diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/xsave.c | 17 |
2 files changed, 15 insertions, 6 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e8f7faa..46a6a82 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1834,8 +1834,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. enabling legacy floating-point and sse state. eagerfpu= [X86] - on enable eager fpu restore (default for xsaveopt) + on enable eager fpu restore off disable eager fpu restore + auto selects the default scheme, which automatically + enables eagerfpu restore for xsaveopt. nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or wfi(ARM) instruction doesn't work correctly and not to diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index e99f754..4e89b3d 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; |