a48b6afea4
Add a bit to indicate when VMOVDQU is also atomic if aligned. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
100 lines
3.4 KiB
C
100 lines
3.4 KiB
C
/*
|
|
* SPDX-License-Identifier: GPL-2.0-or-later
|
|
* Host specific cpu indentification for x86.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "host/cpuinfo.h"
|
|
#ifdef CONFIG_CPUID_H
|
|
# include "qemu/cpuid.h"
|
|
#endif
|
|
|
|
unsigned cpuinfo;
|
|
|
|
/* Called both as constructor and (possibly) via other constructors. */
|
|
unsigned __attribute__((constructor)) cpuinfo_init(void)
|
|
{
|
|
unsigned info = cpuinfo;
|
|
|
|
if (info) {
|
|
return info;
|
|
}
|
|
|
|
#ifdef CONFIG_CPUID_H
|
|
unsigned max, a, b, c, d, b7 = 0, c7 = 0;
|
|
|
|
max = __get_cpuid_max(0, 0);
|
|
|
|
if (max >= 7) {
|
|
__cpuid_count(7, 0, a, b7, c7, d);
|
|
info |= (b7 & bit_BMI ? CPUINFO_BMI1 : 0);
|
|
info |= (b7 & bit_BMI2 ? CPUINFO_BMI2 : 0);
|
|
}
|
|
|
|
if (max >= 1) {
|
|
__cpuid(1, a, b, c, d);
|
|
|
|
info |= (d & bit_CMOV ? CPUINFO_CMOV : 0);
|
|
info |= (d & bit_SSE2 ? CPUINFO_SSE2 : 0);
|
|
info |= (c & bit_SSE4_1 ? CPUINFO_SSE4 : 0);
|
|
info |= (c & bit_MOVBE ? CPUINFO_MOVBE : 0);
|
|
info |= (c & bit_POPCNT ? CPUINFO_POPCNT : 0);
|
|
|
|
/* For AVX features, we must check available and usable. */
|
|
if ((c & bit_AVX) && (c & bit_OSXSAVE)) {
|
|
unsigned bv = xgetbv_low(0);
|
|
|
|
if ((bv & 6) == 6) {
|
|
info |= CPUINFO_AVX1;
|
|
info |= (b7 & bit_AVX2 ? CPUINFO_AVX2 : 0);
|
|
|
|
if ((bv & 0xe0) == 0xe0) {
|
|
info |= (b7 & bit_AVX512F ? CPUINFO_AVX512F : 0);
|
|
info |= (b7 & bit_AVX512VL ? CPUINFO_AVX512VL : 0);
|
|
info |= (b7 & bit_AVX512BW ? CPUINFO_AVX512BW : 0);
|
|
info |= (b7 & bit_AVX512DQ ? CPUINFO_AVX512DQ : 0);
|
|
info |= (c7 & bit_AVX512VBMI2 ? CPUINFO_AVX512VBMI2 : 0);
|
|
}
|
|
|
|
/*
|
|
* The Intel SDM has added:
|
|
* Processors that enumerate support for Intel® AVX
|
|
* (by setting the feature flag CPUID.01H:ECX.AVX[bit 28])
|
|
* guarantee that the 16-byte memory operations performed
|
|
* by the following instructions will always be carried
|
|
* out atomically:
|
|
* - MOVAPD, MOVAPS, and MOVDQA.
|
|
* - VMOVAPD, VMOVAPS, and VMOVDQA when encoded with VEX.128.
|
|
* - VMOVAPD, VMOVAPS, VMOVDQA32, and VMOVDQA64 when encoded
|
|
* with EVEX.128 and k0 (masking disabled).
|
|
* Note that these instructions require the linear addresses
|
|
* of their memory operands to be 16-byte aligned.
|
|
*
|
|
* AMD has provided an even stronger guarantee that processors
|
|
* with AVX provide 16-byte atomicity for all cachable,
|
|
* naturally aligned single loads and stores, e.g. MOVDQU.
|
|
*
|
|
* See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104688
|
|
*/
|
|
__cpuid(0, a, b, c, d);
|
|
if (c == signature_INTEL_ecx) {
|
|
info |= CPUINFO_ATOMIC_VMOVDQA;
|
|
} else if (c == signature_AMD_ecx) {
|
|
info |= CPUINFO_ATOMIC_VMOVDQA | CPUINFO_ATOMIC_VMOVDQU;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
max = __get_cpuid_max(0x8000000, 0);
|
|
if (max >= 1) {
|
|
__cpuid(0x80000001, a, b, c, d);
|
|
info |= (c & bit_LZCNT ? CPUINFO_LZCNT : 0);
|
|
}
|
|
#endif
|
|
|
|
info |= CPUINFO_ALWAYS;
|
|
cpuinfo = info;
|
|
return info;
|
|
}
|