diff options
author | Dave Hansen <dave.hansen@linux.intel.com> | 2015-09-03 01:31:29 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-09-14 12:21:59 +0200 |
commit | 633d54c47a5bedfb42f10e6a63eeeebd35abdb4c (patch) | |
tree | 45237ce470657344893177c898ef7e9b831c6d7c /arch | |
parent | x86/fpu: Remove 'xfeature_nr' (diff) | |
download | linux-633d54c47a5bedfb42f10e6a63eeeebd35abdb4c.tar.xz linux-633d54c47a5bedfb42f10e6a63eeeebd35abdb4c.zip |
x86/fpu: Add xfeature_enabled() helper instead of test_bit()
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: 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/20150902233129.B1534F86@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 61ec60bcbb63..ba6b6e0baf88 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -226,6 +226,16 @@ static void __init print_xstate_features(void) } /* + * 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(void) 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(void) 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_xstate_size(void) 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; } |