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2017-08-23powerpc/64s: Merge HV and non-HV paths for doorbell IRQ replayNicholas Piggin1-2/+0
This results in smaller code, and fewer branches. This relies on the fact that both the 0xe80 and 0xa00 handlers call the same upper level code, namely doorbell_exception(). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Mention we rely on the implementation of the 0xe80/0xa00 handlers] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-23powerpc/64: Cleanup __check_irq_replay()Nicholas Piggin1-22/+23
Move the clearing of irq_happened bits into the condition where they were found to be set. This reduces instruction count slightly, and reduces stores into irq_happened. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-23Merge branch 'fixes' into nextMichael Ellerman1-1/+14
There's a non-trivial dependency between some commits we want to put in next and the KVM prefetch work around that went into fixes. So merge fixes into next.
2017-08-10powerpc/8xx: Getting rid of remaining use of CONFIG_8xxChristophe Leroy1-1/+1
Two config options exist to define powerpc MPC8xx: * CONFIG_PPC_8xx * CONFIG_8xx arch/powerpc/platforms/Kconfig.cputype has contained the following comment about CONFIG_8xx item for some years: "# this is temp to handle compat with arch=ppc" arch/powerpc is now the only place with remaining use of CONFIG_8xx: get rid of them. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc: Add irq accounting for watchdog interruptsNicholas Piggin1-0/+10
This adds an irq counter for the watchdog soft-NMI. This interrupt only fires when interrupts are soft-disabled, so it will not increment much even when the watchdog is running. However it's useful for debugging and sanity checking. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-10powerpc: Add irq accounting for system reset interruptsNicholas Piggin1-0/+6
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-04powerpc/64: Fix __check_irq_replay missing decrementer interruptNicholas Piggin1-1/+14
If the decrementer wraps again and de-asserts the decrementer exception while hard-disabled, __check_irq_replay() has a test to notice the wrap when interrupts are re-enabled. The decrementer check must be done when clearing the PACA_IRQ_HARD_DIS flag, not when the PACA_IRQ_DEC flag is tested. Previously this worked because the decrementer interrupt was always the first one checked after clearing the hard disable flag, but HMI check was moved ahead of that, which introduced this bug. This can cause a missed decrementer interrupt if we soft-disable interrupts then take an HMI which is recorded in irq_happened, then hard-disable interrupts for > 4s to wrap the decrementer. Fixes: e0e0d6b7390b ("powerpc/64: Replay hypervisor maintenance interrupt first") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-19powerpc/64s/idle: Process interrupts from system reset wakeupNicholas Piggin1-0/+29
When the CPU wakes from low power state, it begins at the system reset interrupt with the exception that caused the wakeup encoded in SRR1. Today, powernv idle wakeup ignores the wakeup reason (except a special case for HMI), and the regular interrupt corresponding to the exception will fire after the idle wakeup exits. Change this to replay the interrupt from the idle wakeup before interrupts are hard-enabled. Test on POWER8 of context_switch selftests benchmark with polling idle disabled (e.g., always nap, giving cross-CPU IPIs) gives the following results: original wakeup direct Different threads, same core: 315k/s 264k/s Different cores: 235k/s 242k/s There is a slowdown for doorbell IPI (same core) case because system reset wakeup does not clear the message and the doorbell interrupt fires again needlessly. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-19powerpc/64s/idle: Move soft interrupt mask logic into C codeNicholas Piggin1-1/+32
This simplifies the asm and fixes irq-off tracing over sleep instructions. Also move powersave_nap check for POWER8 into C code, and move PSSCR register value calculation for POWER9 into C. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-15Revert "powerpc: Handle simultaneous interrupts at once"Michael Ellerman1-5/+1
This reverts commit 45cb08f4791ce6a15c54598b4cb73db4b4b8294f. For some reason this is causing IRQ problems on Freescale Book3E machines, eg on my p5020ds: irq 25: nobody cared (try booting with the "irqpoll" option) CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc3-gcc-6.3.1-00037-g45cb08f4791c #624 Call Trace: [c0000000fffdbb10] [c00000000049962c] .dump_stack+0xa8/0xe8 (unreliable) [c0000000fffdbba0] [c0000000000babf4] .__report_bad_irq+0x54/0x140 [c0000000fffdbc40] [c0000000000bb11c] .note_interrupt+0x324/0x380 [c0000000fffdbd00] [c0000000000b7110] .handle_irq_event_percpu+0x68/0x88 [c0000000fffdbd90] [c0000000000b718c] .handle_irq_event+0x5c/0xa8 [c0000000fffdbe10] [c0000000000bc01c] .handle_fasteoi_irq+0xe4/0x298 [c0000000fffdbe90] [c0000000000b59c4] .generic_handle_irq+0x50/0x74 [c0000000fffdbf10] [c0000000000075d8] .__do_irq+0x74/0x1f0 [c0000000fffdbf90] [c0000000000189f8] .call_do_irq+0x14/0x24 [c0000000f7173060] [c0000000000077e4] .do_IRQ+0x90/0x120 [c0000000f7173100] [c00000000001d93c] exc_0x500_common+0xfc/0x100 --- interrupt: 501 at .prepare_to_wait_event+0xc/0x14c LR = .fsl_elbc_run_command+0xc8/0x23c [c0000000f71734d0] [c00000000065f418] .nand_reset+0xb8/0x168 [c0000000f7173560] [c00000000065fec4] .nand_scan_ident+0x2b0/0x1638 [c0000000f7173650] [c000000000666cd8] .fsl_elbc_nand_probe+0x34c/0x5f0 ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300) [c0000000f7173750] [c0000000005a3c60] .platform_drv_probe+0x64/0xb0 [c0000000f71737d0] [c0000000005a12e0] .really_probe+0x290/0x334 [c0000000f7173870] [c0000000005a14a0] .__driver_attach+0x11c/0x120 [c0000000f7173900] [c00000000059e6a0] .bus_for_each_dev+0x98/0xfc [c0000000f71739a0] [c0000000005a0b3c] .driver_attach+0x34/0x4c [c0000000f7173a20] [c0000000005a04b0] .bus_add_driver+0x1ac/0x2e0 [c0000000f7173ac0] [c0000000005a2170] .driver_register+0x94/0x160 [c0000000f7173b40] [c0000000005a3be0] .__platform_driver_register+0x60/0x7c [c0000000f7173bc0] [c000000000d6aab4] .fsl_elbc_nand_driver_init+0x24/0x38 [c0000000f7173c30] [c000000000001934] .do_one_initcall+0x68/0x1b8 [c0000000f7173d00] [c000000000d210f8] .kernel_init_freeable+0x260/0x338 [c0000000f7173db0] [c0000000000021b0] .kernel_init+0x20/0xe70 [c0000000f7173e30] [c0000000000009bc] .ret_from_kernel_thread+0x58/0x9c handlers: [<c000000000ed85c8>] .fsl_lbc_ctrl_irq Disabling IRQ #25 Ben also had concerns with the implementation being potentially slow on some PICs, so revert it for now. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-06-02powerpc: Handle simultaneous interrupts at onceChristophe Leroy1-1/+5
It often happens to have simultaneous interrupts, for instance when having double Ethernet attachment. With the current implementation, we suffer the cost of kernel entry/exit for each interrupt. This patch introduces a loop in __do_irq() to handle all interrupts at once before returning. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-12Merge branch 'topic/xive' (early part) into nextMichael Ellerman1-40/+0
This merges the arch part of the XIVE support, leaving the final commit with the KVM specific pieces dangling on the branch for Paul to merge via the kvm-ppc tree.
2017-04-11powerpc: Remove unnecessary includes of asm/debug.hMichael Ellerman1-1/+0
These files don't seem to have any need for asm/debug.h, now that all it includes are the debugger hooks and breakpoint definitions. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-07powerpc/smp: Remove migrate_irq() custom implementationBenjamin Herrenschmidt1-40/+0
Some powerpc platforms use this to move IRQs away from a CPU being unplugged. This function has several bugs such as not taking the right locks or failing to NULL check pointers. There's a new generic function doing exactly the same thing without all the bugs, so let's use it instead. mpe: The obvious place for the select of GENERIC_IRQ_MIGRATION is on HOTPLUG_CPU, but that doesn't work. On some configs PM_SLEEP_SMP will select HOTPLUG_CPU even though its dependencies are not met, which means the select of GENERIC_IRQ_MIGRATION doesn't happen. That leads to the build breaking. Fix it by moving the select of GENERIC_IRQ_MIGRATION to SMP. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-20powerpc: Remove all usages of NO_IRQMichael Ellerman1-1/+1
NO_IRQ has been == 0 on powerpc for just over ten years (since commit 0ebfff1491ef ("[POWERPC] Add new interrupt mapping core and change platforms to use it")). It's also 0 on most other arches. Although it's fairly harmless, every now and then it causes confusion when a driver is built on powerpc and another arch which doesn't define NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least some of which are to work around that problem. So we'd like to remove it. This is fairly trivial in the arch code, we just convert: if (irq == NO_IRQ) to if (!irq) if (irq != NO_IRQ) to if (irq) irq = NO_IRQ; to irq = 0; return NO_IRQ; to return 0; And a few other odd cases as well. At least for now we keep the #define NO_IRQ, because there is driver code that uses NO_IRQ and the fixes to remove those will go via other trees. Note we also change some occurrences in PPC sound drivers, drivers/ps3, and drivers/macintosh. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-20powerpc/64: Replay hypervisor maintenance interrupt firstNicholas Piggin1-5/+9
The HMI (Hypervisor Maintenance Interrupt) is defined by the architecture to be higher priority than other maskable interrupts, so replay it first, as a best-effort to replay according to hardware priorities. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-13powerpc/sparse: Add more assembler prototypesDaniel Axtens1-0/+1
Another set of things that are only called from assembler and so need prototypes to keep sparse happy. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01powerpc: Move cpu_has_feature() to a separate fileKevin Hao1-0/+1
We plan to use jump label for cpu_has_feature(). In order to implement this we need to include the linux/jump_label.h in asm/cputable.h. Unfortunately if we do that it leads to an include loop. The root of the problem seems to be that reg.h needs cputable.h (for CPU_FTRs), and then cputable.h via jump_label.h eventually pulls in hw_irq.h which needs reg.h (for MSR_EE). So move cpu_has_feature() to a separate file on its own. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Rename to cpu_has_feature.h and flesh out change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-17powerpc/irq: Add mechanism to force a replay of interruptsBenjamin Herrenschmidt1-0/+15
Calling this function with interrupts soft-disabled will cause a replay of the external interrupt vector when they are re-enabled. This will be used by the OPAL XICS backend (and latter by the native XIVE code) to handle EOI signaling that there are more interrupts to fetch from the hardware since the hardware won't issue another HW interrupt in that case. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-08powerpc: Fix typo in comment reference to CONFIG_TRACE_IRQFLAGSAndrew Donnellan1-1/+1
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-14powerpc/livepatch: Add livepatch stack to struct thread_infoMichael Ellerman1-0/+3
In order to support live patching we need to maintain an alternate stack of TOC & LR values. We use the base of the stack for this, and store the "live patch stack pointer" in struct thread_info. Unlike the other fields of thread_info, we can not statically initialise that value, so it must be done at run time. This patch just adds the code to support that, it is not enabled until the next patch which actually adds live patch support. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Balbir Singh <bsingharora@gmail.com>
2015-09-15powerpc, irq: Use access helper irq_data_get_affinity_mask()Jiang Liu1-1/+1
Use access helper irq_data_get_affinity_mask() so we can move the affinity mask to irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1433145945-789-25-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-10powerpc: Remove superfluous bootmem includesAnton Blanchard1-1/+0
Lots of places included bootmem.h even when not using bootmem. Signed-off-by: Anton Blanchard <anton@samba.org> Tested-by: Emil Medve <Emilian.Medve@Freescale.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-03powerpc: Replace __get_cpu_var usesChristoph Lameter1-2/+2
This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-15powerpc: Rename __get_SP() to current_stack_pointer()Anton Blanchard1-1/+1
Michael points out that __get_SP() is a pretty horrible function name. Let's give it a better name. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-02powerpc: Add printk levels to powerpc codeAnton Blanchard1-3/+3
Add printk levels to some places in the powerpc port. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-08-05powerpc/book3s: Add basic infrastructure to handle HMI in Linux.Mahesh Salgaonkar1-0/+14
Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements basic infrastructure to handle HMI in Linux host. The design is to invoke opal handle hmi in real mode for recovery and set irq_pending when we hit HMI. During check_irq_replay pull opal hmi event and print hmi info on console. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-06powerpc: update comments for generic idle conversionGeert Uytterhoeven1-1/+1
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 Gleixner1-6/+2
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 Hao1-0/+5
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.du1-3/+9
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 git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-16/+1
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 Herrenschmidt1-2/+3
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 Weisbecker1-16/+1
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 Herrenschmidt1-12/+0
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 Herrenschmidt1-52/+52
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 Ellerman1-1/+1
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 Herrenschmidt1-1/+1
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 decrementer_check_overflowKevin Hao1-2/+0
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 Herrenschmidt1-1/+1
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 Munsie1-0/+12
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 Munsie1-2/+9
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 Zhong1-4/+4
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 Herrenschmidt1-1/+1
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 Herrenschmidt1-0/+46
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 Rostedt1-1/+1
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 Phillips1-1/+1
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 Herrenschmidt1-0/+13
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 Herrenschmidt1-1/+7
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>
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