[PATCH] powerpc/irq: Enable facility unavailable exceptions in /proc/interrupts
Anshuman Khandual
khandual at linux.vnet.ibm.com
Wed Jul 8 20:26:04 AEST 2015
This patch enables facility unavailable exceptions for generic facility,
FPU, ALTIVEC and VSX in /proc/interrupts listing by incrementing their
respective newly added IRQ statistical counters as and when these IRQs
happen. This also adds multiple helper functions which will be called
from within the interrupt handler context to update their statistics.
With this patch being applied, /proc/interrupts looks something
like this after running various workloads which create these exceptions.
------------------------------------------------------------------------
CPU0 CPU1
16: 4262 6166 XICS 2 Level IPI
17: 0 0 XICS 4101 Level virtio0
18: 0 0 XICS 4100 Level ohci_hcd:usb1
20: 0 0 XICS 4096 Level RAS_EPOW
21: 5730 1744 XICS 4102 Level ibmvscsi
22: 147 0 XICS 4103 Level hvc_console
24: 0 0 XICS 4104 Level virtio1-config
25: 19 167 XICS 4105 Level virtio1-input.0
26: 1 0 XICS 4106 Level virtio1-output.0
LOC: 5278 7996 Local timer interrupts for timer event device
LOC: 49 24 Local timer interrupts for others
SPU: 0 0 Spurious interrupts
PMI: 0 0 Performance monitoring interrupts
MCE: 0 0 Machine check exceptions
DBL: 0 0 Doorbell interrupts
FAC: 0 0 Facility unavailable excpetions
FPU: 12172 2549 FPU unavailable excpetions
ALT: 22454 7226 ALTIVEC unavailable excpetions
VSX: 14 90 VSX unavailable excpetions
-----------------------------------------------------------------------
Signed-off-by: Anshuman Khandual <khandual at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/hardirq.h | 4 ++++
arch/powerpc/kernel/exceptions-64s.S | 2 ++
arch/powerpc/kernel/irq.c | 23 +++++++++++++++++++++++
arch/powerpc/kernel/traps.c | 29 +++++++++++++++++++++++++++++
4 files changed, 58 insertions(+)
diff --git a/arch/powerpc/include/asm/hardirq.h b/arch/powerpc/include/asm/hardirq.h
index 8add8b8..bd31390 100644
--- a/arch/powerpc/include/asm/hardirq.h
+++ b/arch/powerpc/include/asm/hardirq.h
@@ -15,6 +15,10 @@ typedef struct {
#ifdef CONFIG_PPC_DOORBELL
unsigned int doorbell_irqs;
#endif
+ unsigned int fac_unav_exceptions;
+ unsigned int fpu_unav_exceptions;
+ unsigned int altivec_unav_exceptions;
+ unsigned int vsx_unav_exceptions;
} ____cacheline_aligned irq_cpustat_t;
DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 0a0399c2..a86180c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1158,6 +1158,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
bl load_up_fpu
+ bl fpu_unav_exceptions_count
b fast_exception_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
@@ -1184,6 +1185,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_NESTED(CPU_FTR_TM, CPU_FTR_TM, 69)
#endif
bl load_up_altivec
+ bl altivec_unav_exceptions_count
b fast_exception_return
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
2: /* User process was in a transaction */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 4509603..fa6559c 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -397,6 +397,25 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_printf(p, " Doorbell interrupts\n");
}
#endif
+ seq_printf(p, "%*s: ", prec, "FAC");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).fac_unav_exceptions);
+ seq_printf(p, " Facility unavailable excpetions\n");
+
+ seq_printf(p, "%*s: ", prec, "FPU");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).fpu_unav_exceptions);
+ seq_printf(p, " FPU unavailable excpetions\n");
+
+ seq_printf(p, "%*s: ", prec, "ALT");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).altivec_unav_exceptions);
+ seq_printf(p, " ALTIVEC unavailable excpetions\n");
+
+ seq_printf(p, "%*s: ", prec, "VSX");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", per_cpu(irq_stat, j).vsx_unav_exceptions);
+ seq_printf(p, " VSX unavailable excpetions\n");
return 0;
}
@@ -416,6 +435,10 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
#ifdef CONFIG_PPC_DOORBELL
sum += per_cpu(irq_stat, cpu).doorbell_irqs;
#endif
+ sum += per_cpu(irq_stat, cpu).fac_unav_exceptions;
+ sum += per_cpu(irq_stat, cpu).fpu_unav_exceptions;
+ sum += per_cpu(irq_stat, cpu).altivec_unav_exceptions;
+ sum += per_cpu(irq_stat, cpu).vsx_unav_exceptions;
return sum;
}
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 6530f1b..25fd58d 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1322,6 +1322,8 @@ void kernel_fp_unavailable_exception(struct pt_regs *regs)
{
enum ctx_state prev_state = exception_enter();
+ __this_cpu_inc(irq_stat.fpu_unav_exceptions);
+
printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
"%lx at %lx\n", regs->trap, regs->nip);
die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
@@ -1333,6 +1335,8 @@ void altivec_unavailable_exception(struct pt_regs *regs)
{
enum ctx_state prev_state = exception_enter();
+ __this_cpu_inc(irq_stat.altivec_unav_exceptions);
+
if (user_mode(regs)) {
/* A user program has executed an altivec instruction,
but this kernel doesn't support altivec. */
@@ -1350,6 +1354,8 @@ bail:
void vsx_unavailable_exception(struct pt_regs *regs)
{
+ __this_cpu_inc(irq_stat.vsx_unav_exceptions);
+
if (user_mode(regs)) {
/* A user program has executed an vsx instruction,
but this kernel doesn't support vsx. */
@@ -1381,6 +1387,8 @@ void facility_unavailable_exception(struct pt_regs *regs)
u8 status;
bool hv;
+ __this_cpu_inc(irq_stat.fac_unav_exceptions);
+
hv = (regs->trap == 0xf80);
if (hv)
value = mfspr(SPRN_HFSCR);
@@ -1453,10 +1461,27 @@ void facility_unavailable_exception(struct pt_regs *regs)
}
#endif
+void fpu_unav_exceptions_count(void)
+{
+ __this_cpu_inc(irq_stat.fpu_unav_exceptions);
+}
+
+void altivec_unav_exceptions_count(void)
+{
+ __this_cpu_inc(irq_stat.altivec_unav_exceptions);
+}
+
+void vsx_unav_exceptions_count(void)
+{
+ __this_cpu_inc(irq_stat.vsx_unav_exceptions);
+}
+
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
void fp_unavailable_tm(struct pt_regs *regs)
{
+ __this_cpu_inc(irq_stat.fpu_unav_exceptions);
+
/* Note: This does not handle any kind of FP laziness. */
TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n",
@@ -1493,6 +1518,8 @@ void fp_unavailable_tm(struct pt_regs *regs)
void altivec_unavailable_tm(struct pt_regs *regs)
{
+ __this_cpu_inc(irq_stat.altivec_unav_exceptions);
+
/* See the comments in fp_unavailable_tm(). This function operates
* the same way.
*/
@@ -1515,6 +1542,8 @@ void vsx_unavailable_tm(struct pt_regs *regs)
{
unsigned long orig_msr = regs->msr;
+ __this_cpu_inc(irq_stat.vsx_unav_exceptions);
+
/* See the comments in fp_unavailable_tm(). This works similarly,
* though we're loading both FP and VEC registers in here.
*
--
2.1.0
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