Commit-ID: 633d54c47a5bedfb42f10e6a63eeeebd35abdb4c Gitweb: http://git.kernel.org/tip/633d54c47a5bedfb42f10e6a63eeeebd35abdb4c Author: Dave Hansen <dave.han...@linux.intel.com> AuthorDate: Wed, 2 Sep 2015 16:31:29 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 14 Sep 2015 12:21:59 +0200
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.han...@linux.intel.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: Fenghua Yu <fenghua...@intel.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Tim Chen <tim.c.c...@linux.intel.com> Cc: d...@sr71.net Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20150902233129.b1534...@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/fpu/xstate.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 61ec60b..ba6b6e0 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
