diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-22 16:41:22 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-22 16:41:22 (GMT) |
commit | 35cb8d9e18c0bb33b90d7e574abadbe23b65427d (patch) | |
tree | 7bf2ce00ce1203a54ad5ace4f707a10f4fe0b14b /arch/x86/kernel | |
parent | 02c502566ef505d0469fa27567f48766c1f5f7af (diff) | |
parent | 1361b83a13d4d92e53fbb6c877528713e118b821 (diff) | |
download | linux-fsl-qoriq-35cb8d9e18c0bb33b90d7e574abadbe23b65427d.tar.xz |
Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/fpu changes from Ingo Molnar.
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
i387: Split up <asm/i387.h> into exported and internal interfaces
i387: Uninline the generic FP helpers that we expose to kernel modules
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/cpu/common.c | 3 | ||||
-rw-r--r-- | arch/x86/kernel/i387.c | 83 | ||||
-rw-r--r-- | arch/x86/kernel/process.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/process_32.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/process_64.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/ptrace.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/signal.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/traps.c | 1 | ||||
-rw-r--r-- | arch/x86/kernel/xsave.c | 1 |
9 files changed, 90 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index b3e0081..ade9c79 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -28,6 +28,7 @@ #include <asm/apic.h> #include <asm/desc.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mtrr.h> #include <linux/numa.h> #include <asm/asm.h> @@ -1045,7 +1046,6 @@ DEFINE_PER_CPU(char *, irq_stack_ptr) = DEFINE_PER_CPU(unsigned int, irq_count) = -1; DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); -EXPORT_PER_CPU_SYMBOL(fpu_owner_task); /* * Special IST stacks which the CPU switches to when it calls @@ -1115,7 +1115,6 @@ void debug_stack_reset(void) DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); -EXPORT_PER_CPU_SYMBOL(fpu_owner_task); #ifdef CONFIG_CC_STACKPROTECTOR DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 739d859..7734bcb 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -16,6 +16,7 @@ #include <asm/uaccess.h> #include <asm/ptrace.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/user.h> #ifdef CONFIG_X86_64 @@ -32,6 +33,86 @@ # define user32_fxsr_struct user_fxsr_struct #endif +/* + * Were we in an interrupt that interrupted kernel mode? + * + * We can do a kernel_fpu_begin/end() pair *ONLY* if that + * pair does nothing at all: the thread must not have fpu (so + * that we don't try to save the FPU state), and TS must + * be set (so that the clts/stts pair does nothing that is + * visible in the interrupted kernel thread). + */ +static inline bool interrupted_kernel_fpu_idle(void) +{ + return !__thread_has_fpu(current) && + (read_cr0() & X86_CR0_TS); +} + +/* + * Were we in user mode (or vm86 mode) when we were + * interrupted? + * + * Doing kernel_fpu_begin/end() is ok if we are running + * in an interrupt context from user mode - we'll just + * save the FPU state as required. + */ +static inline bool interrupted_user_mode(void) +{ + struct pt_regs *regs = get_irq_regs(); + return regs && user_mode_vm(regs); +} + +/* + * Can we use the FPU in kernel mode with the + * whole "kernel_fpu_begin/end()" sequence? + * + * It's always ok in process context (ie "not interrupt") + * but it is sometimes ok even from an irq. + */ +bool irq_fpu_usable(void) +{ + return !in_interrupt() || + interrupted_user_mode() || + interrupted_kernel_fpu_idle(); +} +EXPORT_SYMBOL(irq_fpu_usable); + +void kernel_fpu_begin(void) +{ + struct task_struct *me = current; + + WARN_ON_ONCE(!irq_fpu_usable()); + preempt_disable(); + if (__thread_has_fpu(me)) { + __save_init_fpu(me); + __thread_clear_has_fpu(me); + /* We do 'stts()' in kernel_fpu_end() */ + } else { + percpu_write(fpu_owner_task, NULL); + clts(); + } +} +EXPORT_SYMBOL(kernel_fpu_begin); + +void kernel_fpu_end(void) +{ + stts(); + preempt_enable(); +} +EXPORT_SYMBOL(kernel_fpu_end); + +void unlazy_fpu(struct task_struct *tsk) +{ + preempt_disable(); + if (__thread_has_fpu(tsk)) { + __save_init_fpu(tsk); + __thread_fpu_end(tsk); + } else + tsk->fpu_counter = 0; + preempt_enable(); +} +EXPORT_SYMBOL(unlazy_fpu); + #ifdef CONFIG_MATH_EMULATION # define HAVE_HWFP (boot_cpu_data.hard_math) #else @@ -44,7 +125,7 @@ EXPORT_SYMBOL_GPL(xstate_size); unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32); static struct i387_fxsave_struct fx_scratch __cpuinitdata; -void __cpuinit mxcsr_feature_mask_init(void) +static void __cpuinit mxcsr_feature_mask_init(void) { unsigned long mask = 0; diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 44eefde..14baf78 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -21,6 +21,7 @@ #include <asm/idle.h> #include <asm/uaccess.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/debugreg.h> struct kmem_cache *task_xstate_cachep; diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 49888fe..9d7d484 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -45,6 +45,7 @@ #include <asm/ldt.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/desc.h> #ifdef CONFIG_MATH_EMULATION #include <asm/math_emu.h> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 442e7bf..292da13 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -43,6 +43,7 @@ #include <asm/system.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mmu_context.h> #include <asm/prctl.h> #include <asm/desc.h> diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 5026738..78f05e4 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -27,6 +27,7 @@ #include <asm/system.h> #include <asm/processor.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/debugreg.h> #include <asm/ldt.h> #include <asm/desc.h> diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 46a01bdc..25edcfc 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -24,6 +24,7 @@ #include <asm/processor.h> #include <asm/ucontext.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/vdso.h> #include <asm/mce.h> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 4bbe04d..ec61d4c 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -54,6 +54,7 @@ #include <asm/traps.h> #include <asm/desc.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mce.h> #include <asm/mach_traps.h> diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index 7110911..e62728e 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -6,6 +6,7 @@ #include <linux/bootmem.h> #include <linux/compat.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #ifdef CONFIG_IA32_EMULATION #include <asm/sigcontext32.h> #endif |