From 08f1ec8a594c60bf3856e3c45b6d15fd691d90bb Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 10 Apr 2012 17:21:35 +1000 Subject: powerpc: Fix page fault with lockdep regression commit a546498f3bf9aac311c66f965186373aee2ca0b0 introduced a regression on 32-bit when irq tracing is enabled by exposing an old bug in our irq tracing code for exception entry. The code would save and restore some GPRs around the calls to the C lockdep code, however, it tries to be too smart for its own good and restores some of the GPRs from the exception frame (as saved there on exception entry). However, for page faults, we do replace those GPRs with arguments to do_page_fault before we call transfer_to_handler and so restoring from the exception frame is plain wrong in this case. This was fine as long as we didn't touch the interrupt state when taking page fault, but when I started doing it, it would trigger the lockdep calls and the bug. This fixes it by cleaning up that code a bit. It did create a small stack frame for the sake of backtraces, so let's make it a bit bigger and use it to save and restore the stuff we care about. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/entry_32.S | 39 +++++++++++++++++++++------------------ 1 file changed, 21 insertions(+), 18 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 3e57a00b8cba..ba3aeb4bc06a 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -206,40 +206,43 @@ reenable_mmu: /* re-enable mmu so we can */ andi. r10,r10,MSR_EE /* Did EE change? */ beq 1f - /* Save handler and return address into the 2 unused words - * of the STACK_FRAME_OVERHEAD (sneak sneak sneak). Everything - * else can be recovered from the pt_regs except r3 which for - * normal interrupts has been set to pt_regs and for syscalls - * is an argument, so we temporarily use ORIG_GPR3 to save it - */ - stw r9,8(r1) - stw r11,12(r1) - stw r3,ORIG_GPR3(r1) /* * The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1. * If from user mode there is only one stack frame on the stack, and * accessing CALLER_ADDR1 will cause oops. So we need create a dummy * stack frame to make trace_hardirqs_off happy. + * + * This is handy because we also need to save a bunch of GPRs, + * r3 can be different from GPR3(r1) at this point, r9 and r11 + * contains the old MSR and handler address respectively, + * r4 & r5 can contain page fault arguments that need to be passed + * along as well. r12, CCR, CTR, XER etc... are left clobbered as + * they aren't useful past this point (aren't syscall arguments), + * the rest is restored from the exception frame. */ + stwu r1,-32(r1) + stw r9,8(r1) + stw r11,12(r1) + stw r3,16(r1) + stw r4,20(r1) + stw r5,24(r1) andi. r12,r12,MSR_PR - beq 11f - stwu r1,-16(r1) + b 11f bl trace_hardirqs_off - addi r1,r1,16 b 12f - 11: bl trace_hardirqs_off 12: + lwz r5,24(r1) + lwz r4,20(r1) + lwz r3,16(r1) + lwz r11,12(r1) + lwz r9,8(r1) + addi r1,r1,32 lwz r0,GPR0(r1) - lwz r3,ORIG_GPR3(r1) - lwz r4,GPR4(r1) - lwz r5,GPR5(r1) lwz r6,GPR6(r1) lwz r7,GPR7(r1) lwz r8,GPR8(r1) - lwz r9,8(r1) - lwz r11,12(r1) 1: mtctr r11 mtlr r9 bctr /* jump to handler */ -- cgit v1.2.1 From fae2e0fb24c61ca68c98d854a34732549ebc1854 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 11 Apr 2012 10:42:15 +1000 Subject: powerpc: Fix typo in runlatch code Commit fe1952fc0afb9a2e4c79f103c08aef5d13db1873 "powerpc: Rework runlatch code" has a nasty typo where it uses "TLF_RUNLATCH" instead of "_TLF_RUNLATCH" (bit number instead of bit mask), causing some flags to be potentially lost such as _TLF_RESTORE_SIGMASK (Brown paper bag for me ! We should be able to make that break at compile time with a bit of magic, any volunteer ?) Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/process.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index f88698c0f332..4937c9690090 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1235,7 +1235,7 @@ void __ppc64_runlatch_on(void) ctrl |= CTRL_RUNLATCH; mtspr(SPRN_CTRLT, ctrl); - ti->local_flags |= TLF_RUNLATCH; + ti->local_flags |= _TLF_RUNLATCH; } /* Called with hard IRQs off */ @@ -1244,7 +1244,7 @@ void __ppc64_runlatch_off(void) struct thread_info *ti = current_thread_info(); unsigned long ctrl; - ti->local_flags &= ~TLF_RUNLATCH; + ti->local_flags &= ~_TLF_RUNLATCH; ctrl = mfspr(SPRN_CTRLF); ctrl &= ~CTRL_RUNLATCH; -- cgit v1.2.1 From a699e4e49ec3fb62c4a44394357d14081df10bef Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Tue, 3 Apr 2012 07:11:04 -0600 Subject: irq: Kill pointless irqd_to_hw export 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 Acked-by: Thomas Gleixner Cc: Benjamin Herrenschmidt --- arch/powerpc/kernel/irq.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 243dbabfe74d..5ec1b2354ca6 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -560,12 +560,6 @@ void do_softirq(void) local_irq_restore(flags); } -irq_hw_number_t irqd_to_hwirq(struct irq_data *d) -{ - return d->hwirq; -} -EXPORT_SYMBOL_GPL(irqd_to_hwirq); - irq_hw_number_t virq_to_hw(unsigned int virq) { struct irq_data *irq_data = irq_get_irq_data(virq); -- cgit v1.2.1 From eda713e219c9a7d02b8263ab3fba44092e919b07 Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Thu, 19 Apr 2012 09:32:06 +0300 Subject: powerpc: fix build when CONFIG_BOOKE_WDT is enabled Commit ae3a197e (Disintegrate asm/system.h for PowerPC) broke build of assembly files when CONFIG_BOOKE_WDT is enabled as follows: AS arch/powerpc/lib/string.o /home/baruch/git/stable/arch/powerpc/include/asm/reg_booke.h: Assembler messages: /home/baruch/git/stable/arch/powerpc/include/asm/reg_booke.h:19: Error: Unrecognized opcode: `extern' /home/baruch/git/stable/arch/powerpc/include/asm/reg_booke.h:20: Error: Unrecognized opcode: `extern' Since setup_32.c is the only user of the booke_wdt configuration variables, move the declarations there. Cc: David Howells Signed-off-by: Baruch Siach Signed-off-by: Kumar Gala --- arch/powerpc/kernel/setup_32.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 9825f29d1faf..ec8a53fa9e8f 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -150,6 +150,9 @@ notrace void __init machine_init(u64 dt_ptr) } #ifdef CONFIG_BOOKE_WDT +extern u32 booke_wdt_enabled; +extern u32 booke_wdt_period; + /* Checks wdt=x and wdt_period=xx command-line option */ notrace int __init early_parse_wdt(char *p) { -- cgit v1.2.1