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* powerpc/Makefiles: Change to new flag variablesmatt mooney2010-10-132-6/+6
| | | | | | | Replace EXTRA_CFLAGS with ccflags-y and EXTRA_AFLAGS with asflags-y. Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pci: Cleanup device dma setup codeNishanth Aravamudan2010-10-131-3/+1
| | | | | | | | | Use set_dma_ops and remove unused oddly-named temp pointer sd. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/viobus: Free TCE table on device releaseNishanth Aravamudan2010-10-131-1/+6
| | | | | | | | | Release the TCE table as the XXX suggests, except on FW_FEATURE_ISERIES, where the tables are allocated globally and reused. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/vio: Use put_device() on device_register failureNishanth Aravamudan2010-10-131-2/+1
| | | | | | | | | | The kernel doc for device_register (and device_initialize) very clearly state to call put_device not kfree after calling, even on error. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/dma: Fix check for direct DMA supportNishanth Aravamudan2010-10-131-1/+1
| | | | | | | | | | The current check is wrong because it does not take the DMA offset intot account, and in the case of a driver which doesn't actually support 64bits would falsely report that device as working. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/dma: Fix dma_iommu_dma_supported compareNishanth Aravamudan2010-10-131-10/+11
| | | | | | | | | | | The table offset is in entries, each of which imply a dma address of an IOMMU page. Also, we should check the device can reach the whole IOMMU table. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/irq.c: Add of_node_put to avoid memory leakJulia Lawall2010-10-131-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this case, a device_node structure is stored in another structure that is then freed without first decrementing the reference count of the device_node structure. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r exists@ expression x; identifier f; position p1,p2; @@ x@p1->f = \(of_find_node_by_path\|of_find_node_by_name\|of_find_node_by_phandle\|of_get_parent\|of_get_next_parent\|of_get_next_child\|of_find_compatible_node\|of_match_node\|of_find_node_by_type\|of_find_node_with_property\|of_find_matching_node\|of_parse_phandle\|of_node_get\)(...); ... when != of_node_put(x) kfree@p2(x) @script:python@ p1 << r.p1; p2 << r.p2; @@ cocci.print_main("call",p1) cocci.print_secs("free",p2) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use static const char arraysJoe Perches2010-10-131-1/+1
| | | | | | Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pseries: Export rtas_ibm_suspend_me()Nathan Fontenot2010-10-131-2/+2
| | | | | | | | Export the rtas_ibm_suspend_me() routine. This is needed to perform partition migration in the kernel. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge remote branch 'kumar/merge' into nextBenjamin Herrenschmidt2010-10-134-9/+4
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| * powerpc: remove unused variableStephen Rothwell2010-10-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | Since powerpc uses -Werror on arch powerpc, the build was broken like this: cc1: warnings being treated as errors arch/powerpc/kernel/module.c: In function 'module_finalize': arch/powerpc/kernel/module.c:66: error: unused variable 'err' Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * modules: Fix module_bug_list list corruption raceLinus Torvalds2010-10-051-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With all the recent module loading cleanups, we've minimized the code that sits under module_mutex, fixing various deadlocks and making it possible to do most of the module loading in parallel. However, that whole conversion totally missed the rather obscure code that adds a new module to the list for BUG() handling. That code was doubly obscure because (a) the code itself lives in lib/bugs.c (for dubious reasons) and (b) it gets called from the architecture-specific "module_finalize()" rather than from generic code. Calling it from arch-specific code makes no sense what-so-ever to begin with, and is now actively wrong since that code isn't protected by the module loading lock any more. So this commit moves the "module_bug_{finalize,cleanup}()" calls away from the arch-specific code, and into the generic code - and in the process protects it with the module_mutex so that the list operations are now safe. Future fixups: - move the module list handling code into kernel/module.c where it belongs. - get rid of 'module_bug_list' and just use the regular list of modules (called 'modules' - imagine that) that we already create and maintain for other reasons. Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Adrian Bunk <bunk@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * powerpc: fix double syscall restartsAl Viro2010-09-223-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sigreturn zero regs->trap, make do_signal() do the same on all paths. As it is, signal interrupting e.g. read() from fd 512 (== ERESTARTSYS) with another signal getting unblocked when the first handler finishes will lead to restart one insn earlier than it ought to. Same for multiple signals with in-kernel handlers interrupting that sucker at the same time. Same for multiple signals of any kind interrupting that sucker on 64bit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | powerpc/perf: Fix sampling enable for PPC970Paul Mackerras2010-09-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The logic to distinguish marked instruction events from ordinary events on PPC970 and derivatives was flawed. The result is that instruction sampling didn't get enabled in the PMU for some marked instruction events, so they would never trigger. This fixes it by adding the appropriate break statements in the switch statement. Reported-by: David Binderman <dcb314@hotmail.com> Cc: stable@kernel.org Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc/dma: Add optional platform override of dma_set_mask()Benjamin Herrenschmidt2010-09-021-0/+18
| | | | | | | | | | | | | | | | Some platforms may want to override dma_set_mask() to take into account some specific "features" such as the availability of a direct-map window in addition to an iommu. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Use is_32bit_task() helper to test 32-bit binaryDenis Kirjanov2010-09-022-4/+4
| | | | | | | | | | | | | | This patch removes all explicit tests for the TIF_32BIT flag Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Remove fpscr use from [kvm_]cvt_{fd,df}Andreas Schwab2010-09-022-12/+2
| | | | | | | | | | | | | | | | Neither lfs nor stfs touch the fpscr, so remove the restore/save of it around them. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc/pseries: Re-enable dispatch trace log userspace interfacePaul Mackerras2010-09-021-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the cpu accounting code uses the hypervisor dispatch trace log now when CONFIG_VIRT_CPU_ACCOUNTING = y, the previous commit disabled access to it via files in the /sys/kernel/debug/powerpc/dtl/ directory in that case. This restores those files. To do this, we now have a hook that the cpu accounting code will call as it processes each entry from the hypervisor dispatch trace log. The code in dtl.c now uses that to fill up its ring buffer, rather than having the hypervisor fill the ring buffer directly. This also fixes dtl_file_read() to handle overflow conditions a bit better and adds a spinlock to ensure that race conditions (multiple processes opening or reading the file concurrently) are handled correctly. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Account time using timebase rather than PURRPaul Mackerras2010-09-025-150/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, when CONFIG_VIRT_CPU_ACCOUNTING is enabled, we use the PURR register for measuring the user and system time used by processes, as well as other related times such as hardirq and softirq times. This turns out to be quite confusing for users because it means that a program will often be measured as taking less time when run on a multi-threaded processor (SMT2 or SMT4 mode) than it does when run on a single-threaded processor (ST mode), even though the program takes longer to finish. The discrepancy is accounted for as stolen time, which is also confusing, particularly when there are no other partitions running. This changes the accounting to use the timebase instead, meaning that the reported user and system times are the actual number of real-time seconds that the program was executing on the processor thread, regardless of which SMT mode the processor is in. Thus a program will generally show greater user and system times when run on a multi-threaded processor than on a single-threaded processor. On pSeries systems on POWER5 or later processors, we measure the stolen time (time when this partition wasn't running) using the hypervisor dispatch trace log. We check for new entries in the log on every entry from user mode and on every transition from kernel process context to soft or hard IRQ context (i.e. when account_system_vtime() gets called). So that we can correctly distinguish time stolen from user time and time stolen from system time, without having to check the log on every exit to user mode, we store separate timestamps for exit to user mode and entry from user mode. On systems that have a SPURR (POWER6 and POWER7), we read the SPURR in account_system_vtime() (as before), and then apportion the SPURR ticks since the last time we read it between scaled user time and scaled system time according to the relative proportions of user time and system time over the same interval. This avoids having to read the SPURR on every kernel entry and exit. On systems that have PURR but not SPURR (i.e., POWER5), we do the same using the PURR rather than the SPURR. This disables the DTL user interface in /sys/debug/kernel/powerpc/dtl for now since it conflicts with the use of the dispatch trace log by the time accounting code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Dynamically allocate most lppaca structsPaul Mackerras2010-09-021-2/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This arranges for the lppaca structs for most cpus to be dynamically allocated in the same manner as the paca structs. If we don't include support for legacy iSeries, only the first lppaca is statically allocated; the rest are dynamically allocated. If we include legacy iSeries support, then we statically allocate the first 64 lppaca structs, since the iSeries hypervisor requires that the lppaca structs be present in the data section of the kernel image, but legacy iSeries supports at most 64 cpus. With CONFIG_NR_CPUS, the kernel image size for a typical pSeries config went from: text data bss dec hex filename 9524478 4734564 8469944 22728986 15ad11a ../test-1024/vmlinux to: text data bss dec hex filename 9524482 3751508 8469944 21745934 14bd10e ../test-1024/vmlinux a reduction of 983052 bytes overall. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Abstract indexing of lppaca structsPaul Mackerras2010-09-021-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | Currently we have the lppaca structs as a simple array of NR_CPUS entries, taking up space in the data section of the kernel image. In future we would like to allocate them dynamically, so this abstracts out the accesses to the array, making it easier to change how we locate the lppaca for a given cpu in future. Specifically, lppaca[cpu] changes to lppaca_of(cpu). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Move arch_sd_sibling_asym_packing() to smp.cMichael Neuling2010-09-022-11/+9
| | | | | | | | | | | | | | | | | | | | Simple cleanup by moving arch_sd_sibling_asym_packing from process.c to smp.c to save an #ifdef CONFIG_SMP No functionality change. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: Feature nop out reservation clear when stcx checks addressAnton Blanchard2010-09-021-0/+22
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The POWER architecture does not require stcx to check that it is operating on the same address as the larx. This means it is possible for an an exception handler to execute a larx, get a reservation, decide not to do the stcx and then return back with an active reservation. If the interrupted code was in the middle of a larx/stcx sequence the stcx could incorrectly succeed. All recent POWER CPUs check the address before letting the stcx succeed so we can create a CPU feature and nop it out. As Ben suggested, we can only do this in our syscall path because there is a remote possibility some kernel code gets interrupted by an exception that ends up operating on the same cacheline. Thanks to Paul Mackerras and Derek Williams for the idea. To test this I used a very simple null syscall (actually getppid) testcase at http://ozlabs.org/~anton/junkcode/null_syscall.c I tested against 2.6.35-git10 with the following changes against the pseries_defconfig: CONFIG_VIRT_CPU_ACCOUNTING=n CONFIG_AUDIT=n CONFIG_PPC_4K_PAGES=n CONFIG_PPC_64K_PAGES=y CONFIG_FORCE_MAX_ZONEORDER=9 CONFIG_PPC_SUBPAGE_PROT=n CONFIG_FUNCTION_TRACER=n CONFIG_FUNCTION_GRAPH_TRACER=n CONFIG_IRQSOFF_TRACER=n CONFIG_STACK_TRACER=n to remove the overhead of virtual CPU accounting, syscall auditing and the ftrace mcount tracers. 64kB pages were enabled to minimise TLB misses. POWER6: +8.2% POWER7: +7.0% Another suggestion was to use a larx to something in the L1 instead of a stcx. This was almost as fast as removing the larx on POWER6, but only 3.5% faster on POWER7. We can use this to speed up the reservation clear in our exception exit code. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Don't use kernel stack with translation offMichael Neuling2010-08-311-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In f761622e59433130bc33ad086ce219feee9eb961 we changed early_setup_secondary so it's called using the proper kernel stack rather than the emergency one. Unfortunately, this stack pointer can't be used when translation is off on PHYP as this stack pointer might be outside the RMO. This results in the following on all non zero cpus: cpu 0x1: Vector: 300 (Data Access) at [c00000001639fd10] pc: 000000000001c50c lr: 000000000000821c sp: c00000001639ff90 msr: 8000000000001000 dar: c00000001639ffa0 dsisr: 42000000 current = 0xc000000016393540 paca = 0xc000000006e00200 pid = 0, comm = swapper The original patch was only tested on bare metal system, so it never caught this problem. This changes __secondary_start so that we calculate the new stack pointer but only start using it after we've called early_setup_secondary. With this patch, the above problem goes away. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/perf_event: Reduce latency of calling perf_event_do_pendingPaul Mackerras2010-08-311-12/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0fe1ac48 ("powerpc/perf_event: Fix oops due to perf_event_do_pending call") moved the call to perf_event_do_pending in timer_interrupt() down so that it was after the irq_enter() call. Unfortunately this moved it after the code that checks whether it is time for the next decrementer clock event. The result is that the call to perf_event_do_pending() won't happen until the next decrementer clock event is due. This was pointed out by Milton Miller. This fixes it by moving the check for whether it's time for the next decrementer clock event down to the point where we're about to call the event handler, after we've called perf_event_do_pending. This has the side effect that on old pre-Core99 Powermacs where we use the ppc_n_lost_interrupts mechanism to replay interrupts, a replayed interrupt will incur a little more latency since it will now do the code from the irq_enter down to the irq_exit, that it used to skip. However, these machines are now old and rare enough that this doesn't matter. To make it clear that ppc_n_lost_interrupts is only used on Powermacs, and to speed up the code slightly on non-Powermac ppc32 machines, the code that tests ppc_n_lost_interrupts is now conditional on CONFIG_PMAC as well as CONFIG_PPC32. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/kexec: Adds correct calling convention for kexec purgatoryMatthew McClintock2010-08-311-0/+3
| | | | | | | | | | | | | | | | | | Call kexec purgatory code correctly. We were getting lucky before. If you examine the powerpc 32bit kexec "purgatory" code you will see it expects the following: >From kexec-tools: purgatory/arch/ppc/v2wrap_32.S -> calling convention: -> r3 = physical number of this cpu (all cpus) -> r4 = address of this chunk (master only) As such, we need to set r3 to the current core, r4 happens to be unused by purgatory at the moment but we go ahead and set it here as well Signed-off-by: Matthew McClintock <msm@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Wire up fanotify_init, fanotify_mark, prlimit64 syscallsAndreas Schwab2010-08-241-0/+8
| | | | | Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pci: Fix checking for child bridges in PCI code.Grant Likely2010-08-241-1/+2
| | | | | | | | | | pci_device_to_OF_node() can return null, and list_for_each_entry will never enter the loop when dev is NULL, so it looks like this test is a typo. Reported-by: Julia Lawall <julia@diku.dk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Initialise paca->kstack before early_setup_secondaryMatt Evans2010-08-241-3/+3
| | | | | | | | | | | | | | | | | | As early setup calls down to slb_initialize(), we must have kstack initialised before checking "should we add a bolted SLB entry for our kstack?" Failing to do so means stack access requires an SLB miss exception to refill an entry dynamically, if the stack isn't accessible via SLB(0) (kernel text & static data). It's not always allowable to take such a miss, and intermittent crashes will result. Primary CPUs don't have this issue; an SLB entry is not bolted for their stack anyway (as that lives within SLB(0)). This patch therefore only affects the init of secondaries. Signed-off-by: Matt Evans <matt@ozlabs.org> Cc: stable <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix bogus it_blocksize in VIO iommu codeAnton Blanchard2010-08-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When looking at some issues with the virtual ethernet driver I noticed that TCE allocation was following a very strange pattern: address 00e9000 length 2048 address 0409000 length 2048 <----- address 0429000 length 2048 address 0449000 length 2048 address 0469000 length 2048 address 0489000 length 2048 address 04a9000 length 2048 address 04c9000 length 2048 address 04e9000 length 2048 address 4009000 length 2048 <----- address 4029000 length 2048 Huge unexplained gaps in what should be an empty TCE table. It turns out it_blocksize, the amount we want to align the next allocation to, was c0000000fe903b20. Completely bogus. Initialise it to something reasonable in the VIO IOMMU code, and use kzalloc everywhere to protect against this when we next add a non compulsary field to iommu code and forget to initialise it. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Inline ppc64_runlatch_offAnton Blanchard2010-08-241-8/+6
| | | | | | | | | | I'm sick of seeing ppc64_runlatch_off in our profiles, so inline it into the callers. To avoid a mess of circular includes I didn't add it as an inline function. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Correct smt_enabled=X boot option for > 2 threads per coreNathan Fontenot2010-08-241-27/+36
| | | | | | | | | | | The 'smt_enabled=X' boot option does not handle values of X > 2. For Power 7 processors with smt modes of 0,1,2,3, and 4 this does not work. This patch allows the smt_enabled option to be set to any value limited to a max equal to the number of threads per core. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Silence __cpu_up() under normal operationSigned-off-by: Darren Hart2010-08-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | During CPU offline/online tests __cpu_up would flood the logs with the following message: Processor 0 found. This provides no useful information to the user as there is no context provided, and since the operation was a success (to this point) it is expected that the CPU will come back online, providing all the feedback necessary. Change the "Processor found" message to DBG() similar to other such messages in the same function. Also, add an appropriate log level for the "Processor is stuck" message. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Re-enable preemption before cpu_die()Signed-off-by: Darren Hart2010-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | start_secondary() is called shortly after _start and also via cpu_idle()->cpu_die()->pseries_mach_cpu_die() start_secondary() expects a preempt_count() of 0. pseries_mach_cpu_die() is called via the cpu_idle() routine with preemption disabled, resulting in the following repeating message during rapid cpu offline/online tests with CONFIG_PREEMPT=y: BUG: scheduling while atomic: swapper/0/0x00000002 Modules linked in: autofs4 binfmt_misc dm_mirror dm_region_hash dm_log [last unloaded: scsi_wait_scan] Call Trace: [c00000010e7079c0] [c0000000000133ec] .show_stack+0xd8/0x218 (unreliable) [c00000010e707aa0] [c0000000006a47f0] .dump_stack+0x28/0x3c [c00000010e707b20] [c00000000006e7a4] .__schedule_bug+0x7c/0x9c [c00000010e707bb0] [c000000000699d9c] .schedule+0x104/0x800 [c00000010e707cd0] [c000000000015b24] .cpu_idle+0x1c4/0x1d8 [c00000010e707d70] [c0000000006aa1b4] .start_secondary+0x398/0x3d4 [c00000010e707e30] [c000000000008278] .start_secondary_resume+0x10/0x14 Move the cpu_die() call inside the existing preemption enabled block of cpu_idle(). This is safe as the idle task is affined to a single CPU so the debug_smp_processor_id() tests (from cpu_should_die()) won't trigger as we are in a "migration disabled" region. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pci: Drop unnecessary null testJulia Lawall2010-08-241-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | list_for_each_entry binds its first argument to a non-null value, and thus any null test on the value of that argument is superfluous. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ iterator I; expression x,E,E1,E2; statement S,S1,S2; @@ I(x,...) { <... - if (x != NULL || ...) S ...> } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/kdump: Stop all other CPUs before running crash handlersAnton Blanchard2010-08-241-11/+13
| | | | | | | | | | | During kdump we run the crash handlers first then stop all other CPUs. We really want to stop all CPUs as close to the fail as possible and also have a very controlled environment for running the crash handlers, so it makes sense to reverse the order. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Matt Evans <matt@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use is_32bit_task() helper to test 32 bit binaryDenis Kirjanov2010-08-241-3/+3
| | | | | | | Use is_32bit_task() helper to test 32 bit binary. Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge remote branch 'jwb/merge' into mergeBenjamin Herrenschmidt2010-08-244-12/+18
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| * powerpc/4xx: Index interrupt stacks by physical cpuDave Kleikamp2010-08-232-11/+14
| | | | | | | | | | | | | | | | | | The interrupt stacks need to be indexed by the physical cpu since the critical, debug and machine check handlers use the contents of SPRN_PIR to index the critirq_ctx, dbgirq_ctx, and mcheckirq_ctx arrays. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
| * powerpc/47x: Remove redundant line from cputable.cDave Kleikamp2010-08-231-1/+0
| | | | | | | | | | | | | | | | There are two entries for .cpu_user_features in arch/powerpc/kernel/cputable.c. Remove the one that doesn't belong Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
| * powerpc/47x: Make sure mcsr is cleared before enabling machine check interruptsDave Kleikamp2010-08-231-0/+4
| | | | | | | | | | | | | | | | | | Clear the machine check syndrom register before enabling machine check interrupts. The initial state of the tlb can lead to parity errors being flagged early after a cold boot. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
* | Make do_execve() take a const filename pointerDavid Howells2010-08-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make do_execve() take a const filename pointer so that kernel_execve() compiles correctly on ARM: arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type This also requires the argv and envp arguments to be consted twice, once for the pointer array and once for the strings the array points to. This is because do_execve() passes a pointer to the filename (now const) to copy_strings_kernel(). A simpler alternative would be to cast the filename pointer in do_execve() when it's passed to copy_strings_kernel(). do_execve() may not change any of the strings it is passed as part of the argv or envp lists as they are some of them in .rodata, so marking these strings as const should be fine. Further kernel_execve() and sys_execve() need to be changed to match. This has been test built on x86_64, frv, arm and mips. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Mark arguments to certain syscalls as being constDavid Howells2010-08-132-2/+2
|/ | | | | | | | | | | | | | | | Mark arguments to certain system calls as being const where they should be but aren't. The list includes: (*) The filename arguments of various stat syscalls, execve(), various utimes syscalls and some mount syscalls. (*) The filename arguments of some syscall helpers relating to the above. (*) The buffer argument of various write syscalls. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: fix i8042 module build errorGrant Likely2010-08-061-0/+2
| | | | | | of_i8042_{kbd,aux}_irq needs to be exported Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* Merge branch 'timers-timekeeping-for-linus' of ↵Linus Torvalds2010-08-061-33/+27
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: um: Fix read_persistent_clock fallout kgdb: Do not access xtime directly powerpc: Clean up obsolete code relating to decrementer and timebase powerpc: Rework VDSO gettimeofday to prevent time going backwards clocksource: Add __clocksource_updatefreq_hz/khz methods x86: Convert common clocksources to use clocksource_register_hz/khz timekeeping: Make xtime and wall_to_monotonic static hrtimer: Cleanup direct access to wall_to_monotonic um: Convert to use read_persistent_clock timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset powerpc: Cleanup xtime usage powerpc: Simplify update_vsyscall time: Kill off CONFIG_GENERIC_TIME time: Implement timespec_add x86: Fix vtime/file timestamp inconsistencies Trivial conflicts in Documentation/feature-removal-schedule.txt Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as per Thomas' earlier merge commit 47916be4e28c ("Merge branch 'powerpc.cherry-picks' into timers/clocksource")
| * Merge branch 'powerpc.cherry-picks' into timers/clocksourceThomas Gleixner2010-07-285-345/+72
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/kernel/time.c Reason: The powerpc next tree contains two commits which conflict with the timekeeping changes: 8fd63a9e powerpc: Rework VDSO gettimeofday to prevent time going backwards c1aa687d powerpc: Clean up obsolete code relating to decrementer and timebase John Stultz identified them and provided the conflict resolution. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * powerpc: Clean up obsolete code relating to decrementer and timebasePaul Mackerras2010-07-282-135/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the decrementer and timekeeping code was moved over to using the generic clockevents and timekeeping infrastructure, several variables and functions have been obsolete and effectively unused. This deletes them. In particular, wakeup_decrementer() is no longer needed since the generic code reprograms the decrementer as part of the process of resuming the timekeeping code, which happens during sysdev resume. Thus the wakeup_decrementer calls in the suspend_enter methods for 52xx platforms have been removed. The call in the powermac cpu frequency change code has been replaced by set_dec(1), which will cause a timer interrupt as soon as interrupts are enabled, and the generic code will then reprogram the decrementer with the correct value. This also simplifies the generic_suspend_en/disable_irqs functions and makes them static since they are not referenced outside time.c. The preempt_enable/disable calls are removed because the generic code has disabled all but the boot cpu at the point where these functions are called, so we can't be moved to another cpu. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| | * powerpc: Rework VDSO gettimeofday to prevent time going backwardsPaul Mackerras2010-07-284-237/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently it is possible for userspace to see the result of gettimeofday() going backwards by 1 microsecond, assuming that userspace is using the gettimeofday() in the VDSO. The VDSO gettimeofday() algorithm computes the time in "xsecs", which are units of 2^-20 seconds, or approximately 0.954 microseconds, using the algorithm now = (timebase - tb_orig_stamp) * tb_to_xs + stamp_xsec and then converts the time in xsecs to seconds and microseconds. The kernel updates the tb_orig_stamp and stamp_xsec values every tick in update_vsyscall(). If the length of the tick is not an integer number of xsecs, then some precision is lost in converting the current time to xsecs. For example, with CONFIG_HZ=1000, the tick is 1ms long, which is 1048.576 xsecs. That means that stamp_xsec will advance by either 1048 or 1049 on each tick. With the right conditions, it is possible for userspace to get (timebase - tb_orig_stamp) * tb_to_xs being 1049 if the kernel is slightly late in updating the vdso_datapage, and then for stamp_xsec to advance by 1048 when the kernel does update it, and for userspace to then see (timebase - tb_orig_stamp) * tb_to_xs being zero due to integer truncation. The result is that time appears to go backwards by 1 microsecond. To fix this we change the VDSO gettimeofday to use a new field in the VDSO datapage which stores the nanoseconds part of the time as a fractional number of seconds in a 0.32 binary fraction format. (Or put another way, as a 32-bit number in units of 0.23283 ns.) This is convenient because we can use the mulhwu instruction to convert it to either microseconds or nanoseconds. Since it turns out that computing the time of day using this new field is simpler than either using stamp_xsec (as gettimeofday does) or stamp_xtime.tv_nsec (as clock_gettime does), this converts both gettimeofday and clock_gettime to use the new field. The existing __do_get_tspec function is converted to use the new field and take a parameter in r7 that indicates the desired resolution, 1,000,000 for microseconds or 1,000,000,000 for nanoseconds. The __do_get_xsec function is then unused and is deleted. The new algorithm is now = ((timebase - tb_orig_stamp) << 12) * tb_to_xs + (stamp_xtime_seconds << 32) + stamp_sec_fraction with 'now' in units of 2^-32 seconds. That is then converted to seconds and either microseconds or nanoseconds with seconds = now >> 32 partseconds = ((now & 0xffffffff) * resolution) >> 32 The 32-bit VDSO code also makes a further simplification: it ignores the bottom 32 bits of the tb_to_xs value, which is a 0.64 format binary fraction. Doing so gets rid of 4 multiply instructions. Assuming a timebase frequency of 1GHz or less and an update interval of no more than 10ms, the upper 32 bits of tb_to_xs will be at least 4503599, so the error from ignoring the low 32 bits will be at most 2.2ns, which is more than an order of magnitude less than the time taken to do gettimeofday or clock_gettime on our fastest processors, so there is no possibility of seeing inconsistent values due to this. This also moves update_gtod() down next to its only caller, and makes update_vsyscall use the time passed in via the wall_time argument rather than accessing xtime directly. At present, wall_time always points to xtime, but that could change in future. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | timkeeping: Fix update_vsyscall to provide wall_to_monotonic offsetJohn Stultz2010-07-271-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | update_vsyscall() did not provide the wall_to_monotoinc offset, so arch specific implementations tend to reference wall_to_monotonic directly. This limits future cleanups in the timekeeping core, so this patch fixes the update_vsyscall interface to provide wall_to_monotonic, allowing wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Tony Luck <tony.luck@intel.com> LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | powerpc: Cleanup xtime usageJohn Stultz2010-07-271-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes powerpc's direct xtime usage, allowing for further generic timeekeping cleanups Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Anton Blanchard <anton@samba.org> LKML-Reference: <1279068988-21864-6-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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