From 9c1e105238c474d19905af504f2e7f42d4f71f9e Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 17 Aug 2009 15:17:54 +1000 Subject: powerpc: Allow perf_counters to access user memory at interrupt time This provides a mechanism to allow the perf_counters code to access user memory in a PMU interrupt routine. Such an access can cause various kinds of interrupt: SLB miss, MMU hash table miss, segment table miss, or TLB miss, depending on the processor. This commit only deals with 64-bit classic/server processors, which use an MMU hash table. 32-bit processors are already able to access user memory at interrupt time. Since we don't soft-disable on 32-bit, we avoid the possibility of reentering hash_page or the TLB miss handlers, since they run with interrupts disabled. On 64-bit processors, an SLB miss interrupt on a user address will update the slb_cache and slb_cache_ptr fields in the paca. This is OK except in the case where a PMU interrupt occurs in switch_slb, which also accesses those fields. To prevent this, we hard-disable interrupts in switch_slb. Interrupts are already soft-disabled at this point, and will get hard-enabled when they get soft-enabled later. This also reworks slb_flush_and_rebolt: to avoid hard-disabling twice, and to make sure that it clears the slb_cache_ptr when called from other callers than switch_slb, the existing routine is renamed to __slb_flush_and_rebolt, which is called by switch_slb and the new version of slb_flush_and_rebolt. Similarly, switch_stab (used on POWER3 and RS64 processors) gets a hard_irq_disable() to protect the per-cpu variables used there and in ste_allocate. If a MMU hashtable miss interrupt occurs, normally we would call hash_page to look up the Linux PTE for the address and create a HPTE. However, hash_page is fairly complex and takes some locks, so to avoid the possibility of deadlock, we check the preemption count to see if we are in a (pseudo-)NMI handler, and if so, we don't call hash_page but instead treat it like a bad access that will get reported up through the exception table mechanism. An interrupt whose handler runs even though the interrupt occurred when soft-disabled (such as the PMU interrupt) is considered a pseudo-NMI handler, which should use nmi_enter()/nmi_exit() rather than irq_enter()/irq_exit(). Acked-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/asm-offsets.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/powerpc/kernel/asm-offsets.c') diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 561b6465231..197b15646ee 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -67,6 +67,8 @@ int main(void) DEFINE(MMCONTEXTID, offsetof(struct mm_struct, context.id)); #ifdef CONFIG_PPC64 DEFINE(AUDITCONTEXT, offsetof(struct task_struct, audit_context)); + DEFINE(SIGSEGV, SIGSEGV); + DEFINE(NMI_MASK, NMI_MASK); #else DEFINE(THREAD_INFO, offsetof(struct task_struct, stack)); #endif /* CONFIG_PPC64 */ -- cgit From 57e2a99f74b0d3720c97a6aadb57ae6aad3c61ea Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 28 Jul 2009 11:59:34 +1000 Subject: powerpc: Add memory management headers for new 64-bit BookE This adds the PTE and pgtable format definitions, along with changes to the kernel memory map and other definitions related to implementing support for 64-bit Book3E. This also shields some asm-offset bits that are currently only relevant on 32-bit We also move the definition of the "linux" page size constants to the common mmu.h file and add a few sizes that are relevant to embedded processors. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/asm-offsets.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/asm-offsets.c') diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 561b6465231..0a9f30b5495 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -52,9 +52,11 @@ #include #endif +#ifdef CONFIG_PPC32 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) #include "head_booke.h" #endif +#endif #if defined(CONFIG_FSL_BOOKE) #include "../mm/mmu_decl.h" @@ -260,6 +262,7 @@ int main(void) DEFINE(_SRR1, STACK_FRAME_OVERHEAD+sizeof(struct pt_regs)+8); #endif /* CONFIG_PPC64 */ +#if defined(CONFIG_PPC32) #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) DEFINE(EXC_LVL_SIZE, STACK_EXC_LVL_FRAME_SIZE); DEFINE(MAS0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0)); @@ -278,7 +281,7 @@ int main(void) DEFINE(_DSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr1)); DEFINE(SAVED_KSP_LIMIT, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, saved_ksp_limit)); #endif - +#endif DEFINE(CLONE_VM, CLONE_VM); DEFINE(CLONE_UNTRACED, CLONE_UNTRACED); -- cgit From dce6670aaa7efece0558010b48d5ef9d421154be Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 23 Jul 2009 23:15:42 +0000 Subject: powerpc: Add PACA fields specific to 64-bit Book3E processors This adds various fields in the PACA that are for use specifically by Book3E processors, such as exception save areas, current pgd pointer, special exceptions kernel stacks etc... Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/asm-offsets.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'arch/powerpc/kernel/asm-offsets.c') diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 0a9f30b5495..b9e010d0fc9 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -140,6 +140,20 @@ int main(void) context.high_slices_psize)); DEFINE(MMUPSIZEDEFSIZE, sizeof(struct mmu_psize_def)); #endif /* CONFIG_PPC_MM_SLICES */ + +#ifdef CONFIG_PPC_BOOK3E + DEFINE(PACAPGD, offsetof(struct paca_struct, pgd)); + DEFINE(PACA_KERNELPGD, offsetof(struct paca_struct, kernel_pgd)); + DEFINE(PACA_EXGEN, offsetof(struct paca_struct, exgen)); + DEFINE(PACA_EXTLB, offsetof(struct paca_struct, extlb)); + DEFINE(PACA_EXMC, offsetof(struct paca_struct, exmc)); + DEFINE(PACA_EXCRIT, offsetof(struct paca_struct, excrit)); + DEFINE(PACA_EXDBG, offsetof(struct paca_struct, exdbg)); + DEFINE(PACA_MC_STACK, offsetof(struct paca_struct, mc_kstack)); + DEFINE(PACA_CRIT_STACK, offsetof(struct paca_struct, crit_kstack)); + DEFINE(PACA_DBG_STACK, offsetof(struct paca_struct, dbg_kstack)); +#endif /* CONFIG_PPC_BOOK3E */ + #ifdef CONFIG_PPC_STD_MMU_64 DEFINE(PACASTABREAL, offsetof(struct paca_struct, stab_real)); DEFINE(PACASTABVIRT, offsetof(struct paca_struct, stab_addr)); -- cgit From cdd6c482c9ff9c55475ee7392ec8f672eddb7be6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 12:02:48 +0200 Subject: perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian Acked-by: Peter Zijlstra Acked-by: Paul Mackerras Reviewed-by: Arjan van de Ven Cc: Mike Galbraith Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Steven Rostedt Cc: Benjamin Herrenschmidt Cc: David Howells Cc: Kyle McMartin Cc: Martin Schwidefsky Cc: "David S. Miller" Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: LKML-Reference: Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/asm-offsets.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/asm-offsets.c') diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index f0df285f0f8..0812b0f414b 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -133,7 +133,7 @@ int main(void) DEFINE(PACAKMSR, offsetof(struct paca_struct, kernel_msr)); DEFINE(PACASOFTIRQEN, offsetof(struct paca_struct, soft_enabled)); DEFINE(PACAHARDIRQEN, offsetof(struct paca_struct, hard_enabled)); - DEFINE(PACAPERFPEND, offsetof(struct paca_struct, perf_counter_pending)); + DEFINE(PACAPERFPEND, offsetof(struct paca_struct, perf_event_pending)); DEFINE(PACACONTEXTID, offsetof(struct paca_struct, context.id)); #ifdef CONFIG_PPC_MM_SLICES DEFINE(PACALOWSLICESPSIZE, offsetof(struct paca_struct, -- cgit