x86/fpu: Rename XSAVE macros

There are two concepts that have some confusing naming:
 1. Extended State Component numbers (currently called
    XFEATURE_BIT_*)
 2. Extended State Component masks (currently called XSTATE_*)

The numbers are (currently) from 0-9.  State component 3 is the
bounds registers for MPX, for instance.

But when we want to enable "state component 3", we go set a bit
in XCR0.  The bit we set is 1<<3.  We can check to see if a
state component feature is enabled by looking at its bit.

The current 'xfeature_bit's are at best xfeature bit _numbers_.
Calling them bits is at best inconsistent with ending the enum
list with 'XFEATURES_NR_MAX'.

This patch renames the enum to be 'xfeature'.  These also
happen to be what the Intel documentation calls a "state
component".

We also want to differentiate these from the "XSTATE_*" macros.
The "XSTATE_*" macros are a mask, and we rename them to match.

These macros are reasonably widely used so this patch is a
wee bit big, but this really is just a rename.

The only non-mechanical part of this is the

	s/XSTATE_EXTEND_MASK/XFEATURE_MASK_EXTEND/

We need a better name for it, but that's another patch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
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: Fenghua Yu <fenghua.yu@intel.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>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233126.38653250@viggo.jf.intel.com
[ Ported to v4.3-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 2fbea25..156441b 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -30,7 +30,7 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted)
 	int feature_bit = 0;
 	u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
 
-	xstate_bv &= XSTATE_EXTEND_MASK;
+	xstate_bv &= XFEATURE_MASK_EXTEND;
 	while (xstate_bv) {
 		if (xstate_bv & 0x1) {
 		        u32 eax, ebx, ecx, edx, offset;
@@ -51,7 +51,7 @@ u64 kvm_supported_xcr0(void)
 	u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
 
 	if (!kvm_x86_ops->mpx_supported())
-		xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
+		xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
 
 	return xcr0;
 }