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| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2012-09-10 19:32:32 +0200 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-09-19 00:52:24 +0200 |
| commit | e00229819f306b1f86134095347e9187dc346bd1 (patch) | |
| tree | 58184b30fb2dca0f14c0b2cdc60b958529154893 /arch | |
| parent | x86, fpu: enable eagerfpu by default for xsaveopt (diff) | |
| download | linux-e00229819f306b1f86134095347e9187dc346bd1.tar.xz linux-e00229819f306b1f86134095347e9187dc346bd1.zip | |
x86, fpu: make eagerfpu= boot param tri-state
Add the "eagerfpu=auto" (that selects the default scheme in
enabling eagerfpu) which can override compiled-in boot parameters
like "eagerfpu=on/off" (that force enable/disable eagerfpu).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1347300665-6209-5-git-send-email-suresh.b.siddha@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/xsave.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index e99f75439f6d..4e89b3dd408d 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -508,13 +508,15 @@ static void __init setup_init_fpu_buf(void) xsave_state(init_xstate_buf, -1); } -static int disable_eagerfpu; +static enum { AUTO, ENABLE, DISABLE } eagerfpu = AUTO; static int __init eager_fpu_setup(char *s) { if (!strcmp(s, "on")) - setup_force_cpu_cap(X86_FEATURE_EAGER_FPU); + eagerfpu = ENABLE; else if (!strcmp(s, "off")) - disable_eagerfpu = 1; + eagerfpu = DISABLE; + else if (!strcmp(s, "auto")) + eagerfpu = AUTO; return 1; } __setup("eagerfpu=", eager_fpu_setup); @@ -557,8 +559,9 @@ static void __init xstate_enable_boot_cpu(void) prepare_fx_sw_frame(); setup_init_fpu_buf(); - if (cpu_has_xsaveopt && !disable_eagerfpu) - setup_force_cpu_cap(X86_FEATURE_EAGER_FPU); + /* Auto enable eagerfpu for xsaveopt */ + if (cpu_has_xsaveopt && eagerfpu != DISABLE) + eagerfpu = ENABLE; pr_info("enabled xstate_bv 0x%llx, cntxt size 0x%x\n", pcntxt_mask, xstate_size); @@ -598,6 +601,10 @@ void __cpuinit eager_fpu_init(void) clear_used_math(); current_thread_info()->status = 0; + + if (eagerfpu == ENABLE) + setup_force_cpu_cap(X86_FEATURE_EAGER_FPU); + if (!cpu_has_eager_fpu) { stts(); return; |