[tip:x86/fpu] x86/fpu: Make __raw_xsave_addr() use a feature number instead of mask

tip-bot for Sebastian Andrzej Siewior
2019-04-13T20:54:03Z

Commit-ID: 07baeb04f37c952981d63359ff840118ce8f5434
Gitweb: https://git.kernel.org/tip/07baeb04f37c952981d63359ff840118ce8f5434
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Wed, 3 Apr 2019 18:41:39 +0200
Committer: Borislav Petkov <bp@suse.de>
CommitDate: Wed, 10 Apr 2019 16:33:45 +0200

x86/fpu: Make __raw_xsave_addr() use a feature number instead of mask

Most users of __raw_xsave_addr() use a feature number, shift it to a
mask and then __raw_xsave_addr() shifts it back to the feature number.

Make __raw_xsave_addr() use the feature number as an argument.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-11-bigeasy@linutronix.de
---
arch/x86/kernel/fpu/xstate.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 8bfcc5b9e04b..4f7f3c5d0d0c 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -805,20 +805,18 @@ void fpu__resume_cpu(void)
}

/*
- * Given an xstate feature mask, calculate where in the xsave
+ * Given an xstate feature nr, calculate where in the xsave
* buffer the state is. Callers should ensure that the buffer
* is valid.
*/
-static void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask)
+static void *__raw_xsave_addr(struct xregs_state *xsave, int xfeature_nr)
{
- int feature_nr = fls64(xstate_feature_mask) - 1;
-
- if (!xfeature_enabled(feature_nr)) {
+ if (!xfeature_enabled(xfeature_nr)) {
WARN_ON_FPU(1);
return NULL;
}

- return (void *)xsave + xstate_comp_offsets[feature_nr];
+ return (void *)xsave + xstate_comp_offsets[xfeature_nr];
}
/*
* Given the xsave area and a state inside, this function returns the
@@ -840,6 +838,7 @@ static void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask
*/
void *get_xsave_addr(struct xregs_state *xsave, int xstate_feature)
{
+ int xfeature_nr;
/*
* Do we even *have* xsave state?
*/
@@ -867,7 +866,8 @@ void *get_xsave_addr(struct xregs_state *xsave, int xstate_feature)
if (!(xsave->header.xfeatures & xstate_feature))
return NULL;

- return __raw_xsave_addr(xsave, xstate_feature);
+ xfeature_nr = fls64(xstate_feature) - 1;
+ return __raw_xsave_addr(xsave, xfeature_nr);
}
EXPORT_SYMBOL_GPL(get_xsave_addr);

@@ -1014,7 +1014,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
* Copy only in-use xstates:
*/
if ((header.xfeatures >> i) & 1) {
- void *src = __raw_xsave_addr(xsave, 1 << i);
+ void *src = __raw_xsave_addr(xsave, i);

offset = xstate_offsets[i];
size = xstate_sizes[i];
@@ -1100,7 +1100,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i
* Copy only in-use xstates:
*/
if ((header.xfeatures >> i) & 1) {
- void *src = __raw_xsave_addr(xsave, 1 << i);
+ void *src = __raw_xsave_addr(xsave, i);

offset = xstate_offsets[i];
size = xstate_sizes[i];
@@ -1157,7 +1157,7 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)
u64 mask = ((u64)1 << i);

if (hdr.xfeatures & mask) {
- void *dst = __raw_xsave_addr(xsave, 1 << i);
+ void *dst = __raw_xsave_addr(xsave, i);

offset = xstate_offsets[i];
size = xstate_sizes[i];
@@ -1211,7 +1211,7 @@ int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf)
u64 mask = ((u64)1 << i);

if (hdr.xfeatures & mask) {
- void *dst = __raw_xsave_addr(xsave, 1 << i);
+ void *dst = __raw_xsave_addr(xsave, i);

offset = xstate_offsets[i];
size = xstate_sizes[i];