linux-kernel - [patch V3 33/66] x86/fpu: Rename copy_fpregs_to_fpstate() to save_fpregs_to

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Message-Id: <20210618143448.139321010@linutronix.de>
Date:   Fri, 18 Jun 2021 16:18:56 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Yu-cheng Yu <yu-cheng.yu@...el.com>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Borislav Petkov <bp@...e.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Kan Liang <kan.liang@...ux.intel.com>
Subject: [patch V3 33/66] x86/fpu: Rename copy_fpregs_to_fpstate() to
 save_fpregs_to_fpstate()

A copy is guaranteed to leave the source intact, which is not the case when
FNSAVE is used as that reinitilizes the registers.

Save does not make such guarantees and it matches what this is about,
i.e. to save the state for a later restore.

Rename it to save_fpregs_to_fpstate(). 

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/include/asm/fpu/internal.h |    4 ++--
 arch/x86/kernel/fpu/core.c          |   10 +++++-----
 arch/x86/kvm/x86.c                  |    2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -375,7 +375,7 @@ static inline int os_xrstor_safe(struct
 	return err;
 }
 
-extern int copy_fpregs_to_fpstate(struct fpu *fpu);
+extern int save_fpregs_to_fpstate(struct fpu *fpu);
 
 static inline void __copy_kernel_to_fpregs(union fpregs_state *fpstate, u64 mask)
 {
@@ -507,7 +507,7 @@ static inline void __fpregs_load_activat
 static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu)
 {
 	if (static_cpu_has(X86_FEATURE_FPU) && !(current->flags & PF_KTHREAD)) {
-		if (!copy_fpregs_to_fpstate(old_fpu))
+		if (!save_fpregs_to_fpstate(old_fpu))
 			old_fpu->last_cpu = -1;
 		else
 			old_fpu->last_cpu = cpu;
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -92,7 +92,7 @@ EXPORT_SYMBOL(irq_fpu_usable);
  * Modern FPU state can be kept in registers, if there are
  * no pending FP exceptions.
  */
-int copy_fpregs_to_fpstate(struct fpu *fpu)
+int save_fpregs_to_fpstate(struct fpu *fpu)
 {
 	if (likely(use_xsave())) {
 		os_xsave(&fpu->state.xsave);
@@ -119,7 +119,7 @@ int copy_fpregs_to_fpstate(struct fpu *f
 
 	return 0;
 }
-EXPORT_SYMBOL(copy_fpregs_to_fpstate);
+EXPORT_SYMBOL(save_fpregs_to_fpstate);
 
 void kernel_fpu_begin_mask(unsigned int kfpu_mask)
 {
@@ -137,7 +137,7 @@ void kernel_fpu_begin_mask(unsigned int
 		 * Ignore return value -- we don't care if reg state
 		 * is clobbered.
 		 */
-		copy_fpregs_to_fpstate(&current->thread.fpu);
+		save_fpregs_to_fpstate(&current->thread.fpu);
 	}
 	__cpu_invalidate_fpregs_state();
 
@@ -172,7 +172,7 @@ void fpu__save(struct fpu *fpu)
 	trace_x86_fpu_before_save(fpu);
 
 	if (!test_thread_flag(TIF_NEED_FPU_LOAD)) {
-		if (!copy_fpregs_to_fpstate(fpu)) {
+		if (!save_fpregs_to_fpstate(fpu)) {
 			copy_kernel_to_fpregs(&fpu->state);
 		}
 	}
@@ -255,7 +255,7 @@ int fpu__copy(struct task_struct *dst, s
 	if (test_thread_flag(TIF_NEED_FPU_LOAD))
 		memcpy(&dst_fpu->state, &src_fpu->state, fpu_kernel_xstate_size);
 
-	else if (!copy_fpregs_to_fpstate(dst_fpu))
+	else if (!save_fpregs_to_fpstate(dst_fpu))
 		copy_kernel_to_fpregs(&dst_fpu->state);
 
 	fpregs_unlock();
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9618,7 +9618,7 @@ static void kvm_save_current_fpu(struct
 		memcpy(&fpu->state, &current->thread.fpu.state,
 		       fpu_kernel_xstate_size);
 	else
-		copy_fpregs_to_fpstate(fpu);
+		save_fpregs_to_fpstate(fpu);
 }
 
 /* Swap (qemu) user FPU context for the guest FPU context. */