - not be a guarantee that a future submission would succeed. - - The availablility of DAX coprocessor command service is indicated by the presence of the DAX virtual - device node in the guest MD (Section 8.24.17, “Database Analytics Accelerators (DAX) virtual-device - node”). - -36.1.1. DAX Compatibility Property - The query functionality may vary based on the compatibility property of the virtual device: - -36.1.1.1. "ORCL,sun4v-dax" Device Compatibility - Available CCB commands: - - • No-op/Sync - - • Extract - - • Scan Value - - • Inverted Scan Value - - • Scan Range - - - 509 - Coprocessor services - - - • Inverted Scan Range - - • Translate - - • Inverted Translate - - • Select - - See Section 36.2.1, “Query CCB Command Formats” for the corresponding CCB input and output formats. - - Only version 0 CCBs are available. - -36.1.1.2. "ORCL,sun4v-dax-fc" Device Compatibility - "ORCL,sun4v-dax-fc" is compatible with the "ORCL,sun4v-dax" interface, and includes additional CCB - bit fields and controls. - -36.1.1.3. "ORCL,sun4v-dax2" Device Compatibility - Available CCB commands: - - • No-op/Sync - - • Extract - - • Scan Value - - • Inverted Scan Value - - • Scan Range - - • Inverted Scan Range - - • Translate - - • Inverted Translate - - • Select - - See Section 36.2.1, “Query CCB Command Formats” for the corresponding CCB input and output formats. - - Version 0 and 1 CCBs are available. Only version 0 CCBs may use Huffman encoded data, whereas only - version 1 CCBs may use OZIP. - -36.1.2. DAX Virtual Device Interrupts - The DAX virtual device has multiple interrupts associated with it which may be used by the guest if - desired. The number of device interrupts available to the guest is indicated in the virtual device node of the - guest MD (Section 8.24.17, “Database Analytics Accelerators (DAX) virtual-device node”). If the device - node indicates N interrupts available, the guest may use any value from 0 to N - 1 (inclusive) in a CCB - interrupt number field. Using values outside this range will result in the CCB being rejected for an invalid - field value. - - The interrupts may be bound and managed using the standard sun4v device interrupts API (Chapter 16, - Device interrupt services). Sysino interrupts are not available for DAX devices. - -36.2. Coprocessor Control Block (CCB) - CCBs are either 64 or 128 bytes long, depending on the operation type. The exact contents of the CCB - are command specific, but all CCBs contain at least one memory buffer address. All memory locations - - - 510 - Coprocessor services - - -referenced by a CCB must be pinned in memory until the CCB either completes execution or is killed -via the ccb_kill API call. Changes in virtual address mappings occurring after CCB submission are not -guaranteed to be visible, and as such all virtual address updates need to be synchronized with CCB -execution. - -All CCBs begin with a common 32-bit header. - -Table 36.1. CCB Header Format -Bits Field Description -[31:28] CCB version. For API version 2.0: set to 1 if CCB uses OZIP encoding; set to 0 if the CCB - uses Huffman encoding; otherwise either 0 or 1. For API version 1.0: always set to 0. -[27] When API version 2.0 is negotiated, this is the Pipeline Flag [512]. It is reserved in - API version 1.0 -[26] Long CCB flag [512] -[25] Conditional synchronization flag [512] -[24] Serial synchronization flag -[23:16] CCB operation code: - 0x00 No Operation (No-op) or Sync - 0x01 Extract - 0x02 Scan Value - 0x12 Inverted Scan Value - 0x03 Scan Range - 0x13 Inverted Scan Range - 0x04 Translate - 0x14 Inverted Translate - 0x05 Select -[15:13] Reserved -[12:11] Table address type - 0b'00 No address - 0b'01 Alternate context virtual address - 0b'10 Real address - 0b'11 Primary context virtual address -[10:8] Output/Destination address type - 0b'000 No address - 0b'001 Alternate context virtual address - 0b'010 Real address - 0b'011 Primary context virtual address - 0b'100 Reserved - 0b'101 Reserved - 0b'110 Reserved - 0b'111 Reserved -[7:5] Secondary source address type - - - 511 - Coprocessor services - - -Bits Field Description - 0b'000 No address - 0b'001 Alternate context virtual address - 0b'010 Real address - 0b'011 Primary context virtual address - 0b'100 Reserved - 0b'101 Reserved - 0b'110 Reserved - 0b'111 Reserved -[4:2] Primary source address type - 0b'000 No address - 0b'001 Alternate context virtual address - 0b'010 Real address - 0b'011 Primary context virtual address - 0b'100 Reserved - 0b'101 Reserved - 0b'110 Reserved - 0b'111 Reserved -[1:0] Completion area address type - 0b'00 No address - 0b'01 Alternate context virtual address - 0b'10 Real address - 0b'11 Primary context virtual address - -The Long CCB flag indicates whether the submitted CCB is 64 or 128 bytes long; value is 0 for 64 bytes -and 1 for 128 bytes. - -The Serial and Conditional flags allow simple relative ordering between CCBs. Any CCB with the Serial -flag set will execute sequentially relative to any previous CCB that is also marked as Serial in the same -CCB submission. CCBs without the Serial flag set execute independently, even if they are between CCBs -with the Serial flag set. CCBs marked solely with the Serial flag will execute upon the completion of the -previous Serial CCB, regardless of the completion status of that CCB. The Conditional flag allows CCBs -to conditionally execute based on the successful execution of the closest CCB marked with the Serial flag. -A CCB may only be conditional on exactly one CCB, however, a CCB may be marked both Conditional -and Serial to allow execution chaining. The flags do NOT allow fan-out chaining, where multiple CCBs -execute in parallel based on the completion of another CCB. - -The Pipeline flag is an optimization that directs the output of one CCB (the "source" CCB) directly to -the input of the next CCB (the "target" CCB). The target CCB thus does not need to read the input from -memory. The Pipeline flag is advisory and may be dropped. - -Both the Pipeline and Serial bits must be set in the source CCB. The Conditional bit must be set in the -target CCB. Exactly one CCB must be made conditional on the source CCB; either 0 or 2 target CCBs -is invalid. However, Pipelines can be extended beyond two CCBs: the sequence would start with a CCB -with both the Pipeline and Serial bits set, proceed through CCBs with the Pipeline, Serial, and Conditional -bits set, and terminate at a CCB that has the Conditional bit set, but not the Pipeline bit. - - - 512 - Coprocessor services - - - The input of the target CCB must start within 64 bytes of the output of the source CCB or the pipeline flag - will be ignored. All CCBs in a pipeline must be submitted in the same call to ccb_submit. - - The various address type fields indicate how the various address values used in the CCB should be - interpreted by the virtual machine. Not all of the types specified are used by every CCB format. Types - which are not applicable to the given CCB command should be indicated as type 0 (No address). Virtual - addresses used in the CCB must have translation entries present in either the TLB or a configured TSB - for the submitting virtual processor. Virtual addresses which cannot be translated by the virtual machine - will result in the CCB submission being rejected, with the causal virtual address indicated. The CCB - may be resubmitted after inserting the translation, or the address may be translated by guest software and - resubmitted using the real address translation. - -36.2.1. Query CCB Command Formats -36.2.1.1. Supported Data Formats, Elements Sizes and Offsets - Data for query commands may be encoded in multiple possible formats. The data query commands use a - common set of values to indicate the encoding formats of the data being processed. Some encoding formats - require multiple data streams for processing, requiring the specification of both primary data formats (the - encoded data) and secondary data streams (meta-data for the encoded data). - -36.2.1.1.1. Primary Input Format - - The primary input format code is a 4-bit field when it is used. There are 10 primary input formats available. - The packed formats are not endian neutral. Code values not listed below are reserved. - - Code Format Description - 0x0 Fixed width byte packed Up to 16 bytes - 0x1 Fixed width bit packed Up to 15 bits (CCB version 0) or 23 bits (CCB version - 1); bits are read most significant bit to least significant bit - within a byte - 0x2 Variable width byte packed Data stream of lengths must be provided as a secondary - input - 0x4 Fixed width byte packed with run Up to 16 bytes; data stream of run lengths must be - length encoding provided as a secondary input - 0x5 Fixed width bit packed with run Up to 15 bits (CCB version 0) or 23 bits (CCB version - length encoding 1); bits are read most significant bit to least significant bit - within a byte; data stream of run lengths must be provided - as a secondary input - 0x8 Fixed width byte packed with Up to 16 bytes before the encoding; compressed stream - Huffman (CCB version 0) or bits are read most significant bit to least significant bit - OZIP (CCB version 1) encoding within a byte; pointer to the encoding table must be - provided - 0x9 Fixed width bit packed with Up to 15 bits (CCB version 0) or 23 bits (CCB version - Huffman (CCB version 0) or 1); compressed stream bits are read most significant bit to - OZIP (CCB version 1) encoding least significant bit within a byte; pointer to the encoding - table must be provided - 0xA Variable width byte packed with Up to 16 bytes before the encoding; compressed stream - Huffman (CCB version 0) or bits are read most significant bit to least significant bit - OZIP (CCB version 1) encoding within a byte; data stream of lengths must be provided as - a secondary input; pointer to the encoding table must be - provided - - - 513 - Coprocessor services - - - Code Format Description - 0xC Fixed width byte packed with Up to 16 bytes before the encoding; compressed stream - run length encoding, followed by bits are read most significant bit to least significant bit - Huffman (CCB version 0) or within a byte; data stream of run lengths must be provided - OZIP (CCB version 1) encoding as a secondary input; pointer to the encoding table must - be provided - 0xD Fixed width bit packed with Up to 15 bits (CCB version 0) or 23 bits(CCB version 1) - run length encoding, followed by before the encoding; compressed stream bits are read most - Huffman (CCB version 0) or significant bit to least significant bit within a byte; data - OZIP (CCB version 1) encoding stream of run lengths must be provided as a secondary - input; pointer to the encoding table must be provided - - If OZIP encoding is used, there must be no reserved bytes in the table. - -36.2.1.1.2. Primary Input Element Size - - For primary input data streams with fixed size elements, the element size must be indicated in the CCB - command. The size is encoded as the number of bits or bytes, minus one. The valid value range for this - field depends on the input format selected, as listed in the table above. - -36.2.1.1.3. Secondary Input Format - - For primary input data streams which require a secondary input stream, the secondary input stream is - always encoded in a fixed width, bit-packed format. The bits are read from most significant bit to least - significant bit within a byte. There are two encoding options for the secondary input stream data elements, - depending on whether the value of 0 is needed: - - Secondary Input Description - Format Code - 0 Element is stored as value minus 1 (0 evaluates to 1, 1 evaluates - to 2, etc) - 1 Element is stored as value - -36.2.1.1.4. Secondary Input Element Size - - Secondary input element size is encoded as a two bit field: - - Secondary Input Size Description - Code - 0x0 1 bit - 0x1 2 bits - 0x2 4 bits - 0x3 8 bits - -36.2.1.1.5. Input Element Offsets - - Bit-wise input data streams may have any alignment within the base addressed byte. The offset, specified - from most significant bit to least significant bit, is provided as a fixed 3 bit field for each input type. A - value of 0 indicates that the first input element begins at the most significant bit in the first byte, and a - value of 7 indicates it begins with the least significant bit. - - This field should be zero for any byte-wise primary input data streams. - - - 514 - Coprocessor services - - -36.2.1.1.6. Output Format - - Query commands support multiple sizes and encodings for output data streams. There are four possible - output encodings, and up to four supported element sizes per encoding. Not all output encodings are - supported for every command. The format is indicated by a 4-bit field in the CCB: - - Output Format Code Description - 0x0 Byte aligned, 1 byte elements - 0x1 Byte aligned, 2 byte elements - 0x2 Byte aligned, 4 byte elements - 0x3 Byte aligned, 8 byte elements - 0x4 16 byte aligned, 16 byte elements - 0x5 Reserved - 0x6 Reserved - 0x7 Reserved - 0x8 Packed vector of single bit elements - 0x9 Reserved - 0xA Reserved - 0xB Reserved - 0xC Reserved - 0xD 2 byte elements where each element is the index value of a bit, - from an bit vector, which was 1. - 0xE 4 byte elements where each element is the index value of a bit, - from an bit vector, which was 1. - 0xF Reserved - -36.2.1.1.7. Application Data Integrity (ADI) - - On platforms which support ADI, the ADI version number may be specified for each separate memory - access type used in the CCB command. ADI checking only occurs when reading data. When writing data, - the specified ADI version number overwrites any existing ADI value in memory. - - An ADI version value of 0 or 0xF indicates the ADI checking is disabled for that data access, even if it is - enabled in memory. By setting the appropriate flag in CCB_SUBMIT (Section 36.3.1, “ccb_submit”) it is - also an option to disable ADI checking for all inputs accessed via virtual address for all CCBs submitted - during that hypercall invocation. - - The ADI value is only guaranteed to be checked on the first 64 bytes of each data access. Mismatches on - subsequent data chunks may not be detected, so guest software should be careful to use page size checking - to protect against buffer overruns. - -36.2.1.1.8. Page size checking - - All data accesses used in CCB commands must be bounded within a single memory page. When addresses - are provided using a virtual address, the page size for checking is extracted from the TTE for that virtual - address. When using real addresses, the guest must supply the page size in the same field as the address - value. The page size must be one of the sizes supported by the underlying virtual machine. Using a value - that is not supported may result in the CCB submission being rejected or the generation of a CCB parsing - error in the completion area. - - - 515 - Coprocessor services - - -36.2.1.2. Extract command - - Converts an input vector in one format to an output vector in another format. All input format types are - supported. - - The only supported output format is a padded, byte-aligned output stream, using output codes 0x0 - 0x4. - When the specified output element size is larger than the extracted input element size, zeros are padded to - the extracted input element. First, if the decompressed input size is not a whole number of bytes, 0 bits are - padded to the most significant bit side till the next byte boundary. Next, if the output element size is larger - than the byte padded input element, bytes of value 0 are added based on the Padding Direction bit in the - CCB. If the output element size is smaller than the byte-padded input element size, the input element is - truncated by dropped from the least significant byte side until the selected output size is reached. - - The return value of the CCB completion area is invalid. The “number of elements processed” field in the - CCB completion area will be valid. - - The extract CCB is a 64-byte “short format” CCB. - - The extract CCB command format can be specified by the following packed C structure for a big-endian - machine: - - - struct extract_ccb { - uint32_t header; - uint32_t control; - uint64_t completion; - uint64_t primary_input; - uint64_t data_access_control; - uint64_t secondary_input; - uint64_t reserved; - uint64_t output; - uint64_t table; - }; - - - The exact field offsets, sizes, and composition are as follows: - - Offset Size Field Description - 0 4 CCB header (Table 36.1, “CCB Header Format”) - 4 4 Command control - Bits Field Description - [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input - Format”) - [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary - Input Element Size”) - [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary - Input Format”) - [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - - - 516 - Coprocessor services - - -Offset Size Field Description - Bits Field Description - [15:14] Secondary Input Element Size (see Section 36.2.1.1.4, - “Secondary Input Element Size” - [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”) - [9] Padding Direction selector: A value of 1 causes padding bytes - to be added to the left side of output elements. A value of 0 - causes padding bytes to be added to the right side of output - elements. - [8:0] Reserved -8 8 Completion - Bits Field Description - [63:60] ADI version (see Section 36.2.1.1.7, “Application Data - Integrity (ADI)”) - [59] If set to 1, a virtual device interrupt will be generated using - the device interrupt number specified in the lower bits of this - completion word. If 0, the lower bits of this completion word - are ignored. - [58:6] Completion area address bits [58:6]. Address type is - determined by CCB header. - [5:0] Virtual device interrupt number for completion interrupt, if - enabled. -16 8 Primary Input - Bits Field Description - [63:60] ADI version (see Section 36.2.1.1.7, “Application Data - Integrity (ADI)”) - [59:56] If using real address, these bits should be filled in with the - page size code for the page boundary checking the guest wants - the virtual machine to use when accessing this data stream - (checking is only guaranteed to be performed when using API - version 1.1 and later). If using a virtual address, this field will - be used as as primary input address bits [59:56]. - [55:0] Primary input address bits [55:0]. Address type is determined - by CCB header. -24 8 Data Access Control - Bits Field Description - [63:62] Flow Control - Value Description - 0b'00 Disable flow control - 0b'01 Enable flow control (only valid with "ORCL,sun4v- - dax-fc" compatible virtual device variants) - 0b'10 Reserved - 0b'11 Reserved - [61:60] Reserved (API 1.0) - - - 517 - Coprocessor services - - -Offset Size Field Description - Bits Field Description - Pipeline target (API 2.0) - Value Description - 0b'00 Connect to primary input - 0b'01 Connect to secondary input - 0b'10 Reserved - 0b'11 Reserved - [59:40] Output buffer size given in units of 64 bytes, minus 1. Value of - 0 means 64 bytes, value of 1 means 128 bytes, etc. Buffer size is - only enforced if flow control is enabled in Flow Control field. - [39:32] Reserved - [31:30] Output Data Cache Allocation - Value Description - 0b'00 Do not allocate cache lines for output data stream. - 0b'01 Force cache lines for output data stream to be - allocated in the cache that is local to the submitting - virtual cpu. - 0b'10 Allocate cache lines for output data stream, but allow - existing cache lines associated with the data to remain - in their current cache instance. Any memory not - already in cache will be allocated in the cache local - to the submitting virtual cpu. - 0b'11 Reserved - [29:26] Reserved - [25:24] Primary Input Length Format - Value Description - 0b'00 Number of primary symbols - 0b'01 Number of primary bytes - 0b'10 Number of primary bits - 0b'11 Reserved - [23:0] Primary Input Length - Format Field Value - # of primary symbols Number of input elements to process, - minus 1. Command execution stops - once count is reached. - # of primary bytes Number of input bytes to process, - minus 1. Command execution stops - once count is reached. The count is - done before any decompression or - decoding. - # of primary bits Number of input bits to process, - minus 1. Command execution stops - - - - 518 - Coprocessor services - - - Offset Size Field Description - Bits Field Description - Format Field Value - once count is reached. The count is - done before any decompression or - decoding, and does not include any - bits skipped by the Primary Input - Offset field value of the command - control word. - 32 8 Secondary Input, if used by Primary Input Format. Same fields as Primary - Input. - 40 8 Reserved - 48 8 Output (same fields as Primary Input) - 56 8 Symbol Table (if used by Primary Input) - Bits Field Description - [63:60] ADI version (see Section 36.2.1.1.7, “Application Data - Integrity (ADI)”) - [59:56] If using real address, these bits should be filled in with the - page size code for the page boundary checking the guest wants - the virtual machine to use when accessing this data stream - (checking is only guaranteed to be performed when using API - version 1.1 and later). If using a virtual address, this field will - be used as as symbol table address bits [59:56]. - [55:4] Symbol table address bits [55:4]. Address type is determined - by CCB header. - [3:0] Symbol table version - Value Description - 0 Huffman encoding. Must use 64 byte aligned table - address. (Only available when using version 0 CCBs) - 1 OZIP encoding. Must use 16 byte aligned table - address. (Only available when using version 1 CCBs) - - -36.2.1.3. Scan commands - - The scan commands search a stream of input data elements for values which match the selection criteria. - All the input format types are supported. There are multiple formats for the scan commands, allowing the - scan to search for exact matches to one value, exact matches to either of two values, or any value within - a specified range. The specific type of scan is indicated by the command code in the CCB header. For the - scan range commands, the boundary conditions can be specified as greater-than-or-equal-to a value, less- - than-or-equal-to a value, or both by using two boundary values. - - There are two supported formats for the output stream: the bit vector and index array formats (codes 0x8, - 0xD, and 0xE). For the standard scan command using the bit vector output, for each input element there - exists one bit in the vector that is set if the input element matched the scan criteria, or clear if not. The - inverted scan command inverts the polarity of the bits in the output. The most significant bit of the first - byte of the output stream corresponds to the first element in the input stream. The standard index array - output format contains one array entry for each input element that matched the scan criteria. Each array - - - - 519 - Coprocessor services - - -entry is the index of an input element that matched the scan criteria. An inverted scan command produces -a similar array, but of all the input elements which did NOT match the scan criteria. - -The return value of the CCB completion area contains the number of input elements found which match -the scan criteria (or number that did not match for the inverted scans). The “number of elements processed” -field in the CCB completion area will be valid, indicating the number of input elements processed. - -These commands are 128-byte “long format” CCBs. - -The scan CCB command format can be specified by the following packed C structure for a big-endian -machine: - - - struct scan_ccb { - uint32_t header; - uint32_t control; - uint64_t completion; - uint64_t primary_input; - uint64_t data_access_control; - uint64_t secondary_input; - uint64_t match_criteria0; - uint64_t output; - uint64_t table; - uint64_t match_criteria1; - uint64_t match_criteria2; - uint64_t match_criteria3; - uint64_t reserved[5]; - }; - - -The exact field offsets, sizes, and composition are as follows: - -Offset Size Field Description -0 4 CCB header (Table 36.1, “CCB Header Format”) -4 4 Command control - Bits Field Description - [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input - Format”) - [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary - Input Element Size”) - [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary - Input Format”) - [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [15:14] Secondary Input Element Size (see Section 36.2.1.1.4, - “Secondary Input Element Size” - [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”) - [9:5] Operand size for first scan criteria value. In a scan value - operation, this is one of two potential exact match values. - In a scan range operation, this is the size of the upper range - - - 520 - Coprocessor services - - -Offset Size Field Description - Bits Field Description - boundary. The value of this field is the number of bytes in the - operand, minus 1. Values 0xF-0x1E are reserved. A value of - 0x1F indicates this operand is not in use for this scan operation. - [4:0] Operand size for second scan criteria value. In a scan value - operation, this is one of two potential exact match values. - In a scan range operation, this is the size of the lower range - boundary. The value of this field is the number of bytes in the - operand, minus 1. Values 0xF-0x1E are reserved. A value of - 0x1F indicates this operand is not in use for this scan operation. -8 8 Completion (same fields as Section 36.2.1.2, “Extract command”) -16 8 Primary Input (same fields as Section 36.2.1.2, “Extract command”) -24 8 Data Access Control (same fields as Section 36.2.1.2, “Extract command”) -32 8 Secondary Input, if used by Primary Input Format. Same fields as Primary - Input. -40 4 Most significant 4 bytes of first scan criteria operand. If first operand is less - than 4 bytes, the value is left-aligned to the lowest address bytes. -44 4 Most significant 4 bytes of second scan criteria operand. If second operand - is less than 4 bytes, the value is left-aligned to the lowest address bytes. -48 8 Output (same fields as Primary Input) -56 8 Symbol Table (if used by Primary Input). Same fields as Section 36.2.1.2, - “Extract command” -64 4 Next 4 most significant bytes of first scan criteria operand occurring after the - bytes specified at offset 40, if needed by the operand size. If first operand - is less than 8 bytes, the valid bytes are left-aligned to the lowest address. -68 4 Next 4 most significant bytes of second scan criteria operand occurring after - the bytes specified at offset 44, if needed by the operand size. If second - operand is less than 8 bytes, the valid bytes are left-aligned to the lowest - address. -72 4 Next 4 most significant bytes of first scan criteria operand occurring after the - bytes specified at offset 64, if needed by the operand size. If first operand - is less than 12 bytes, the valid bytes are left-aligned to the lowest address. -76 4 Next 4 most significant bytes of second scan criteria operand occurring after - the bytes specified at offset 68, if needed by the operand size. If second - operand is less than 12 bytes, the valid bytes are left-aligned to the lowest - address. -80 4 Next 4 most significant bytes of first scan criteria operand occurring after the - bytes specified at offset 72, if needed by the operand size. If first operand - is less than 16 bytes, the valid bytes are left-aligned to the lowest address. -84 4 Next 4 most significant bytes of second scan criteria operand occurring after - the bytes specified at offset 76, if needed by the operand size. If second - operand is less than 16 bytes, the valid bytes are left-aligned to the lowest - address. - - - - - 521 - Coprocessor services - - -36.2.1.4. Translate commands - - The translate commands takes an input array of indices, and a table of single bit values indexed by those - indices, and outputs a bit vector or index array created by reading the tables bit value at each index in - the input array. The output should therefore contain exactly one bit per index in the input data stream, - when outputting as a bit vector. When outputting as an index array, the number of elements depends on the - values read in the bit table, but will always be less than, or equal to, the number of input elements. Only - a restricted subset of the possible input format types are supported. No variable width or Huffman/OZIP - encoded input streams are allowed. The primary input data element size must be 3 bytes or less. - - The maximum table index size allowed is 15 bits, however, larger input elements may be used to provide - additional processing of the output values. If 2 or 3 byte values are used, the least significant 15 bits are - used as an index into the bit table. The most significant 9 bits (when using 3-byte input elements) or single - bit (when using 2-byte input elements) are compared against a fixed 9-bit test value provided in the CCB. - If the values match, the value from the bit table is used as the output element value. If the values do not - match, the output data element value is forced to 0. - - In the inverted translate operation, the bit value read from bit table is inverted prior to its use. The additional - additional processing based on any additional non-index bits remains unchanged, and still forces the output - element value to 0 on a mismatch. The specific type of translate command is indicated by the command - code in the CCB header. - - There are two supported formats for the output stream: the bit vector and index array formats (codes 0x8, - 0xD, and 0xE). The index array format is an array of indices of bits which would have been set if the - output format was a bit array. - - The return value of the CCB completion area contains the number of bits set in the output bit vector, - or number of elements in the output index array. The “number of elements processed” field in the CCB - completion area will be valid, indicating the number of input elements processed. - - These commands are 64-byte “short format” CCBs. - - The translate CCB command format can be specified by the following packed C structure for a big-endian - machine: - - - struct translate_ccb { - uint32_t header; - uint32_t control; - uint64_t completion; - uint64_t primary_input; - uint64_t data_access_control; - uint64_t secondary_input; - uint64_t reserved; - uint64_t output; - uint64_t table; - }; - - - The exact field offsets, sizes, and composition are as follows: - - - Offset Size Field Description - 0 4 CCB header (Table 36.1, “CCB Header Format”) - - - 522 - Coprocessor services - - -Offset Size Field Description -4 4 Command control - Bits Field Description - [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input - Format”) - [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary - Input Element Size”) - [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary - Input Format”) - [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [15:14] Secondary Input Element Size (see Section 36.2.1.1.4, - “Secondary Input Element Size” - [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”) - [9] Reserved - [8:0] Test value used for comparison against the most significant bits - in the input values, when using 2 or 3 byte input elements. -8 8 Completion (same fields as Section 36.2.1.2, “Extract command” -16 8 Primary Input (same fields as Section 36.2.1.2, “Extract command” -24 8 Data Access Control (same fields as Section 36.2.1.2, “Extract command”, - except Primary Input Length Format may not use the 0x0 value) -32 8 Secondary Input, if used by Primary Input Format. Same fields as Primary - Input. -40 8 Reserved -48 8 Output (same fields as Primary Input) -56 8 Bit Table - Bits Field Description - [63:60] ADI version (see Section 36.2.1.1.7, “Application Data - Integrity (ADI)”) - [59:56] If using real address, these bits should be filled in with the - page size code for the page boundary checking the guest wants - the virtual machine to use when accessing this data stream - (checking is only guaranteed to be performed when using API - version 1.1 and later). If using a virtual address, this field will - be used as as bit table address bits [59:56] - [55:4] Bit table address bits [55:4]. Address type is determined by - CCB header. Address must be 64-byte aligned (CCB version - 0) or 16-byte aligned (CCB version 1). - [3:0] Bit table version - Value Description - 0 4KB table size - 1 8KB table size - - - - 523 - Coprocessor services - - -36.2.1.5. Select command - The select command filters the primary input data stream by using a secondary input bit vector to determine - which input elements to include in the output. For each bit set at a given index N within the bit vector, - the Nth input element is included in the output. If the bit is not set, the element is not included. Only a - restricted subset of the possible input format types are supported. No variable width or run length encoded - input streams are allowed, since the secondary input stream is used for the filtering bit vector. - - The only supported output format is a padded, byte-aligned output stream. The stream follows the same - rules and restrictions as padded output stream described in Section 36.2.1.2, “Extract command”. - - The return value of the CCB completion area contains the number of bits set in the input bit vector. The - "number of elements processed" field in the CCB completion area will be valid, indicating the number - of input elements processed. - - The select CCB is a 64-byte “short format” CCB. - - The select CCB command format can be specified by the following packed C structure for a big-endian - machine: - - - struct select_ccb { - uint32_t header; - uint32_t control; - uint64_t completion; - uint64_t primary_input; - uint64_t data_access_control; - uint64_t secondary_input; - uint64_t reserved; - uint64_t output; - uint64_t table; - }; - - - The exact field offsets, sizes, and composition are as follows: - - Offset Size Field Description - 0 4 CCB header (Table 36.1, “CCB Header Format”) - 4 4 Command control - Bits Field Description - [31:28] Primary Input Format (see Section 36.2.1.1.1, “Primary Input - Format”) - [27:23] Primary Input Element Size (see Section 36.2.1.1.2, “Primary - Input Element Size”) - [22:20] Primary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [19] Secondary Input Format (see Section 36.2.1.1.3, “Secondary - Input Format”) - [18:16] Secondary Input Starting Offset (see Section 36.2.1.1.5, “Input - Element Offsets”) - [15:14] Secondary Input Element Size (see Section 36.2.1.1.4, - “Secondary Input Element Size” - - - 524 - Coprocessor services - - - Offset Size Field Description - Bits Field Description - [13:10] Output Format (see Section 36.2.1.1.6, “Output Format”) - [9] Padding Direction selector: A value of 1 causes padding bytes - to be added to the left side of output elements. A value of 0 - causes padding bytes to be added to the right side of output - elements. - [8:0] Reserved - 8 8 Completion (same fields as Section 36.2.1.2, “Extract command” - 16 8 Primary Input (same fields as Section 36.2.1.2, “Extract command” - 24 8 Data Access Control (same fields as Section 36.2.1.2, “Extract command”) - 32 8 Secondary Bit Vector Input. Same fields as Primary Input. - 40 8 Reserved - 48 8 Output (same fields as Primary Input) - 56 8 Symbol Table (if used by Primary Input). Same fields as Section 36.2.1.2, - “Extract command” - -36.2.1.6. No-op and Sync commands - The no-op (no operation) command is a CCB which has no processing effect. The CCB, when processed - by the virtual machine, simply updates the completion area with its execution status. The CCB may have - the serial-conditional flags set in order to restrict when it executes. - - The sync command is a variant of the no-op command which with restricted execution timing. A sync - command CCB will only execute when all previous commands submitted in the same request have - completed. This is stronger than the conditional flag sequencing, which is only dependent on a single - previous serial CCB. While the relative ordering is guaranteed, virtual machine implementations with - shared hardware resources may cause the sync command to wait for longer than the minimum required - time. - - The return value of the CCB completion area is invalid for these CCBs. The “number of elements - processed” field is also invalid for these CCBs. - - These commands are 64-byte “short format” CCBs. - - The no-op CCB command format can be specified by the following packed C structure for a big-endian - machine: - - - struct nop_ccb { - uint32_t header; - uint32_t control; - uint64_t completion; - uint64_t reserved[6]; - }; - - - The exact field offsets, sizes, and composition are as follows: - - Offset Size Field Description - 0 4 CCB header (Table 36.1, “CCB Header Format”) - - - 525 - Coprocessor services - - - Offset Size Field Description - 4 4 Command control - Bits Field Description - [31] If set, this CCB functions as a Sync command. If clear, this - CCB functions as a No-op command. - [30:0] Reserved - 8 8 Completion (same fields as Section 36.2.1.2, “Extract command” - 16 46 Reserved - -36.2.2. CCB Completion Area - All CCB commands use a common 128-byte Completion Area format, which can be specified by the - following packed C structure for a big-endian machine: - - - struct completion_area { - uint8_t status_flag; - uint8_t error_note; - uint8_t rsvd0[2]; - uint32_t error_values; - uint32_t output_size; - uint32_t rsvd1; - uint64_t run_time; - uint64_t run_stats; - uint32_t elements; - uint8_t rsvd2[20]; - uint64_t return_value; - uint64_t extra_return_value[8]; - }; - - - The Completion Area must be a 128-byte aligned memory location. The exact layout can be described - using byte offsets and sizes relative to the memory base: - - Offset Size Field Description - 0 1 CCB execution status - 0x0 Command not yet completed - 0x1 Command ran and succeeded - 0x2 Command ran and failed (partial results may be been - produced) - 0x3 Command ran and was killed (partial execution may - have occurred) - 0x4 Command was not run - 0x5-0xF Reserved - 1 1 Error reason code - 0x0 Reserved - 0x1 Buffer overflow - - - 526 - Coprocessor services - - -Offset Size Field Description - 0x2 CCB decoding error - 0x3 Page overflow - 0x4-0x6 Reserved - 0x7 Command was killed - 0x8 Command execution timeout - 0x9 ADI miscompare error - 0xA Data format error - 0xB-0xD Reserved - 0xE Unexpected hardware error (Do not retry) - 0xF Unexpected hardware error (Retry is ok) - 0x10-0x7F Reserved - 0x80 Partial Symbol Warning - 0x81-0xFF Reserved -2 2 Reserved -4 4 If a partial symbol warning was generated, this field contains the number - of remaining bits which were not decoded. -8 4 Number of bytes of output produced -12 4 Reserved -16 8 Runtime of command (unspecified time units) -24 8 Reserved -32 4 Number of elements processed -36 20 Reserved -56 8 Return value -64 64 Extended return value - -The CCB completion area should be treated as read-only by guest software. The CCB execution status -byte will be cleared by the Hypervisor to reflect the pending execution status when the CCB is submitted -successfully. All other fields are considered invalid upon CCB submission until the CCB execution status -byte becomes non-zero. - -CCBs which complete with status 0x2 or 0x3 may produce partial results and/or side effects due to partial -execution of the CCB command. Some valid data may be accessible depending on the fault type, however, -it is recommended that guest software treat the destination buffer as being in an unknown state. If a CCB -completes with a status byte of 0x2, the error reason code byte can be read to determine what corrective -action should be taken. - -A buffer overflow indicates that the results of the operation exceeded the size of the output buffer indicated -in the CCB. The operation can be retried by resubmitting the CCB with a larger output buffer. - -A CCB decoding error indicates that the CCB contained some invalid field values. It may be also be -triggered if the CCB output is directed at a non-existent secondary input and the pipelining hint is followed. - -A page overflow error indicates that the operation required accessing a memory location beyond the page -size associated with a given address. No data will have been read or written past the page boundary, but -partial results may have been written to the destination buffer. The CCB can be resubmitted with a larger -page size memory allocation to complete the operation. - - - 527 - Coprocessor services - - - In the case of pipelined CCBs, a page overflow error will be triggered if the output from the pipeline source - CCB ends before the input of the pipeline target CCB. Page boundaries are ignored when the pipeline - hint is followed. - - Command kill indicates that the CCB execution was halted or prevented by use of the ccb_kill API call. - - Command timeout indicates that the CCB execution began, but did not complete within a pre-determined - limit set by the virtual machine. The command may have produced some or no output. The CCB may be - resubmitted with no alterations. - - ADI miscompare indicates that the memory buffer version specified in the CCB did not match the value - in memory when accessed by the virtual machine. Guest software should not attempt to resubmit the CCB - without determining the cause of the version mismatch. - - A data format error indicates that the input data stream did not follow the specified data input formatting - selected in the CCB. - - Some CCBs which encounter hardware errors may be resubmitted without change. Persistent hardware - errors may result in multiple failures until RAS software can identify and isolate the faulty component. - - The output size field indicates the number of bytes of valid output in the destination buffer. This field is - not valid for all possible CCB commands. - - The runtime field indicates the execution time of the CCB command once it leaves the internal virtual - machine queue. The time units are fixed, but unspecified, allowing only relative timing comparisons - by guest software. The time units may also vary by hardware platform, and should not be construed to - represent any absolute time value. - - Some data query commands process data in units of elements. If applicable to the command, the number of - elements processed is indicated in the listed field. This field is not valid for all possible CCB commands. - - The return value and extended return value fields are output locations for commands which do not use - a destination output buffer, or have secondary return results. The field is not valid for all possible CCB - commands. - -36.3. Hypervisor API Functions -36.3.1. ccb_submit - trap# FAST_TRAP - function# CCB_SUBMIT - arg0 address - arg1 length - arg2 flags - arg3 reserved - ret0 status - ret1 length - ret2 status data - ret3 reserved - - Submit one or more coprocessor control blocks (CCBs) for evaluation and processing by the virtual - machine. The CCBs are passed in a linear array indicated by address. length indicates the size of - the array in bytes. - - - 528 - Coprocessor services - - -The address should be aligned to the size indicated by length, rounded up to the nearest power of -two. Virtual machines implementations may reject submissions which do not adhere to that alignment. -length must be a multiple of 64 bytes. If length is zero, the maximum supported array length will be -returned as length in ret1. In all other cases, the length value in ret1 will reflect the number of bytes -successfully consumed from the input CCB array. - - Implementation note - Virtual machines should never reject submissions based on the alignment of address if the - entire array is contained within a single memory page of the smallest page size supported by the - virtual machine. - -A guest may choose to submit addresses used in this API function, including the CCB array address, -as either a real or virtual addresses, with the type of each address indicated in flags. Virtual addresses -must be present in either the TLB or an active TSB to be processed. The translation context for virtual -addresses is determined by a combination of CCB contents and the flags argument. - -The flags argument is divided into multiple fields defined as follows: - - -Bits Field Description -[63:16] Reserved -[15] Disable ADI for VA reads (in API 2.0) - Reserved (in API 1.0) -[14] Virtual addresses within CCBs are translated in privileged context -[13:12] Alternate translation context for virtual addresses within CCBs: - 0b'00 CCBs requesting alternate context are rejected - 0b'01 Reserved - 0b'10 CCBs requesting alternate context use secondary context - 0b'11 CCBs requesting alternate context use nucleus context -[11:9] Reserved -[8] Queue info flag -[7] All-or-nothing flag -[6] If address is a virtual address, treat its translation context as privileged -[5:4] Address type of address: - 0b'00 Real address - 0b'01 Virtual address in primary context - 0b'10 Virtual address in secondary context - 0b'11 Virtual address in nucleus context -[3:2] Reserved -[1:0] CCB command type: - 0b'00 Reserved - 0b'01 Reserved - 0b'10 Query command - 0b'11 Reserved - - - - 529 - Coprocessor services - - - The CCB submission type and address type for the CCB array must be provided in the flags argument. - All other fields are optional values which change the default behavior of the CCB processing. - - When set to one, the "Disable ADI for VA reads" bit will turn off ADI checking when using a virtual - address to load data. ADI checking will still be done when loading real-addressed memory. This bit is only - available when using major version 2 of the coprocessor API group; at major version 1 it is reserved. For - more information about using ADI and DAX, see Section 36.2.1.1.7, “Application Data Integrity (ADI)”. - - By default, all virtual addresses are treated as user addresses. If the virtual address translations are - privileged, they must be marked as such in the appropriate flags field. The virtual addresses used within - the submitted CCBs must all be translated with the same privilege level. - - By default, all virtual addresses used within the submitted CCBs are translated using the primary context - active at the time of the submission. The address type field within a CCB allows each address to request - translation in an alternate address context. The address context used when the alternate address context is - requested is selected in the flags argument. - - The all-or-nothing flag specifies whether the virtual machine should allow partial submissions of the - input CCB array. When using CCBs with serial-conditional flags, it is strongly recommended to use - the all-or-nothing flag to avoid broken conditional chains. Using long CCB chains on a machine under - high coprocessor load may make this impractical, however, and require submitting without the flag. - When submitting serial-conditional CCBs without the all-or-nothing flag, guest software must manually - implement the serial-conditional behavior at any point where the chain was not submitted in a single API - call, and resubmission of the remaining CCBs should clear any conditional flag that might be set in the - first remaining CCB. Failure to do so will produce indeterminate CCB execution status and ordering. - - When the all-or-nothing flag is not specified, callers should check the value of length in ret1 to determine - how many CCBs from the array were successfully submitted. Any remaining CCBs can be resubmitted - without modifications. - - The value of length in ret1 is also valid when the API call returns an error, and callers should always - check its value to determine which CCBs in the array were already processed. This will additionally - identify which CCB encountered the processing error, and was not submitted successfully. - - If the queue info flag is used during submission, and at least one CCB was successfully submitted, the - length value in ret1 will be a multi-field value defined as follows: - Bits Field Description - [63:48] DAX unit instance identifier - [47:32] DAX queue instance identifier - [31:16] Reserved - [15:0] Number of CCB bytes successfully submitted - - The value of status data depends on the status value. See error status code descriptions for details. - The value is undefined for status values that do not specifically list a value for the status data. - - The API has a reserved input and output register which will be used in subsequent minor versions of this - API function. Guest software implementations should treat that register as voltile across the function call - in order to maintain forward compatibility. - -36.3.1.1. Errors - EOK One or more CCBs have been accepted and enqueued in the virtual machine - and no errors were been encountered during submission. Some submitted - CCBs may not have been enqueued due to internal virtual machine limitations, - and may be resubmitted without changes. - - - 530 - Coprocessor services - - -EWOULDBLOCK An internal resource conflict within the virtual machine has prevented it from - being able to complete the CCB submissions sufficiently quickly, requiring - it to abandon processing before it was complete. Some CCBs may have been - successfully enqueued prior to the block, and all remaining CCBs may be - resubmitted without changes. -EBADALIGN CCB array is not on a 64-byte boundary, or the array length is not a multiple - of 64 bytes. -ENORADDR A real address used either for the CCB array, or within one of the submitted - CCBs, is not valid for the guest. Some CCBs may have been enqueued prior - to the error being detected. -ENOMAP A virtual address used either for the CCB array, or within one of the submitted - CCBs, could not be translated by the virtual machine using either the TLB - or TSB contents. The submission may be retried after adding the required - mapping, or by converting the virtual address into a real address. Due to the - shared nature of address translation resources, there is no theoretical limit on - the number of times the translation may fail, and it is recommended all guests - implement some real address based backup. The virtual address which failed - translation is returned as status data in ret2. Some CCBs may have been - enqueued prior to the error being detected. -EINVAL The virtual machine detected an invalid CCB during submission, or invalid - input arguments, such as bad flag values. Note that not all invalid CCB values - will be detected during submission, and some may be reported as errors in the - completion area instead. Some CCBs may have been enqueued prior to the - error being detected. This error may be returned if the CCB version is invalid. -ETOOMANY The request was submitted with the all-or-nothing flag set, and the array size is - greater than the virtual machine can support in a single request. The maximum - supported size for the current virtual machine can be queried by submitting a - request with a zero length array, as described above. -ENOACCESS The guest does not have permission to submit CCBs, or an address used in a - CCBs lacks sufficient permissions to perform the required operation (no write - permission on the destination buffer address, for example). A virtual address - which fails permission checking is returned as status data in ret2. Some - CCBs may have been enqueued prior to the error being detected. -EUNAVAILABLE The requested CCB operation could not be performed at this time. The - restricted operation availability may apply only to the first unsuccessfully - submitted CCB, or may apply to a larger scope. The status should not be - interpreted as permanent, and the guest should attempt to submit CCBs in - the future which had previously been unable to be performed. The status - data provides additional information about scope of the restricted availability - as follows: - Value Description - 0 Processing for the exact CCB instance submitted was unavailable, - and it is recommended the guest emulate the operation. The - guest should continue to submit all other CCBs, and assume no - restrictions beyond this exact CCB instance. - 1 Processing is unavailable for all CCBs using the requested opcode, - and it is recommended the guest emulate the operation. The - guest should continue to submit all other CCBs that use different - opcodes, but can expect continued rejections of CCBs using the - same opcode in the near future. - - - 531 - Coprocessor services - - - Value Description - 2 Processing is unavailable for all CCBs using the requested CCB - version, and it is recommended the guest emulate the operation. - The guest should continue to submit all other CCBs that use - different CCB versions, but can expect continued rejections of - CCBs using the same CCB version in the near future. - 3 Processing is unavailable for all CCBs on the submitting vcpu, - and it is recommended the guest emulate the operation or resubmit - the CCB on a different vcpu. The guest should continue to submit - CCBs on all other vcpus but can expect continued rejections of all - CCBs on this vcpu in the near future. - 4 Processing is unavailable for all CCBs, and it is recommended - the guest emulate the operation. The guest should expect all CCB - submissions to be similarly rejected in the near future. - - -36.3.2. ccb_info - - trap# FAST_TRAP - function# CCB_INFO - arg0 address - ret0 status - ret1 CCB state - ret2 position - ret3 dax - ret4 queue - - Requests status information on a previously submitted CCB. The previously submitted CCB is identified - by the 64-byte aligned real address of the CCBs completion area. - - A CCB can be in one of 4 states: - - - State Value Description - COMPLETED 0 The CCB has been fetched and executed, and is no longer active in - the virtual machine. - ENQUEUED 1 The requested CCB is current in a queue awaiting execution. - INPROGRESS 2 The CCB has been fetched and is currently being executed. It may still - be possible to stop the execution using the ccb_kill hypercall. - NOTFOUND 3 The CCB could not be located in the virtual machine, and does not - appear to have been executed. This may occur if the CCB was lost - due to a hardware error, or the CCB may not have been successfully - submitted to the virtual machine in the first place. - - Implementation note - Some platforms may not be able to report CCBs that are currently being processed, and therefore - guest software should invoke the ccb_kill hypercall prior to assuming the request CCB will never - be executed because it was in the NOTFOUND state. - - - 532 - Coprocessor services - - - The position return value is only valid when the state is ENQUEUED. The value returned is the number - of other CCBs ahead of the requested CCB, to provide a relative estimate of when the CCB may execute. - - The dax return value is only valid when the state is ENQUEUED. The value returned is the DAX unit - instance identifier for the DAX unit processing the queue where the requested CCB is located. The value - matches the value that would have been, or was, returned by ccb_submit using the queue info flag. - - The queue return value is only valid when the state is ENQUEUED. The value returned is the DAX - queue instance identifier for the DAX unit processing the queue where the requested CCB is located. The - value matches the value that would have been, or was, returned by ccb_submit using the queue info flag. - -36.3.2.1. Errors - - EOK The request was processed and the CCB state is valid. - EBADALIGN address is not on a 64-byte aligned. - ENORADDR The real address provided for address is not valid. - EINVAL The CCB completion area contents are not valid. - EWOULDBLOCK Internal resource constraints prevented the CCB state from being queried at this - time. The guest should retry the request. - ENOACCESS The guest does not have permission to access the coprocessor virtual device - functionality. - -36.3.3. ccb_kill - - trap# FAST_TRAP - function# CCB_KILL - arg0 address - ret0 status - ret1 result - - Request to stop execution of a previously submitted CCB. The previously submitted CCB is identified by - the 64-byte aligned real address of the CCBs completion area. - - The kill attempt can produce one of several values in the result return value, reflecting the CCB state - and actions taken by the Hypervisor: - - Result Value Description - COMPLETED 0 The CCB has been fetched and executed, and is no longer active in - the virtual machine. It could not be killed and no action was taken. - DEQUEUED 1 The requested CCB was still enqueued when the kill request was - submitted, and has been removed from the queue. Since the CCB - never began execution, no memory modifications were produced by - it, and the completion area will never be updated. The same CCB may - be submitted again, if desired, with no modifications required. - KILLED 2 The CCB had been fetched and was being executed when the kill - request was submitted. The CCB execution was stopped, and the CCB - is no longer active in the virtual machine. The CCB completion area - will reflect the killed status, with the subsequent implications that - partial results may have been produced. Partial results may include full - - - 533 - Coprocessor services - - - Result Value Description - command execution if the command was stopped just prior to writing - to the completion area. - NOTFOUND 3 The CCB could not be located in the virtual machine, and does not - appear to have been executed. This may occur if the CCB was lost - due to a hardware error, or the CCB may not have been successfully - submitted to the virtual machine in the first place. CCBs in the state - are guaranteed to never execute in the future unless resubmitted. - -36.3.3.1. Interactions with Pipelined CCBs - - If the pipeline target CCB is killed but the pipeline source CCB was skipped, the completion area of the - target CCB may contain status (4,0) "Command was skipped" instead of (3,7) "Command was killed". - - If the pipeline source CCB is killed, the pipeline target CCB's completion status may read (1,0) "Success". - This does not mean the target CCB was processed; since the source CCB was killed, there was no - meaningful output on which the target CCB could operate. - -36.3.3.2. Errors - - EOK The request was processed and the result is valid. - EBADALIGN address is not on a 64-byte aligned. - ENORADDR The real address provided for address is not valid. - EINVAL The CCB completion area contents are not valid. - EWOULDBLOCK Internal resource constraints prevented the CCB from being killed at this time. - The guest should retry the request. - ENOACCESS The guest does not have permission to access the coprocessor virtual device - functionality. - -36.3.4. dax_info - trap# FAST_TRAP - function# DAX_INFO - ret0 status - ret1 Number of enabled DAX units - ret2 Number of disabled DAX units - - Returns the number of DAX units that are enabled for the calling guest to submit CCBs. The number of - DAX units that are disabled for the calling guest are also returned. A disabled DAX unit would have been - available for CCB submission to the calling guest had it not been offlined. - -36.3.4.1. Errors - - EOK The request was processed and the number of enabled/disabled DAX units - are valid. - - - - - 534 - diff --git a/Documentation/sparc/oradax/oracle-dax.rst b/Documentation/sparc/oradax/oracle-dax.rst deleted file mode 100644 index d1e14d572918..000000000000 --- a/Documentation/sparc/oradax/oracle-dax.rst +++ /dev/null @@ -1,445 +0,0 @@ -======================================= -Oracle Data Analytics Accelerator (DAX) -======================================= - -DAX is a coprocessor which resides on the SPARC M7 (DAX1) and M8 -(DAX2) processor chips, and has direct access to the CPU's L3 caches -as well as physical memory. It can perform several operations on data -streams with various input and output formats. A driver provides a -transport mechanism and has limited knowledge of the various opcodes -and data formats. A user space library provides high level services -and translates these into low level commands which are then passed -into the driver and subsequently the Hypervisor and the coprocessor. -The library is the recommended way for applications to use the -coprocessor, and the driver interface is not intended for general use. -This document describes the general flow of the driver, its -structures, and its programmatic interface. It also provides example -code sufficient to write user or kernel applications that use DAX -functionality. - -The user library is open source and available at: - - https://oss.oracle.com/git/gitweb.cgi?p=libdax.git - -The Hypervisor interface to the coprocessor is described in detail in -the accompanying document, dax-hv-api.txt, which is a plain text -excerpt of the (Oracle internal) "UltraSPARC Virtual Machine -Specification" version 3.0.20+15, dated 2017-09-25. - - -High Level Overview -=================== - -A coprocessor request is described by a Command Control Block -(CCB). The CCB contains an opcode and various parameters. The opcode -specifies what operation is to be done, and the parameters specify -options, flags, sizes, and addresses. The CCB (or an array of CCBs) -is passed to the Hypervisor, which handles queueing and scheduling of -requests to the available coprocessor execution units. A status code -returned indicates if the request was submitted successfully or if -there was an error. One of the addresses given in each CCB is a -pointer to a "completion area", which is a 128 byte memory block that -is written by the coprocessor to provide execution status. No -interrupt is generated upon completion; the completion area must be -polled by software to find out when a transaction has finished, but -the M7 and later processors provide a mechanism to pause the virtual -processor until the completion status has been updated by the -coprocessor. This is done using the monitored load and mwait -instructions, which are described in more detail later. The DAX -coprocessor was designed so that after a request is submitted, the -kernel is no longer involved in the processing of it. The polling is -done at the user level, which results in almost zero latency between -completion of a request and resumption of execution of the requesting -thread. - - -Addressing Memory -================= - -The kernel does not have access to physical memory in the Sun4v -architecture, as there is an additional level of memory virtualization -present. This intermediate level is called "real" memory, and the -kernel treats this as if it were physical. The Hypervisor handles the -translations between real memory and physical so that each logical -domain (LDOM) can have a partition of physical memory that is isolated -from that of other LDOMs. When the kernel sets up a virtual mapping, -it specifies a virtual address and the real address to which it should -be mapped. - -The DAX coprocessor can only operate on physical memory, so before a -request can be fed to the coprocessor, all the addresses in a CCB must -be converted into physical addresses. The kernel cannot do this since -it has no visibility into physical addresses. So a CCB may contain -either the virtual or real addresses of the buffers or a combination -of them. An "address type" field is available for each address that -may be given in the CCB. In all cases, the Hypervisor will translate -all the addresses to physical before dispatching to hardware. Address -translations are performed using the context of the process initiating -the request. - - -The Driver API -============== - -An application makes requests to the driver via the write() system -call, and gets results (if any) via read(). The completion areas are -made accessible via mmap(), and are read-only for the application. - -The request may either be an immediate command or an array of CCBs to -be submitted to the hardware. - -Each open instance of the device is exclusive to the thread that -opened it, and must be used by that thread for all subsequent -operations. The driver open function creates a new context for the -thread and initializes it for use. This context contains pointers and -values used internally by the driver to keep track of submitted -requests. The completion area buffer is also allocated, and this is -large enough to contain the completion areas for many concurrent -requests. When the device is closed, any outstanding transactions are -flushed and the context is cleaned up. - -On a DAX1 system (M7), the device will be called "oradax1", while on a -DAX2 system (M8) it will be "oradax2". If an application requires one -or the other, it should simply attempt to open the appropriate -device. Only one of the devices will exist on any given system, so the -name can be used to determine what the platform supports. - -The immediate commands are CCB_DEQUEUE, CCB_KILL, and CCB_INFO. For -all of these, success is indicated by a return value from write() -equal to the number of bytes given in the call. Otherwise -1 is -returned and errno is set. - -CCB_DEQUEUE ------------ - -Tells the driver to clean up resources associated with past -requests. Since no interrupt is generated upon the completion of a -request, the driver must be told when it may reclaim resources. No -further status information is returned, so the user should not -subsequently call read(). - -CCB_KILL --------- - -Kills a CCB during execution. The CCB is guaranteed to not continue -executing once this call returns successfully. On success, read() must -be called to retrieve the result of the action. - -CCB_INFO --------- - -Retrieves information about a currently executing CCB. Note that some -Hypervisors might return 'notfound' when the CCB is in 'inprogress' -state. To ensure a CCB in the 'notfound' state will never be executed, -CCB_KILL must be invoked on that CCB. Upon success, read() must be -called to retrieve the details of the action. - -Submission of an array of CCBs for execution ---------------------------------------------- - -A write() whose length is a multiple of the CCB size is treated as a -submit operation. The file offset is treated as the index of the -completion area to use, and may be set via lseek() or using the -pwrite() system call. If -1 is returned then errno is set to indicate -the error. Otherwise, the return value is the length of the array that -was actually accepted by the coprocessor. If the accepted length is -equal to the requested length, then the submission was completely -successful and there is no further status needed; hence, the user -should not subsequently call read(). Partial acceptance of the CCB -array is indicated by a return value less than the requested length, -and read() must be called to retrieve further status information. The -status will reflect the error caused by the first CCB that was not -accepted, and status_data will provide additional data in some cases. - -MMAP ----- - -The mmap() function provides access to the completion area allocated -in the driver. Note that the completion area is not writeable by the -user process, and the mmap call must not specify PROT_WRITE. - - -Completion of a Request -======================= - -The first byte in each completion area is the command status which is -updated by the coprocessor hardware. Software may take advantage of -new M7/M8 processor capabilities to efficiently poll this status byte. -First, a "monitored load" is achieved via a Load from Alternate Space -(ldxa, lduba, etc.) with ASI 0x84 (ASI_MONITOR_PRIMARY). Second, a -"monitored wait" is achieved via the mwait instruction (a write to -%asr28). This instruction is like pause in that it suspends execution -of the virtual processor for the given number of nanoseconds, but in -addition will terminate early when one of several events occur. If the -block of data containing the monitored location is modified, then the -mwait terminates. This causes software to resume execution immediately -(without a context switch or kernel to user transition) after a -transaction completes. Thus the latency between transaction completion -and resumption of execution may be just a few nanoseconds. - - -Application Life Cycle of a DAX Submission -========================================== - - - open dax device - - call mmap() to get the completion area address - - allocate a CCB and fill in the opcode, flags, parameters, addresses, etc. - - submit CCB via write() or pwrite() - - go into a loop executing monitored load + monitored wait and - terminate when the command status indicates the request is complete - (CCB_KILL or CCB_INFO may be used any time as necessary) - - perform a CCB_DEQUEUE - - call munmap() for completion area - - close the dax device - - -Memory Constraints -================== - -The DAX hardware operates only on physical addresses. Therefore, it is -not aware of virtual memory mappings and the discontiguities that may -exist in the physical memory that a virtual buffer maps to. There is -no I/O TLB or any scatter/gather mechanism. All buffers, whether input -or output, must reside in a physically contiguous region of memory. - -The Hypervisor translates all addresses within a CCB to physical -before handing off the CCB to DAX. The Hypervisor determines the -virtual page size for each virtual address given, and uses this to -program a size limit for each address. This prevents the coprocessor -from reading or writing beyond the bound of the virtual page, even -though it is accessing physical memory directly. A simpler way of -saying this is that a DAX operation will never "cross" a virtual page -boundary. If an 8k virtual page is used, then the data is strictly -limited to 8k. If a user's buffer is larger than 8k, then a larger -page size must be used, or the transaction size will be truncated to -8k. - -Huge pages. A user may allocate huge pages using standard interfaces. -Memory buffers residing on huge pages may be used to achieve much -larger DAX transaction sizes, but the rules must still be followed, -and no transaction will cross a page boundary, even a huge page. A -major caveat is that Linux on Sparc presents 8Mb as one of the huge -page sizes. Sparc does not actually provide a 8Mb hardware page size, -and this size is synthesized by pasting together two 4Mb pages. The -reasons for this are historical, and it creates an issue because only -half of this 8Mb page can actually be used for any given buffer in a -DAX request, and it must be either the first half or the second half; -it cannot be a 4Mb chunk in the middle, since that crosses a -(hardware) page boundary. Note that this entire issue may be hidden by -higher level libraries. - - -CCB Structure -------------- -A CCB is an array of 8 64-bit words. Several of these words provide -command opcodes, parameters, flags, etc., and the rest are addresses -for the completion area, output buffer, and various inputs:: - - struct ccb { - u64 control; - u64 completion; - u64 input0; - u64 access; - u64 input1; - u64 op_data; - u64 output; - u64 table; - }; - -See libdax/common/sys/dax1/dax1_ccb.h for a detailed description of -each of these fields, and see dax-hv-api.txt for a complete description -of the Hypervisor API available to the guest OS (ie, Linux kernel). - -The first word (control) is examined by the driver for the following: - - CCB version, which must be consistent with hardware version - - Opcode, which must be one of the documented allowable commands - - Address types, which must be set to "virtual" for all the addresses - given by the user, thereby ensuring that the application can - only access memory that it owns - - -Example Code -============ - -The DAX is accessible to both user and kernel code. The kernel code -can make hypercalls directly while the user code must use wrappers -provided by the driver. The setup of the CCB is nearly identical for -both; the only difference is in preparation of the completion area. An -example of user code is given now, with kernel code afterwards. - -In order to program using the driver API, the file -arch/sparc/include/uapi/asm/oradax.h must be included. - -First, the proper device must be opened. For M7 it will be -/dev/oradax1 and for M8 it will be /dev/oradax2. The simplest -procedure is to attempt to open both, as only one will succeed:: - - fd = open("/dev/oradax1", O_RDWR); - if (fd < 0) - fd = open("/dev/oradax2", O_RDWR); - if (fd < 0) - /* No DAX found */ - -Next, the completion area must be mapped:: - - completion_area = mmap(NULL, DAX_MMAP_LEN, PROT_READ, MAP_SHARED, fd, 0); - -All input and output buffers must be fully contained in one hardware -page, since as explained above, the DAX is strictly constrained by -virtual page boundaries. In addition, the output buffer must be -64-byte aligned and its size must be a multiple of 64 bytes because -the coprocessor writes in units of cache lines. - -This example demonstrates the DAX Scan command, which takes as input a -vector and a match value, and produces a bitmap as the output. For -each input element that matches the value, the corresponding bit is -set in the output. - -In this example, the input vector consists of a series of single bits, -and the match value is 0. So each 0 bit in the input will produce a 1 -in the output, and vice versa, which produces an output bitmap which -is the input bitmap inverted. - -For details of all the parameters and bits used in this CCB, please -refer to section 36.2.1.3 of the DAX Hypervisor API document, which -describes the Scan command in detail:: - - ccb->control = /* Table 36.1, CCB Header Format */ - (2L << 48) /* command = Scan Value */ - | (3L << 40) /* output address type = primary virtual */ - | (3L << 34) /* primary input address type = primary virtual */ - /* Section 36.2.1, Query CCB Command Formats */ - | (1 << 28) /* 36.2.1.1.1 primary input format = fixed width bit packed */ - | (0 << 23) /* 36.2.1.1.2 primary input element size = 0 (1 bit) */ - | (8 << 10) /* 36.2.1.1.6 output format = bit vector */ - | (0 << 5) /* 36.2.1.3 First scan criteria size = 0 (1 byte) */ - | (31 << 0); /* 36.2.1.3 Disable second scan criteria */ - - ccb->completion = 0; /* Completion area address, to be filled in by driver */ - - ccb->input0 = (unsigned long) input; /* primary input address */ - - ccb->access = /* Section 36.2.1.2, Data Access Control */ - (2 << 24) /* Primary input length format = bits */ - | (nbits - 1); /* number of bits in primary input stream, minus 1 */ - - ccb->input1 = 0; /* secondary input address, unused */ - - ccb->op_data = 0; /* scan criteria (value to be matched) */ - - ccb->output = (unsigned long) output; /* output address */ - - ccb->table = 0; /* table address, unused */ - -The CCB submission is a write() or pwrite() system call to the -driver. If the call fails, then a read() must be used to retrieve the -status:: - - if (pwrite(fd, ccb, 64, 0) != 64) { - struct ccb_exec_result status; - read(fd, &status, sizeof(status)); - /* bail out */ - } - -After a successful submission of the CCB, the completion area may be -polled to determine when the DAX is finished. Detailed information on -the contents of the completion area can be found in section 36.2.2 of -the DAX HV API document:: - - while (1) { - /* Monitored Load */ - __asm__ __volatile__("lduba [%1] 0x84, %0\n" - : "=r" (status) - : "r" (completion_area)); - - if (status) /* 0 indicates command in progress */ - break; - - /* MWAIT */ - __asm__ __volatile__("wr %%g0, 1000, %%asr28\n" ::); /* 1000 ns */ - } - -A completion area status of 1 indicates successful completion of the -CCB and validity of the output bitmap, which may be used immediately. -All other non-zero values indicate error conditions which are -described in section 36.2.2:: - - if (completion_area[0] != 1) { /* section 36.2.2, 1 = command ran and succeeded */ - /* completion_area[0] contains the completion status */ - /* completion_area[1] contains an error code, see 36.2.2 */ - } - -After the completion area has been processed, the driver must be -notified that it can release any resources associated with the -request. This is done via the dequeue operation:: - - struct dax_command cmd; - cmd.command = CCB_DEQUEUE; - if (write(fd, &cmd, sizeof(cmd)) != sizeof(cmd)) { - /* bail out */ - } - -Finally, normal program cleanup should be done, i.e., unmapping -completion area, closing the dax device, freeing memory etc. - -Kernel example --------------- - -The only difference in using the DAX in kernel code is the treatment -of the completion area. Unlike user applications which mmap the -completion area allocated by the driver, kernel code must allocate its -own memory to use for the completion area, and this address and its -type must be given in the CCB:: - - ccb->control |= /* Table 36.1, CCB Header Format */ - (3L << 32); /* completion area address type = primary virtual */ - - ccb->completion = (unsigned long) completion_area; /* Completion area address */ - -The dax submit hypercall is made directly. The flags used in the -ccb_submit call are documented in the DAX HV API in section 36.3.1/ - -:: - - #include <asm/hypervisor.h> - - hv_rv = sun4v_ccb_submit((unsigned long)ccb, 64, - HV_CCB_QUERY_CMD | - HV_CCB_ARG0_PRIVILEGED | HV_CCB_ARG0_TYPE_PRIMARY | - HV_CCB_VA_PRIVILEGED, - 0, &bytes_accepted, &status_data); - - if (hv_rv != HV_EOK) { - /* hv_rv is an error code, status_data contains */ - /* potential additional status, see 36.3.1.1 */ - } - -After the submission, the completion area polling code is identical to -that in user land:: - - while (1) { - /* Monitored Load */ - __asm__ __volatile__("lduba [%1] 0x84, %0\n" - : "=r" (status) - : "r" (completion_area)); - - if (status) /* 0 indicates command in progress */ - break; - - /* MWAIT */ - __asm__ __volatile__("wr %%g0, 1000, %%asr28\n" ::); /* 1000 ns */ - } - - if (completion_area[0] != 1) { /* section 36.2.2, 1 = command ran and succeeded */ - /* completion_area[0] contains the completion status */ - /* completion_area[1] contains an error code, see 36.2.2 */ - } - -The output bitmap is ready for consumption immediately after the -completion status indicates success. - -Excer[t from UltraSPARC Virtual Machine Specification -===================================================== - - .. include:: dax-hv-api.txt - :literal: |