[PATCH 135/208] x86/fpu: Remove failure paths from fpstate-alloc low level functions
From: Ingo Molnar
Date: Tue May 05 2015 - 14:20:41 EST
Now that we always allocate the FPU context as part of task_struct there's
no need for separate allocations - remove them and their primary failure
handling code.
( Note that there's still secondary error codes that have become superfluous,
those will be removed in separate patches. )
Move the somewhat misplaced setup_xstate_comp() call to the core.
Reviewed-by: Borislav Petkov <bp@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/fpu/internal.h | 4 ----
arch/x86/kernel/fpu/core.c | 51 ++-------------------------------------------------
arch/x86/kernel/fpu/init.c | 1 +
arch/x86/kernel/process.c | 10 ----------
arch/x86/kvm/x86.c | 11 -----------
5 files changed, 3 insertions(+), 74 deletions(-)
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index 4ce830fb3f31..9454f21f0edf 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -558,10 +558,6 @@ static inline unsigned short get_fpu_mxcsr(struct task_struct *tsk)
}
}
-extern void fpstate_cache_init(void);
-
-extern int fpstate_alloc(struct fpu *fpu);
-extern void fpstate_free(struct fpu *fpu);
extern int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu);
static inline unsigned long
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 422cbb4bbe01..7d42a54b5f23 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -226,34 +226,6 @@ void fpstate_init(struct fpu *fpu)
EXPORT_SYMBOL_GPL(fpstate_init);
/*
- * FPU state allocation:
- */
-static struct kmem_cache *task_xstate_cachep;
-
-void fpstate_cache_init(void)
-{
- task_xstate_cachep =
- kmem_cache_create("task_xstate", xstate_size,
- __alignof__(union thread_xstate),
- SLAB_PANIC | SLAB_NOTRACK, NULL);
- setup_xstate_comp();
-}
-
-int fpstate_alloc(struct fpu *fpu)
-{
- /* The CPU requires the FPU state to be aligned to 16 byte boundaries: */
- WARN_ON((unsigned long)&fpu->state & 15);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(fpstate_alloc);
-
-void fpstate_free(struct fpu *fpu)
-{
-}
-EXPORT_SYMBOL_GPL(fpstate_free);
-
-/*
* Copy the current task's FPU state to a new task's FPU context.
*
* In the 'eager' case we just save to the destination context.
@@ -280,13 +252,9 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
dst_fpu->fpregs_active = 0;
dst_fpu->last_cpu = -1;
- if (src_fpu->fpstate_active) {
- int err = fpstate_alloc(dst_fpu);
-
- if (err)
- return err;
+ if (src_fpu->fpstate_active)
fpu_copy(dst_fpu, src_fpu);
- }
+
return 0;
}
@@ -305,13 +273,6 @@ int fpstate_alloc_init(struct fpu *fpu)
if (WARN_ON_ONCE(fpu->fpstate_active))
return -EINVAL;
- /*
- * Memory allocation at the first usage of the FPU and other state.
- */
- ret = fpstate_alloc(fpu);
- if (ret)
- return ret;
-
fpstate_init(fpu);
/* Safe to do for the current task: */
@@ -356,13 +317,6 @@ static int fpu__unlazy_stopped(struct fpu *child_fpu)
return 0;
}
- /*
- * Memory allocation at the first usage of the FPU and other state.
- */
- ret = fpstate_alloc(child_fpu);
- if (ret)
- return ret;
-
fpstate_init(child_fpu);
/* Safe to do for stopped child tasks: */
@@ -423,7 +377,6 @@ void fpu__clear(struct task_struct *tsk)
if (!use_eager_fpu()) {
/* FPU state will be reallocated lazily at the first use. */
drop_fpu(fpu);
- fpstate_free(fpu);
} else {
if (!fpu->fpstate_active) {
/* kthread execs. TODO: cleanup this horror. */
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 7ae5a62918c7..460e7e2c6186 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -265,6 +265,7 @@ void fpu__init_system(struct cpuinfo_x86 *c)
fpu__init_system_generic();
fpu__init_system_xstate_size_legacy();
fpu__init_system_xstate();
+ setup_xstate_comp();
fpu__init_system_ctx_switch();
}
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 2bd188501ac9..4b4b16c8e6ee 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -86,16 +86,6 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
return fpu__copy(&dst->thread.fpu, &src->thread.fpu);
}
-void arch_release_task_struct(struct task_struct *tsk)
-{
- fpstate_free(&tsk->thread.fpu);
-}
-
-void arch_task_cache_init(void)
-{
- fpstate_cache_init();
-}
-
/*
* Free current thread data structures etc..
*/
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8bb0de5bf9c0..68529251e897 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7008,10 +7008,6 @@ int fx_init(struct kvm_vcpu *vcpu)
{
int err;
- err = fpstate_alloc(&vcpu->arch.guest_fpu);
- if (err)
- return err;
-
fpstate_init(&vcpu->arch.guest_fpu);
if (cpu_has_xsaves)
vcpu->arch.guest_fpu.state.xsave.header.xcomp_bv =
@@ -7028,11 +7024,6 @@ int fx_init(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(fx_init);
-static void fx_free(struct kvm_vcpu *vcpu)
-{
- fpstate_free(&vcpu->arch.guest_fpu);
-}
-
void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_fpu_loaded)
@@ -7070,7 +7061,6 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
kvmclock_reset(vcpu);
free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
- fx_free(vcpu);
kvm_x86_ops->vcpu_free(vcpu);
}
@@ -7126,7 +7116,6 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
kvm_mmu_unload(vcpu);
vcpu_put(vcpu);
- fx_free(vcpu);
kvm_x86_ops->vcpu_free(vcpu);
}
--
2.1.0
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