Module: xenomai-forge
Branch: next
Commit: ee15006a565d68270ec5b7fc72e6dda70c82e8d5
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=ee15006a565d68270ec5b7fc72e6dda70c82e8d5
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Tue Jun 4 07:47:26 2013 +0200
x86: fix FPU features detection
Unconditionnaly using cpuid 1 to detect fpu features does not work:
- the cpuid instruction is not available on all cpus
- on cpus with cpuid instruction, it is necessary to invoke cpuid 0 to
know if cpuid 1 is supported.
So, instead of re-implementing what the Linux kernel already implements,
use the macro it provides in kernel-space, and the flags exported by
/proc/cpuinfo in user-space, like we do on ARM.
---
include/asm-x86/fptest.h | 72 ++++++++++++++++++++++++++++-----------------
1 files changed, 45 insertions(+), 27 deletions(-)
diff --git a/include/asm-x86/fptest.h b/include/asm-x86/fptest.h
index 6c98027..2611389 100644
--- a/include/asm-x86/fptest.h
+++ b/include/asm-x86/fptest.h
@@ -4,6 +4,19 @@
#ifdef __KERNEL__
#include <linux/module.h>
#include <asm/i387.h>
+#include <asm/processor.h>
+
+#ifndef cpu_has_xmm2
+#ifdef cpu_has_sse2
+#define cpu_has_xmm2 cpu_has_sse2
+#else
+#define cpu_has_xmm2 0
+#endif
+#endif
+
+#ifndef cpu_has_avx
+#define cpu_has_avx 0
+#endif
static inline int fp_kernel_supported(void)
{
@@ -39,38 +52,43 @@ static inline void fp_linux_end(void)
kernel_fpu_end();
}
+static inline void fp_features_init(void)
+{
+}
+
#else /* !__KERNEL__ */
#include <stdio.h>
#define printk printf
-#endif /* !__KERNEL__ */
#define FP_FEATURE_SSE2 0x01
#define FP_FEATURE_AVX 0x02
-#define FP_CPUID_SSE2_MASK (1 << 26)
-#define FP_CPUID_AVX_MASK ((1 << 27) | (1 << 28))
-
static unsigned long fp_features;
-static inline void fp_features_init(void)
+#define cpu_has_xmm2 (fp_features & FP_FEATURE_SSE2)
+#define cpu_has_avx (fp_features & FP_FEATURE_AVX)
+
+static void fp_features_init(void)
{
- unsigned int eax, ebx, ecx, edx;
-
- eax = 1;
- __asm__ __volatile__("cpuid"
- : "=a" (eax),
- "=b" (ebx),
- "=c" (ecx),
- "=d" (edx)
- : "0" (eax)
- : "memory");
-
- if (edx & FP_CPUID_SSE2_MASK)
- fp_features |= FP_FEATURE_SSE2;
- /* check for both xsave and avx */
- if ((ecx & FP_CPUID_AVX_MASK) == FP_CPUID_AVX_MASK)
- fp_features |= FP_FEATURE_AVX;
+ char buffer[1024];
+ FILE *f = fopen("/proc/cpuinfo", "r");
+ if(!f)
+ return;
+
+ while(fgets(buffer, sizeof(buffer), f)) {
+ if(strncmp(buffer, "flags", sizeof("flags") - 1))
+ continue;
+
+ if (strstr(buffer, "sse2"))
+ fp_features |= FP_FEATURE_SSE2;
+ if (strstr(buffer, "avx"))
+ fp_features |= FP_FEATURE_AVX;
+ break;
+ }
+
+ fclose(f);
}
+#endif /* !__KERNEL__ */
static inline void fp_regs_set(unsigned val)
{
@@ -79,7 +97,7 @@ static inline void fp_regs_set(unsigned val)
for (i = 0; i < 8; i++)
__asm__ __volatile__("fildl %0": /* no output */ :"m"(val));
- if (fp_features & FP_FEATURE_AVX)
+ if (cpu_has_avx)
__asm__ __volatile__(
"vmovupd %0,%%ymm0;"
"vmovupd %0,%%ymm1;"
@@ -90,7 +108,7 @@ static inline void fp_regs_set(unsigned val)
"vmovupd %0,%%ymm6;"
"vmovupd %0,%%ymm7;"
: : "m" (vec[0]));
- else if (fp_features & FP_FEATURE_SSE2)
+ else if (cpu_has_xmm2)
__asm__ __volatile__(
"movupd %0,%%xmm0;"
"movupd %0,%%xmm1;"
@@ -111,7 +129,7 @@ static inline unsigned fp_regs_check(unsigned val)
for (i = 0; i < 8; i++)
__asm__ __volatile__("fistpl %0":"=m"(e[7 - i]));
- if (fp_features & FP_FEATURE_AVX) {
+ if (cpu_has_avx) {
__asm__ __volatile__(
"vmovupd %%ymm0,%0;"
"vmovupd %%ymm1,%1;"
@@ -125,7 +143,7 @@ static inline unsigned fp_regs_check(unsigned val)
"=m" (vec[2][0]), "=m" (vec[3][0]),
"=m" (vec[4][0]), "=m" (vec[5][0]),
"=m" (vec[6][0]), "=m" (vec[7][0]));
- } else if (fp_features & FP_FEATURE_SSE2) {
+ } else if (cpu_has_xmm2) {
__asm__ __volatile__(
"movupd %%xmm0,%0;"
"movupd %%xmm1,%1;"
@@ -147,7 +165,7 @@ static inline unsigned fp_regs_check(unsigned val)
result = e[i];
}
- if (fp_features & FP_FEATURE_AVX) {
+ if (cpu_has_avx) {
for (i = 0; i < 8; i++) {
int error = 0;
if (vec[i][0] != val) {
@@ -164,7 +182,7 @@ static inline unsigned fp_regs_check(unsigned val)
(unsigned long long)vec[i][2],
val, val);
}
- } else if (fp_features & FP_FEATURE_SSE2) {
+ } else if (cpu_has_xmm2) {
for (i = 0; i < 8; i++)
if (vec[i][0] != val) {
printk("xmm%d: %llu != %u\n",
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