[patch V4 27/65] x86/fpu: Rename fxregs related copy functions

From: Thomas Gleixner
Date: Wed Jun 23 2021 - 08:25:22 EST


The function names for fxsave/fxrstor operations are horribly named and
a permanent source of confusion.

Rename:
copy_fxregs_to_kernel() to fxsave()
copy_kernel_to_fxregs() to fxrstor()
copy_fxregs_to_user() to fxsave_to_user_sigframe()
copy_user_to_fxregs() to fxrstor_from_user_sigframe()

so it's clear what these are doing. All these functions are really low
level wrappers around the equaly named instructions, so mapping to the
documentation is just natural.

While at it replace the static_cpu_has(X86_FEATURE_FXSR) with use_fxsr() to
be consistent with the rest of the code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
V4: Replace the static_cpu_has() in the code and not just talk about it (Boris)
V3: Rename (Boris)
---
arch/x86/include/asm/fpu/internal.h | 18 +++++-------------
arch/x86/kernel/fpu/core.c | 6 +++---
arch/x86/kernel/fpu/signal.c | 10 +++++-----
3 files changed, 13 insertions(+), 21 deletions(-)

--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -129,7 +129,7 @@ static inline int copy_fregs_to_user(str
return user_insn(fnsave %[fx]; fwait, [fx] "=m" (*fx), "m" (*fx));
}

-static inline int copy_fxregs_to_user(struct fxregs_state __user *fx)
+static inline int fxsave_to_user_sigframe(struct fxregs_state __user *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
return user_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));
@@ -138,7 +138,7 @@ static inline int copy_fxregs_to_user(st

}

-static inline void copy_kernel_to_fxregs(struct fxregs_state *fx)
+static inline void fxrstor(struct fxregs_state *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
kernel_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
@@ -146,7 +146,7 @@ static inline void copy_kernel_to_fxregs
kernel_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
}

-static inline int copy_kernel_to_fxregs_err(struct fxregs_state *fx)
+static inline int fxrstor_safe(struct fxregs_state *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
return kernel_insn_err(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
@@ -154,7 +154,7 @@ static inline int copy_kernel_to_fxregs_
return kernel_insn_err(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
}

-static inline int copy_user_to_fxregs(struct fxregs_state __user *fx)
+static inline int fxrstor_from_user_sigframe(struct fxregs_state __user *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
return user_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
@@ -177,14 +177,6 @@ static inline int copy_user_to_fregs(str
return user_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));
}

-static inline void copy_fxregs_to_kernel(struct fpu *fpu)
-{
- if (IS_ENABLED(CONFIG_X86_32))
- asm volatile( "fxsave %[fx]" : [fx] "=m" (fpu->state.fxsave));
- else
- asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave));
-}
-
static inline void fxsave(struct fxregs_state *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
@@ -391,7 +383,7 @@ static inline void __copy_kernel_to_fpre
os_xrstor(&fpstate->xsave, mask);
} else {
if (use_fxsr())
- copy_kernel_to_fxregs(&fpstate->fxsave);
+ fxrstor(&fpstate->fxsave);
else
copy_kernel_to_fregs(&fpstate->fsave);
}
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -107,7 +107,7 @@ int copy_fpregs_to_fpstate(struct fpu *f
}

if (likely(use_fxsr())) {
- copy_fxregs_to_kernel(fpu);
+ fxsave(&fpu->state.fxsave);
return 1;
}

@@ -315,8 +315,8 @@ static inline void copy_init_fpstate_to_
{
if (use_xsave())
os_xrstor(&init_fpstate.xsave, features_mask);
- else if (static_cpu_has(X86_FEATURE_FXSR))
- copy_kernel_to_fxregs(&init_fpstate.fxsave);
+ else if (use_fxsr())
+ fxrstor(&init_fpstate.fxsave);
else
copy_kernel_to_fregs(&init_fpstate.fsave);

--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -64,7 +64,7 @@ static inline int save_fsave_header(stru

fpregs_lock();
if (!test_thread_flag(TIF_NEED_FPU_LOAD))
- copy_fxregs_to_kernel(&tsk->thread.fpu);
+ fxsave(&tsk->thread.fpu.state.fxsave);
fpregs_unlock();

convert_from_fxsr(&env, tsk);
@@ -131,7 +131,7 @@ static inline int copy_fpregs_to_sigfram
if (use_xsave())
err = xsave_to_user_sigframe(buf);
else if (use_fxsr())
- err = copy_fxregs_to_user((struct fxregs_state __user *) buf);
+ err = fxsave_to_user_sigframe((struct fxregs_state __user *) buf);
else
err = copy_fregs_to_user((struct fregs_state __user *) buf);

@@ -259,7 +259,7 @@ static int copy_user_to_fpregs_zeroing(v
if (fx_only) {
init_bv = xfeatures_mask_user() & ~XFEATURE_MASK_FPSSE;

- r = copy_user_to_fxregs(buf);
+ r = fxrstor_from_user_sigframe(buf);
if (!r)
os_xrstor(&init_fpstate.xsave, init_bv);
return r;
@@ -272,7 +272,7 @@ static int copy_user_to_fpregs_zeroing(v
return r;
}
} else if (use_fxsr()) {
- return copy_user_to_fxregs(buf);
+ return fxrstor_from_user_sigframe(buf);
} else
return copy_user_to_fregs(buf);
}
@@ -458,7 +458,7 @@ static int __fpu__restore_sig(void __use
os_xrstor(&init_fpstate.xsave, init_bv);
}

- ret = copy_kernel_to_fxregs_err(&fpu->state.fxsave);
+ ret = fxrstor_safe(&fpu->state.fxsave);
} else {
ret = __copy_from_user(&fpu->state.fsave, buf_fx, state_size);
if (ret)