From: Dave Hansen <dave@sr71.net>
To: dave@sr71.net
Cc: dave.hansen@linux.intel.com, mingo@redhat.com, x86@kernel.org,
bp@alien8.de, fenghua.yu@intel.com, tim.c.chen@linux.intel.com,
linux-kernel@vger.kernel.org
Subject: [PATCH 09/15] x86, fpu: add helper xfeature_enabled() instead of test_bit()
Date: Wed, 02 Sep 2015 16:31:29 -0700 [thread overview]
Message-ID: <20150902233129.B1534F86@viggo.jf.intel.com> (raw)
In-Reply-To: <20150902233123.3A7E5FB0@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
We currently use test_bit() in a few places to see if an xfeature
is enabled. It ends up being a bit ugly because 'xfeatures_mask'
is a u64 and test_bit wants an 'unsigned long' so it requires a
cast. The *_bit() functions are also techincally atomic, which
we have no need for here.
So, remove the test_bit()s and replace with the new
xfeature_enabled() helper.
This also provides a central place to add a comment about the
future need to support 'system xstates'.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
---
b/arch/x86/kernel/fpu/xstate.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff -puN arch/x86/kernel/fpu/xstate.c~use-xfeature_enabled arch/x86/kernel/fpu/xstate.c
--- a/arch/x86/kernel/fpu/xstate.c~use-xfeature_enabled 2015-09-02 15:52:54.829114131 -0700
+++ b/arch/x86/kernel/fpu/xstate.c 2015-09-02 16:23:59.357839810 -0700
@@ -226,6 +226,16 @@ static void __init print_xstate_features
}
/*
+ * Note that in the future we will likely need a pair of
+ * functions here: one for user xstates and the other for
+ * system xstates. For now, they are the same.
+ */
+static int xfeature_enabled(enum xfeature xfeature)
+{
+ return !!(xfeatures_mask & (1UL << xfeature));
+}
+
+/*
* This function sets up offsets and sizes of all extended states in
* xsave area. This supports both standard format and compacted format
* of the xsave aread.
@@ -245,7 +255,7 @@ static void __init setup_xstate_comp(voi
if (!cpu_has_xsaves) {
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
- if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
+ if (xfeature_enabled(i)) {
xstate_comp_offsets[i] = xstate_offsets[i];
xstate_comp_sizes[i] = xstate_sizes[i];
}
@@ -257,7 +267,7 @@ static void __init setup_xstate_comp(voi
FXSAVE_SIZE + XSAVE_HDR_SIZE;
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
- if (test_bit(i, (unsigned long *)&xfeatures_mask))
+ if (xfeature_enabled(i))
xstate_comp_sizes[i] = xstate_sizes[i];
else
xstate_comp_sizes[i] = 0;
@@ -319,7 +329,7 @@ static unsigned int __init calculate_xst
calculated_xstate_size = FXSAVE_SIZE + XSAVE_HDR_SIZE;
for (i = FIRST_EXTENDED_XFEATURE; i < 64; i++) {
- if (test_bit(i, (unsigned long *)&xfeatures_mask)) {
+ if (xfeature_enabled(i)) {
cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
calculated_xstate_size += eax;
}
_
next prev parent reply other threads:[~2015-09-02 23:33 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-02 23:31 [PATCH 00/15] [v4] x86, fpu: XSAVE cleanups and sanity checks Dave Hansen
2015-09-02 23:31 ` [PATCH 01/15] x86, fpu: print xfeature buffer size in decimal Dave Hansen
2015-09-14 12:19 ` [tip:x86/fpu] x86/fpu: Print " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 02/15] x86, fpu: move XSAVE-disabling code to a helper Dave Hansen
2015-09-14 12:19 ` [tip:x86/fpu] x86/fpu: Move " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 03/15] x86, fpu: remove XSTATE_RESERVE Dave Hansen
2015-09-14 12:20 ` [tip:x86/fpu] x86/fpu: Remove XSTATE_RESERVE tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 04/15] x86, fpu: kill LWP support Dave Hansen
2015-09-14 12:20 ` [tip:x86/fpu] x86/fpu: Remove partial LWP support definitions tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 05/15] x86, fpu: XSAVE macro renames Dave Hansen
2015-09-14 12:21 ` [tip:x86/fpu] x86/fpu: Rename XSAVE macros tip-bot for Dave Hansen
2015-09-23 10:49 ` Borislav Petkov
2015-09-24 7:24 ` [tip:x86/fpu] x86/fpu: Fixup uninitialized feature_name warning tip-bot for Borislav Petkov
2015-09-02 23:31 ` [PATCH 06/15] x86, fpu: rename XFEATURES_NR_MAX Dave Hansen
2015-09-14 12:21 ` [tip:x86/fpu] x86/fpu: Rename XFEATURES_NR_MAX tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 08/15] x86, fpu: remove xfeature_nr Dave Hansen
2015-09-14 12:22 ` [tip:x86/fpu] x86/fpu: Remove 'xfeature_nr' tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 07/15] x86, fpu: rework XSTATE_* macros to remove magic '2' Dave Hansen
2015-09-14 12:21 ` [tip:x86/fpu] x86/fpu: Rework " tip-bot for Dave Hansen
2015-09-02 23:31 ` Dave Hansen [this message]
2015-09-14 12:22 ` [tip:x86/fpu] x86/fpu: Add xfeature_enabled() helper instead of test_bit() tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 10/15] x86, fpu: rework MPX 'xstate' types Dave Hansen
2015-09-14 12:22 ` [tip:x86/fpu] x86/fpu/mpx: Rework " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 12/15] x86, fpu: add C structures for AVX-512 state components Dave Hansen
2015-09-14 12:23 ` [tip:x86/fpu] x86/fpu: Add " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 11/15] x86, fpu: rework YMM definition Dave Hansen
2015-09-14 12:23 ` [tip:x86/fpu] x86/fpu: Rework " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 14/15] x86, fpu: check to ensure increasing-offset xstate offsets Dave Hansen
2015-09-14 12:24 ` [tip:x86/fpu] x86/fpu: Check " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 13/15] x86, fpu: correct and check XSAVE xstate size calculations Dave Hansen
2015-09-14 12:23 ` [tip:x86/fpu] x86/fpu: Correct " tip-bot for Dave Hansen
2015-09-02 23:31 ` [PATCH 15/15] x86, fpu: check CPU-provided sizes against struct declarations Dave Hansen
2015-09-14 12:24 ` [tip:x86/fpu] x86/fpu: Check " tip-bot for Dave Hansen
2015-09-14 10:07 ` [PATCH 00/15] [v4] x86, fpu: XSAVE cleanups and sanity checks Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2015-08-31 22:20 [PATCH 00/15] [v3] " Dave Hansen
2015-08-31 22:20 ` [PATCH 09/15] x86, fpu: add helper xfeature_enabled() instead of test_bit() Dave Hansen
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