linux/arch/x86/kernel/cpu/scattered.c
Alexander Shishkin ed69628b3b x86: Add Intel Processor Trace (INTEL_PT) cpu feature detection
Intel Processor Trace is an architecture extension that allows for program
flow tracing.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-11-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02 17:14:18 +02:00

78 lines
2.3 KiB
C

/*
* Routines to identify additional cpu features that are scattered in
* cpuid space.
*/
#include <linux/cpu.h>
#include <asm/pat.h>
#include <asm/processor.h>
#include <asm/apic.h>
struct cpuid_bit {
u16 feature;
u8 reg;
u8 bit;
u32 level;
u32 sub_leaf;
};
enum cpuid_regs {
CR_EAX = 0,
CR_ECX,
CR_EDX,
CR_EBX
};
void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
{
u32 max_level;
u32 regs[4];
const struct cpuid_bit *cb;
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_DTHERM, CR_EAX, 0, 0x00000006, 0 },
{ X86_FEATURE_IDA, CR_EAX, 1, 0x00000006, 0 },
{ X86_FEATURE_ARAT, CR_EAX, 2, 0x00000006, 0 },
{ X86_FEATURE_PLN, CR_EAX, 4, 0x00000006, 0 },
{ X86_FEATURE_PTS, CR_EAX, 6, 0x00000006, 0 },
{ X86_FEATURE_HWP, CR_EAX, 7, 0x00000006, 0 },
{ X86_FEATURE_HWP_NOITFY, CR_EAX, 8, 0x00000006, 0 },
{ X86_FEATURE_HWP_ACT_WINDOW, CR_EAX, 9, 0x00000006, 0 },
{ X86_FEATURE_HWP_EPP, CR_EAX,10, 0x00000006, 0 },
{ X86_FEATURE_HWP_PKG_REQ, CR_EAX,11, 0x00000006, 0 },
{ X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 },
{ X86_FEATURE_APERFMPERF, CR_ECX, 0, 0x00000006, 0 },
{ X86_FEATURE_EPB, CR_ECX, 3, 0x00000006, 0 },
{ X86_FEATURE_HW_PSTATE, CR_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CR_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CR_EDX,11, 0x80000007, 0 },
{ X86_FEATURE_NPT, CR_EDX, 0, 0x8000000a, 0 },
{ X86_FEATURE_LBRV, CR_EDX, 1, 0x8000000a, 0 },
{ X86_FEATURE_SVML, CR_EDX, 2, 0x8000000a, 0 },
{ X86_FEATURE_NRIPS, CR_EDX, 3, 0x8000000a, 0 },
{ X86_FEATURE_TSCRATEMSR, CR_EDX, 4, 0x8000000a, 0 },
{ X86_FEATURE_VMCBCLEAN, CR_EDX, 5, 0x8000000a, 0 },
{ X86_FEATURE_FLUSHBYASID, CR_EDX, 6, 0x8000000a, 0 },
{ X86_FEATURE_DECODEASSISTS, CR_EDX, 7, 0x8000000a, 0 },
{ X86_FEATURE_PAUSEFILTER, CR_EDX,10, 0x8000000a, 0 },
{ X86_FEATURE_PFTHRESHOLD, CR_EDX,12, 0x8000000a, 0 },
{ 0, 0, 0, 0, 0 }
};
for (cb = cpuid_bits; cb->feature; cb++) {
/* Verify that the level is valid */
max_level = cpuid_eax(cb->level & 0xffff0000);
if (max_level < cb->level ||
max_level > (cb->level | 0xffff))
continue;
cpuid_count(cb->level, cb->sub_leaf, &regs[CR_EAX],
&regs[CR_EBX], &regs[CR_ECX], &regs[CR_EDX]);
if (regs[cb->reg] & (1 << cb->bit))
set_cpu_cap(c, cb->feature);
}
}