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2014-06-06powerpc: update comments for generic idle conversionGeert Uytterhoeven
As of commit 799fef06123f ("powerpc: Use generic idle loop"), this applies to arch_cpu_idle() instead of cpu_idle(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04powerpc: Irq: Use generic_handle_irqThomas Gleixner
No functional change Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: ppc <linuxppc-dev@lists.ozlabs.org> Link: http://lkml.kernel.org/r/20140223212736.333718121@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-02-11powerpc/ppc32: Fix the bug in the init of non-base exception stack for UPKevin Hao
We would allocate one specific exception stack for each kind of non-base exceptions for every CPU. For ppc32 the CPU hard ID is used as the subscript to get the specific exception stack for one CPU. But for an UP kernel, there is only one element in the each kind of exception stack array. We would get stuck if the CPU hard ID is not equal to '0'. So in this case we should use the subscript '0' no matter what the CPU hard ID is. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02powerpc: Make irq_stat.timers_irqs counting more specificfan.du
Current irq_stat.timers_irqs counting doesn't discriminate timer event handler and other timer interrupt(like arch_irq_work_raise). Sometimes we need to know exactly how much interrupts timer event handler fired, so let's be more specific on this. Signed-off-by: Fan Du <fan.du@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-12Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull IRQ changes from Ingo Molnar: "The biggest change this cycle are the softirq/hardirq stack interaction and nesting fixes, cleanups and reorganizations from Frederic. This is the longer followup story to the softirq nesting fix that is already upstream (commit ded797547548: "irq: Force hardirq exit's softirq processing on its own stack")" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro powerpc: Tell about irq stack coverage x86: Tell about irq stack coverage irq: Optimize softirq stack selection in irq exit irq: Justify the various softirq stack choices irq: Improve a bit softirq debugging irq: Optimize call to softirq on hardirq exit irq: Consolidate do_softirq() arch overriden implementations x86/irq: Correct comment about i8259 initialization
2013-10-07powerpc/irq: Don't switch to irq stack from softirq stackBenjamin Herrenschmidt
irq_exit() is now called on the irq stack, which can trigger a switch to the softirq stack from the irq stack. If an interrupt happens at that point, we will not properly detect the re-entrancy and clobber the original return context on the irq stack. This fixes it. The side effect is to prevent all nesting from softirq stack to irq stack even in the "safe" case but it's simpler that way and matches what x86_64 does. Reported-by: Cédric Le Goater <clg@fr.ibm.com> Tested-by: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-01irq: Consolidate do_softirq() arch overriden implementationsFrederic Weisbecker
All arch overriden implementations of do_softirq() share the following common code: disable irqs (to avoid races with the pending check), check if there are softirqs pending, then execute __do_softirq() on a specific stack. Consolidate the common parts such that archs only worry about the stack switch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org>
2013-09-25powerpc: Remove ksp_limit on ppc64Benjamin Herrenschmidt
We've been keeping that field in thread_struct for a while, it contains the "limit" of the current stack pointer and is meant to be used for detecting stack overflows. It has a few problems however: - First, it was never actually *used* on 64-bit. Set and updated but not actually exploited - When switching stack to/from irq and softirq stacks, it's update is racy unless we hard disable interrupts, which is costly. This is fine on 32-bit as we don't soft-disable there but not on 64-bit. Thus rather than fixing 2 in order to implement 1 in some hypothetical future, let's remove the code completely from 64-bit. In order to avoid a clutter of ifdef's, we remove the updates from C code completely during interrupt stack switching, and instead maintain it from the asm helper that is used to do the stack switching in the first place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-25powerpc/irq: Run softirqs off the top of the irq stackBenjamin Herrenschmidt
Nowadays, irq_exit() calls __do_softirq() pretty much directly instead of calling do_softirq() which switches to the decicated softirq stack. This has lead to observed stack overflows on powerpc since we call irq_enter() and irq_exit() outside of the scope that switches to the irq stack. This fixes it by moving the stack switching up a level, making irq_enter() and irq_exit() run off the irq stack. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-01powerpc: Rename PMU interrupts from CNT to PMIMichael Ellerman
Back in commit 89713ed "Add timer, performance monitor and machine check counts to /proc/interrupts" we added a count of PMU interrupts to the output of /proc/interrupts. At the time we named them "CNT" to match x86. However in commit 89ccf46 "Rename 'performance counter interrupt'", the x86 guys renamed theirs from "CNT" to "PMI". Arguably changing the name could break someone's script, but I think the chance of that is minimal, and it's preferable to have a name that 1) is somewhat meaningful, and 2) matches x86. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01Merge tag 'v3.10' into nextBenjamin Herrenschmidt
Merge 3.10 in order to get some of the last minute powerpc changes, resolve conflicts and add additional fixes on top of them.
2013-06-20powerpc: Remove the unneeded trigger of decrementer interrupt in ↵Kevin Hao
decrementer_check_overflow Previously in order to handle the edge sensitive decrementers, we choose to set the decrementer to 1 to trigger a decrementer interrupt when re-enabling interrupts. But with the rework of the lazy EE, we would replay the decrementer interrupt when re-enabling interrupts if a decrementer interrupt occurs with irq soft-disabled. So there is no need to trigger a decrementer interrupt in this case any more. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-15powerpc: Fix missing/delayed calls to irq_workBenjamin Herrenschmidt
When replaying interrupts (as a result of the interrupt occurring while soft-disabled), in the case of the decrementer, we are exclusively testing for a pending timer target. However we also use decrementer interrupts to trigger the new "irq_work", which in this case would be missed. This change the logic to force a replay in both cases of a timer boundary reached and a decrementer interrupt having actually occurred while disabled. The former test is still useful to catch cases where a CPU having been hard-disabled for a long time completely misses the interrupt due to a decrementer rollover. CC: <stable@vger.kernel.org> [v3.4+] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Steven Rostedt <rostedt@goodmis.org>
2013-04-18powerpc: Add accounting for Doorbell interruptsIan Munsie
This patch adds a new line to /proc/interrupts to account for the doorbell interrupts that each hardware thread has received. The total interrupt count in /proc/stat will now also include doorbells. # cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 16: 551 1267 281 175 XICS Level IPI LOC: 2037 1503 1688 1625 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts CNT: 0 0 0 0 Performance monitoring interrupts MCE: 0 0 0 0 Machine check exceptions DBL: 42 550 20 91 Doorbell interrupts Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
2013-01-10powerpc: Add code to handle soft-disabled doorbells on serverIan Munsie
This patch adds the logic to properly handle doorbells that come in when interrupts have been soft disabled and to replay them when interrupts are re-enabled: - masked_##_H##interrupt is modified to leave interrupts enabled when a doorbell has come in since doorbells are edge sensitive and as such won't be automatically re-raised. - __check_irq_replay now tests if a doorbell happened on book3s, and returns either 0xe80 or 0xa00 depending on whether we are the hypervisor or not. - restore_check_irq_replay now tests for the two possible server doorbell vector numbers to replay. - __replay_interrupt also adds tests for the two server doorbell vector numbers, and is modified to use a compare instruction rather than an andi. on the single bit difference between 0x500 and 0x900. The last two use a CPU feature section to avoid needlessly testing against the hypervisor vector if it is not the hypervisor, and vice versa. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-09-17powerpc/trace: Fix interrupt tracepoints vs. RCULi Zhong
There are a few tracepoints in the interrupt code path, which is before irq_enter(), or after irq_exit(), like trace_irq_entry()/trace_irq_exit() in do_IRQ(), trace_timer_interrupt_entry()/trace_timer_interrupt_exit() in timer_interrupt(). If the interrupt is from idle(), and because tracepoint contains RCU read-side critical section, we could see following suspicious RCU usage reported: [ 145.127743] =============================== [ 145.127747] [ INFO: suspicious RCU usage. ] [ 145.127752] 3.6.0-rc3+ #1 Not tainted [ 145.127755] ------------------------------- [ 145.127759] /root/.workdir/linux/arch/powerpc/include/asm/trace.h:33 suspicious rcu_dereference_check() usage! [ 145.127765] [ 145.127765] other info that might help us debug this: [ 145.127765] [ 145.127771] [ 145.127771] RCU used illegally from idle CPU! [ 145.127771] rcu_scheduler_active = 1, debug_locks = 0 [ 145.127777] RCU used illegally from extended quiescent state! [ 145.127781] no locks held by swapper/0/0. [ 145.127785] [ 145.127785] stack backtrace: [ 145.127789] Call Trace: [ 145.127796] [c00000000108b530] [c000000000013c40] .show_stack +0x70/0x1c0 (unreliable) [ 145.127806] [c00000000108b5e0] [c0000000000f59d8] .lockdep_rcu_suspicious+0x118/0x150 [ 145.127813] [c00000000108b680] [c00000000000fc58] .do_IRQ+0x498/0x500 [ 145.127820] [c00000000108b750] [c000000000003950] hardware_interrupt_common+0x150/0x180 [ 145.127828] --- Exception: 501 at .plpar_hcall_norets+0x84/0xd4 [ 145.127828] LR = .check_and_cede_processor+0x38/0x70 [ 145.127836] [c00000000108bab0] [c0000000000665dc] .shared_cede_loop +0x5c/0x100 [ 145.127844] [c00000000108bb70] [c000000000588ab0] .cpuidle_enter +0x30/0x50 [ 145.127850] [c00000000108bbe0] [c000000000588b0c] .cpuidle_enter_state+0x3c/0xb0 [ 145.127857] [c00000000108bc60] [c000000000589730] .cpuidle_idle_call +0x150/0x6c0 [ 145.127863] [c00000000108bd30] [c000000000058440] .pSeries_idle +0x10/0x40 [ 145.127870] [c00000000108bda0] [c00000000001683c] .cpu_idle +0x18c/0x2d0 [ 145.127876] [c00000000108be60] [c00000000000b434] .rest_init +0x124/0x1b0 [ 145.127884] [c00000000108bef0] [c0000000009d0d28] .start_kernel +0x568/0x588 [ 145.127890] [c00000000108bf90] [c000000000009660] .start_here_common +0x20/0x40 This is because the RCU usage in interrupt context should be used in area marked by rcu_irq_enter()/rcu_irq_exit(), called in irq_enter()/irq_exit() respectively. Move them into the irq_enter()/irq_exit() area to avoid the reporting. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10powerpc: Fix build of some debug irq codeBenjamin Herrenschmidt
There was a typo, checking for CONFIG_TRACE_IRQFLAG instead of CONFIG_TRACE_IRQFLAGS causing some useful debug code to not be built This in turns causes a build error on BookE 64-bit due to incorrect semicolons at the end of a couple of macros, so let's fix that too Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: stable@vger.kernel.org [v3.4]
2012-07-10powerpc: More fixes for lazy IRQ vs. idleBenjamin Herrenschmidt
Looks like we still have issues with pSeries and Cell idle code vs. the lazy irq state. In fact, the reset fixes that went upstream are exposing the problem more by causing BUG_ON() to trigger (which this patch turns into a WARN_ON instead). We need to be careful when using a variant of low power state that has the side effect of turning interrupts back on, to properly set all the SW & lazy state to look as if everything is enabled before we enter the low power state with MSR:EE off as we will return with MSR:EE on. If not, we have a discrepancy of state which can cause things to go very wrong later on. This patch moves the logic into a helper and uses it from the pseries and cell idle code. The power4/970 idle code already got things right (in assembly even !) so I'm not touching it. The power7 "bare metal" idle code is subtly different and correct. Remains PA6T and some hypervisor based Cell platforms which have questionable code in there, but they are mostly dead platforms so I'll fix them when I manage to get final answers from the respective maintainers about how the low power state actually works on them. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: stable@vger.kernel.org [v3.4]
2012-06-29powerpc/ftrace: Do not trace restore_interrupts()Steven Rostedt
As I was adding code that affects all archs, I started testing function tracer against PPC64 and found that it currently locks up with 3.4 kernel. I figured it was due to tracing a function that shouldn't be, so I went through the following process to bisect to find the culprit: cat /debug/tracing/available_filter_functions > t num=`wc -l t` sed -ne "1,${num}p" t > t1 let num=num+1 sed -ne "${num},$p" t > t2 cat t1 > /debug/tracing/set_ftrace_filter echo function /debug/tracing/current_tracer <failed? bisect t1, if not bisect t2> It finally came down to this function: restore_interrupts() I'm not sure why this locks up the system. It just seems to prevent scheduling from occurring. Interrupts seem to still work, as I can ping the box. But all user processes freeze. When restore_interrupts() is not traced, function tracing works fine. Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-22powerpc: Fix irq distributionKim Phillips
setting CONFIG_IRQ_ALL_CPUS distributes IRQs to CPUs only when the number of online CPUs equals NR_CPUS. See commit 280ff97494e0fef4124bee5c52e39b23a18dd283 "sparc64: fix and optimize irq distribution" for more details. Using the online mask fixes IRQ-to-CPU distribution on systems that boot with less than NR_CPUS. Signed-off-by: Kim Phillips <kim.phillips@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-12powerpc/irq: Fix another case of lazy IRQ state getting out of syncBenjamin Herrenschmidt
So we have another case of paca->irq_happened getting out of sync with the HW irq state. This can happen when a perfmon interrupt occurs while soft disabled, as it will return to a soft disabled but hard enabled context while leaving a stale PACA_IRQ_HARD_DIS flag set. This patch fixes it, and also adds a test for the condition of those flags being out of sync in arch_local_irq_restore() when CONFIG_TRACE_IRQFLAGS is enabled. This helps catching those gremlins faster (and so far I can't seem see any anymore, so that's good news). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-09powerpc/irq: Fix bug with new lazy IRQ handling codeBenjamin Herrenschmidt
We had a case where we could turn on hard interrupts while leaving the PACA_IRQ_HARD_DIS bit set in the PACA. This can in turn cause a BUG_ON() to hit in __check_irq_replay() due to interrupt state getting out of sync. The assembly code was also way too convoluted. Instead, we now leave it to the C code to do the right thing which ends up being smaller and more readable. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-30powerpc/irqdomain: Fix broken NR_IRQ referencesGrant Likely
The switch from using irq_map to irq_alloc_desc*() for managing irq number allocations introduced new bugs in some of the powerpc interrupt code. Several functions rely on the value of NR_IRQS to determine the maximum irq number that could get allocated. However, with sparse_irq and using irq_alloc_desc*() the maximum possible irq number is now specified with 'nr_irqs' which may be a number larger than NR_IRQS. This has caused breakage on powermac when CONFIG_NR_IRQS is set to 32. This patch removes most of the direct references to NR_IRQS in the powerpc code and replaces them with either a nr_irqs reference or by using the common for_each_irq_desc() macro. The powerpc-specific for_each_irq() macro is removed at the same time. Also, the Cell axon_msi driver is refactored to remove the global build assumption on the size of NR_IRQS and instead add a limit to the maximum irq number when calling irq_domain_add_nomap(). Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-04-10irq: Kill pointless irqd_to_hw exportGrant Likely
It makes no sense to export this trivial function. Make it a static inline instead. This patch also drops virq_to_hw from arch/c6x since it is unused by that architecture. v2: Move irq_hw_number_t into types.h to fix ARM build failure Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system Pull "Disintegrate and delete asm/system.h" from David Howells: "Here are a bunch of patches to disintegrate asm/system.h into a set of separate bits to relieve the problem of circular inclusion dependencies. I've built all the working defconfigs from all the arches that I can and made sure that they don't break. The reason for these patches is that I recently encountered a circular dependency problem that came about when I produced some patches to optimise get_order() by rewriting it to use ilog2(). This uses bitops - and on the SH arch asm/bitops.h drags in asm-generic/get_order.h by a circuituous route involving asm/system.h. The main difficulty seems to be asm/system.h. It holds a number of low level bits with no/few dependencies that are commonly used (eg. memory barriers) and a number of bits with more dependencies that aren't used in many places (eg. switch_to()). These patches break asm/system.h up into the following core pieces: (1) asm/barrier.h Move memory barriers here. This already done for MIPS and Alpha. (2) asm/switch_to.h Move switch_to() and related stuff here. (3) asm/exec.h Move arch_align_stack() here. Other process execution related bits could perhaps go here from asm/processor.h. (4) asm/cmpxchg.h Move xchg() and cmpxchg() here as they're full word atomic ops and frequently used by atomic_xchg() and atomic_cmpxchg(). (5) asm/bug.h Move die() and related bits. (6) asm/auxvec.h Move AT_VECTOR_SIZE_ARCH here. Other arch headers are created as needed on a per-arch basis." Fixed up some conflicts from other header file cleanups and moving code around that has happened in the meantime, so David's testing is somewhat weakened by that. We'll find out anything that got broken and fix it.. * tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits) Delete all instances of asm/system.h Remove all #inclusions of asm/system.h Add #includes needed to permit the removal of asm/system.h Move all declarations of free_initmem() to linux/mm.h Disintegrate asm/system.h for OpenRISC Split arch_align_stack() out from asm-generic/system.h Split the switch_to() wrapper out of asm-generic/system.h Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h Create asm-generic/barrier.h Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h Disintegrate asm/system.h for Xtensa Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt] Disintegrate asm/system.h for Tile Disintegrate asm/system.h for Sparc Disintegrate asm/system.h for SH Disintegrate asm/system.h for Score Disintegrate asm/system.h for S390 Disintegrate asm/system.h for PowerPC Disintegrate asm/system.h for PA-RISC Disintegrate asm/system.h for MN10300 ...
2012-03-28Disintegrate asm/system.h for PowerPCDavid Howells
Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
2012-03-28powerpc: Random little legacy iSeries removal tidy upsStephen Rothwell
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-28powerpc: Remove NO_IRQ_IGNOREStephen Rothwell
Now that legacy iSeries is gone, this is no longer used. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-21Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc merge from Benjamin Herrenschmidt: "Here's the powerpc batch for this merge window. It is going to be a bit more nasty than usual as in touching things outside of arch/powerpc mostly due to the big iSeriesectomy :-) We finally got rid of the bugger (legacy iSeries support) which was a PITA to maintain and that nobody really used anymore. Here are some of the highlights: - Legacy iSeries is gone. Thanks Stephen ! There's still some bits and pieces remaining if you do a grep -ir series arch/powerpc but they are harmless and will be removed in the next few weeks hopefully. - The 'fadump' functionality (Firmware Assisted Dump) replaces the previous (equivalent) "pHyp assisted dump"... it's a rewrite of a mechanism to get the hypervisor to do crash dumps on pSeries, the new implementation hopefully being much more reliable. Thanks Mahesh Salgaonkar. - The "EEH" code (pSeries PCI error handling & recovery) got a big spring cleaning, motivated by the need to be able to implement a new backend for it on top of some new different type of firwmare. The work isn't complete yet, but a good chunk of the cleanups is there. Note that this adds a field to struct device_node which is not very nice and which Grant objects to. I will have a patch soon that moves that to a powerpc private data structure (hopefully before rc1) and we'll improve things further later on (hopefully getting rid of the need for that pointer completely). Thanks Gavin Shan. - I dug into our exception & interrupt handling code to improve the way we do lazy interrupt handling (and make it work properly with "edge" triggered interrupt sources), and while at it found & fixed a wagon of issues in those areas, including adding support for page fault retry & fatal signals on page faults. - Your usual random batch of small fixes & updates, including a bunch of new embedded boards, both Freescale and APM based ones, etc..." I fixed up some conflicts with the generalized irq-domain changes from Grant Likely, hopefully correctly. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (141 commits) powerpc/ps3: Do not adjust the wrapper load address powerpc: Remove the rest of the legacy iSeries include files powerpc: Remove the remaining CONFIG_PPC_ISERIES pieces init: Remove CONFIG_PPC_ISERIES powerpc: Remove FW_FEATURE ISERIES from arch code tty/hvc_vio: FW_FEATURE_ISERIES is no longer selectable powerpc/spufs: Fix double unlocks powerpc/5200: convert mpc5200 to use of_platform_populate() powerpc/mpc5200: add options to mpc5200_defconfig powerpc/mpc52xx: add a4m072 board support powerpc/mpc5200: update mpc5200_defconfig to fit for charon board Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup powerpc/44x: Add additional device support for APM821xx SoC and Bluestone board powerpc/44x: Add support PCI-E for APM821xx SoC and Bluestone board MAINTAINERS: Update PowerPC 4xx tree powerpc/44x: The bug fixed support for APM821xx SoC and Bluestone board powerpc: document the FSL MPIC message register binding powerpc: add support for MPIC message register API powerpc/fsl: Added aliased MSIIR register address to MSI node in dts powerpc/85xx: mpc8548cds - add 36-bit dts ...
2012-03-21Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds
Pull irq_domain support for all architectures from Grant Likely: "Generialize powerpc's irq_host as irq_domain This branch takes the PowerPC irq_host infrastructure (reverse mapping from Linux IRQ numbers to hardware irq numbering), generalizes it, renames it to irq_domain, and makes it available to all architectures. Originally the plan has been to create an all-new irq_domain implementation which addresses some of the powerpc shortcomings such as not handling 1:1 mappings well, but doing that proved to be far more difficult and invasive than generalizing the working code and refactoring it in-place. So, this branch rips out the 'new' irq_domain and replaces it with the modified powerpc version (in a fully bisectable way of course). It converts all users over to the new API and makes irq_domain selectable on any architecture. No architecture is forced to enable irq_domain, but the infrastructure is required for doing OpenFirmware style irq translations. It will even work on SPARC even though SPARC has it's own mechanism for translating irqs at boot time. MIPS, microblaze, embedded x86 and c6x are converted too. The resulting irq_domain code is probably still too verbose and can be optimized more, but that can be done incrementally and is a task for follow-on patches." * tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6: (31 commits) dt: fix twl4030 for non-dt compile on x86 mfd: twl-core: Add IRQ_DOMAIN dependency devicetree: Add empty of_platform_populate() for !CONFIG_OF_ADDRESS (sparc) irq_domain: Centralize definition of irq_dispose_mapping() irq_domain/mips: Allow irq_domain on MIPS irq_domain/x86: Convert x86 (embedded) to use common irq_domain ppc-6xx: fix build failure in flipper-pic.c and hlwd-pic.c irq_domain/microblaze: Convert microblaze to use irq_domains irq_domain/powerpc: Replace custom xlate functions with library functions irq_domain/powerpc: constify irq_domain_ops irq_domain/c6x: Use library of xlate functions irq_domain/c6x: constify irq_domain structures irq_domain/c6x: Convert c6x to use generic irq_domain support. irq_domain: constify irq_domain_ops irq_domain: Create common xlate functions that device drivers can use irq_domain: Remove irq_domain_add_simple() irq_domain: Remove 'new' irq_domain in favour of the ppc one mfd: twl-core.c: Fix the number of interrupts managed by twl4030 of/address: add empty static inlines for !CONFIG_OF irq_domain: Add support for base irq and hwirq in legacy mappings ...
2012-03-21powerpc: Remove FW_FEATURE ISERIES from arch codeStephen Rothwell
This is no longer selectable, so just remove all the dependent code. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-09powerpc: Rework lazy-interrupt handlingBenjamin Herrenschmidt
The current implementation of lazy interrupts handling has some issues that this tries to address. We don't do the various workarounds we need to do when re-enabling interrupts in some cases such as when returning from an interrupt and thus we may still lose or get delayed decrementer or doorbell interrupts. The current scheme also makes it much harder to handle the external "edge" interrupts provided by some BookE processors when using the EPR facility (External Proxy) and the Freescale Hypervisor. Additionally, we tend to keep interrupts hard disabled in a number of cases, such as decrementer interrupts, external interrupts, or when a masked decrementer interrupt is pending. This is sub-optimal. This is an attempt at fixing it all in one go by reworking the way we do the lazy interrupt disabling from the ground up. The base idea is to replace the "hard_enabled" field with a "irq_happened" field in which we store a bit mask of what interrupt occurred while soft-disabled. When re-enabling, either via arch_local_irq_restore() or when returning from an interrupt, we can now decide what to do by testing bits in that field. We then implement replaying of the missed interrupts either by re-using the existing exception frame (in exception exit case) or via the creation of a new one from an assembly trampoline (in the arch_local_irq_enable case). This removes the need to play with the decrementer to try to create fake interrupts, among others. In addition, this adds a few refinements: - We no longer hard disable decrementer interrupts that occur while soft-disabled. We now simply bump the decrementer back to max (on BookS) or leave it stopped (on BookE) and continue with hard interrupts enabled, which means that we'll potentially get better sample quality from performance monitor interrupts. - Timer, decrementer and doorbell interrupts now hard-enable shortly after removing the source of the interrupt, which means they no longer run entirely hard disabled. Again, this will improve perf sample quality. - On Book3E 64-bit, we now make the performance monitor interrupt act as an NMI like Book3S (the necessary C code for that to work appear to already be present in the FSL perf code, notably calling nmi_enter instead of irq_enter). (This also fixes a bug where BookE perfmon interrupts could clobber r14 ... oops) - We could make "masked" decrementer interrupts act as NMIs when doing timer-based perf sampling to improve the sample quality. Signed-off-by-yet: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- v2: - Add hard-enable to decrementer, timer and doorbells - Fix CR clobber in masked irq handling on BookE - Make embedded perf interrupt act as an NMI - Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want to retrigger an interrupt without preventing hard-enable v3: - Fix or vs. ori bug on Book3E - Fix enabling of interrupts for some exceptions on Book3E v4: - Fix resend of doorbells on return from interrupt on Book3E v5: - Rebased on top of my latest series, which involves some significant rework of some aspects of the patch. v6: - 32-bit compile fix - more compile fixes with various .config combos - factor out the asm code to soft-disable interrupts - remove the C wrapper around preempt_schedule_irq v7: - Fix a bug with hard irq state tracking on native power7
2012-03-07powerpc: Make SPARSE_IRQ requiredGrant Likely
All IRQs on powerpc are managed via irq_domain anyway, there isn't really any advantage to turning SPARSE_IRQ off, and it's the direction we want to take the kernel design anyway. This patch makes powerpc always use SPARSE_IRQ. On pseries_defconfig, SPARSE_IRQ adds only about 0x300 bytes to the .text sections, and removes about 0x20000 from the data section for the static irq_desc table. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-02-16irq_domain: Move irq_domain code from powerpc to kernel/irqGrant Likely
This patch only moves the code. It doesn't make any changes, and the code is still only compiled for powerpc. Follow-on patches will generalize the code for other architectures. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Milton Miller <miltonm@bga.com> Tested-by: Olof Johansson <olof@lixom.net>
2012-02-16irq_domain/powerpc: Eliminate virq_is_host()Grant Likely
There is only one user, and it is trivial to open-code. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Milton Miller <miltonm@bga.com> Tested-by: Olof Johansson <olof@lixom.net>
2012-02-14irq_domain/powerpc: eliminate irq_map; use irq_alloc_desc() insteadGrant Likely
This patch drops the powerpc-specific irq_map table and replaces it with directly using the irq_alloc_desc()/irq_free_desc() interfaces for allocating and freeing irq_desc structures. This patch is a preparation step for generalizing the powerpc-specific virq infrastructure to become irq_domains. As part of this change, the irq_big_lock is changed to a mutex from a raw spinlock. There is no longer any need to use a spin lock since the irq_desc allocation code is now responsible for the critical section of finding an unused range of irq numbers. The radix lookup table is also changed to store the irq_data pointer instead of the irq_map entry since the irq_map is removed. This should end up being functionally equivalent since only allocated irq_descs are ever added to the radix tree. v5: - Really don't ever allocate virq 0. The previous version could still do it if hint == 0 - Respect irq_virq_count setting for NOMAP. Some NOMAP domains cannot use virq values above irq_virq_count. - Use numa_node_id() when allocating irq_descs. Ideally the API should obtain that value from the caller, but that touches a lot of call sites so will be deferred to a follow-on patch. - Fix irq_find_mapping() to include irq numbers lower than NUM_ISA_INTERRUPTS. With the switch to irq_alloc_desc*(), the lowest possible allocated irq is now returned by arch_probe_nr_irqs(). v4: - Fix incorrect access to irq_data structure in debugfs code - Don't ever allocate virq 0 Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Milton Miller <miltonm@bga.com> Tested-by: Olof Johansson <olof@lixom.net>
2012-02-14irq_domain/powerpc: Use common irq_domain structure instead of irq_hostGrant Likely
This patch drops the powerpc-specific irq_host structures and uses the common irq_domain strucutres defined in linux/irqdomain.h. It also fixes all the users to use the new structure names. Renaming irq_host to irq_domain has been discussed for a long time, and this patch is a step in the process of generalizing the powerpc virq code to be usable by all architecture. An astute reader will notice that this patch actually removes the irq_host structure instead of renaming it. This is because the irq_domain structure already exists in include/linux/irqdomain.h and has the needed data members. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Milton Miller <miltonm@bga.com> Tested-by: Olof Johansson <olof@lixom.net>
2012-02-14powerpc: Fix WARN_ON in decrementer_check_overflowBenjamin Herrenschmidt
We use __get_cpu_var() which triggers a false positive warning in smp_processor_id() thinking interrupts are enabled (at this point, they are soft-enabled but hard-disabled). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-08powerpc/ps3: Fix hcall lv1_get_version_infoGeoff Levand
The lv1_get_version_info hcall takes 2, not 1 output arguments. Adjust the lv1 hcall table and all calls. Usage: int lv1_get_version_info(u64 *version_number, u64 *vendor_id) Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25powerpc/time: Optimise decrementer_check_overflowAnton Blanchard
decrementer_check_overflow is called from arch_local_irq_restore so we want to make it as light weight as possible. As such, turn decrementer_check_overflow into an inline function. To avoid a circular mess of includes, separate out the two components of struct decrementer_clock and keep the struct clock_event_device part local to time.c. The fast path improves from: arch_local_irq_restore 0: mflr r0 4: std r0,16(r1) 8: stdu r1,-112(r1) c: stb r3,578(r13) 10: cmpdi cr7,r3,0 14: beq- cr7,24 <.arch_local_irq_restore+0x24> ... 24: addi r1,r1,112 28: ld r0,16(r1) 2c: mtlr r0 30: blr to: arch_local_irq_restore 0: std r30,-16(r1) 4: ld r30,0(r2) 8: stb r3,578(r13) c: cmpdi cr7,r3,0 10: beq- cr7,6c <.arch_local_irq_restore+0x6c> ... 6c: ld r30,-16(r1) 70: blr Unfortunately we still setup a local TOC (due to -mminimal-toc). Yet another sign we should be moving to -mcmodel=medium. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-25powerpc/time: Handle wrapping of decrementerAnton Blanchard
When re-enabling interrupts we have code to handle edge sensitive decrementers by resetting the decrementer to 1 whenever it is negative. If interrupts were disabled long enough that the decrementer wrapped to positive we do nothing. This means interrupts can be delayed for a long time until it finally goes negative again. While we hope interrupts are never be disabled long enough for the decrementer to go positive, we have a very good test team that can drive any kernel into the ground. The softlockup data we get back from these fails could be seconds in the future, completely missing the cause of the lockup. We already keep track of the timebase of the next event so use that to work out if we should trigger a decrementer exception. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-10-31powerpc: various straight conversions from module.h --> export.hPaul Gortmaker
All these files were including module.h just for the basic EXPORT_SYMBOL infrastructure. We can shift them off to the export.h header which is a way smaller footprint and thus realize some compile time gains. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-22powerpc: Copy back TIF flags on return from softirq stackBenjamin Herrenschmidt
We already did it for hard IRQs but it looks like we forgot to do it for softirqs. Without this, we would lose flags such as TIF_NEED_RESCHED set using current_thread_info() by something running of a softirq. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-07-19powerpc/irq: Quieten irq mapping printksAnton Blanchard
HFI creates interrupts each time a window is setup. This results in a lot of messages in the kernel log buffer: irq: irq 199007 on host null mapped to virtual irq 351 This box has over 3500 of them, causing more important kernel messages to be overwritten. We can get at this information via debugfs now so we may as well turn it into a pr_debug. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-06-29powerpc/book3e-64: Reraise doorbell when masked by soft-irq-disableScott Wood
Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-06-22powerpc: make irq_choose_cpu() available to all PIC driversStuart Yoder
Move irq_choose_cpu() into arch/powerpc/kernel/irq.c so that it can be used by other PIC drivers. The function is not MPIC-specific. Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com> Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-05-26powerpc: Fix irq_free_virt by adjusting bounds before loopMilton Miller
Instead of looping over each irq and checking against the irq array bounds, adjust the bounds before looping. The old code will not free any irq if the irq + count is above irq_virq_count because the test in the loop is testing irq + count instead of irq + i. This code checks the limits to avoid unsigned integer overflows. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-26powerpc/irq: Protect irq_radix_revmap_lookup against irq_free_virtMilton Miller
The radix-tree code uses call_rcu when freeing internal elements. We must protect against the elements being freed while we traverse the tree, even if the returned pointer will still be valid. While preparing a patch to expand the context in which irq_radix_revmap_lookup will be called, I realized that the radix tree was not locked. When asked For a normal call_rcu usage, is it allowed to read the structure in irq_enter / irq_exit, without additional rcu_read_lock? Could an element freed with call_rcu advance with the cpu still between irq_enter/irq_exit (and irq_disabled())? Paul McKenney replied: Absolutely illegal to do so. OK for call_rcu_sched(), but a flaming bug for call_rcu(). And thank you very much for finding this!!! Further analysis: In the current CONFIG_TREE_RCU implementation. CONFIG_TREE_PREEMPT_RCU (and CONFIG_TINY_PREEMPT_RCU) uses explicit counters. These counters are reflected from per-CPU to global in the scheduling-clock-interrupt handler, so disabling irq does prevent the grace period from completing. But there are real-time implementations (such as the one use by the Concurrent guys) where disabling irq does -not- prevent the grace period from completing. While an alternative fix would be to switch radix-tree to rcu_sched, I don't want to audit the other users of radix trees (nor put alternative freeing in the library). The normal overhead for rcu_read_lock and unlock are a local counter increment and decrement. This does not show up in the rcu lockdep because in 2.6.34 commit 2676a58c98 (radix-tree: Disable RCU lockdep checking in radix tree) deemed it too hard to pass the condition of the protecting lock to the library. Signed-off-by: Milton Miller <miltonm@bga.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-26powerpc/irq: Check desc in handle_one_irq and expand generic_handle_irqMilton Miller
Look up the descriptor and check that it is found in handle_one_irq before checking if we are on the irq stack, and call the handler directly using the descriptor if we are on the stack. We need check irq_to_desc finds the descriptor to avoid a NULL pointer dereference. It could have failed because the number from ppc_md.get_irq was above NR_IRQS, or various exceptional conditions with sparse irqs (eg race conditions while freeing an irq if its was not shutdown in the controller). fe12bc2c99 (genirq: Uninline and sanity check generic_handle_irq()) moved generic_handle_irq out of line to allow its use by interrupt controllers in modules. However, handle_one_irq is core arch code. It already knows the details of struct irq_desc and handling irqs in the nested irq case. This will avoid the extra stack frame to return the value we don't check. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-26powerpc/irq: Always free duplicate IRQ_LEGACY hostsMilton Miller
Since kmem caches are allocated before init_IRQ as noted in 3af259d155 (powerpc: Radix trees are available before init_IRQ), we now call kmalloc in all cases and can can always call kfree if we are asked to allocate a duplicate or conflicting IRQ_HOST_MAP_LEGACY host. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>