[PATCH 1/3] x86/fpu/xstate: Fix small issues before adding supervisor xstates

[Yu-cheng Yu]

In response to earlier comments, fix small issues before introducing XSAVES
supervisor states:
- Add spaces around '*'.
- Fix comments of xfeature_is_supervisor().
- Replace ((u64)1 << 63) with XCOMP_BV_COMPACTED_FORMAT.

No functional changes from this patch.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 arch/x86/kernel/fpu/xstate.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index e5cb67d67c03..cfcac7b42e5e 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -60,7 +60,7 @@ u64 xfeatures_mask __read_mostly;
 
 static unsigned int xstate_offsets[XFEATURE_MAX] = { [ 0 ... XFEATURE_MAX - 1] = -1};
 static unsigned int xstate_sizes[XFEATURE_MAX]   = { [ 0 ... XFEATURE_MAX - 1] = -1};
-static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask)*8];
+static unsigned int xstate_comp_offsets[sizeof(xfeatures_mask) * 8];
 
 /*
  * The XSAVE area of kernel can be in standard or compacted format;
@@ -110,12 +110,9 @@ EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
 static int xfeature_is_supervisor(int xfeature_nr)
 {
 	/*
-	 * We currently do not support supervisor states, but if
-	 * we did, we could find out like this.
-	 *
-	 * SDM says: If state component 'i' is a user state component,
-	 * ECX[0] return 0; if state component i is a supervisor
-	 * state component, ECX[0] returns 1.
+	 * Extended State Enumeration Sub-leaves (EAX = 0DH, ECX = n, n > 1)
+	 * returns ECX[0] set to (1) for a supervisor state, and cleared (0)
+	 * for a user state.
 	 */
 	u32 eax, ebx, ecx, edx;
 
@@ -342,7 +339,7 @@ static int xfeature_is_aligned(int xfeature_nr)
  */
 static void __init setup_xstate_comp(void)
 {
-	unsigned int xstate_comp_sizes[sizeof(xfeatures_mask)*8];
+	unsigned int xstate_comp_sizes[sizeof(xfeatures_mask) * 8];
 	int i;
 
 	/*
@@ -415,7 +412,8 @@ static void __init setup_init_fpu_buf(void)
 	print_xstate_features();
 
 	if (boot_cpu_has(X86_FEATURE_XSAVES))
-		init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask;
+		init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT |
+						     xfeatures_mask;
 
 	/*
 	 * Init all the features state with header.xfeatures being 0x0
-- 
2.17.1