From 416821d3d68164909b2cbcf398e4ba0797f5f8a2 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Fri, 10 May 2013 21:24:01 +0000 Subject: parisc: implement irq stacks - part 2 (v2) This patch fixes few build issues which were introduced with the last irq stack patch, e.g. the combination of stack overflow check and irq stack. Furthermore we now do proper locking and change the irq bh handler to use the irq stack as well. In /proc/interrupts one now can monitor how huge the irq stack has grown and how often it was preferred over the kernel stack. IRQ stacks are now enabled by default just to make sure that we not overflow the kernel stack by accident. Signed-off-by: Helge Deller --- arch/parisc/kernel/irq.c | 101 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 87 insertions(+), 14 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index e255db0bb761..55237a70e197 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -166,22 +166,32 @@ int arch_show_interrupts(struct seq_file *p, int prec) seq_printf(p, "%*s: ", prec, "STK"); for_each_online_cpu(j) seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage); - seq_printf(p, " Kernel stack usage\n"); + seq_puts(p, " Kernel stack usage\n"); +# ifdef CONFIG_IRQSTACKS + seq_printf(p, "%*s: ", prec, "IST"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_stack_usage); + seq_puts(p, " Interrupt stack usage\n"); + seq_printf(p, "%*s: ", prec, "ISC"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_stack_counter); + seq_puts(p, " Interrupt stack usage counter\n"); +# endif #endif #ifdef CONFIG_SMP seq_printf(p, "%*s: ", prec, "RES"); for_each_online_cpu(j) seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count); - seq_printf(p, " Rescheduling interrupts\n"); + seq_puts(p, " Rescheduling interrupts\n"); seq_printf(p, "%*s: ", prec, "CAL"); for_each_online_cpu(j) seq_printf(p, "%10u ", irq_stats(j)->irq_call_count); - seq_printf(p, " Function call interrupts\n"); + seq_puts(p, " Function call interrupts\n"); #endif seq_printf(p, "%*s: ", prec, "TLB"); for_each_online_cpu(j) seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count); - seq_printf(p, " TLB shootdowns\n"); + seq_puts(p, " TLB shootdowns\n"); return 0; } @@ -378,6 +388,7 @@ static inline void stack_overflow_check(struct pt_regs *regs) unsigned long sp = regs->gr[30]; unsigned long stack_usage; unsigned int *last_usage; + int cpu = smp_processor_id(); /* if sr7 != 0, we interrupted a userspace process which we do not want * to check for stack overflow. We will only check the kernel stack. */ @@ -386,7 +397,31 @@ static inline void stack_overflow_check(struct pt_regs *regs) /* calculate kernel stack usage */ stack_usage = sp - stack_start; - last_usage = &per_cpu(irq_stat.kernel_stack_usage, smp_processor_id()); +#ifdef CONFIG_IRQSTACKS + if (likely(stack_usage <= THREAD_SIZE)) + goto check_kernel_stack; /* found kernel stack */ + + /* check irq stack usage */ + stack_start = (unsigned long) &per_cpu(irq_stack_union, cpu).stack; + stack_usage = sp - stack_start; + + last_usage = &per_cpu(irq_stat.irq_stack_usage, cpu); + if (unlikely(stack_usage > *last_usage)) + *last_usage = stack_usage; + + if (likely(stack_usage < (IRQ_STACK_SIZE - STACK_MARGIN))) + return; + + pr_emerg("stackcheck: %s will most likely overflow irq stack " + "(sp:%lx, stk bottom-top:%lx-%lx)\n", + current->comm, sp, stack_start, stack_start + IRQ_STACK_SIZE); + goto panic_check; + +check_kernel_stack: +#endif + + /* check kernel stack usage */ + last_usage = &per_cpu(irq_stat.kernel_stack_usage, cpu); if (unlikely(stack_usage > *last_usage)) *last_usage = stack_usage; @@ -398,31 +433,69 @@ static inline void stack_overflow_check(struct pt_regs *regs) "(sp:%lx, stk bottom-top:%lx-%lx)\n", current->comm, sp, stack_start, stack_start + THREAD_SIZE); +#ifdef CONFIG_IRQSTACKS +panic_check: +#endif if (sysctl_panic_on_stackoverflow) panic("low stack detected by irq handler - check messages\n"); #endif } #ifdef CONFIG_IRQSTACKS -DEFINE_PER_CPU(union irq_stack_union, irq_stack_union); +DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = { + .lock = __RAW_SPIN_LOCK_UNLOCKED((irq_stack_union).lock) + }; static void execute_on_irq_stack(void *func, unsigned long param1) { - unsigned long *irq_stack_start; + union irq_stack_union *union_ptr; unsigned long irq_stack; - int cpu = smp_processor_id(); + raw_spinlock_t *irq_stack_in_use; - irq_stack_start = &per_cpu(irq_stack_union, cpu).stack[0]; - irq_stack = (unsigned long) irq_stack_start; - irq_stack = ALIGN(irq_stack, 16); /* align for stack frame usage */ + union_ptr = &per_cpu(irq_stack_union, smp_processor_id()); + irq_stack = (unsigned long) &union_ptr->stack; + irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.lock), + 64); /* align for stack frame usage */ - BUG_ON(*irq_stack_start); /* report bug if we were called recursive. */ - *irq_stack_start = 1; + /* We may be called recursive. If we are already using the irq stack, + * just continue to use it. Use spinlocks to serialize + * the irq stack usage. + */ + irq_stack_in_use = &union_ptr->lock; + if (!raw_spin_trylock(irq_stack_in_use)) { + void (*direct_call)(unsigned long p1) = func; + + /* We are using the IRQ stack already. + * Do direct call on current stack. */ + direct_call(param1); + return; + } /* This is where we switch to the IRQ stack. */ call_on_stack(param1, func, irq_stack); - *irq_stack_start = 0; + __inc_irq_stat(irq_stack_counter); + + /* free up irq stack usage. */ + do_raw_spin_unlock(irq_stack_in_use); +} + +asmlinkage void do_softirq(void) +{ + __u32 pending; + unsigned long flags; + + if (in_interrupt()) + return; + + local_irq_save(flags); + + pending = local_softirq_pending(); + + if (pending) + execute_on_irq_stack(__do_softirq, 0); + + local_irq_restore(flags); } #endif /* CONFIG_IRQSTACKS */ -- cgit v1.2.2 From f0a18819e261afc5fdbd8c5c6f9943123c5461ba Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Fri, 10 May 2013 23:21:38 +0000 Subject: parisc: fix SMP races when updating PTE and TLB entries in entry.S Currently, race conditions exist in the handling of TLB interruptions in entry.S. In particular, dirty bit updates can be lost if an accessed interruption occurs just after the dirty bit interruption on a different cpu. Lost dirty bit updates result in user pages not being flushed and general system instability. This change adds lock and unlock macros to synchronize all PTE and TLB updates done in entry.S. As a result, userspace stability is significantly improved. Signed-off-by: John David Anglin Signed-off-by: Helge Deller --- arch/parisc/kernel/entry.S | 155 ++++++++++++++++++++++++--------------------- 1 file changed, 83 insertions(+), 72 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 4bb96ad9b0b1..ae27cb6ce19a 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -452,9 +452,41 @@ L2_ptep \pgd,\pte,\index,\va,\fault .endm + /* Acquire pa_dbit_lock lock. */ + .macro dbit_lock spc,tmp,tmp1 +#ifdef CONFIG_SMP + cmpib,COND(=),n 0,\spc,2f + load32 PA(pa_dbit_lock),\tmp +1: LDCW 0(\tmp),\tmp1 + cmpib,COND(=) 0,\tmp1,1b + nop +2: +#endif + .endm + + /* Release pa_dbit_lock lock without reloading lock address. */ + .macro dbit_unlock0 spc,tmp +#ifdef CONFIG_SMP + or,COND(=) %r0,\spc,%r0 + stw \spc,0(\tmp) +#endif + .endm + + /* Release pa_dbit_lock lock. */ + .macro dbit_unlock1 spc,tmp +#ifdef CONFIG_SMP + load32 PA(pa_dbit_lock),\tmp + dbit_unlock0 \spc,\tmp +#endif + .endm + /* Set the _PAGE_ACCESSED bit of the PTE. Be clever and * don't needlessly dirty the cache line if it was already set */ - .macro update_ptep ptep,pte,tmp,tmp1 + .macro update_ptep spc,ptep,pte,tmp,tmp1 +#ifdef CONFIG_SMP + or,COND(=) %r0,\spc,%r0 + LDREG 0(\ptep),\pte +#endif ldi _PAGE_ACCESSED,\tmp1 or \tmp1,\pte,\tmp and,COND(<>) \tmp1,\pte,%r0 @@ -463,7 +495,11 @@ /* Set the dirty bit (and accessed bit). No need to be * clever, this is only used from the dirty fault */ - .macro update_dirty ptep,pte,tmp + .macro update_dirty spc,ptep,pte,tmp +#ifdef CONFIG_SMP + or,COND(=) %r0,\spc,%r0 + LDREG 0(\ptep),\pte +#endif ldi _PAGE_ACCESSED|_PAGE_DIRTY,\tmp or \tmp,\pte,\pte STREG \pte,0(\ptep) @@ -1111,11 +1147,13 @@ dtlb_miss_20w: L3_ptep ptp,pte,t0,va,dtlb_check_alias_20w - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot idtlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1135,11 +1173,13 @@ nadtlb_miss_20w: L3_ptep ptp,pte,t0,va,nadtlb_check_alias_20w - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot idtlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1161,7 +1201,8 @@ dtlb_miss_11: L2_ptep ptp,pte,t0,va,dtlb_check_alias_11 - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb_11 spc,pte,prot @@ -1172,6 +1213,7 @@ dtlb_miss_11: idtlbp prot,(%sr1,va) mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 rfir nop @@ -1192,7 +1234,8 @@ nadtlb_miss_11: L2_ptep ptp,pte,t0,va,nadtlb_check_alias_11 - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb_11 spc,pte,prot @@ -1204,6 +1247,7 @@ nadtlb_miss_11: idtlbp prot,(%sr1,va) mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 rfir nop @@ -1224,13 +1268,15 @@ dtlb_miss_20: L2_ptep ptp,pte,t0,va,dtlb_check_alias_20 - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot f_extend pte,t0 idtlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1250,13 +1296,15 @@ nadtlb_miss_20: L2_ptep ptp,pte,t0,va,nadtlb_check_alias_20 - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot f_extend pte,t0 idtlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1357,11 +1405,13 @@ itlb_miss_20w: L3_ptep ptp,pte,t0,va,itlb_fault - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot iitlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1379,11 +1429,13 @@ naitlb_miss_20w: L3_ptep ptp,pte,t0,va,naitlb_check_alias_20w - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot iitlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1405,7 +1457,8 @@ itlb_miss_11: L2_ptep ptp,pte,t0,va,itlb_fault - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb_11 spc,pte,prot @@ -1416,6 +1469,7 @@ itlb_miss_11: iitlbp prot,(%sr1,va) mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 rfir nop @@ -1427,7 +1481,8 @@ naitlb_miss_11: L2_ptep ptp,pte,t0,va,naitlb_check_alias_11 - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb_11 spc,pte,prot @@ -1438,6 +1493,7 @@ naitlb_miss_11: iitlbp prot,(%sr1,va) mtsp t0, %sr1 /* Restore sr1 */ + dbit_unlock1 spc,t0 rfir nop @@ -1459,13 +1515,15 @@ itlb_miss_20: L2_ptep ptp,pte,t0,va,itlb_fault - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot f_extend pte,t0 iitlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1477,13 +1535,15 @@ naitlb_miss_20: L2_ptep ptp,pte,t0,va,naitlb_check_alias_20 - update_ptep ptp,pte,t0,t1 + dbit_lock spc,t0,t1 + update_ptep spc,ptp,pte,t0,t1 make_insert_tlb spc,pte,prot f_extend pte,t0 iitlbt pte,prot + dbit_unlock1 spc,t0 rfir nop @@ -1507,29 +1567,13 @@ dbit_trap_20w: L3_ptep ptp,pte,t0,va,dbit_fault -#ifdef CONFIG_SMP - cmpib,COND(=),n 0,spc,dbit_nolock_20w - load32 PA(pa_dbit_lock),t0 - -dbit_spin_20w: - LDCW 0(t0),t1 - cmpib,COND(=) 0,t1,dbit_spin_20w - nop - -dbit_nolock_20w: -#endif - update_dirty ptp,pte,t1 + dbit_lock spc,t0,t1 + update_dirty spc,ptp,pte,t1 make_insert_tlb spc,pte,prot idtlbt pte,prot -#ifdef CONFIG_SMP - cmpib,COND(=),n 0,spc,dbit_nounlock_20w - ldi 1,t1 - stw t1,0(t0) - -dbit_nounlock_20w: -#endif + dbit_unlock0 spc,t0 rfir nop @@ -1543,18 +1587,8 @@ dbit_trap_11: L2_ptep ptp,pte,t0,va,dbit_fault -#ifdef CONFIG_SMP - cmpib,COND(=),n 0,spc,dbit_nolock_11 - load32 PA(pa_dbit_lock),t0 - -dbit_spin_11: - LDCW 0(t0),t1 - cmpib,= 0,t1,dbit_spin_11 - nop - -dbit_nolock_11: -#endif - update_dirty ptp,pte,t1 + dbit_lock spc,t0,t1 + update_dirty spc,ptp,pte,t1 make_insert_tlb_11 spc,pte,prot @@ -1565,13 +1599,7 @@ dbit_nolock_11: idtlbp prot,(%sr1,va) mtsp t1, %sr1 /* Restore sr1 */ -#ifdef CONFIG_SMP - cmpib,COND(=),n 0,spc,dbit_nounlock_11 - ldi 1,t1 - stw t1,0(t0) - -dbit_nounlock_11: -#endif + dbit_unlock0 spc,t0 rfir nop @@ -1583,32 +1611,15 @@ dbit_trap_20: L2_ptep ptp,pte,t0,va,dbit_fault -#ifdef CONFIG_SMP - cmpib,COND(=),n 0,spc,dbit_nolock_20 - load32 PA(pa_dbit_lock),t0 - -dbit_spin_20: - LDCW 0(t0),t1 - cmpib,= 0,t1,dbit_spin_20 - nop - -dbit_nolock_20: -#endif - update_dirty ptp,pte,t1 + dbit_lock spc,t0,t1 + update_dirty spc,ptp,pte,t1 make_insert_tlb spc,pte,prot f_extend pte,t1 idtlbt pte,prot - -#ifdef CONFIG_SMP - cmpib,COND(=),n 0,spc,dbit_nounlock_20 - ldi 1,t1 - stw t1,0(t0) - -dbit_nounlock_20: -#endif + dbit_unlock0 spc,t0 rfir nop -- cgit v1.2.2 From 949451b9b19da5e998778eb78929aafc73b5c227 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Thu, 16 May 2013 20:42:39 +0000 Subject: parisc: add rp5470 entry to machine database Signed-off-by: Helge Deller --- arch/parisc/kernel/hardware.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/hardware.c b/arch/parisc/kernel/hardware.c index f7752f6af29e..9e2d2e408529 100644 --- a/arch/parisc/kernel/hardware.c +++ b/arch/parisc/kernel/hardware.c @@ -222,6 +222,7 @@ static struct hp_hardware hp_hardware_list[] = { {HPHW_NPROC,0x5DD,0x4,0x81,"Duet W2"}, {HPHW_NPROC,0x5DE,0x4,0x81,"Piccolo W+"}, {HPHW_NPROC,0x5DF,0x4,0x81,"Cantata W2"}, + {HPHW_NPROC,0x5DF,0x0,0x00,"Marcato W+? (rp5470)"}, {HPHW_NPROC,0x5E0,0x4,0x91,"Cantata DC- W2"}, {HPHW_NPROC,0x5E1,0x4,0x91,"Crescendo DC- W2"}, {HPHW_NPROC,0x5E2,0x4,0x91,"Crescendo 650 W2"}, -- cgit v1.2.2 From d845b5fb36edbd16563bde49ae1217b3f5132eec Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Thu, 16 May 2013 20:51:41 +0000 Subject: parisc: use PAGE_SHIFT instead of hardcoded value 12 in pacache.S additionally clean up some whitespaces & tabs. Signed-off-by: Helge Deller --- arch/parisc/kernel/pacache.S | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S index 5e1de6072be5..36d7f402e48e 100644 --- a/arch/parisc/kernel/pacache.S +++ b/arch/parisc/kernel/pacache.S @@ -605,14 +605,14 @@ ENTRY(copy_user_page_asm) convert_phys_for_tlb_insert20 %r26 /* convert phys addr to tlb insert format */ convert_phys_for_tlb_insert20 %r23 /* convert phys addr to tlb insert format */ depd %r24,63,22, %r28 /* Form aliased virtual address 'to' */ - depdi 0, 63,PAGE_SHIFT, %r28 /* Clear any offset bits */ + depdi 0, 63,PAGE_SHIFT, %r28 /* Clear any offset bits */ copy %r28, %r29 depdi 1, 41,1, %r29 /* Form aliased virtual address 'from' */ #else extrw,u %r26, 24,25, %r26 /* convert phys addr to tlb insert format */ extrw,u %r23, 24,25, %r23 /* convert phys addr to tlb insert format */ depw %r24, 31,22, %r28 /* Form aliased virtual address 'to' */ - depwi 0, 31,12, %r28 /* Clear any offset bits */ + depwi 0, 31,PAGE_SHIFT, %r28 /* Clear any offset bits */ copy %r28, %r29 depwi 1, 9,1, %r29 /* Form aliased virtual address 'from' */ #endif @@ -762,7 +762,7 @@ ENTRY(clear_user_page_asm) #else extrw,u %r26, 24,25, %r26 /* convert phys addr to tlb insert format */ depw %r25, 31,22, %r28 /* Form aliased virtual address 'to' */ - depwi 0, 31,12, %r28 /* Clear any offset bits */ + depwi 0, 31,PAGE_SHIFT, %r28 /* Clear any offset bits */ #endif /* Purge any old translation */ @@ -846,7 +846,7 @@ ENTRY(flush_dcache_page_asm) #else extrw,u %r26, 24,25, %r26 /* convert phys addr to tlb insert format */ depw %r25, 31,22, %r28 /* Form aliased virtual address 'to' */ - depwi 0, 31,12, %r28 /* Clear any offset bits */ + depwi 0, 31,PAGE_SHIFT, %r28 /* Clear any offset bits */ #endif /* Purge any old translation */ @@ -918,11 +918,11 @@ ENTRY(flush_icache_page_asm) #endif convert_phys_for_tlb_insert20 %r26 /* convert phys addr to tlb insert format */ depd %r25, 63,22, %r28 /* Form aliased virtual address 'to' */ - depdi 0, 63,PAGE_SHIFT, %r28 /* Clear any offset bits */ + depdi 0, 63,PAGE_SHIFT, %r28 /* Clear any offset bits */ #else extrw,u %r26, 24,25, %r26 /* convert phys addr to tlb insert format */ depw %r25, 31,22, %r28 /* Form aliased virtual address 'to' */ - depwi 0, 31,12, %r28 /* Clear any offset bits */ + depwi 0, 31,PAGE_SHIFT, %r28 /* Clear any offset bits */ #endif /* Purge any old translation */ -- cgit v1.2.2 From d0c3be806a3fe7f4abdb0f7e7287addb55e73f35 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Sat, 18 May 2013 19:35:44 +0000 Subject: parisc: show number of FPE and unaligned access handler calls in /proc/interrupts Show number of floating point assistant and unaligned access fixup handler in /proc/interrupts file. Signed-off-by: Helge Deller --- arch/parisc/kernel/irq.c | 8 ++++++++ arch/parisc/kernel/traps.c | 1 + arch/parisc/kernel/unaligned.c | 3 +++ 3 files changed, 12 insertions(+) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 55237a70e197..9c2d953f3de5 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -188,6 +188,14 @@ int arch_show_interrupts(struct seq_file *p, int prec) seq_printf(p, "%10u ", irq_stats(j)->irq_call_count); seq_puts(p, " Function call interrupts\n"); #endif + seq_printf(p, "%*s: ", prec, "UAH"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_unaligned_count); + seq_puts(p, " Unaligned access handler traps\n"); + seq_printf(p, "%*s: ", prec, "FPA"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_fpassist_count); + seq_puts(p, " Floating point assist traps\n"); seq_printf(p, "%*s: ", prec, "TLB"); for_each_online_cpu(j) seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count); diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index fe41a98043bb..04e47c6a4562 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -646,6 +646,7 @@ void notrace handle_interruption(int code, struct pt_regs *regs) case 14: /* Assist Exception Trap, i.e. floating point exception. */ die_if_kernel("Floating point exception", regs, 0); /* quiet */ + __inc_irq_stat(irq_fpassist_count); handle_fpe(regs); return; diff --git a/arch/parisc/kernel/unaligned.c b/arch/parisc/kernel/unaligned.c index 234e3682cf09..d7c0acb35ec2 100644 --- a/arch/parisc/kernel/unaligned.c +++ b/arch/parisc/kernel/unaligned.c @@ -27,6 +27,7 @@ #include #include #include +#include /* #define DEBUG_UNALIGNED 1 */ @@ -454,6 +455,8 @@ void handle_unaligned(struct pt_regs *regs) struct siginfo si; register int flop=0; /* true if this is a flop */ + __inc_irq_stat(irq_unaligned_count); + /* log a message with pacing */ if (user_mode(regs)) { if (current->thread.flags & PARISC_UAC_SIGBUS) { -- cgit v1.2.2 From b63a2bbc0b9b106a93e11952ab057e2408f2eb02 Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Mon, 20 May 2013 16:42:53 +0000 Subject: parisc: make interrupt and interruption stack allocation reentrant The get_stack_use_cr30 and get_stack_use_r30 macros allocate a stack frame for external interrupts and interruptions requiring a stack frame. They are currently not reentrant in that they save register context before the stack is set or adjusted. I have observed a number of system crashes where there was clear evidence of stack corruption during interrupt processing, and as a result register corruption. Some interruptions can still occur during interruption processing, however external interrupts are disabled and data TLB misses don't occur for absolute accesses. So, it's not entirely clear what triggers this issue. Also, if an interruption occurs when Q=0, it is generally not possible to recover as the shadowed registers are not copied. The attached patch reworks the get_stack_use_cr30 and get_stack_use_r30 macros to allocate stack before doing register saves. The new code is a couple of instructions shorter than the old implementation. Thus, it's an improvement even if it doesn't fully resolve the stack corruption issue. Based on limited testing, it improves SMP system stability. Signed-off-by: John David Anglin Signed-off-by: Helge Deller --- arch/parisc/kernel/entry.S | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index ae27cb6ce19a..e8f07dd28401 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -65,15 +65,11 @@ rsm PSW_SM_I, %r0 /* barrier for "Relied upon Translation */ mtsp %r0, %sr4 mtsp %r0, %sr5 - mfsp %sr7, %r1 - or,= %r0,%r1,%r0 /* Only save sr7 in sr3 if sr7 != 0 */ - mtsp %r1, %sr3 + mtsp %r0, %sr6 tovirt_r1 %r29 load32 KERNEL_PSW, %r1 rsm PSW_SM_QUIET,%r0 /* second "heavy weight" ctl op */ - mtsp %r0, %sr6 - mtsp %r0, %sr7 mtctl %r0, %cr17 /* Clear IIASQ tail */ mtctl %r0, %cr17 /* Clear IIASQ head */ mtctl %r1, %ipsw @@ -119,17 +115,20 @@ /* we save the registers in the task struct */ + copy %r30, %r17 mfctl %cr30, %r1 + ldo THREAD_SZ_ALGN(%r1), %r30 + mtsp %r0,%sr7 + mtsp %r16,%sr3 tophys %r1,%r9 LDREG TI_TASK(%r9), %r1 /* thread_info -> task_struct */ tophys %r1,%r9 ldo TASK_REGS(%r9),%r9 - STREG %r30, PT_GR30(%r9) + STREG %r17,PT_GR30(%r9) STREG %r29,PT_GR29(%r9) STREG %r26,PT_GR26(%r9) + STREG %r16,PT_SR7(%r9) copy %r9,%r29 - mfctl %cr30, %r1 - ldo THREAD_SZ_ALGN(%r1), %r30 .endm .macro get_stack_use_r30 @@ -137,10 +136,12 @@ /* we put a struct pt_regs on the stack and save the registers there */ tophys %r30,%r9 - STREG %r30,PT_GR30(%r9) + copy %r30,%r1 ldo PT_SZ_ALGN(%r30),%r30 + STREG %r1,PT_GR30(%r9) STREG %r29,PT_GR29(%r9) STREG %r26,PT_GR26(%r9) + STREG %r16,PT_SR7(%r9) copy %r9,%r29 .endm -- cgit v1.2.2 From d96b51ec14650b490ab98e738bcc02309396e5bc Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Fri, 24 May 2013 21:27:35 +0000 Subject: parisc: fix irq stack on UP and SMP The logic to detect if the irq stack was already in use with raw_spin_trylock() is wrong, because it will generate a "trylock failure on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y. arch_spin_trylock() can't be used either since in the CONFIG_SMP=n case no atomic protection is given and we are reentrant here. A mutex didn't worked either and brings more overhead by turning off interrupts. So, let's use the fastest path for parisc which is the ldcw instruction. Counting how often the irq stack was used is pretty useless, so just drop this piece of code. Signed-off-by: Helge Deller --- arch/parisc/kernel/irq.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) (limited to 'arch/parisc/kernel') diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 9c2d953f3de5..2e6443b1e922 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -27,11 +27,11 @@ #include #include #include -#include #include #include #include +#include #undef PARISC_IRQ_CR16_COUNTS @@ -172,10 +172,6 @@ int arch_show_interrupts(struct seq_file *p, int prec) for_each_online_cpu(j) seq_printf(p, "%10u ", irq_stats(j)->irq_stack_usage); seq_puts(p, " Interrupt stack usage\n"); - seq_printf(p, "%*s: ", prec, "ISC"); - for_each_online_cpu(j) - seq_printf(p, "%10u ", irq_stats(j)->irq_stack_counter); - seq_puts(p, " Interrupt stack usage counter\n"); # endif #endif #ifdef CONFIG_SMP @@ -384,6 +380,24 @@ static inline int eirr_to_irq(unsigned long eirr) return (BITS_PER_LONG - bit) + TIMER_IRQ; } +#ifdef CONFIG_IRQSTACKS +/* + * IRQ STACK - used for irq handler + */ +#define IRQ_STACK_SIZE (4096 << 2) /* 16k irq stack size */ + +union irq_stack_union { + unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)]; + volatile unsigned int slock[4]; + volatile unsigned int lock[1]; +}; + +DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = { + .slock = { 1,1,1,1 }, + }; +#endif + + int sysctl_panic_on_stackoverflow = 1; static inline void stack_overflow_check(struct pt_regs *regs) @@ -450,27 +464,26 @@ panic_check: } #ifdef CONFIG_IRQSTACKS -DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = { - .lock = __RAW_SPIN_LOCK_UNLOCKED((irq_stack_union).lock) - }; +/* in entry.S: */ +void call_on_stack(unsigned long p1, void *func, unsigned long new_stack); static void execute_on_irq_stack(void *func, unsigned long param1) { union irq_stack_union *union_ptr; unsigned long irq_stack; - raw_spinlock_t *irq_stack_in_use; + volatile unsigned int *irq_stack_in_use; union_ptr = &per_cpu(irq_stack_union, smp_processor_id()); irq_stack = (unsigned long) &union_ptr->stack; - irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.lock), + irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.slock), 64); /* align for stack frame usage */ /* We may be called recursive. If we are already using the irq stack, * just continue to use it. Use spinlocks to serialize * the irq stack usage. */ - irq_stack_in_use = &union_ptr->lock; - if (!raw_spin_trylock(irq_stack_in_use)) { + irq_stack_in_use = (volatile unsigned int *)__ldcw_align(union_ptr); + if (!__ldcw(irq_stack_in_use)) { void (*direct_call)(unsigned long p1) = func; /* We are using the IRQ stack already. @@ -482,10 +495,8 @@ static void execute_on_irq_stack(void *func, unsigned long param1) /* This is where we switch to the IRQ stack. */ call_on_stack(param1, func, irq_stack); - __inc_irq_stat(irq_stack_counter); - /* free up irq stack usage. */ - do_raw_spin_unlock(irq_stack_in_use); + *irq_stack_in_use = 1; } asmlinkage void do_softirq(void) -- cgit v1.2.2