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* PCI/DOE: Fix destroy_work_on_stack() raceIra Weiny2023-07-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following debug object splat was observed in testing: ODEBUG: free active (active state 0) object: 0000000097d23782 object type: work_struct hint: doe_statemachine_work+0x0/0x510 WARNING: CPU: 1 PID: 71 at lib/debugobjects.c:514 debug_print_object+0x7d/0xb0 ... Workqueue: pci 0000:36:00.0 DOE [1 doe_statemachine_work RIP: 0010:debug_print_object+0x7d/0xb0 ... Call Trace: ? debug_print_object+0x7d/0xb0 ? __pfx_doe_statemachine_work+0x10/0x10 debug_object_free.part.0+0x11b/0x150 doe_statemachine_work+0x45e/0x510 process_one_work+0x1d4/0x3c0 This occurs because destroy_work_on_stack() was called after signaling the completion in the calling thread. This creates a race between destroy_work_on_stack() and the task->work struct going out of scope in pci_doe(). Signal the work complete after destroying the work struct. This is safe because signal_task_complete() is the final thing the work item does and the workqueue code is careful not to access the work struct after. Fixes: abf04be0e707 ("PCI/DOE: Fix memory leak with CONFIG_DEBUG_OBJECTS=y") Link: https://lore.kernel.org/r/20230726-doe-fix-v1-1-af07e614d4dd@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Acked-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Relax restrictions on request and response sizeLukas Wunner2023-04-181-25/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | An upcoming user of DOE is CMA (Component Measurement and Authentication, PCIe r6.0 sec 6.31). It builds on SPDM (Security Protocol and Data Model): https://www.dmtf.org/dsp/DSP0274 SPDM message sizes are not always a multiple of dwords. To transport them over DOE without using bounce buffers, allow sending requests and receiving responses whose final dword is only partially populated. To be clear, PCIe r6.0 sec 6.30.1 specifies the Data Object Header 2 "Length" in dwords and pci_doe_send_req() and pci_doe_recv_resp() read/write dwords. So from a spec point of view, DOE is still specified in dwords and allowing non-dword request/response buffers is merely for the convenience of callers. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/151b1a6a1794afb65d941287ecbc032c5b8004b9.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Make mailbox creation API privateLukas Wunner2023-04-181-37/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PCI core has just been amended to create a pci_doe_mb struct for every DOE instance on device enumeration. CXL (the only in-tree DOE user so far) has been migrated to use those mailboxes instead of creating its own. That leaves pcim_doe_create_mb() and pci_doe_for_each_off() without any callers, so drop them. pci_doe_supports_prot() is now only used internally, so declare it static. pci_doe_destroy_mb() is no longer used as callback for devm_add_action(), so refactor it to accept a struct pci_doe_mb pointer instead of a generic void pointer. Because pci_doe_create_mb() is only called on device enumeration, i.e. before driver binding, the workqueue name never contains a driver name. So replace dev_driver_string() with dev_bus_name() when generating the workqueue name. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/64f614b6584982986c55d2c6229b4ee2b276dd59.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Create mailboxes on device enumerationLukas Wunner2023-04-181-0/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently a DOE instance cannot be shared by multiple drivers because each driver creates its own pci_doe_mb struct for a given DOE instance. For the same reason a DOE instance cannot be shared between the PCI core and a driver. Moreover, finding out which protocols a DOE instance supports requires creating a pci_doe_mb for it. If a device has multiple DOE instances, a driver looking for a specific protocol may need to create a pci_doe_mb for each of the device's DOE instances and then destroy those which do not support the desired protocol. That's obviously an inefficient way to do things. Overcome these issues by creating mailboxes in the PCI core on device enumeration. Provide a pci_find_doe_mailbox() API call to allow drivers to get a pci_doe_mb for a given (pci_dev, vendor, protocol) triple. This API is modeled after pci_find_capability() and can later be amended with a pci_find_next_doe_mailbox() call to iterate over all mailboxes of a given pci_dev which support a specific protocol. On removal, destroy the mailboxes in pci_destroy_dev(), after the driver is unbound. This allows drivers to use DOE in their ->remove() hook. On surprise removal, cancel ongoing DOE exchanges and prevent new ones from being scheduled. Thereby ensure that a hot-removed device doesn't needlessly wait for a running exchange to time out. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/40a6f973f72ef283d79dd55e7e6fddc7481199af.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Allow mailbox creation without devres managementLukas Wunner2023-04-181-37/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DOE mailbox creation is currently only possible through a devres-managed API. The lifetime of mailboxes thus ends with driver unbinding. An upcoming commit will create DOE mailboxes upon device enumeration by the PCI core. Their lifetime shall not be limited by a driver. Therefore rework pcim_doe_create_mb() into the non-devres-managed pci_doe_create_mb(). Add pci_doe_destroy_mb() for mailbox destruction on device removal. Provide a devres-managed wrapper under the existing pcim_doe_create_mb() name. The error path of pcim_doe_create_mb() previously called xa_destroy() if alloc_ordered_workqueue() failed. That's unnecessary because the xarray is still empty at that point. It doesn't need to be destroyed until it's been populated by pci_doe_cache_protocols(). Arrange the error path of the new pci_doe_create_mb() accordingly. pci_doe_cancel_tasks() is no longer used as callback for devm_add_action(), so refactor it to accept a struct pci_doe_mb pointer instead of a generic void pointer. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/7c9a63867d70233c5e9d26cd8bf956742cd6d650.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Deduplicate mailbox flushingLukas Wunner2023-04-181-6/+3
| | | | | | | | | | | | | | | | | | | | When a DOE mailbox is torn down, its workqueue is flushed once in pci_doe_flush_mb() through a call to flush_workqueue() and subsequently flushed once more in pci_doe_destroy_workqueue() through a call to destroy_workqueue(). Deduplicate by dropping flush_workqueue() from pci_doe_flush_mb(). Rename pci_doe_flush_mb() to pci_doe_cancel_tasks() to more aptly describe what it now does. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/1f009f60b326d1c6d776641d4b20aff27de0c234.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Make asynchronous API privateLukas Wunner2023-04-181-2/+43
| | | | | | | | | | | | | | | | | | A synchronous API for DOE has just been introduced. CXL (the only in-tree DOE user so far) was converted to use it instead of the asynchronous API. Consequently, pci_doe_submit_task() as well as the pci_doe_task struct are only used internally, so make them private. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/cc19544068483681e91dfe27545c2180cd09f931.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Provide synchronous API and use it internallyLukas Wunner2023-04-181-15/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | The DOE API only allows asynchronous exchanges and forces callers to provide a completion callback. Yet all existing callers only perform synchronous exchanges. Upcoming commits for CMA (Component Measurement and Authentication, PCIe r6.0 sec 6.31) likewise require only synchronous DOE exchanges. Provide a synchronous pci_doe() API call which builds on the internal asynchronous machinery. Convert the internal pci_doe_discovery() to the new call. The new API allows submission of const-declared requests, necessitating the addition of a const qualifier in struct pci_doe_task. Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ming Li <ming4.li@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/0f444206da9615c56301fbaff459c0f45d27f122.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Fix memory leak with CONFIG_DEBUG_OBJECTS=yLukas Wunner2023-04-031-0/+1
| | | | | | | | | | | | | | | | | After a pci_doe_task completes, its work_struct needs to be destroyed to avoid a memory leak with CONFIG_DEBUG_OBJECTS=y. Fixes: 9d24322e887b ("PCI/DOE: Add DOE mailbox support functions") Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: stable@vger.kernel.org # v6.0+ Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/775768b4912531c3b887d405fc51a50e465e1bf9.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Silence WARN splat with CONFIG_DEBUG_OBJECTS=yLukas Wunner2023-04-031-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gregory Price reports a WARN splat with CONFIG_DEBUG_OBJECTS=y upon CXL probing because pci_doe_submit_task() invokes INIT_WORK() instead of INIT_WORK_ONSTACK() for a work_struct that was allocated on the stack. All callers of pci_doe_submit_task() allocate the work_struct on the stack, so replace INIT_WORK() with INIT_WORK_ONSTACK() as a backportable short-term fix. The long-term fix implemented by a subsequent commit is to move to a synchronous API which allocates the work_struct internally in the DOE library. Stacktrace for posterity: WARNING: CPU: 0 PID: 23 at lib/debugobjects.c:545 __debug_object_init.cold+0x18/0x183 CPU: 0 PID: 23 Comm: kworker/u2:1 Not tainted 6.1.0-0.rc1.20221019gitaae703b02f92.17.fc38.x86_64 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Call Trace: pci_doe_submit_task+0x5d/0xd0 pci_doe_discovery+0xb4/0x100 pcim_doe_create_mb+0x219/0x290 cxl_pci_probe+0x192/0x430 local_pci_probe+0x41/0x80 pci_device_probe+0xb3/0x220 really_probe+0xde/0x380 __driver_probe_device+0x78/0x170 driver_probe_device+0x1f/0x90 __driver_attach_async_helper+0x5c/0xe0 async_run_entry_fn+0x30/0x130 process_one_work+0x294/0x5b0 Fixes: 9d24322e887b ("PCI/DOE: Add DOE mailbox support functions") Link: https://lore.kernel.org/linux-cxl/Y1bOniJliOFszvIK@memverge.com/ Reported-by: Gregory Price <gregory.price@memverge.com> Tested-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Gregory Price <gregory.price@memverge.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Gregory Price <gregory.price@memverge.com> Cc: stable@vger.kernel.org # v6.0+ Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/67a9117f463ecdb38a2dbca6a20391ce2f1e7a06.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* cxl/pci: Fix CDAT retrieval on big endianLukas Wunner2023-03-211-11/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CDAT exposed in sysfs differs between little endian and big endian arches: On big endian, every 4 bytes are byte-swapped. PCI Configuration Space is little endian (PCI r3.0 sec 6.1). Accessors such as pci_read_config_dword() implicitly swap bytes on big endian. That way, the macros in include/uapi/linux/pci_regs.h work regardless of the arch's endianness. For an example of implicit byte-swapping, see ppc4xx_pciex_read_config(), which calls in_le32(), which uses lwbrx (Load Word Byte-Reverse Indexed). DOE Read/Write Data Mailbox Registers are unlike other registers in Configuration Space in that they contain or receive a 4 byte portion of an opaque byte stream (a "Data Object" per PCIe r6.0 sec 7.9.24.5f). They need to be copied to or from the request/response buffer verbatim. So amend pci_doe_send_req() and pci_doe_recv_resp() to undo the implicit byte-swapping. The CXL_DOE_TABLE_ACCESS_* and PCI_DOE_DATA_OBJECT_DISC_* macros assume implicit byte-swapping. Byte-swap requests after constructing them with those macros and byte-swap responses before parsing them. Change the request and response type to __le32 to avoid sparse warnings. Per a request from Jonathan, replace sizeof(u32) with sizeof(__le32) for consistency. Fixes: c97006046c79 ("cxl/port: Read CDAT table") Tested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org # v6.0+ Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/3051114102f41d19df3debbee123129118fc5e6d.1678543498.git.lukas@wunner.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* PCI/DOE: Fix maximum data object length miscalculationLi Ming2022-11-161-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | Per PCIe r6.0, sec 6.30.1, a data object Length of 0x0 indicates 2^18 DWORDs (256K DW or 1MB) being transferred. Adjust the value of data object length for this case on both sending side and receiving side. Don't bother checking whether Length is greater than SZ_1M because all values of the 18-bit Length field are valid, and it is impossible to represent anything larger than SZ_1M: 0x00000 256K DW (1M bytes) 0x00001 1 DW (4 bytes) ... 0x3ffff 256K-1 DW (1M - 4 bytes) [bhelgaas: commit log] Link: https://lore.kernel.org/r/20221116015637.3299664-1-ming4.li@intel.com Fixes: 9d24322e887b ("PCI/DOE: Add DOE mailbox support functions") Signed-off-by: Li Ming <ming4.li@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v6.0+
* PCI/DOE: Add DOE mailbox support functionsJonathan Cameron2022-07-191-0/+536
Introduced in a PCIe r6.0, sec 6.30, DOE provides a config space based mailbox with standard protocol discovery. Each mailbox is accessed through a DOE Extended Capability. Each DOE mailbox must support the DOE discovery protocol in addition to any number of additional protocols. Define core PCIe functionality to manage a single PCIe DOE mailbox at a defined config space offset. Functionality includes iterating, creating, query of supported protocol, and task submission. Destruction of the mailboxes is device managed. Cc: "Li, Ming" <ming4.li@intel.com> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Acked-by: Bjorn Helgaas <helgaas@kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20220719205249.566684-4-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>