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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 11:45:26 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 11:45:26 -0700 |
commit | ab2486a9ee3243c8342549f58a13cdfa9abb497a (patch) | |
tree | fb922114a814e6d8f5ddb4b0881d5755513ff53a | |
parent | 0d37dde70655be73575d011be1bffaf0e3b16ea9 (diff) | |
parent | 7891bc0ab739a31538b5f879a523232b8b07a0d3 (diff) | |
download | linux-ab2486a9ee3243c8342549f58a13cdfa9abb497a.tar.bz2 |
Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 FPU updates from Thomas Gleixner:
"A small set of updates for the FPU code:
- Make the no387/nofxsr command line options useful by restricting
them to 32bit and actually clearing all dependencies to prevent
random crashes and malfunction.
- Simplify and cleanup the kernel_fpu_*() helpers"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Inline fpu__xstate_clear_all_cpu_caps()
x86/fpu: Make 'no387' and 'nofxsr' command line options useful
x86/fpu: Remove the fpu__save() export
x86/fpu: Simplify kernel_fpu_begin()
x86/fpu: Simplify kernel_fpu_end()
-rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 1 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/cpuid-deps.c | 5 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/core.c | 52 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/init.c | 19 | ||||
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 11 |
5 files changed, 29 insertions, 59 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 7e42b285c856..c6136d79f8c0 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -47,7 +47,6 @@ extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; extern void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask); -void fpu__xstate_clear_all_cpu_caps(void); void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); const void *get_xsave_field_ptr(int xfeature_nr); int using_compacted_format(void); diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 2c0bd38a44ab..e794e3860fc8 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -20,6 +20,7 @@ struct cpuid_dep { * but it's difficult to tell that to the init reference checker. */ static const struct cpuid_dep cpuid_deps[] = { + { X86_FEATURE_FXSR, X86_FEATURE_FPU }, { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE }, { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE }, { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE }, @@ -27,7 +28,11 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_PKU, X86_FEATURE_XSAVE }, { X86_FEATURE_MPX, X86_FEATURE_XSAVE }, { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE }, + { X86_FEATURE_CMOV, X86_FEATURE_FXSR }, + { X86_FEATURE_MMX, X86_FEATURE_FXSR }, + { X86_FEATURE_MMXEXT, X86_FEATURE_MMX }, { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR }, + { X86_FEATURE_XSAVE, X86_FEATURE_FXSR }, { X86_FEATURE_XMM, X86_FEATURE_FXSR }, { X86_FEATURE_XMM2, X86_FEATURE_XMM }, { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 649fbc3fcf9f..12c70840980e 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -43,18 +43,6 @@ static DEFINE_PER_CPU(bool, in_kernel_fpu); */ DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); -static void kernel_fpu_disable(void) -{ - WARN_ON_FPU(this_cpu_read(in_kernel_fpu)); - this_cpu_write(in_kernel_fpu, true); -} - -static void kernel_fpu_enable(void) -{ - WARN_ON_FPU(!this_cpu_read(in_kernel_fpu)); - this_cpu_write(in_kernel_fpu, false); -} - static bool kernel_fpu_disabled(void) { return this_cpu_read(in_kernel_fpu); @@ -94,42 +82,33 @@ bool irq_fpu_usable(void) } EXPORT_SYMBOL(irq_fpu_usable); -static void __kernel_fpu_begin(void) +void kernel_fpu_begin(void) { - struct fpu *fpu = ¤t->thread.fpu; + preempt_disable(); WARN_ON_FPU(!irq_fpu_usable()); + WARN_ON_FPU(this_cpu_read(in_kernel_fpu)); - kernel_fpu_disable(); + this_cpu_write(in_kernel_fpu, true); - if (!(current->flags & PF_KTHREAD)) { - if (!test_thread_flag(TIF_NEED_FPU_LOAD)) { - set_thread_flag(TIF_NEED_FPU_LOAD); - /* - * Ignore return value -- we don't care if reg state - * is clobbered. - */ - copy_fpregs_to_fpstate(fpu); - } + if (!(current->flags & PF_KTHREAD) && + !test_thread_flag(TIF_NEED_FPU_LOAD)) { + set_thread_flag(TIF_NEED_FPU_LOAD); + /* + * Ignore return value -- we don't care if reg state + * is clobbered. + */ + copy_fpregs_to_fpstate(¤t->thread.fpu); } __cpu_invalidate_fpregs_state(); } - -static void __kernel_fpu_end(void) -{ - kernel_fpu_enable(); -} - -void kernel_fpu_begin(void) -{ - preempt_disable(); - __kernel_fpu_begin(); -} EXPORT_SYMBOL_GPL(kernel_fpu_begin); void kernel_fpu_end(void) { - __kernel_fpu_end(); + WARN_ON_FPU(!this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, false); preempt_enable(); } EXPORT_SYMBOL_GPL(kernel_fpu_end); @@ -155,7 +134,6 @@ void fpu__save(struct fpu *fpu) trace_x86_fpu_after_save(fpu); fpregs_unlock(); } -EXPORT_SYMBOL_GPL(fpu__save); /* * Legacy x87 fpstate state init: diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index ef0030e3fe6b..6ce7e0a23268 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -204,12 +204,6 @@ static void __init fpu__init_system_xstate_size_legacy(void) */ if (!boot_cpu_has(X86_FEATURE_FPU)) { - /* - * Disable xsave as we do not support it if i387 - * emulation is enabled. - */ - setup_clear_cpu_cap(X86_FEATURE_XSAVE); - setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); fpu_kernel_xstate_size = sizeof(struct swregs_state); } else { if (boot_cpu_has(X86_FEATURE_FXSR)) @@ -252,17 +246,20 @@ static void __init fpu__init_parse_early_param(void) char *argptr = arg; int bit; +#ifdef CONFIG_X86_32 if (cmdline_find_option_bool(boot_command_line, "no387")) +#ifdef CONFIG_MATH_EMULATION setup_clear_cpu_cap(X86_FEATURE_FPU); +#else + pr_err("Option 'no387' required CONFIG_MATH_EMULATION enabled.\n"); +#endif - if (cmdline_find_option_bool(boot_command_line, "nofxsr")) { + if (cmdline_find_option_bool(boot_command_line, "nofxsr")) setup_clear_cpu_cap(X86_FEATURE_FXSR); - setup_clear_cpu_cap(X86_FEATURE_FXSR_OPT); - setup_clear_cpu_cap(X86_FEATURE_XMM); - } +#endif if (cmdline_find_option_bool(boot_command_line, "noxsave")) - fpu__xstate_clear_all_cpu_caps(); + setup_clear_cpu_cap(X86_FEATURE_XSAVE); if (cmdline_find_option_bool(boot_command_line, "noxsaveopt")) setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 3c36dd1784db..7b4c52aa929f 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -68,15 +68,6 @@ static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8]; unsigned int fpu_user_xstate_size; /* - * Clear all of the X86_FEATURE_* bits that are unavailable - * when the CPU has no XSAVE support. - */ -void fpu__xstate_clear_all_cpu_caps(void) -{ - setup_clear_cpu_cap(X86_FEATURE_XSAVE); -} - -/* * Return whether the system supports a given xfeature. * * Also return the name of the (most advanced) feature that the caller requested: @@ -709,7 +700,7 @@ static void fpu__init_disable_system_xstate(void) { xfeatures_mask = 0; cr4_clear_bits(X86_CR4_OSXSAVE); - fpu__xstate_clear_all_cpu_caps(); + setup_clear_cpu_cap(X86_FEATURE_XSAVE); } /* |