On Tue, 27 Nov 2007, Olof Johansson wrote:
> On Tue, Nov 27, 2007 at 03:56:53PM +0100, Geert Uytterhoeven wrote:
> > include/asm-powerpc/emulator.h | 60
> > ++++++++++++++++++++++++++++++++++++++
>
> This name stood out as being a bit too generic, emulator could mean
> system support for running under some sort of emulator as well. How
> about emulated_ops.h?
Changed.
> > +config DEBUG_WARN_EMULATED
> > + bool "Warn if emulated instructions are used"
> > + depends on DEBUG_KERNEL && SYSFS
> > + help
> > + This option will cause messages to be printed if an instruction is
> > + emulated.
> > + Counters for emulated instruction usages are always available under
> > + /sys/devices/system/cpu/cpu*/emulated/, irrespective of the state
> > + of this option.
>
> How about making it a sysctl instead, so it can be flipped at runtime
> (but default off)?
Converted to a sysctl.
Subject: powerpc: Keep track of emulated instructions
From: Geert Uytterhoeven <[EMAIL PROTECTED]>
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),
rate-limited warnings can be printed to the console when instructions are
emulated.
Signed-off-by: Geert Uytterhoeven <[EMAIL PROTECTED]>
---
arch/powerpc/kernel/align.c | 17 ++++--
arch/powerpc/kernel/sysfs.c | 100 ++++++++++++++++++++++++++++++++++++-
arch/powerpc/kernel/traps.c | 24 ++++++++
include/asm-powerpc/emulated_ops.h | 52 +++++++++++++++++++
4 files changed, 186 insertions(+), 7 deletions(-)
--- 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;
@@ -696,8 +697,10 @@ 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_EMULATE(spe);
return emulate_spe(regs, reg, instr);
+ }
#endif
instr = (dsisr >> 10) & 0x7f;
@@ -731,17 +734,21 @@ int fix_alignment(struct pt_regs *regs)
/* 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_EMULATE(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_EMULATE(multiple);
return emulate_multiple(regs, addr, reg, nb,
flags, instr, swiz);
+ }
/* Verify the address of the operand */
if (unlikely(user_mode(regs) &&
@@ -758,8 +765,10 @@ int fix_alignment(struct pt_regs *regs)
}
/* Special case for 16-byte FP loads and stores */
- if (nb == 16)
+ if (nb == 16) {
+ WARN_EMULATE(fp_pair);
return emulate_fp_pair(regs, addr, reg, flags);
+ }
/* If we are loading, get the data from user space, else
* get it from register values
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -8,6 +8,7 @@
#include <linux/nodemask.h>
#include <linux/cpumask.h>
#include <linux/notifier.h>
+#include <linux/sysctl.h>
#include <asm/current.h>
#include <asm/processor.h>
@@ -19,6 +20,7 @@
#include <asm/lppaca.h>
#include <asm/machdep.h>
#include <asm/smp.h>
+#include <asm/emulated_ops.h>
static DEFINE_PER_CPU(struct cpu, cpu_devices);
@@ -291,12 +293,101 @@ static struct sysdev_attribute pa6t_attr
};
+#define SYSFS_EMULATED_SETUP(type) \
+DEFINE_PER_CPU(atomic_long_t, emulated_ ## type); \
+static ssize_t show_emulated_ ## type (struct sys_device *dev, \
+ 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, \
+};
+
+SYSFS_EMULATED_SETUP(dcba);
+SYSFS_EMULATED_SETUP(dcbz);
+SYSFS_EMULATED_SETUP(fp_pair);
+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
+
+static struct attribute *emulated_attrs[] = {
+ &emulated_dcba_attr.attr,
+ &emulated_dcbz_attr.attr,
+ &emulated_fp_pair_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
+ NULL
+};
+
+static struct attribute_group emulated_attr_group = {
+ .attrs = emulated_attrs,
+ .name = "emulated"
+};
+
+int sysctl_warn_emulated;
+
+#ifdef CONFIG_SYSCTL
+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,
+ },
+ {}
+};
+
+static inline void warn_emulated_sysctl_register(void)
+{
+ int res = register_sysctl_table(warn_emulated_sysctl_root);
+ printk("@@@ register_sysctl_table() returned %d\n", res);
+}
+#else /* !CONFIG_SYSCTL */
+static inline void warn_emulated_sysctl_register(void) {}
+#endif /* !CONFIG_SYSCTL */
+
+
static void 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;
if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
cpu_has_feature(CPU_FTR_SMT))
@@ -339,6 +430,11 @@ static void register_cpu_online(unsigned
if (cpu_has_feature(CPU_FTR_DSCR))
sysdev_create_file(s, &attr_dscr);
+
+ 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
@@ -560,6 +656,8 @@ static int __init topology_init(void)
register_cpu_online(cpu);
}
+ warn_emulated_sysctl_register();
+
return 0;
}
subsys_initcall(topology_init);
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -53,6 +53,7 @@
#include <asm/processor.h>
#endif
#include <asm/kexec.h>
+#include <asm/emulated_ops.h>
#ifdef CONFIG_DEBUGGER
int (*__debugger)(struct pt_regs *regs);
@@ -707,6 +708,13 @@ static int emulate_popcntb_inst(struct p
return 0;
}
+void do_warn_emulate(const char *type)
+{
+ if (printk_ratelimit())
+ pr_warning("%s used emulated %s instruction\n", current->comm,
+ type);
+}
+
static int emulate_instruction(struct pt_regs *regs)
{
u32 instword;
@@ -721,31 +729,38 @@ static int emulate_instruction(struct pt
/* Emulate the mfspr rD, PVR. */
if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
+ WARN_EMULATE(mfpvr);
rd = (instword >> 21) & 0x1f;
regs->gpr[rd] = mfspr(SPRN_PVR);
return 0;
}
/* Emulating the dcba insn is just a no-op. */
- if ((instword & INST_DCBA_MASK) == INST_DCBA)
+ if ((instword & INST_DCBA_MASK) == INST_DCBA) {
+ WARN_EMULATE(dcba);
return 0;
+ }
/* Emulate the mcrxr insn. */
if ((instword & INST_MCRXR_MASK) == INST_MCRXR) {
int shift = (instword >> 21) & 0x1c;
unsigned long msk = 0xf0000000UL >> shift;
+ WARN_EMULATE(mcrxr);
regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
regs->xer &= ~0xf0000000UL;
return 0;
}
/* Emulate load/store string insn. */
- if ((instword & INST_STRING_GEN_MASK) == INST_STRING)
+ if ((instword & INST_STRING_GEN_MASK) == INST_STRING) {
+ WARN_EMULATE(string);
return emulate_string_inst(regs, instword);
+ }
/* Emulate the popcntb (Population Count Bytes) instruction. */
if ((instword & INST_POPCNTB_MASK) == INST_POPCNTB) {
+ WARN_EMULATE(popcntb);
return emulate_popcntb_inst(regs, instword);
}
@@ -929,6 +944,8 @@ void SoftwareEmulation(struct pt_regs *r
#ifdef CONFIG_MATH_EMULATION
errcode = do_mathemu(regs);
+ if (errcode >= 0)
+ WARN_EMULATE(math);
switch (errcode) {
case 0:
@@ -950,6 +967,9 @@ void SoftwareEmulation(struct pt_regs *r
#elif defined(CONFIG_8XX_MINIMAL_FPEMU)
errcode = Soft_emulate_8xx(regs);
+ if (errcode >= 0)
+ WARN_EMULATE(8xx);
+
switch (errcode) {
case 0:
emulate_single_step(regs);
--- /dev/null
+++ b/include/asm-powerpc/emulated_ops.h
@@ -0,0 +1,52 @@
+/*
+ * 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>
+
+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_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
+
+extern int sysctl_warn_emulated;
+extern void do_warn_emulate(const char *type);
+
+#define WARN_EMULATE(type) \
+ do { \
+ atomic_long_inc(&per_cpu(emulated_ ## type, \
+ raw_smp_processor_id())); \
+ if (sysctl_warn_emulated) \
+ do_warn_emulate(#type); \
+ } while (0)
+
+
+#endif /* _ASM_POWERPC_EMULATED_OPS_H */
With kind regards,
Geert Uytterhoeven
Software Architect
Sony Network and Software Technology Center 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: [EMAIL PROTECTED]
Internet: http://www.sony-europe.com/
Sony Network and Software Technology Center Europe
A division of Sony Service Centre (Europe) N.V.
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