[PATCH] powerpc: Keep track of emulated instructions
Geert Uytterhoeven
Geert.Uytterhoeven at sonycom.com
Fri Apr 3 23:08:21 EST 2009
Hi Ben, Kumar,
Finally (after ca. 1.5 years), he're an updated version of my patch to keep
track of emulated instructions. In the light of Kumar's `Emulate enough of SPE
instructions to make gcc happy' patch, he probably also wants to keep track of
the actual runtime overhead.
Changes since last version:
- arch/powerpc/kernel/sysfs.c is now compiled on ppc32, so we can provide
counters in sysfs on ppc32, too,
- WARN_EMULATED() is a no-op if CONFIG_SYSCTL is disabled,
- Add warnings for altivec,
- Add warnings for recently introduced emulation of vsx and isel
instructions.
Tested with `mfpvr' on PS3 and AMCC `Sequoia' EV-440EPX.
---
>From 8df6f7d77f28c9a5b82c9512b9dd7688d94d4e33 Mon Sep 17 00:00:00 2001
From: Geert Uytterhoeven <Geert.Uytterhoeven at sonycom.com>
Date: Thu, 26 Mar 2009 17:00:12 +0100
Subject: [PATCH] powerpc: Keep track of emulated instructions
Counters for the various classes of emulated instructions are available under
/sys/devices/system/cpu/cpu*/emulated/.
Optionally (controlled by /proc/sys/kernel/cpu_emulation_warnings, if
CONFIG_SYSCTL=y), rate-limited warnings can be printed to the console when
instructions are emulated.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven at sonycom.com>
---
arch/powerpc/include/asm/emulated_ops.h | 63 +++++++++++++++++++++++++
arch/powerpc/kernel/align.c | 18 ++++++--
arch/powerpc/kernel/sysfs.c | 78 ++++++++++++++++++++++++++++++-
arch/powerpc/kernel/traps.c | 60 +++++++++++++++++++++++-
4 files changed, 212 insertions(+), 7 deletions(-)
create mode 100644 arch/powerpc/include/asm/emulated_ops.h
diff --git a/arch/powerpc/include/asm/emulated_ops.h b/arch/powerpc/include/asm/emulated_ops.h
new file mode 100644
index 0000000..e655034
--- /dev/null
+++ b/arch/powerpc/include/asm/emulated_ops.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2007 Sony Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _ASM_POWERPC_EMULATED_OPS_H
+#define _ASM_POWERPC_EMULATED_OPS_H
+
+#include <linux/percpu.h>
+
+#include <asm/atomic.h>
+
+#ifdef CONFIG_ALTIVEC
+DECLARE_PER_CPU(atomic_long_t, emulated_altivec);
+#endif
+DECLARE_PER_CPU(atomic_long_t, emulated_dcba);
+DECLARE_PER_CPU(atomic_long_t, emulated_dcbz);
+DECLARE_PER_CPU(atomic_long_t, emulated_fp_pair);
+DECLARE_PER_CPU(atomic_long_t, emulated_isel);
+DECLARE_PER_CPU(atomic_long_t, emulated_mcrxr);
+DECLARE_PER_CPU(atomic_long_t, emulated_mfpvr);
+DECLARE_PER_CPU(atomic_long_t, emulated_multiple);
+DECLARE_PER_CPU(atomic_long_t, emulated_popcntb);
+DECLARE_PER_CPU(atomic_long_t, emulated_spe);
+DECLARE_PER_CPU(atomic_long_t, emulated_string);
+#ifdef CONFIG_MATH_EMULATION
+DECLARE_PER_CPU(atomic_long_t, emulated_math);
+#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
+DECLARE_PER_CPU(atomic_long_t, emulated_8xx);
+#endif
+#ifdef CONFIG_VSX
+DECLARE_PER_CPU(atomic_long_t, emulated_vsx);
+#endif
+
+extern void warn_emulated_print(const char *type);
+
+#ifdef CONFIG_SYSCTL
+extern int sysctl_warn_emulated;
+#else
+#define sysctl_warn_emulated 0
+#endif
+
+#define WARN_EMULATED(type) \
+ do { \
+ atomic_long_inc(&per_cpu(emulated_ ## type, \
+ raw_smp_processor_id())); \
+ if (sysctl_warn_emulated) \
+ warn_emulated_print(#type); \
+ } while (0)
+
+#endif /* _ASM_POWERPC_EMULATED_OPS_H */
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index 5ffcfaa..0f3c31b 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -24,6 +24,7 @@
#include <asm/system.h>
#include <asm/cache.h>
#include <asm/cputable.h>
+#include <asm/emulated_ops.h>
struct aligninfo {
unsigned char len;
@@ -730,8 +731,10 @@ int fix_alignment(struct pt_regs *regs)
areg = dsisr & 0x1f; /* register to update */
#ifdef CONFIG_SPE
- if ((instr >> 26) == 0x4)
+ if ((instr >> 26) == 0x4) {
+ WARN_EMULATED(spe);
return emulate_spe(regs, reg, instr);
+ }
#endif
instr = (dsisr >> 10) & 0x7f;
@@ -783,23 +786,28 @@ int fix_alignment(struct pt_regs *regs)
flags |= SPLT;
nb = 8;
}
+ WARN_EMULATED(vsx);
return emulate_vsx(addr, reg, areg, regs, flags, nb);
}
#endif
/* A size of 0 indicates an instruction we don't support, with
* the exception of DCBZ which is handled as a special case here
*/
- if (instr == DCBZ)
+ if (instr == DCBZ) {
+ WARN_EMULATED(dcbz);
return emulate_dcbz(regs, addr);
+ }
if (unlikely(nb == 0))
return 0;
/* Load/Store Multiple instructions are handled in their own
* function
*/
- if (flags & M)
+ if (flags & M) {
+ WARN_EMULATED(multiple);
return emulate_multiple(regs, addr, reg, nb,
flags, instr, swiz);
+ }
/* Verify the address of the operand */
if (unlikely(user_mode(regs) &&
@@ -816,8 +824,10 @@ int fix_alignment(struct pt_regs *regs)
}
/* Special case for 16-byte FP loads and stores */
- if (nb == 16)
+ if (nb == 16) {
+ WARN_EMULATED(fp_pair);
return emulate_fp_pair(addr, reg, flags);
+ }
/* If we are loading, get the data from user space, else
* get it from register values
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index f41aec8..344d03f 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -17,6 +17,7 @@
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/smp.h>
+#include <asm/emulated_ops.h>
#include "cacheinfo.h"
@@ -322,12 +323,82 @@ static struct sysdev_attribute pa6t_attrs[] = {
#endif /* HAS_PPC_PMC_PA6T */
#endif /* HAS_PPC_PMC_CLASSIC */
+#define SYSFS_EMULATED_SETUP(type) \
+DEFINE_PER_CPU(atomic_long_t, emulated_ ## type); \
+static ssize_t show_emulated_ ## type (struct sys_device *dev, \
+ struct sysdev_attribute *attr, \
+ char *buf) \
+{ \
+ struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
+ \
+ return sprintf(buf, "%lu\n", \
+ atomic_long_read(&per_cpu(emulated_ ## type, \
+ cpu->sysdev.id))); \
+} \
+ \
+static struct sysdev_attribute emulated_ ## type ## _attr = { \
+ .attr = { .name = #type, .mode = 0400 }, \
+ .show = show_emulated_ ## type, \
+};
+
+#ifdef CONFIG_ALTIVEC
+SYSFS_EMULATED_SETUP(altivec);
+#endif
+SYSFS_EMULATED_SETUP(dcba);
+SYSFS_EMULATED_SETUP(dcbz);
+SYSFS_EMULATED_SETUP(fp_pair);
+SYSFS_EMULATED_SETUP(isel);
+SYSFS_EMULATED_SETUP(mcrxr);
+SYSFS_EMULATED_SETUP(mfpvr);
+SYSFS_EMULATED_SETUP(multiple);
+SYSFS_EMULATED_SETUP(popcntb);
+SYSFS_EMULATED_SETUP(spe);
+SYSFS_EMULATED_SETUP(string);
+#ifdef CONFIG_MATH_EMULATION
+SYSFS_EMULATED_SETUP(math);
+#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
+SYSFS_EMULATED_SETUP(8xx);
+#endif
+#ifdef CONFIG_VSX
+SYSFS_EMULATED_SETUP(vsx);
+#endif
+
+static struct attribute *emulated_attrs[] = {
+#ifdef CONFIG_ALTIVEC
+ &emulated_altivec_attr.attr,
+#endif
+ &emulated_dcba_attr.attr,
+ &emulated_dcbz_attr.attr,
+ &emulated_fp_pair_attr.attr,
+ &emulated_isel_attr.attr,
+ &emulated_mcrxr_attr.attr,
+ &emulated_mfpvr_attr.attr,
+ &emulated_multiple_attr.attr,
+ &emulated_popcntb_attr.attr,
+ &emulated_spe_attr.attr,
+ &emulated_string_attr.attr,
+#ifdef CONFIG_MATH_EMULATION
+ &emulated_math_attr.attr,
+#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
+ &emulated_8xx_attr.attr,
+#endif
+#ifdef CONFIG_VSX
+ &emulated_vsx_attr.attr,
+#endif
+ NULL
+};
+
+static struct attribute_group emulated_attr_group = {
+ .attrs = emulated_attrs,
+ .name = "emulated"
+};
+
static void __cpuinit register_cpu_online(unsigned int cpu)
{
struct cpu *c = &per_cpu(cpu_devices, cpu);
struct sys_device *s = &c->sysdev;
struct sysdev_attribute *attrs, *pmc_attrs;
- int i, nattrs;
+ int i, nattrs, res;
#ifdef CONFIG_PPC64
if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
@@ -387,6 +458,11 @@ static void __cpuinit register_cpu_online(unsigned int cpu)
#endif /* CONFIG_PPC64 */
cacheinfo_cpu_online(cpu);
+
+ res = sysfs_create_group(&s->kobj, &emulated_attr_group);
+ if (res)
+ pr_warning("Cannot create emulated sysfs group for cpu %u\n",
+ cpu);
}
#ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 678fbff..6cf1e13 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -33,7 +33,9 @@
#include <linux/backlight.h>
#include <linux/bug.h>
#include <linux/kdebug.h>
+#include <linux/sysctl.h>
+#include <asm/emulated_ops.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -757,36 +759,44 @@ static int emulate_instruction(struct pt_regs *regs)
/* Emulate the mfspr rD, PVR. */
if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
+ WARN_EMULATED(mfpvr);
rd = (instword >> 21) & 0x1f;
regs->gpr[rd] = mfspr(SPRN_PVR);
return 0;
}
/* Emulating the dcba insn is just a no-op. */
- if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA)
+ if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
+ WARN_EMULATED(dcba);
return 0;
+ }
/* Emulate the mcrxr insn. */
if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
int shift = (instword >> 21) & 0x1c;
unsigned long msk = 0xf0000000UL >> shift;
+ WARN_EMULATED(mcrxr);
regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
regs->xer &= ~0xf0000000UL;
return 0;
}
/* Emulate load/store string insn. */
- if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING)
+ if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
+ WARN_EMULATED(string);
return emulate_string_inst(regs, instword);
+ }
/* Emulate the popcntb (Population Count Bytes) instruction. */
if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
+ WARN_EMULATED(popcntb);
return emulate_popcntb_inst(regs, instword);
}
/* Emulate isel (Integer Select) instruction */
if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
+ WARN_EMULATED(isel);
return emulate_isel(regs, instword);
}
@@ -984,6 +994,8 @@ void SoftwareEmulation(struct pt_regs *regs)
#ifdef CONFIG_MATH_EMULATION
errcode = do_mathemu(regs);
+ if (errcode >= 0)
+ WARN_EMULATED(math);
switch (errcode) {
case 0:
@@ -1005,6 +1017,9 @@ void SoftwareEmulation(struct pt_regs *regs)
#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
errcode = Soft_emulate_8xx(regs);
+ if (errcode >= 0)
+ WARN_EMULATED(8xx);
+
switch (errcode) {
case 0:
emulate_single_step(regs);
@@ -1088,6 +1103,7 @@ void altivec_assist_exception(struct pt_regs *regs)
flush_altivec_to_thread(current);
+ WARN_EMULATED(altivec);
err = emulate_altivec(regs);
if (err == 0) {
regs->nip += 4; /* skip emulated instruction */
@@ -1286,3 +1302,43 @@ void kernel_bad_stack(struct pt_regs *regs)
void __init trap_init(void)
{
}
+
+#ifdef CONFIG_SYSCTL
+int sysctl_warn_emulated;
+
+static ctl_table warn_emulated_ctl_table[] = {
+ {
+ .procname = "cpu_emulation_warnings",
+ .data = &sysctl_warn_emulated,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {}
+};
+
+static ctl_table warn_emulated_sysctl_root[] = {
+ {
+ .ctl_name = CTL_KERN,
+ .procname = "kernel",
+ .mode = 0555,
+ .child = warn_emulated_ctl_table,
+ },
+ {}
+};
+
+void warn_emulated_print(const char *type)
+{
+ if (printk_ratelimit())
+ pr_warning("%s used emulated %s instruction\n", current->comm,
+ type);
+}
+
+static inline int __init warn_emulated_sysctl_register(void)
+{
+ register_sysctl_table(warn_emulated_sysctl_root);
+ return 0;
+}
+
+device_initcall(warn_emulated_sysctl_register);
+#endif /* !CONFIG_SYSCTL */
--
1.6.0.4
With kind regards,
Geert Uytterhoeven
Software Architect
Sony Techsoft Centre Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium
Phone: +32 (0)2 700 8453
Fax: +32 (0)2 700 8622
E-mail: Geert.Uytterhoeven at sonycom.com
Internet: http://www.sony-europe.com/
A division of Sony Europe (Belgium) N.V.
VAT BE 0413.825.160 · RPR Brussels
Fortis · BIC GEBABEBB · IBAN BE41293037680010
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