lkml.org 
[lkml]   [2019]   [Dec]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/3] x86/fpu/xstate: Fix small issues before adding supervisor xstates
Date
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@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
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
\
 
 \ /
  Last update: 2019-12-05 19:42    [W:0.034 / U:0.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site