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Date: Tue, 5 May 2015 19:49:41 +0200
From: Ingo Molnar <mingo@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Andy Lutomirski <luto@...capital.net>,
Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Fenghua Yu <fenghua.yu@...el.com>,
"H. Peter Anvin" <hpa@...or.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Oleg Nesterov <oleg@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 089/208] x86/fpu: Rename fpu->has_fpu to fpu->fpregs_active
So the current code uses fpu->has_cpu to determine whether a given
user FPU context is actively loaded into the FPU's registers [*] and
that those registers represent the task's current FPU state.
But this term is not unambiguous: especially the distinction between
fpu->has_fpu, PF_USED_MATH and fpu_fpregs_owner_ctx is not clear.
Increase clarity by unambigously signalling that it's about
hardware registers being active right now, by renaming it to
fpu->fpregs_active.
( In later patches we'll use more of the 'fpregs' naming, which will
make it easier to grep for as well. )
[*] There's the kernel_fpu_begin()/end() primitive that also
activates FPU hw registers as well and uses them, without
touching the fpu->fpregs_active flag.
Reviewed-by: Borislav Petkov <bp@...en8.de>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/include/asm/fpu/api.h | 2 +-
arch/x86/include/asm/fpu/internal.h | 12 ++++++------
arch/x86/include/asm/fpu/types.h | 2 +-
arch/x86/kernel/fpu/core.c | 10 +++++-----
4 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index 5bdde8ca87bc..4ca745c0d92e 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -96,7 +96,7 @@ static inline void irq_ts_restore(int TS_state)
*/
static inline int user_has_fpu(void)
{
- return current->thread.fpu.has_fpu;
+ return current->thread.fpu.fpregs_active;
}
extern void fpu__save(struct fpu *fpu);
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index 6eea81c068fb..b546ec816fd6 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -308,7 +308,7 @@ static inline int restore_fpu_checking(struct fpu *fpu)
"fnclex\n\t"
"emms\n\t"
"fildl %P[addr]" /* set F?P to defined value */
- : : [addr] "m" (fpu->has_fpu));
+ : : [addr] "m" (fpu->fpregs_active));
}
return fpu_restore_checking(fpu);
@@ -317,14 +317,14 @@ static inline int restore_fpu_checking(struct fpu *fpu)
/* Must be paired with an 'stts' after! */
static inline void __thread_clear_has_fpu(struct fpu *fpu)
{
- fpu->has_fpu = 0;
+ fpu->fpregs_active = 0;
this_cpu_write(fpu_fpregs_owner_ctx, NULL);
}
/* Must be paired with a 'clts' before! */
static inline void __thread_set_has_fpu(struct fpu *fpu)
{
- fpu->has_fpu = 1;
+ fpu->fpregs_active = 1;
this_cpu_write(fpu_fpregs_owner_ctx, fpu);
}
@@ -357,7 +357,7 @@ static inline void drop_fpu(struct fpu *fpu)
preempt_disable();
fpu->counter = 0;
- if (fpu->has_fpu) {
+ if (fpu->fpregs_active) {
/* Ignore delayed exceptions from user space */
asm volatile("1: fwait\n"
"2:\n"
@@ -416,14 +416,14 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu)
fpu.preload = new_fpu->fpstate_active &&
(use_eager_fpu() || new_fpu->counter > 5);
- if (old_fpu->has_fpu) {
+ if (old_fpu->fpregs_active) {
if (!fpu_save_init(old_fpu))
old_fpu->last_cpu = -1;
else
old_fpu->last_cpu = cpu;
/* But leave fpu_fpregs_owner_ctx! */
- old_fpu->has_fpu = 0;
+ old_fpu->fpregs_active = 0;
/* Don't change CR0.TS if we just switch! */
if (fpu.preload) {
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 8a5120a3b48b..231a8f53b2f8 100644
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -142,7 +142,7 @@ struct fpu {
*/
unsigned int last_cpu;
- unsigned int has_fpu;
+ unsigned int fpregs_active;
union thread_xstate *state;
/*
* This counter contains the number of consecutive context switches
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 35ef1f9b56b3..a7fb56266a2d 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -62,7 +62,7 @@ static bool interrupted_kernel_fpu_idle(void)
if (use_eager_fpu())
return true;
- return !current->thread.fpu.has_fpu && (read_cr0() & X86_CR0_TS);
+ return !current->thread.fpu.fpregs_active && (read_cr0() & X86_CR0_TS);
}
/*
@@ -100,7 +100,7 @@ void __kernel_fpu_begin(void)
kernel_fpu_disable();
- if (fpu->has_fpu) {
+ if (fpu->fpregs_active) {
fpu_save_init(fpu);
} else {
this_cpu_write(fpu_fpregs_owner_ctx, NULL);
@@ -114,7 +114,7 @@ void __kernel_fpu_end(void)
{
struct fpu *fpu = ¤t->thread.fpu;
- if (fpu->has_fpu) {
+ if (fpu->fpregs_active) {
if (WARN_ON(restore_fpu_checking(fpu)))
fpu_reset_state(fpu);
} else if (!use_eager_fpu()) {
@@ -147,7 +147,7 @@ void fpu__save(struct fpu *fpu)
WARN_ON(fpu != ¤t->thread.fpu);
preempt_disable();
- if (fpu->has_fpu) {
+ if (fpu->fpregs_active) {
if (use_eager_fpu()) {
__save_fpu(fpu);
} else {
@@ -243,7 +243,7 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
{
dst_fpu->counter = 0;
- dst_fpu->has_fpu = 0;
+ dst_fpu->fpregs_active = 0;
dst_fpu->state = NULL;
dst_fpu->last_cpu = -1;
--
2.1.0
--
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