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Subject[tip:x86/fpu] x86/fpu: Simplify kernel_fpu_begin()
Commit-ID:  6d79d86f9600510e08ad45c72b9d7e664e439e62
Gitweb: https://git.kernel.org/tip/6d79d86f9600510e08ad45c72b9d7e664e439e62
Author: Christoph Hellwig <hch@lst.de>
AuthorDate: Tue, 4 Jun 2019 09:15:23 +0200
Committer: Borislav Petkov <bp@suse.de>
CommitDate: Mon, 17 Jun 2019 12:19:49 +0200

x86/fpu: Simplify kernel_fpu_begin()

Merge two helpers into the main function, remove a pointless local
variable and flatten a conditional.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190604071524.12835-3-hch@lst.de
---
arch/x86/kernel/fpu/core.c | 36 ++++++++++++------------------------
1 file changed, 12 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 8e046068d20f..3f92cfad88f0 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -43,12 +43,6 @@ static DEFINE_PER_CPU(bool, in_kernel_fpu);
*/
DEFINE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);

-static void kernel_fpu_disable(void)
-{
- WARN_ON_FPU(this_cpu_read(in_kernel_fpu));
- this_cpu_write(in_kernel_fpu, true);
-}
-
static bool kernel_fpu_disabled(void)
{
return this_cpu_read(in_kernel_fpu);
@@ -88,32 +82,26 @@ bool irq_fpu_usable(void)
}
EXPORT_SYMBOL(irq_fpu_usable);

-static void __kernel_fpu_begin(void)
+void kernel_fpu_begin(void)
{
- struct fpu *fpu = &current->thread.fpu;
+ preempt_disable();

WARN_ON_FPU(!irq_fpu_usable());
+ WARN_ON_FPU(this_cpu_read(in_kernel_fpu));

- kernel_fpu_disable();
+ this_cpu_write(in_kernel_fpu, true);

- if (!(current->flags & PF_KTHREAD)) {
- if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
- set_thread_flag(TIF_NEED_FPU_LOAD);
- /*
- * Ignore return value -- we don't care if reg state
- * is clobbered.
- */
- copy_fpregs_to_fpstate(fpu);
- }
+ if (!(current->flags & PF_KTHREAD) &&
+ !test_thread_flag(TIF_NEED_FPU_LOAD)) {
+ set_thread_flag(TIF_NEED_FPU_LOAD);
+ /*
+ * Ignore return value -- we don't care if reg state
+ * is clobbered.
+ */
+ copy_fpregs_to_fpstate(&current->thread.fpu);
}
__cpu_invalidate_fpregs_state();
}
-
-void kernel_fpu_begin(void)
-{
- preempt_disable();
- __kernel_fpu_begin();
-}
EXPORT_SYMBOL_GPL(kernel_fpu_begin);

void kernel_fpu_end(void)
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