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Subject[tip:x86/asm] x86/fpu: Get rid of x87 math exception helpers
Commit-ID:  6aa6dbfced51dec6cde159c6167ad3dad6add823
Gitweb: http://git.kernel.org/tip/6aa6dbfced51dec6cde159c6167ad3dad6add823
Author: Borislav Petkov <bp@suse.de>
AuthorDate: Tue, 5 Apr 2016 08:29:55 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 13 Apr 2016 11:37:44 +0200

x86/fpu: Get rid of x87 math exception helpers

... and integrate their functionality into their single user
fpu__exception_code().

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459837795-2588-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/core.c | 44 +++++++++++++-------------------------------
1 file changed, 13 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 1551b28..9702754 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -506,33 +506,6 @@ void fpu__clear(struct fpu *fpu)
* x87 math exception handling:
*/

-static inline unsigned short get_fpu_cwd(struct fpu *fpu)
-{
- if (boot_cpu_has(X86_FEATURE_FXSR)) {
- return fpu->state.fxsave.cwd;
- } else {
- return (unsigned short)fpu->state.fsave.cwd;
- }
-}
-
-static inline unsigned short get_fpu_swd(struct fpu *fpu)
-{
- if (boot_cpu_has(X86_FEATURE_FXSR)) {
- return fpu->state.fxsave.swd;
- } else {
- return (unsigned short)fpu->state.fsave.swd;
- }
-}
-
-static inline unsigned short get_fpu_mxcsr(struct fpu *fpu)
-{
- if (boot_cpu_has(X86_FEATURE_XMM)) {
- return fpu->state.fxsave.mxcsr;
- } else {
- return MXCSR_DEFAULT;
- }
-}
-
int fpu__exception_code(struct fpu *fpu, int trap_nr)
{
int err;
@@ -547,10 +520,15 @@ int fpu__exception_code(struct fpu *fpu, int trap_nr)
* so if this combination doesn't produce any single exception,
* then we have a bad program that isn't synchronizing its FPU usage
* and it will suffer the consequences since we won't be able to
- * fully reproduce the context of the exception
+ * fully reproduce the context of the exception.
*/
- cwd = get_fpu_cwd(fpu);
- swd = get_fpu_swd(fpu);
+ if (boot_cpu_has(X86_FEATURE_FXSR)) {
+ cwd = fpu->state.fxsave.cwd;
+ swd = fpu->state.fxsave.swd;
+ } else {
+ cwd = (unsigned short)fpu->state.fsave.cwd;
+ swd = (unsigned short)fpu->state.fsave.swd;
+ }

err = swd & ~cwd;
} else {
@@ -560,7 +538,11 @@ int fpu__exception_code(struct fpu *fpu, int trap_nr)
* unmasked exception was caught we must mask the exception mask bits
* at 0x1f80, and then use these to mask the exception bits at 0x3f.
*/
- unsigned short mxcsr = get_fpu_mxcsr(fpu);
+ unsigned short mxcsr = MXCSR_DEFAULT;
+
+ if (boot_cpu_has(X86_FEATURE_XMM))
+ mxcsr = fpu->state.fxsave.mxcsr;
+
err = ~(mxcsr >> 7) & mxcsr;
}

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