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authorBorislav Petkov <bp@suse.de>2019-01-18 00:05:40 +0100
committerBorislav Petkov <bp@suse.de>2019-01-22 14:16:39 +0100
commitbae54dc4f353653bbd3e3081754adad05da1d4dd (patch)
treef9fef256f1861fe1b8e823c4afee8716f8c58289 /arch/x86/include/asm
parentee35b9b9f6d52ba134b4e75442531935f295be7a (diff)
downloadlinux-0-day-bae54dc4f353653bbd3e3081754adad05da1d4dd.tar.gz
linux-0-day-bae54dc4f353653bbd3e3081754adad05da1d4dd.tar.xz
x86/fpu: Get rid of CONFIG_AS_FXSAVEQ
This was a "workaround" to probe for binutils which could generate FXSAVEQ, apparently gas with min version 2.16. In the meantime, minimal required gas version is 2.20 so all those workarounds for older binutils can be dropped. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20190117232408.GH5023@zn.tnic
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/fpu/internal.h50
1 files changed, 6 insertions, 44 deletions
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index fa2c93cb42a2..5d536e3dcc6d 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -137,37 +137,25 @@ static inline int copy_fxregs_to_user(struct fxregs_state __user *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
return user_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));
- else if (IS_ENABLED(CONFIG_AS_FXSAVEQ))
+ else
return user_insn(fxsaveq %[fx], [fx] "=m" (*fx), "m" (*fx));
- /* See comment in copy_fxregs_to_kernel() below. */
- return user_insn(rex64/fxsave (%[fx]), "=m" (*fx), [fx] "R" (fx));
}
static inline void copy_kernel_to_fxregs(struct fxregs_state *fx)
{
- if (IS_ENABLED(CONFIG_X86_32)) {
+ if (IS_ENABLED(CONFIG_X86_32))
kernel_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
- } else {
- if (IS_ENABLED(CONFIG_AS_FXSAVEQ)) {
- kernel_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
- } else {
- /* See comment in copy_fxregs_to_kernel() below. */
- kernel_insn(rex64/fxrstor (%[fx]), "=m" (*fx), [fx] "R" (fx), "m" (*fx));
- }
- }
+ else
+ kernel_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
}
static inline int copy_user_to_fxregs(struct fxregs_state __user *fx)
{
if (IS_ENABLED(CONFIG_X86_32))
return user_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
- else if (IS_ENABLED(CONFIG_AS_FXSAVEQ))
+ else
return user_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
-
- /* See comment in copy_fxregs_to_kernel() below. */
- return user_insn(rex64/fxrstor (%[fx]), "=m" (*fx), [fx] "R" (fx),
- "m" (*fx));
}
static inline void copy_kernel_to_fregs(struct fregs_state *fx)
@@ -184,34 +172,8 @@ 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 if (IS_ENABLED(CONFIG_AS_FXSAVEQ))
+ else
asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave));
- else {
- /* Using "rex64; fxsave %0" is broken because, if the memory
- * operand uses any extended registers for addressing, a second
- * REX prefix will be generated (to the assembler, rex64
- * followed by semicolon is a separate instruction), and hence
- * the 64-bitness is lost.
- *
- * Using "fxsaveq %0" would be the ideal choice, but is only
- * supported starting with gas 2.16.
- *
- * Using, as a workaround, the properly prefixed form below
- * isn't accepted by any binutils version so far released,
- * complaining that the same type of prefix is used twice if
- * an extended register is needed for addressing (fix submitted
- * to mainline 2005-11-21).
- *
- * asm volatile("rex64/fxsave %0" : "=m" (fpu->state.fxsave));
- *
- * This, however, we can work around by forcing the compiler to
- * select an addressing mode that doesn't require extended
- * registers.
- */
- asm volatile( "rex64/fxsave (%[fx])"
- : "=m" (fpu->state.fxsave)
- : [fx] "R" (&fpu->state.fxsave));
- }
}
/* These macros all use (%edi)/(%rdi) as the single memory argument. */