diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-21 02:03:51 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-21 02:03:51 +0300 |
commit | 280d7a1edef214eefb1cb34915c73767355dd1b3 (patch) | |
tree | 4681f25ff0ef4d254269b9df99cd213a97ca354e /arch/x86/kernel/fpu | |
parent | 8a9365a4725a4d6265a416dd63bff937e300308e (diff) | |
parent | 9729017f844431ab2800519297d8d1b0ecbc420d (diff) | |
download | linux-280d7a1edef214eefb1cb34915c73767355dd1b3.tar.xz |
Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu updates from Ingo Molnar:
"The main changes relate to fixes between (lack of) CPUID and FPU
detection that should only affect old or weird CPUs, by Andy
Lutomirski"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Fix the "Giving up, no FPU found" test
x86/fpu: Fix CPUID-less FPU detection
x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message
x86/cpu: Re-apply forced caps every time CPU caps are re-read
x86/cpu: Factor out application of forced CPU caps
x86/cpu: Add X86_FEATURE_CPUID
x86/fpu/xstate: Move XSAVES state init to a function
Diffstat (limited to 'arch/x86/kernel/fpu')
-rw-r--r-- | arch/x86/kernel/fpu/core.c | 9 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/init.c | 29 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 8 |
3 files changed, 23 insertions, 23 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index de7234401275..e1114f070c2d 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -9,7 +9,6 @@ #include <asm/fpu/regset.h> #include <asm/fpu/signal.h> #include <asm/fpu/types.h> -#include <asm/fpu/xstate.h> #include <asm/traps.h> #include <linux/hardirq.h> @@ -179,14 +178,8 @@ void fpstate_init(union fpregs_state *state) memset(state, 0, fpu_kernel_xstate_size); - /* - * XRSTORS requires that this bit is set in xcomp_bv, or - * it will #GP. Make sure it is replaced after the memset(). - */ if (static_cpu_has(X86_FEATURE_XSAVES)) - state->xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | - xfeatures_mask; - + fpstate_init_xstate(&state->xsave); if (static_cpu_has(X86_FEATURE_FXSR)) fpstate_init_fxstate(&state->fxsave); else diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 60dece392b3a..19bdd1bf8160 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -48,13 +48,7 @@ void fpu__init_cpu(void) fpu__init_cpu_xstate(); } -/* - * The earliest FPU detection code. - * - * Set the X86_FEATURE_FPU CPU-capability bit based on - * trying to execute an actual sequence of FPU instructions: - */ -static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) +static bool fpu__probe_without_cpuid(void) { unsigned long cr0; u16 fsw, fcw; @@ -65,18 +59,25 @@ static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) cr0 &= ~(X86_CR0_TS | X86_CR0_EM); write_cr0(cr0); - if (!test_bit(X86_FEATURE_FPU, (unsigned long *)cpu_caps_cleared)) { - asm volatile("fninit ; fnstsw %0 ; fnstcw %1" - : "+m" (fsw), "+m" (fcw)); + asm volatile("fninit ; fnstsw %0 ; fnstcw %1" : "+m" (fsw), "+m" (fcw)); + + pr_info("x86/fpu: Probing for FPU: FSW=0x%04hx FCW=0x%04hx\n", fsw, fcw); - if (fsw == 0 && (fcw & 0x103f) == 0x003f) - set_cpu_cap(c, X86_FEATURE_FPU); + return fsw == 0 && (fcw & 0x103f) == 0x003f; +} + +static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) +{ + if (!boot_cpu_has(X86_FEATURE_CPUID) && + !test_bit(X86_FEATURE_FPU, (unsigned long *)cpu_caps_cleared)) { + if (fpu__probe_without_cpuid()) + setup_force_cpu_cap(X86_FEATURE_FPU); else - clear_cpu_cap(c, X86_FEATURE_FPU); + setup_clear_cpu_cap(X86_FEATURE_FPU); } #ifndef CONFIG_MATH_EMULATION - if (!boot_cpu_has(X86_FEATURE_FPU)) { + if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_FPU)) { pr_emerg("x86/fpu: Giving up, no FPU found and no math emulation present\n"); for (;;) asm volatile("hlt"); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 35f7024aace5..c24ac1efb12d 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -706,8 +706,14 @@ void __init fpu__init_system_xstate(void) WARN_ON_FPU(!on_boot_cpu); on_boot_cpu = 0; + if (!boot_cpu_has(X86_FEATURE_FPU)) { + pr_info("x86/fpu: No FPU detected\n"); + return; + } + if (!boot_cpu_has(X86_FEATURE_XSAVE)) { - pr_info("x86/fpu: Legacy x87 FPU detected.\n"); + pr_info("x86/fpu: x87 FPU will use %s\n", + boot_cpu_has(X86_FEATURE_FXSR) ? "FXSAVE" : "FSAVE"); return; } |