* [PATCH 0/12] x86 FPU cleanups (v2)
@ 2010-09-04 1:17 Brian Gerst
2010-09-04 1:17 ` [PATCH 01/12] x86: Use correct type for %cr4 Brian Gerst
` (12 more replies)
0 siblings, 13 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
This patch set cleans up and merges the 32-bit and 64-bit FPU code.
v2:
- Don't write to %cr4 unless some bits are set
- Reworked the fpu_save_init() merge
[PATCH 01/12] x86: Use correct type for %cr4
[PATCH 02/12] x86: Merge fpu_init()
[PATCH 03/12] x86: Merge tolerant_fwait()
[PATCH 04/12] x86: Merge __save_init_fpu()
[PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU
[PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr()
[PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor
[PATCH 08/12] x86-32: Remove math_emulate stub
[PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code.
[PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros
[PATCH 11/12] x86-32: Rewrite fpu_save_init()
[PATCH 12/12] x86: Merge fpu_save_init()
arch/x86/include/asm/i387.h | 195 ++++++++++---------------------------
arch/x86/include/asm/processor.h | 4 +-
arch/x86/kernel/cpu/common.c | 7 --
arch/x86/kernel/i387.c | 52 +++++------
arch/x86/kernel/process_64.c | 2 +-
arch/x86/kernel/traps.c | 35 +------
6 files changed, 84 insertions(+), 211 deletions(-)
^ permalink raw reply [flat|nested] 40+ messages in thread
* [PATCH 01/12] x86: Use correct type for %cr4
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:45 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 02/12] x86: Merge fpu_init() Brian Gerst
` (11 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
%cr4 is 64-bit in 64-bit mode (although the upper 32-bits are currently reserved).
Use unsigned long for the temporary variable to get the right size.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/processor.h | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 325b7bd..396b80f 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -602,7 +602,7 @@ extern unsigned long mmu_cr4_features;
static inline void set_in_cr4(unsigned long mask)
{
- unsigned cr4;
+ unsigned long cr4;
mmu_cr4_features |= mask;
cr4 = read_cr4();
@@ -612,7 +612,7 @@ static inline void set_in_cr4(unsigned long mask)
static inline void clear_in_cr4(unsigned long mask)
{
- unsigned cr4;
+ unsigned long cr4;
mmu_cr4_features &= ~mask;
cr4 = read_cr4();
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 02/12] x86: Merge fpu_init()
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
2010-09-04 1:17 ` [PATCH 01/12] x86: Use correct type for %cr4 Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:45 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 03/12] x86: Merge tolerant_fwait() Brian Gerst
` (10 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Make fpu_init() handle 32-bit setup.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/kernel/cpu/common.c | 7 -------
arch/x86/kernel/i387.c | 30 ++++++++++++++----------------
arch/x86/kernel/traps.c | 12 ------------
3 files changed, 14 insertions(+), 35 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 490dac6..f9e23e8 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1264,13 +1264,6 @@ void __cpuinit cpu_init(void)
clear_all_debug_regs();
dbg_restore_debug_regs();
- /*
- * Force FPU initialization:
- */
- current_thread_info()->status = 0;
- clear_used_math();
- mxcsr_feature_mask_init();
-
fpu_init();
xsave_init();
}
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index a46cb35..1f082f3 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -80,7 +80,6 @@ static void __cpuinit init_thread_xstate(void)
#endif
}
-#ifdef CONFIG_X86_64
/*
* Called at bootup to set up the initial FPU state that is later cloned
* into all processes.
@@ -88,12 +87,21 @@ static void __cpuinit init_thread_xstate(void)
void __cpuinit fpu_init(void)
{
- unsigned long oldcr0 = read_cr0();
-
- set_in_cr4(X86_CR4_OSFXSR);
- set_in_cr4(X86_CR4_OSXMMEXCPT);
+ unsigned long cr0;
+ unsigned long cr4_mask = 0;
- write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
+ if (cpu_has_fxsr)
+ cr4_mask |= X86_CR4_OSFXSR;
+ if (cpu_has_xmm)
+ cr4_mask |= X86_CR4_OSXMMEXCPT;
+ if (cr4_mask)
+ set_in_cr4(cr4_mask);
+
+ cr0 = read_cr0();
+ cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
+ if (!HAVE_HWFP)
+ cr0 |= X86_CR0_EM;
+ write_cr0(cr0);
if (!smp_processor_id())
init_thread_xstate();
@@ -104,16 +112,6 @@ void __cpuinit fpu_init(void)
clear_used_math();
}
-#else /* CONFIG_X86_64 */
-
-void __cpuinit fpu_init(void)
-{
- if (!smp_processor_id())
- init_thread_xstate();
-}
-
-#endif /* CONFIG_X86_32 */
-
void fpu_finit(struct fpu *fpu)
{
#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 60788de..d0029eb 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -881,18 +881,6 @@ void __init trap_init(void)
#endif
#ifdef CONFIG_X86_32
- if (cpu_has_fxsr) {
- printk(KERN_INFO "Enabling fast FPU save and restore... ");
- set_in_cr4(X86_CR4_OSFXSR);
- printk("done.\n");
- }
- if (cpu_has_xmm) {
- printk(KERN_INFO
- "Enabling unmasked SIMD FPU exception support... ");
- set_in_cr4(X86_CR4_OSXMMEXCPT);
- printk("done.\n");
- }
-
set_system_trap_gate(SYSCALL_VECTOR, &system_call);
set_bit(SYSCALL_VECTOR, used_vectors);
#endif
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 03/12] x86: Merge tolerant_fwait()
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
2010-09-04 1:17 ` [PATCH 01/12] x86: Use correct type for %cr4 Brian Gerst
2010-09-04 1:17 ` [PATCH 02/12] x86: Merge fpu_init() Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:46 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 04/12] x86: Merge __save_init_fpu() Brian Gerst
` (9 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Commit e2e75c91 merged the math exception handler, allowing both 32-bit
and 64-bit to handle math exceptions from kernel mode. Switch to using
the 64-bit version of tolerant_fwait() without fnclex, which simply
ignores the exception if one is still pending from userspace.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 19 ++++---------------
1 files changed, 4 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index a73a8d5..5d8f9a7 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -77,15 +77,6 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
}
#ifdef CONFIG_X86_64
-
-/* Ignore delayed exceptions from user space */
-static inline void tolerant_fwait(void)
-{
- asm volatile("1: fwait\n"
- "2:\n"
- _ASM_EXTABLE(1b, 2b));
-}
-
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
int err;
@@ -220,11 +211,6 @@ extern void finit_soft_fpu(struct i387_soft_struct *soft);
static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
#endif
-static inline void tolerant_fwait(void)
-{
- asm volatile("fnclex ; fwait");
-}
-
/* perform fxrstor iff the processor has extended states, otherwise frstor */
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
@@ -344,7 +330,10 @@ static inline void __unlazy_fpu(struct task_struct *tsk)
static inline void __clear_fpu(struct task_struct *tsk)
{
if (task_thread_info(tsk)->status & TS_USEDFPU) {
- tolerant_fwait();
+ /* Ignore delayed exceptions from user space */
+ asm volatile("1: fwait\n"
+ "2:\n"
+ _ASM_EXTABLE(1b, 2b));
task_thread_info(tsk)->status &= ~TS_USEDFPU;
stts();
}
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 04/12] x86: Merge __save_init_fpu()
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (2 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 03/12] x86: Merge tolerant_fwait() Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:47 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU Brian Gerst
` (8 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
__save_init_fpu() is identical for 32-bit and 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 11 ++---------
1 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 5d8f9a7..88065e3 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -197,12 +197,6 @@ static inline void fpu_save_init(struct fpu *fpu)
fpu_clear(fpu);
}
-static inline void __save_init_fpu(struct task_struct *tsk)
-{
- fpu_save_init(&tsk->thread.fpu);
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
-}
-
#else /* CONFIG_X86_32 */
#ifdef CONFIG_MATH_EMULATION
@@ -285,15 +279,14 @@ end:
;
}
+#endif /* CONFIG_X86_64 */
+
static inline void __save_init_fpu(struct task_struct *tsk)
{
fpu_save_init(&tsk->thread.fpu);
task_thread_info(tsk)->status &= ~TS_USEDFPU;
}
-
-#endif /* CONFIG_X86_64 */
-
static inline int fpu_fxrstor_checking(struct fpu *fpu)
{
return fxrstor_checking(&fpu->state->fxsave);
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (3 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 04/12] x86: Merge __save_init_fpu() Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:47 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr() Brian Gerst
` (7 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Consolidates code and fixes the below race for 64-bit.
commit 9fa2f37bfeb798728241cc4a19578ce6e4258f25
Author: torvalds <torvalds>
Date: Tue Sep 2 07:37:25 2003 +0000
Be a lot more careful about TS_USEDFPU and preemption
We had some races where we testecd (or set) TS_USEDFPU together
with sequences that depended on the setting (like clearing or
setting the TS flag in %cr0) and we could be preempted in between,
which screws up the FPU state, since preemption will itself change
USEDFPU and the TS flag.
This makes it a lot more explicit: the "internal" low-level FPU
functions ("__xxxx_fpu()") all require preemption to be disabled,
and the exported "real" functions will make sure that is the case.
One case - in __switch_to() - was switched to the non-preempt-safe
internal version, since the scheduler itself has already disabled
preemption.
BKrev: 3f5448b5WRiQuyzAlbajs3qoQjSobw
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 15 ---------------
arch/x86/kernel/process_64.c | 2 +-
2 files changed, 1 insertions(+), 16 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 88065e3..8b40a83 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -387,19 +387,6 @@ static inline void irq_ts_restore(int TS_state)
stts();
}
-#ifdef CONFIG_X86_64
-
-static inline void save_init_fpu(struct task_struct *tsk)
-{
- __save_init_fpu(tsk);
- stts();
-}
-
-#define unlazy_fpu __unlazy_fpu
-#define clear_fpu __clear_fpu
-
-#else /* CONFIG_X86_32 */
-
/*
* These disable preemption on their own and are safe
*/
@@ -425,8 +412,6 @@ static inline void clear_fpu(struct task_struct *tsk)
preempt_enable();
}
-#endif /* CONFIG_X86_64 */
-
/*
* i387 state interaction
*/
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 3d9ea53..b3d7a3a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -424,7 +424,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
load_TLS(next, cpu);
/* Must be after DS reload */
- unlazy_fpu(prev_p);
+ __unlazy_fpu(prev_p);
/* Make sure cpu is ready for new context */
if (preload_fpu)
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr()
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (4 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor Brian Gerst
` (6 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
While %ds still contains the userspace selector, %cs is KERNEL_CS at
this point. Always get %cs from pt_regs even for the current task.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/kernel/i387.c | 18 ++++++++----------
1 files changed, 8 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 1f082f3..966fdcb 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -384,19 +384,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
#ifdef CONFIG_X86_64
env->fip = fxsave->rip;
env->foo = fxsave->rdp;
+ /*
+ * should be actually ds/cs at fpu exception time, but
+ * that information is not available in 64bit mode.
+ */
+ env->fcs = task_pt_regs(tsk)->cs;
if (tsk == current) {
- /*
- * should be actually ds/cs at fpu exception time, but
- * that information is not available in 64bit mode.
- */
- asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
- asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
+ savesegment(ds, env->fos);
} else {
- struct pt_regs *regs = task_pt_regs(tsk);
-
- env->fos = 0xffff0000 | tsk->thread.ds;
- env->fcs = regs->cs;
+ env->fos = tsk->thread.ds;
}
+ env->fos |= 0xffff0000;
#else
env->fip = fxsave->fip;
env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (5 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr() Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
` (2 more replies)
2010-09-04 1:17 ` [PATCH 08/12] x86-32: Remove math_emulate stub Brian Gerst
` (5 subsequent siblings)
12 siblings, 3 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Use the "R" constraint (legacy register) instead of listing all the
possible registers. Clean up the comments as well.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 44 ++++++++++++++++--------------------------
1 files changed, 17 insertions(+), 27 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 8b40a83..768fcb2 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -81,6 +81,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
int err;
+ /* See comment in fxsave() below. */
asm volatile("1: rex64/fxrstor (%[fx])\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
@@ -89,11 +90,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err)
-#if 0 /* See comment in fxsave() below. */
- : [fx] "r" (fx), "m" (*fx), "0" (0));
-#else
- : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
-#endif
+ : [fx] "R" (fx), "m" (*fx), "0" (0));
return err;
}
@@ -140,6 +137,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
if (unlikely(err))
return -EFAULT;
+ /* See comment in fxsave() below. */
asm volatile("1: rex64/fxsave (%[fx])\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
@@ -148,11 +146,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err), "=m" (*fx)
-#if 0 /* See comment in fxsave() below. */
- : [fx] "r" (fx), "0" (0));
-#else
- : [fx] "cdaSDb" (fx), "0" (0));
-#endif
+ : [fx] "R" (fx), "0" (0));
if (unlikely(err) &&
__clear_user(fx, sizeof(struct i387_fxsave_struct)))
err = -EFAULT;
@@ -165,26 +159,22 @@ static inline void fpu_fxsave(struct fpu *fpu)
/* Using "rex64; fxsave %0" is broken because, if the memory operand
uses any extended registers for addressing, a second REX prefix
will be generated (to the assembler, rex64 followed by semicolon
- is a separate instruction), and hence the 64-bitness is lost. */
-#if 0
- /* Using "fxsaveq %0" would be the ideal choice, but is only supported
- starting with gas 2.16. */
- __asm__ __volatile__("fxsaveq %0"
- : "=m" (fpu->state->fxsave));
-#elif 0
- /* Using, as a workaround, the properly prefixed form below isn't
+ is a separate instruction), and hence the 64-bitness is lost.
+ Using "fxsaveq %0" would be the ideal choice, but is only supported
+ starting with gas 2.16.
+ asm volatile("fxsaveq %0"
+ : "=m" (fpu->state->fxsave));
+ Using, as a workaround, the properly prefixed form below isn't
accepted by any binutils version so far released, complaining that
the same type of prefix is used twice if an extended register is
- needed for addressing (fix submitted to mainline 2005-11-21). */
- __asm__ __volatile__("rex64/fxsave %0"
- : "=m" (fpu->state->fxsave));
-#else
- /* This, however, we can work around by forcing the compiler to select
+ needed for addressing (fix submitted to mainline 2005-11-21).
+ asm volatile("rex64/fxsave %0"
+ : "=m" (fpu->state->fxsave));
+ This, however, we can work around by forcing the compiler to select
an addressing mode that doesn't require extended registers. */
- __asm__ __volatile__("rex64/fxsave (%1)"
- : "=m" (fpu->state->fxsave)
- : "cdaSDb" (&fpu->state->fxsave));
-#endif
+ asm volatile("rex64/fxsave (%[fx])"
+ : "=m" (fpu->state->fxsave)
+ : [fx] "R" (&fpu->state->fxsave));
}
static inline void fpu_save_init(struct fpu *fpu)
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 08/12] x86-32: Remove math_emulate stub
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (6 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
2010-09-10 1:48 ` [tip:x86/fpu] x86-32, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code Brian Gerst
` (4 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
check_fpu() in bugs.c halts boot if no FPU is found and math emulation
isn't enabled. Therefore this stub will never be used.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/kernel/traps.c | 23 ++++++-----------------
1 files changed, 6 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index d0029eb..d439685 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -776,21 +776,10 @@ asmlinkage void math_state_restore(void)
}
EXPORT_SYMBOL_GPL(math_state_restore);
-#ifndef CONFIG_MATH_EMULATION
-void math_emulate(struct math_emu_info *info)
-{
- printk(KERN_EMERG
- "math-emulation not enabled and no coprocessor found.\n");
- printk(KERN_EMERG "killing %s.\n", current->comm);
- force_sig(SIGFPE, current);
- schedule();
-}
-#endif /* CONFIG_MATH_EMULATION */
-
dotraplinkage void __kprobes
do_device_not_available(struct pt_regs *regs, long error_code)
{
-#ifdef CONFIG_X86_32
+#ifdef CONFIG_MATH_EMULATION
if (read_cr0() & X86_CR0_EM) {
struct math_emu_info info = { };
@@ -798,12 +787,12 @@ do_device_not_available(struct pt_regs *regs, long error_code)
info.regs = regs;
math_emulate(&info);
- } else {
- math_state_restore(); /* interrupts still off */
- conditional_sti(regs);
+ return;
}
-#else
- math_state_restore();
+#endif
+ math_state_restore(); /* interrupts still off */
+#ifdef CONFIG_X86_32
+ conditional_sti(regs);
#endif
}
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code.
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (7 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 08/12] x86-32: Remove math_emulate stub Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:49 ` Pekka Enberg
2010-09-10 1:48 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros Brian Gerst
` (3 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Remove ifdefs for code that the compiler can optimize away on 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 12 ++++++------
arch/x86/kernel/i387.c | 4 ----
2 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 768fcb2..42b507e 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -55,6 +55,12 @@ extern int save_i387_xstate_ia32(void __user *buf);
extern int restore_i387_xstate_ia32(void __user *buf);
#endif
+#ifdef CONFIG_MATH_EMULATION
+extern void finit_soft_fpu(struct i387_soft_struct *soft);
+#else
+static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
+#endif
+
#define X87_FSW_ES (1 << 7) /* Exception Summary */
static __always_inline __pure bool use_xsaveopt(void)
@@ -189,12 +195,6 @@ static inline void fpu_save_init(struct fpu *fpu)
#else /* CONFIG_X86_32 */
-#ifdef CONFIG_MATH_EMULATION
-extern void finit_soft_fpu(struct i387_soft_struct *soft);
-#else
-static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
-#endif
-
/* perform fxrstor iff the processor has extended states, otherwise frstor */
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 966fdcb..9238309 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -74,10 +74,8 @@ static void __cpuinit init_thread_xstate(void)
if (cpu_has_fxsr)
xstate_size = sizeof(struct i387_fxsave_struct);
-#ifdef CONFIG_X86_32
else
xstate_size = sizeof(struct i387_fsave_struct);
-#endif
}
/*
@@ -114,12 +112,10 @@ void __cpuinit fpu_init(void)
void fpu_finit(struct fpu *fpu)
{
-#ifdef CONFIG_X86_32
if (!HAVE_HWFP) {
finit_soft_fpu(&fpu->state->soft);
return;
}
-#endif
if (cpu_has_fxsr) {
struct i387_fxsave_struct *fx = &fpu->state->fxsave;
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (8 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:49 ` Pekka Enberg
2010-09-10 1:49 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 11/12] x86-32: Rewrite fpu_save_init() Brian Gerst
` (2 subsequent siblings)
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
The PSHUFB_XMM5_* macros are no longer used.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 42b507e..907967e 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -465,7 +465,4 @@ extern void fpu_finit(struct fpu *fpu);
#endif /* __ASSEMBLY__ */
-#define PSHUFB_XMM5_XMM0 .byte 0x66, 0x0f, 0x38, 0x00, 0xc5
-#define PSHUFB_XMM5_XMM6 .byte 0x66, 0x0f, 0x38, 0x00, 0xf5
-
#endif /* _ASM_X86_I387_H */
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 11/12] x86-32: Rewrite fpu_save_init()
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (9 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:49 ` [tip:x86/fpu] x86-32, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 12/12] x86: Merge fpu_save_init() Brian Gerst
2010-09-04 6:45 ` [PATCH 0/12] x86 FPU cleanups (v2) Pekka Enberg
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Rewrite fpu_save_init() to prepare for merging with 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 47 ++++++++++++++++++++----------------------
1 files changed, 22 insertions(+), 25 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 907967e..b45abef 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -73,6 +73,11 @@ static __always_inline __pure bool use_xsave(void)
return static_cpu_has(X86_FEATURE_XSAVE);
}
+static __always_inline __pure bool use_fxsr(void)
+{
+ return static_cpu_has(X86_FEATURE_FXSR);
+}
+
extern void __sanitize_i387_state(struct task_struct *);
static inline void sanitize_i387_state(struct task_struct *tsk)
@@ -211,6 +216,12 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
return 0;
}
+static inline void fpu_fxsave(struct fpu *fpu)
+{
+ asm volatile("fxsave %[fx]"
+ : [fx] "=m" (fpu->state->fxsave));
+}
+
/* We need a safe address that is cheap to find and that is already
in L1 during context switch. The best choices are unfortunately
different for UP and SMP */
@@ -226,36 +237,24 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
static inline void fpu_save_init(struct fpu *fpu)
{
if (use_xsave()) {
- struct xsave_struct *xstate = &fpu->state->xsave;
- struct i387_fxsave_struct *fx = &fpu->state->fxsave;
-
fpu_xsave(fpu);
/*
* xsave header may indicate the init state of the FP.
*/
- if (!(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
- goto end;
-
- if (unlikely(fx->swd & X87_FSW_ES))
- asm volatile("fnclex");
-
- /*
- * we can do a simple return here or be paranoid :)
- */
- goto clear_state;
+ if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP))
+ return;
+ } else if (use_fxsr()) {
+ fpu_fxsave(fpu);
+ } else {
+ asm volatile("fsave %[fx]; fwait"
+ : [fx] "=m" (fpu->state->fsave));
+ return;
}
- /* Use more nops than strictly needed in case the compiler
- varies code */
- alternative_input(
- "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
- "fxsave %[fx]\n"
- "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
- X86_FEATURE_FXSR,
- [fx] "m" (fpu->state->fxsave),
- [fsw] "m" (fpu->state->fxsave.swd) : "memory");
-clear_state:
+ if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES))
+ asm volatile("fnclex");
+
/* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
is pending. Clear the x87 state here by setting it to fixed
values. safe_address is a random variable that should be in L1 */
@@ -265,8 +264,6 @@ clear_state:
"fildl %[addr]", /* set F?P to defined value */
X86_FEATURE_FXSAVE_LEAK,
[addr] "m" (safe_address));
-end:
- ;
}
#endif /* CONFIG_X86_64 */
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [PATCH 12/12] x86: Merge fpu_save_init()
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (10 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 11/12] x86-32: Rewrite fpu_save_init() Brian Gerst
@ 2010-09-04 1:17 ` Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:50 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 6:45 ` [PATCH 0/12] x86 FPU cleanups (v2) Pekka Enberg
12 siblings, 2 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-04 1:17 UTC (permalink / raw)
To: hpa; +Cc: x86, linux-kernel, penberg
Make 64-bit use the 32-bit version of fpu_save_init(). Remove
unused clear_fpu_state().
Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
arch/x86/include/asm/i387.h | 48 +++---------------------------------------
1 files changed, 4 insertions(+), 44 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index b45abef..9a28b3c 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -105,36 +105,6 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
return err;
}
-/* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception
- is pending. Clear the x87 state here by setting it to fixed
- values. The kernel data segment can be sometimes 0 and sometimes
- new user value. Both should be ok.
- Use the PDA as safe address because it should be already in L1. */
-static inline void fpu_clear(struct fpu *fpu)
-{
- struct xsave_struct *xstate = &fpu->state->xsave;
- struct i387_fxsave_struct *fx = &fpu->state->fxsave;
-
- /*
- * xsave header may indicate the init state of the FP.
- */
- if (use_xsave() &&
- !(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
- return;
-
- if (unlikely(fx->swd & X87_FSW_ES))
- asm volatile("fnclex");
- alternative_input(ASM_NOP8 ASM_NOP2,
- " emms\n" /* clear stack tags */
- " fildl %%gs:0", /* load to clear state */
- X86_FEATURE_FXSAVE_LEAK);
-}
-
-static inline void clear_fpu_state(struct task_struct *tsk)
-{
- fpu_clear(&tsk->thread.fpu);
-}
-
static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
{
int err;
@@ -188,16 +158,6 @@ static inline void fpu_fxsave(struct fpu *fpu)
: [fx] "R" (&fpu->state->fxsave));
}
-static inline void fpu_save_init(struct fpu *fpu)
-{
- if (use_xsave())
- fpu_xsave(fpu);
- else
- fpu_fxsave(fpu);
-
- fpu_clear(fpu);
-}
-
#else /* CONFIG_X86_32 */
/* perform fxrstor iff the processor has extended states, otherwise frstor */
@@ -222,6 +182,8 @@ static inline void fpu_fxsave(struct fpu *fpu)
: [fx] "=m" (fpu->state->fxsave));
}
+#endif /* CONFIG_X86_64 */
+
/* We need a safe address that is cheap to find and that is already
in L1 during context switch. The best choices are unfortunately
different for UP and SMP */
@@ -259,15 +221,13 @@ static inline void fpu_save_init(struct fpu *fpu)
is pending. Clear the x87 state here by setting it to fixed
values. safe_address is a random variable that should be in L1 */
alternative_input(
- GENERIC_NOP8 GENERIC_NOP2,
+ ASM_NOP8 ASM_NOP2,
"emms\n\t" /* clear stack tags */
- "fildl %[addr]", /* set F?P to defined value */
+ "fildl %P[addr]", /* set F?P to defined value */
X86_FEATURE_FXSAVE_LEAK,
[addr] "m" (safe_address));
}
-#endif /* CONFIG_X86_64 */
-
static inline void __save_init_fpu(struct task_struct *tsk)
{
fpu_save_init(&tsk->thread.fpu);
--
1.7.2.2
^ permalink raw reply related [flat|nested] 40+ messages in thread
* Re: [PATCH 0/12] x86 FPU cleanups (v2)
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
` (11 preceding siblings ...)
2010-09-04 1:17 ` [PATCH 12/12] x86: Merge fpu_save_init() Brian Gerst
@ 2010-09-04 6:45 ` Pekka Enberg
12 siblings, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:45 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> This patch set cleans up and merges the 32-bit and 64-bit FPU code.
Oh, you seem to have dropped all of my previous ACKs.
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 01/12] x86: Use correct type for %cr4
2010-09-04 1:17 ` [PATCH 01/12] x86: Use correct type for %cr4 Brian Gerst
@ 2010-09-04 6:45 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:45 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> %cr4 is 64-bit in 64-bit mode (although the upper 32-bits are currently reserved).
> Use unsigned long for the temporary variable to get the right size.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 02/12] x86: Merge fpu_init()
2010-09-04 1:17 ` [PATCH 02/12] x86: Merge fpu_init() Brian Gerst
@ 2010-09-04 6:45 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:45 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Make fpu_init() handle 32-bit setup.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 03/12] x86: Merge tolerant_fwait()
2010-09-04 1:17 ` [PATCH 03/12] x86: Merge tolerant_fwait() Brian Gerst
@ 2010-09-04 6:46 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:46 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Commit e2e75c91 merged the math exception handler, allowing both 32-bit
> and 64-bit to handle math exceptions from kernel mode. Switch to using
> the 64-bit version of tolerant_fwait() without fnclex, which simply
> ignores the exception if one is still pending from userspace.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 04/12] x86: Merge __save_init_fpu()
2010-09-04 1:17 ` [PATCH 04/12] x86: Merge __save_init_fpu() Brian Gerst
@ 2010-09-04 6:47 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:47 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> __save_init_fpu() is identical for 32-bit and 64-bit.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU
2010-09-04 1:17 ` [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU Brian Gerst
@ 2010-09-04 6:47 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:47 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Consolidates code and fixes the below race for 64-bit.
>
> commit 9fa2f37bfeb798728241cc4a19578ce6e4258f25
> Author: torvalds<torvalds>
> Date: Tue Sep 2 07:37:25 2003 +0000
>
> Be a lot more careful about TS_USEDFPU and preemption
>
> We had some races where we testecd (or set) TS_USEDFPU together
> with sequences that depended on the setting (like clearing or
> setting the TS flag in %cr0) and we could be preempted in between,
> which screws up the FPU state, since preemption will itself change
> USEDFPU and the TS flag.
>
> This makes it a lot more explicit: the "internal" low-level FPU
> functions ("__xxxx_fpu()") all require preemption to be disabled,
> and the exported "real" functions will make sure that is the case.
>
> One case - in __switch_to() - was switched to the non-preempt-safe
> internal version, since the scheduler itself has already disabled
> preemption.
>
> BKrev: 3f5448b5WRiQuyzAlbajs3qoQjSobw
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor
2010-09-04 1:17 ` [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor Brian Gerst
@ 2010-09-04 6:48 ` Pekka Enberg
2010-09-09 21:22 ` H. Peter Anvin
2010-09-10 1:48 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2 siblings, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:48 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Use the "R" constraint (legacy register) instead of listing all the
> possible registers. Clean up the comments as well.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 08/12] x86-32: Remove math_emulate stub
2010-09-04 1:17 ` [PATCH 08/12] x86-32: Remove math_emulate stub Brian Gerst
@ 2010-09-04 6:48 ` Pekka Enberg
2010-09-10 1:48 ` [tip:x86/fpu] x86-32, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:48 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> check_fpu() in bugs.c halts boot if no FPU is found and math emulation
> isn't enabled. Therefore this stub will never be used.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code.
2010-09-04 1:17 ` [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code Brian Gerst
@ 2010-09-04 6:49 ` Pekka Enberg
2010-09-10 1:48 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:49 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Remove ifdefs for code that the compiler can optimize away on 64-bit.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros
2010-09-04 1:17 ` [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros Brian Gerst
@ 2010-09-04 6:49 ` Pekka Enberg
2010-09-10 1:49 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:49 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> The PSHUFB_XMM5_* macros are no longer used.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 11/12] x86-32: Rewrite fpu_save_init()
2010-09-04 1:17 ` [PATCH 11/12] x86-32: Rewrite fpu_save_init() Brian Gerst
@ 2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:49 ` [tip:x86/fpu] x86-32, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:51 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Rewrite fpu_save_init() to prepare for merging with 64-bit.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 12/12] x86: Merge fpu_save_init()
2010-09-04 1:17 ` [PATCH 12/12] x86: Merge fpu_save_init() Brian Gerst
@ 2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:50 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:51 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> Make 64-bit use the 32-bit version of fpu_save_init(). Remove
> unused clear_fpu_state().
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr()
2010-09-04 1:17 ` [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr() Brian Gerst
@ 2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: Pekka Enberg @ 2010-09-04 6:51 UTC (permalink / raw)
To: Brian Gerst; +Cc: hpa, x86, linux-kernel
On 4.9.2010 4.17, Brian Gerst wrote:
> While %ds still contains the userspace selector, %cs is KERNEL_CS at
> this point. Always get %cs from pt_regs even for the current task.
>
> Signed-off-by: Brian Gerst<brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor
2010-09-04 1:17 ` [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
@ 2010-09-09 21:22 ` H. Peter Anvin
2010-09-09 23:43 ` Brian Gerst
2010-09-10 1:48 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2 siblings, 1 reply; 40+ messages in thread
From: H. Peter Anvin @ 2010-09-09 21:22 UTC (permalink / raw)
To: Brian Gerst; +Cc: x86, linux-kernel, penberg
On 09/03/2010 06:17 PM, Brian Gerst wrote:
> Use the "R" constraint (legacy register) instead of listing all the
> possible registers. Clean up the comments as well.
>
> Signed-off-by: Brian Gerst <brgerst@gmail.com>
Hi Brian,
Have you tested this on *old* versions of gcc? Since the whole point of
that butt-ugly code sequence is to support now-historic versions of
binutils, we need to make sure that "R" was supposed on the
corresponding gcc versions...
-hpa
^ permalink raw reply [flat|nested] 40+ messages in thread
* Re: [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor
2010-09-09 21:22 ` H. Peter Anvin
@ 2010-09-09 23:43 ` Brian Gerst
0 siblings, 0 replies; 40+ messages in thread
From: Brian Gerst @ 2010-09-09 23:43 UTC (permalink / raw)
To: H. Peter Anvin; +Cc: x86, linux-kernel, penberg
On Thu, Sep 9, 2010 at 5:22 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 09/03/2010 06:17 PM, Brian Gerst wrote:
>> Use the "R" constraint (legacy register) instead of listing all the
>> possible registers. Clean up the comments as well.
>>
>> Signed-off-by: Brian Gerst <brgerst@gmail.com>
>
> Hi Brian,
>
> Have you tested this on *old* versions of gcc? Since the whole point of
> that butt-ugly code sequence is to support now-historic versions of
> binutils, we need to make sure that "R" was supposed on the
> corresponding gcc versions...
It's documented as far back as the GCC 3.1.1 manual. Whether it
actually works or not on older compilers I have no way of testing.
--
Brian Gerst
^ permalink raw reply [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86: Use correct type for %cr4
2010-09-04 1:17 ` [PATCH 01/12] x86: Use correct type for %cr4 Brian Gerst
2010-09-04 6:45 ` Pekka Enberg
@ 2010-09-10 1:46 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 2df7a6e9e8e67c19e5fe2eac3f2d2223b7bb4a7b
Gitweb: http://git.kernel.org/tip/2df7a6e9e8e67c19e5fe2eac3f2d2223b7bb4a7b
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:08 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:16:13 -0700
x86: Use correct type for %cr4
%cr4 is 64-bit in 64-bit mode (although the upper 32-bits are currently reserved).
Use unsigned long for the temporary variable to get the right size.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-2-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/processor.h | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 325b7bd..396b80f 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -602,7 +602,7 @@ extern unsigned long mmu_cr4_features;
static inline void set_in_cr4(unsigned long mask)
{
- unsigned cr4;
+ unsigned long cr4;
mmu_cr4_features |= mask;
cr4 = read_cr4();
@@ -612,7 +612,7 @@ static inline void set_in_cr4(unsigned long mask)
static inline void clear_in_cr4(unsigned long mask)
{
- unsigned cr4;
+ unsigned long cr4;
mmu_cr4_features &= ~mask;
cr4 = read_cr4();
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86, fpu: Merge fpu_init()
2010-09-04 1:17 ` [PATCH 02/12] x86: Merge fpu_init() Brian Gerst
2010-09-04 6:45 ` Pekka Enberg
@ 2010-09-10 1:46 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 6ac8bac2684235f4caf22a410549c582aa7327d6
Gitweb: http://git.kernel.org/tip/6ac8bac2684235f4caf22a410549c582aa7327d6
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:09 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:16:20 -0700
x86, fpu: Merge fpu_init()
Make fpu_init() handle 32-bit setup.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-3-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/kernel/cpu/common.c | 7 -------
arch/x86/kernel/i387.c | 30 ++++++++++++++----------------
arch/x86/kernel/traps.c | 12 ------------
3 files changed, 14 insertions(+), 35 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 490dac6..f9e23e8 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1264,13 +1264,6 @@ void __cpuinit cpu_init(void)
clear_all_debug_regs();
dbg_restore_debug_regs();
- /*
- * Force FPU initialization:
- */
- current_thread_info()->status = 0;
- clear_used_math();
- mxcsr_feature_mask_init();
-
fpu_init();
xsave_init();
}
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 2605c50..8216651 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -85,7 +85,6 @@ static void __cpuinit init_thread_xstate(void)
#endif
}
-#ifdef CONFIG_X86_64
/*
* Called at bootup to set up the initial FPU state that is later cloned
* into all processes.
@@ -93,12 +92,21 @@ static void __cpuinit init_thread_xstate(void)
void __cpuinit fpu_init(void)
{
- unsigned long oldcr0 = read_cr0();
-
- set_in_cr4(X86_CR4_OSFXSR);
- set_in_cr4(X86_CR4_OSXMMEXCPT);
+ unsigned long cr0;
+ unsigned long cr4_mask = 0;
- write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
+ if (cpu_has_fxsr)
+ cr4_mask |= X86_CR4_OSFXSR;
+ if (cpu_has_xmm)
+ cr4_mask |= X86_CR4_OSXMMEXCPT;
+ if (cr4_mask)
+ set_in_cr4(cr4_mask);
+
+ cr0 = read_cr0();
+ cr0 &= ~(X86_CR0_TS|X86_CR0_EM); /* clear TS and EM */
+ if (!HAVE_HWFP)
+ cr0 |= X86_CR0_EM;
+ write_cr0(cr0);
if (!smp_processor_id())
init_thread_xstate();
@@ -109,16 +117,6 @@ void __cpuinit fpu_init(void)
clear_used_math();
}
-#else /* CONFIG_X86_64 */
-
-void __cpuinit fpu_init(void)
-{
- if (!smp_processor_id())
- init_thread_xstate();
-}
-
-#endif /* CONFIG_X86_32 */
-
void fpu_finit(struct fpu *fpu)
{
#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 60788de..d0029eb 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -881,18 +881,6 @@ void __init trap_init(void)
#endif
#ifdef CONFIG_X86_32
- if (cpu_has_fxsr) {
- printk(KERN_INFO "Enabling fast FPU save and restore... ");
- set_in_cr4(X86_CR4_OSFXSR);
- printk("done.\n");
- }
- if (cpu_has_xmm) {
- printk(KERN_INFO
- "Enabling unmasked SIMD FPU exception support... ");
- set_in_cr4(X86_CR4_OSXMMEXCPT);
- printk("done.\n");
- }
-
set_system_trap_gate(SYSCALL_VECTOR, &system_call);
set_bit(SYSCALL_VECTOR, used_vectors);
#endif
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86, fpu: Merge tolerant_fwait()
2010-09-04 1:17 ` [PATCH 03/12] x86: Merge tolerant_fwait() Brian Gerst
2010-09-04 6:46 ` Pekka Enberg
@ 2010-09-10 1:46 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 51115d4d45700fc7c08306f7ba6e68551f526ae5
Gitweb: http://git.kernel.org/tip/51115d4d45700fc7c08306f7ba6e68551f526ae5
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:10 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:16:25 -0700
x86, fpu: Merge tolerant_fwait()
Commit e2e75c91 merged the math exception handler, allowing both 32-bit
and 64-bit to handle math exceptions from kernel mode. Switch to using
the 64-bit version of tolerant_fwait() without fnclex, which simply
ignores the exception if one is still pending from userspace.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-4-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 19 ++++---------------
1 files changed, 4 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index a73a8d5..5d8f9a7 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -77,15 +77,6 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
}
#ifdef CONFIG_X86_64
-
-/* Ignore delayed exceptions from user space */
-static inline void tolerant_fwait(void)
-{
- asm volatile("1: fwait\n"
- "2:\n"
- _ASM_EXTABLE(1b, 2b));
-}
-
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
int err;
@@ -220,11 +211,6 @@ extern void finit_soft_fpu(struct i387_soft_struct *soft);
static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
#endif
-static inline void tolerant_fwait(void)
-{
- asm volatile("fnclex ; fwait");
-}
-
/* perform fxrstor iff the processor has extended states, otherwise frstor */
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
@@ -344,7 +330,10 @@ static inline void __unlazy_fpu(struct task_struct *tsk)
static inline void __clear_fpu(struct task_struct *tsk)
{
if (task_thread_info(tsk)->status & TS_USEDFPU) {
- tolerant_fwait();
+ /* Ignore delayed exceptions from user space */
+ asm volatile("1: fwait\n"
+ "2:\n"
+ _ASM_EXTABLE(1b, 2b));
task_thread_info(tsk)->status &= ~TS_USEDFPU;
stts();
}
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86, fpu: Merge __save_init_fpu()
2010-09-04 1:17 ` [PATCH 04/12] x86: Merge __save_init_fpu() Brian Gerst
2010-09-04 6:47 ` Pekka Enberg
@ 2010-09-10 1:47 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:47 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: bfd946cb891800d408decaae268a3480775178a3
Gitweb: http://git.kernel.org/tip/bfd946cb891800d408decaae268a3480775178a3
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:11 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:16:30 -0700
x86, fpu: Merge __save_init_fpu()
__save_init_fpu() is identical for 32-bit and 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-5-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 11 ++---------
1 files changed, 2 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 5d8f9a7..88065e3 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -197,12 +197,6 @@ static inline void fpu_save_init(struct fpu *fpu)
fpu_clear(fpu);
}
-static inline void __save_init_fpu(struct task_struct *tsk)
-{
- fpu_save_init(&tsk->thread.fpu);
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
-}
-
#else /* CONFIG_X86_32 */
#ifdef CONFIG_MATH_EMULATION
@@ -285,15 +279,14 @@ end:
;
}
+#endif /* CONFIG_X86_64 */
+
static inline void __save_init_fpu(struct task_struct *tsk)
{
fpu_save_init(&tsk->thread.fpu);
task_thread_info(tsk)->status &= ~TS_USEDFPU;
}
-
-#endif /* CONFIG_X86_64 */
-
static inline int fpu_fxrstor_checking(struct fpu *fpu)
{
return fxrstor_checking(&fpu->state->fxsave);
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86-64, fpu: Disable preemption when using TS_USEDFPU
2010-09-04 1:17 ` [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU Brian Gerst
2010-09-04 6:47 ` Pekka Enberg
@ 2010-09-10 1:47 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:47 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: a4d4fbc7735bba6654b20f859135f9d3f8fe7f76
Gitweb: http://git.kernel.org/tip/a4d4fbc7735bba6654b20f859135f9d3f8fe7f76
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:12 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:16:45 -0700
x86-64, fpu: Disable preemption when using TS_USEDFPU
Consolidates code and fixes the below race for 64-bit.
commit 9fa2f37bfeb798728241cc4a19578ce6e4258f25
Author: torvalds <torvalds>
Date: Tue Sep 2 07:37:25 2003 +0000
Be a lot more careful about TS_USEDFPU and preemption
We had some races where we testecd (or set) TS_USEDFPU together
with sequences that depended on the setting (like clearing or
setting the TS flag in %cr0) and we could be preempted in between,
which screws up the FPU state, since preemption will itself change
USEDFPU and the TS flag.
This makes it a lot more explicit: the "internal" low-level FPU
functions ("__xxxx_fpu()") all require preemption to be disabled,
and the exported "real" functions will make sure that is the case.
One case - in __switch_to() - was switched to the non-preempt-safe
internal version, since the scheduler itself has already disabled
preemption.
BKrev: 3f5448b5WRiQuyzAlbajs3qoQjSobw
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-6-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 15 ---------------
arch/x86/kernel/process_64.c | 2 +-
2 files changed, 1 insertions(+), 16 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 88065e3..8b40a83 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -387,19 +387,6 @@ static inline void irq_ts_restore(int TS_state)
stts();
}
-#ifdef CONFIG_X86_64
-
-static inline void save_init_fpu(struct task_struct *tsk)
-{
- __save_init_fpu(tsk);
- stts();
-}
-
-#define unlazy_fpu __unlazy_fpu
-#define clear_fpu __clear_fpu
-
-#else /* CONFIG_X86_32 */
-
/*
* These disable preemption on their own and are safe
*/
@@ -425,8 +412,6 @@ static inline void clear_fpu(struct task_struct *tsk)
preempt_enable();
}
-#endif /* CONFIG_X86_64 */
-
/*
* i387 state interaction
*/
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 3d9ea53..b3d7a3a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -424,7 +424,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
load_TLS(next, cpu);
/* Must be after DS reload */
- unlazy_fpu(prev_p);
+ __unlazy_fpu(prev_p);
/* Make sure cpu is ready for new context */
if (preload_fpu)
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86-64, fpu: Fix %cs value in convert_from_fxsr()
2010-09-04 1:17 ` [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr() Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
@ 2010-09-10 1:47 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:47 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 10c11f304986a1f84201c2261a428701f9d2dffc
Gitweb: http://git.kernel.org/tip/10c11f304986a1f84201c2261a428701f9d2dffc
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:13 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:16:58 -0700
x86-64, fpu: Fix %cs value in convert_from_fxsr()
While %ds still contains the userspace selector, %cs is KERNEL_CS at
this point. Always get %cs from pt_regs even for the current task.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-7-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/kernel/i387.c | 18 ++++++++----------
1 files changed, 8 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 8216651..f3775f5 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -389,19 +389,17 @@ convert_from_fxsr(struct user_i387_ia32_struct *env, struct task_struct *tsk)
#ifdef CONFIG_X86_64
env->fip = fxsave->rip;
env->foo = fxsave->rdp;
+ /*
+ * should be actually ds/cs at fpu exception time, but
+ * that information is not available in 64bit mode.
+ */
+ env->fcs = task_pt_regs(tsk)->cs;
if (tsk == current) {
- /*
- * should be actually ds/cs at fpu exception time, but
- * that information is not available in 64bit mode.
- */
- asm("mov %%ds, %[fos]" : [fos] "=r" (env->fos));
- asm("mov %%cs, %[fcs]" : [fcs] "=r" (env->fcs));
+ savesegment(ds, env->fos);
} else {
- struct pt_regs *regs = task_pt_regs(tsk);
-
- env->fos = 0xffff0000 | tsk->thread.ds;
- env->fcs = regs->cs;
+ env->fos = tsk->thread.ds;
}
+ env->fos |= 0xffff0000;
#else
env->fip = fxsave->fip;
env->fcs = (u16) fxsave->fcs | ((u32) fxsave->fop << 16);
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86-64, fpu: Simplify constraints for fxsave/fxtstor
2010-09-04 1:17 ` [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
2010-09-09 21:22 ` H. Peter Anvin
@ 2010-09-10 1:48 ` tip-bot for Brian Gerst
2 siblings, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 820241356d6aa9a895fc10def15794a5a5bfcd98
Gitweb: http://git.kernel.org/tip/820241356d6aa9a895fc10def15794a5a5bfcd98
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:14 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:17:06 -0700
x86-64, fpu: Simplify constraints for fxsave/fxtstor
Use the "R" constraint (legacy register) instead of listing all the
possible registers. Clean up the comments as well.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-8-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 44 ++++++++++++++++--------------------------
1 files changed, 17 insertions(+), 27 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 8b40a83..768fcb2 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -81,6 +81,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
int err;
+ /* See comment in fxsave() below. */
asm volatile("1: rex64/fxrstor (%[fx])\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
@@ -89,11 +90,7 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err)
-#if 0 /* See comment in fxsave() below. */
- : [fx] "r" (fx), "m" (*fx), "0" (0));
-#else
- : [fx] "cdaSDb" (fx), "m" (*fx), "0" (0));
-#endif
+ : [fx] "R" (fx), "m" (*fx), "0" (0));
return err;
}
@@ -140,6 +137,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
if (unlikely(err))
return -EFAULT;
+ /* See comment in fxsave() below. */
asm volatile("1: rex64/fxsave (%[fx])\n\t"
"2:\n"
".section .fixup,\"ax\"\n"
@@ -148,11 +146,7 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
".previous\n"
_ASM_EXTABLE(1b, 3b)
: [err] "=r" (err), "=m" (*fx)
-#if 0 /* See comment in fxsave() below. */
- : [fx] "r" (fx), "0" (0));
-#else
- : [fx] "cdaSDb" (fx), "0" (0));
-#endif
+ : [fx] "R" (fx), "0" (0));
if (unlikely(err) &&
__clear_user(fx, sizeof(struct i387_fxsave_struct)))
err = -EFAULT;
@@ -165,26 +159,22 @@ static inline void fpu_fxsave(struct fpu *fpu)
/* Using "rex64; fxsave %0" is broken because, if the memory operand
uses any extended registers for addressing, a second REX prefix
will be generated (to the assembler, rex64 followed by semicolon
- is a separate instruction), and hence the 64-bitness is lost. */
-#if 0
- /* Using "fxsaveq %0" would be the ideal choice, but is only supported
- starting with gas 2.16. */
- __asm__ __volatile__("fxsaveq %0"
- : "=m" (fpu->state->fxsave));
-#elif 0
- /* Using, as a workaround, the properly prefixed form below isn't
+ is a separate instruction), and hence the 64-bitness is lost.
+ Using "fxsaveq %0" would be the ideal choice, but is only supported
+ starting with gas 2.16.
+ asm volatile("fxsaveq %0"
+ : "=m" (fpu->state->fxsave));
+ Using, as a workaround, the properly prefixed form below isn't
accepted by any binutils version so far released, complaining that
the same type of prefix is used twice if an extended register is
- needed for addressing (fix submitted to mainline 2005-11-21). */
- __asm__ __volatile__("rex64/fxsave %0"
- : "=m" (fpu->state->fxsave));
-#else
- /* This, however, we can work around by forcing the compiler to select
+ needed for addressing (fix submitted to mainline 2005-11-21).
+ asm volatile("rex64/fxsave %0"
+ : "=m" (fpu->state->fxsave));
+ This, however, we can work around by forcing the compiler to select
an addressing mode that doesn't require extended registers. */
- __asm__ __volatile__("rex64/fxsave (%1)"
- : "=m" (fpu->state->fxsave)
- : "cdaSDb" (&fpu->state->fxsave));
-#endif
+ asm volatile("rex64/fxsave (%[fx])"
+ : "=m" (fpu->state->fxsave)
+ : [fx] "R" (&fpu->state->fxsave));
}
static inline void fpu_save_init(struct fpu *fpu)
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86-32, fpu: Remove math_emulate stub
2010-09-04 1:17 ` [PATCH 08/12] x86-32: Remove math_emulate stub Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
@ 2010-09-10 1:48 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: a334fe43d85f570ae907acf988a053c5eff78d6e
Gitweb: http://git.kernel.org/tip/a334fe43d85f570ae907acf988a053c5eff78d6e
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:15 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:17:11 -0700
x86-32, fpu: Remove math_emulate stub
check_fpu() in bugs.c halts boot if no FPU is found and math emulation
isn't enabled. Therefore this stub will never be used.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-9-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/kernel/traps.c | 23 ++++++-----------------
1 files changed, 6 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index d0029eb..d439685 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -776,21 +776,10 @@ asmlinkage void math_state_restore(void)
}
EXPORT_SYMBOL_GPL(math_state_restore);
-#ifndef CONFIG_MATH_EMULATION
-void math_emulate(struct math_emu_info *info)
-{
- printk(KERN_EMERG
- "math-emulation not enabled and no coprocessor found.\n");
- printk(KERN_EMERG "killing %s.\n", current->comm);
- force_sig(SIGFPE, current);
- schedule();
-}
-#endif /* CONFIG_MATH_EMULATION */
-
dotraplinkage void __kprobes
do_device_not_available(struct pt_regs *regs, long error_code)
{
-#ifdef CONFIG_X86_32
+#ifdef CONFIG_MATH_EMULATION
if (read_cr0() & X86_CR0_EM) {
struct math_emu_info info = { };
@@ -798,12 +787,12 @@ do_device_not_available(struct pt_regs *regs, long error_code)
info.regs = regs;
math_emulate(&info);
- } else {
- math_state_restore(); /* interrupts still off */
- conditional_sti(regs);
+ return;
}
-#else
- math_state_restore();
+#endif
+ math_state_restore(); /* interrupts still off */
+#ifdef CONFIG_X86_32
+ conditional_sti(regs);
#endif
}
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86, fpu: Remove unnecessary ifdefs from i387 code.
2010-09-04 1:17 ` [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code Brian Gerst
2010-09-04 6:49 ` Pekka Enberg
@ 2010-09-10 1:48 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:48 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 8eb91a577d7763d21628f6761045328784b1911c
Gitweb: http://git.kernel.org/tip/8eb91a577d7763d21628f6761045328784b1911c
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:16 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:17:18 -0700
x86, fpu: Remove unnecessary ifdefs from i387 code.
Remove ifdefs for code that the compiler can optimize away on 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-10-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 12 ++++++------
arch/x86/kernel/i387.c | 4 ----
2 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 768fcb2..42b507e 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -55,6 +55,12 @@ extern int save_i387_xstate_ia32(void __user *buf);
extern int restore_i387_xstate_ia32(void __user *buf);
#endif
+#ifdef CONFIG_MATH_EMULATION
+extern void finit_soft_fpu(struct i387_soft_struct *soft);
+#else
+static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
+#endif
+
#define X87_FSW_ES (1 << 7) /* Exception Summary */
static __always_inline __pure bool use_xsaveopt(void)
@@ -189,12 +195,6 @@ static inline void fpu_save_init(struct fpu *fpu)
#else /* CONFIG_X86_32 */
-#ifdef CONFIG_MATH_EMULATION
-extern void finit_soft_fpu(struct i387_soft_struct *soft);
-#else
-static inline void finit_soft_fpu(struct i387_soft_struct *soft) {}
-#endif
-
/* perform fxrstor iff the processor has extended states, otherwise frstor */
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
{
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index f3775f5..e795e36 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -79,10 +79,8 @@ static void __cpuinit init_thread_xstate(void)
if (cpu_has_fxsr)
xstate_size = sizeof(struct i387_fxsave_struct);
-#ifdef CONFIG_X86_32
else
xstate_size = sizeof(struct i387_fsave_struct);
-#endif
}
/*
@@ -119,12 +117,10 @@ void __cpuinit fpu_init(void)
void fpu_finit(struct fpu *fpu)
{
-#ifdef CONFIG_X86_32
if (!HAVE_HWFP) {
finit_soft_fpu(&fpu->state->soft);
return;
}
-#endif
if (cpu_has_fxsr) {
struct i387_fxsave_struct *fx = &fpu->state->fxsave;
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86, fpu: Remove PSHUFB_XMM5_* macros
2010-09-04 1:17 ` [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros Brian Gerst
2010-09-04 6:49 ` Pekka Enberg
@ 2010-09-10 1:49 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:49 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: eec73f813ab0954253e5e2168119c4555f83f07d
Gitweb: http://git.kernel.org/tip/eec73f813ab0954253e5e2168119c4555f83f07d
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:17 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:17:25 -0700
x86, fpu: Remove PSHUFB_XMM5_* macros
The PSHUFB_XMM5_* macros are no longer used.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-11-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 42b507e..907967e 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -465,7 +465,4 @@ extern void fpu_finit(struct fpu *fpu);
#endif /* __ASSEMBLY__ */
-#define PSHUFB_XMM5_XMM0 .byte 0x66, 0x0f, 0x38, 0x00, 0xc5
-#define PSHUFB_XMM5_XMM6 .byte 0x66, 0x0f, 0x38, 0x00, 0xf5
-
#endif /* _ASM_X86_I387_H */
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86-32, fpu: Rewrite fpu_save_init()
2010-09-04 1:17 ` [PATCH 11/12] x86-32: Rewrite fpu_save_init() Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
@ 2010-09-10 1:49 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:49 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: 58a992b9cbaf449aeebd3575c3695a9eb5d95b5e
Gitweb: http://git.kernel.org/tip/58a992b9cbaf449aeebd3575c3695a9eb5d95b5e
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:18 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:17:31 -0700
x86-32, fpu: Rewrite fpu_save_init()
Rewrite fpu_save_init() to prepare for merging with 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-12-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 47 ++++++++++++++++++++----------------------
1 files changed, 22 insertions(+), 25 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 907967e..b45abef 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -73,6 +73,11 @@ static __always_inline __pure bool use_xsave(void)
return static_cpu_has(X86_FEATURE_XSAVE);
}
+static __always_inline __pure bool use_fxsr(void)
+{
+ return static_cpu_has(X86_FEATURE_FXSR);
+}
+
extern void __sanitize_i387_state(struct task_struct *);
static inline void sanitize_i387_state(struct task_struct *tsk)
@@ -211,6 +216,12 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
return 0;
}
+static inline void fpu_fxsave(struct fpu *fpu)
+{
+ asm volatile("fxsave %[fx]"
+ : [fx] "=m" (fpu->state->fxsave));
+}
+
/* We need a safe address that is cheap to find and that is already
in L1 during context switch. The best choices are unfortunately
different for UP and SMP */
@@ -226,36 +237,24 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
static inline void fpu_save_init(struct fpu *fpu)
{
if (use_xsave()) {
- struct xsave_struct *xstate = &fpu->state->xsave;
- struct i387_fxsave_struct *fx = &fpu->state->fxsave;
-
fpu_xsave(fpu);
/*
* xsave header may indicate the init state of the FP.
*/
- if (!(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
- goto end;
-
- if (unlikely(fx->swd & X87_FSW_ES))
- asm volatile("fnclex");
-
- /*
- * we can do a simple return here or be paranoid :)
- */
- goto clear_state;
+ if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP))
+ return;
+ } else if (use_fxsr()) {
+ fpu_fxsave(fpu);
+ } else {
+ asm volatile("fsave %[fx]; fwait"
+ : [fx] "=m" (fpu->state->fsave));
+ return;
}
- /* Use more nops than strictly needed in case the compiler
- varies code */
- alternative_input(
- "fnsave %[fx] ;fwait;" GENERIC_NOP8 GENERIC_NOP4,
- "fxsave %[fx]\n"
- "bt $7,%[fsw] ; jnc 1f ; fnclex\n1:",
- X86_FEATURE_FXSR,
- [fx] "m" (fpu->state->fxsave),
- [fsw] "m" (fpu->state->fxsave.swd) : "memory");
-clear_state:
+ if (unlikely(fpu->state->fxsave.swd & X87_FSW_ES))
+ asm volatile("fnclex");
+
/* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
is pending. Clear the x87 state here by setting it to fixed
values. safe_address is a random variable that should be in L1 */
@@ -265,8 +264,6 @@ clear_state:
"fildl %[addr]", /* set F?P to defined value */
X86_FEATURE_FXSAVE_LEAK,
[addr] "m" (safe_address));
-end:
- ;
}
#endif /* CONFIG_X86_64 */
^ permalink raw reply related [flat|nested] 40+ messages in thread
* [tip:x86/fpu] x86, fpu: Merge fpu_save_init()
2010-09-04 1:17 ` [PATCH 12/12] x86: Merge fpu_save_init() Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
@ 2010-09-10 1:50 ` tip-bot for Brian Gerst
1 sibling, 0 replies; 40+ messages in thread
From: tip-bot for Brian Gerst @ 2010-09-10 1:50 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, hpa, mingo, brgerst, penberg, suresh.b.siddha, tglx, hpa
Commit-ID: b2b57fe053c9cf8b8af5a0e826a465996afed0ff
Gitweb: http://git.kernel.org/tip/b2b57fe053c9cf8b8af5a0e826a465996afed0ff
Author: Brian Gerst <brgerst@gmail.com>
AuthorDate: Fri, 3 Sep 2010 21:17:19 -0400
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 9 Sep 2010 14:17:36 -0700
x86, fpu: Merge fpu_save_init()
Make 64-bit use the 32-bit version of fpu_save_init(). Remove
unused clear_fpu_state().
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1283563039-3466-13-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/i387.h | 48 +++---------------------------------------
1 files changed, 4 insertions(+), 44 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index b45abef..70626ed 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -105,36 +105,6 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
return err;
}
-/* AMD CPUs don't save/restore FDP/FIP/FOP unless an exception
- is pending. Clear the x87 state here by setting it to fixed
- values. The kernel data segment can be sometimes 0 and sometimes
- new user value. Both should be ok.
- Use the PDA as safe address because it should be already in L1. */
-static inline void fpu_clear(struct fpu *fpu)
-{
- struct xsave_struct *xstate = &fpu->state->xsave;
- struct i387_fxsave_struct *fx = &fpu->state->fxsave;
-
- /*
- * xsave header may indicate the init state of the FP.
- */
- if (use_xsave() &&
- !(xstate->xsave_hdr.xstate_bv & XSTATE_FP))
- return;
-
- if (unlikely(fx->swd & X87_FSW_ES))
- asm volatile("fnclex");
- alternative_input(ASM_NOP8 ASM_NOP2,
- " emms\n" /* clear stack tags */
- " fildl %%gs:0", /* load to clear state */
- X86_FEATURE_FXSAVE_LEAK);
-}
-
-static inline void clear_fpu_state(struct task_struct *tsk)
-{
- fpu_clear(&tsk->thread.fpu);
-}
-
static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
{
int err;
@@ -188,16 +158,6 @@ static inline void fpu_fxsave(struct fpu *fpu)
: [fx] "R" (&fpu->state->fxsave));
}
-static inline void fpu_save_init(struct fpu *fpu)
-{
- if (use_xsave())
- fpu_xsave(fpu);
- else
- fpu_fxsave(fpu);
-
- fpu_clear(fpu);
-}
-
#else /* CONFIG_X86_32 */
/* perform fxrstor iff the processor has extended states, otherwise frstor */
@@ -222,6 +182,8 @@ static inline void fpu_fxsave(struct fpu *fpu)
: [fx] "=m" (fpu->state->fxsave));
}
+#endif /* CONFIG_X86_64 */
+
/* We need a safe address that is cheap to find and that is already
in L1 during context switch. The best choices are unfortunately
different for UP and SMP */
@@ -259,15 +221,13 @@ static inline void fpu_save_init(struct fpu *fpu)
is pending. Clear the x87 state here by setting it to fixed
values. safe_address is a random variable that should be in L1 */
alternative_input(
- GENERIC_NOP8 GENERIC_NOP2,
+ ASM_NOP8 ASM_NOP2,
"emms\n\t" /* clear stack tags */
- "fildl %[addr]", /* set F?P to defined value */
+ "fildl %P[addr]", /* set F?P to defined value */
X86_FEATURE_FXSAVE_LEAK,
[addr] "m" (safe_address));
}
-#endif /* CONFIG_X86_64 */
-
static inline void __save_init_fpu(struct task_struct *tsk)
{
fpu_save_init(&tsk->thread.fpu);
^ permalink raw reply related [flat|nested] 40+ messages in thread
end of thread, other threads:[~2010-09-10 1:55 UTC | newest]
Thread overview: 40+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-09-04 1:17 [PATCH 0/12] x86 FPU cleanups (v2) Brian Gerst
2010-09-04 1:17 ` [PATCH 01/12] x86: Use correct type for %cr4 Brian Gerst
2010-09-04 6:45 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 02/12] x86: Merge fpu_init() Brian Gerst
2010-09-04 6:45 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 03/12] x86: Merge tolerant_fwait() Brian Gerst
2010-09-04 6:46 ` Pekka Enberg
2010-09-10 1:46 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 04/12] x86: Merge __save_init_fpu() Brian Gerst
2010-09-04 6:47 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 05/12] x86-64: Disable preemption when using TS_USEDFPU Brian Gerst
2010-09-04 6:47 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 06/12] x86-64: Fix %cs value in convert_from_fxsr() Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:47 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 07/12] x86-64: Simplify constraints for fxsave/fxtstor Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
2010-09-09 21:22 ` H. Peter Anvin
2010-09-09 23:43 ` Brian Gerst
2010-09-10 1:48 ` [tip:x86/fpu] x86-64, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 08/12] x86-32: Remove math_emulate stub Brian Gerst
2010-09-04 6:48 ` Pekka Enberg
2010-09-10 1:48 ` [tip:x86/fpu] x86-32, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 09/12] x86: Remove unnecessary ifdefs from i387 code Brian Gerst
2010-09-04 6:49 ` Pekka Enberg
2010-09-10 1:48 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 10/12] x86: Remove PSHUFB_XMM5_* macros Brian Gerst
2010-09-04 6:49 ` Pekka Enberg
2010-09-10 1:49 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 11/12] x86-32: Rewrite fpu_save_init() Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:49 ` [tip:x86/fpu] x86-32, fpu: " tip-bot for Brian Gerst
2010-09-04 1:17 ` [PATCH 12/12] x86: Merge fpu_save_init() Brian Gerst
2010-09-04 6:51 ` Pekka Enberg
2010-09-10 1:50 ` [tip:x86/fpu] x86, fpu: " tip-bot for Brian Gerst
2010-09-04 6:45 ` [PATCH 0/12] x86 FPU cleanups (v2) Pekka Enberg
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