diff options
Diffstat (limited to 'arch/x86/kernel/fpu')
| -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/signal.c | 16 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 58 |
4 files changed, 78 insertions, 67 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 466fca686fb9..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->mm) { - 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/signal.c b/arch/x86/kernel/fpu/signal.c index 5a8d118bc423..0071b794ed19 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -5,6 +5,7 @@ #include <linux/compat.h> #include <linux/cpu.h> +#include <linux/pagemap.h> #include <asm/fpu/internal.h> #include <asm/fpu/signal.h> @@ -61,6 +62,11 @@ static inline int save_fsave_header(struct task_struct *tsk, void __user *buf) struct user_i387_ia32_struct env; struct _fpstate_32 __user *fp = buf; + fpregs_lock(); + if (!test_thread_flag(TIF_NEED_FPU_LOAD)) + copy_fxregs_to_kernel(&tsk->thread.fpu); + fpregs_unlock(); + convert_from_fxsr(&env, tsk); if (__copy_to_user(buf, &env, sizeof(env)) || @@ -189,15 +195,7 @@ retry: fpregs_unlock(); if (ret) { - int aligned_size; - int nr_pages; - - aligned_size = offset_in_page(buf_fx) + fpu_user_xstate_size; - nr_pages = DIV_ROUND_UP(aligned_size, PAGE_SIZE); - - ret = get_user_pages_unlocked((unsigned long)buf_fx, nr_pages, - NULL, FOLL_WRITE); - if (ret == nr_pages) + if (!fault_in_pages_writeable(buf_fx, fpu_user_xstate_size)) goto retry; return -EFAULT; } diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 3c36dd1784db..e5cb67d67c03 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -8,6 +8,8 @@ #include <linux/cpu.h> #include <linux/mman.h> #include <linux/pkeys.h> +#include <linux/seq_file.h> +#include <linux/proc_fs.h> #include <asm/fpu/api.h> #include <asm/fpu/internal.h> @@ -68,15 +70,6 @@ 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 +702,7 @@ 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); } /* @@ -1240,3 +1233,48 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf) return 0; } + +#ifdef CONFIG_PROC_PID_ARCH_STATUS +/* + * Report the amount of time elapsed in millisecond since last AVX512 + * use in the task. + */ +static void avx512_status(struct seq_file *m, struct task_struct *task) +{ + unsigned long timestamp = READ_ONCE(task->thread.fpu.avx512_timestamp); + long delta; + + if (!timestamp) { + /* + * Report -1 if no AVX512 usage + */ + delta = -1; + } else { + delta = (long)(jiffies - timestamp); + /* + * Cap to LONG_MAX if time difference > LONG_MAX + */ + if (delta < 0) + delta = LONG_MAX; + delta = jiffies_to_msecs(delta); + } + + seq_put_decimal_ll(m, "AVX512_elapsed_ms:\t", delta); + seq_putc(m, '\n'); +} + +/* + * Report architecture specific information + */ +int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + /* + * Report AVX512 state if the processor and build option supported. + */ + if (cpu_feature_enabled(X86_FEATURE_AVX512F)) + avx512_status(m, task); + + return 0; +} +#endif /* CONFIG_PROC_PID_ARCH_STATUS */ |
