Commit-ID: 03482e08a87d24e5c8c23e6981c482e832cf3bdc Gitweb: http://git.kernel.org/tip/03482e08a87d24e5c8c23e6981c482e832cf3bdc Author: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> AuthorDate: Fri, 17 Jun 2016 13:07:15 -0700 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Sun, 10 Jul 2016 17:12:10 +0200 x86/fpu/xstate: Align xstate components according to CPUID CPUID function 0x0d, sub function (i, i > 1) returns in ecx[1] the alignment requirement of component 'i' when the compacted format is used. If ecx[1] is 0, component 'i' is located immediately following the preceding component. If ecx[1] is 1, component 'i' is located on the next 64-byte boundary following the preceding component. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Quentin Casasnovas <quentin.casasnovas@xxxxxxxxxx> Cc: Ravi V. Shankar <ravi.v.shankar@xxxxxxxxx> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/331e2bef1a0a7a584f06adde095b6bbfbe166472.1466179491.git.yu-cheng.yu@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/fpu/xstate.c | 60 +++++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 28 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 0b01f00..7963029 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -270,6 +270,33 @@ static void __init print_xstate_features(void) } /* + * This check is important because it is easy to get XSTATE_* + * confused with XSTATE_BIT_*. + */ +#define CHECK_XFEATURE(nr) do { \ + WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \ + WARN_ON(nr >= XFEATURE_MAX); \ +} while (0) + +/* + * We could cache this like xstate_size[], but we only use + * it here, so it would be a waste of space. + */ +static int xfeature_is_aligned(int xfeature_nr) +{ + u32 eax, ebx, ecx, edx; + + CHECK_XFEATURE(xfeature_nr); + cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); + /* + * The value returned by ECX[1] indicates the alignment + * of state component 'i' when the compacted format + * of the extended region of an XSAVE area is used: + */ + return !!(ecx & 2); +} + +/* * 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. @@ -306,10 +333,14 @@ static void __init setup_xstate_comp(void) else xstate_comp_sizes[i] = 0; - if (i > FIRST_EXTENDED_XFEATURE) + if (i > FIRST_EXTENDED_XFEATURE) { xstate_comp_offsets[i] = xstate_comp_offsets[i-1] + xstate_comp_sizes[i-1]; + if (xfeature_is_aligned(i)) + xstate_comp_offsets[i] = + ALIGN(xstate_comp_offsets[i], 64); + } } } @@ -366,33 +397,6 @@ static int xfeature_is_user(int xfeature_nr) } */ -/* - * This check is important because it is easy to get XSTATE_* - * confused with XSTATE_BIT_*. - */ -#define CHECK_XFEATURE(nr) do { \ - WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \ - WARN_ON(nr >= XFEATURE_MAX); \ -} while (0) - -/* - * We could cache this like xstate_size[], but we only use - * it here, so it would be a waste of space. - */ -static int xfeature_is_aligned(int xfeature_nr) -{ - u32 eax, ebx, ecx, edx; - - CHECK_XFEATURE(xfeature_nr); - cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx); - /* - * The value returned by ECX[1] indicates the alignment - * of state component i when the compacted format - * of the extended region of an XSAVE area is used - */ - return !!(ecx & 2); -} - static int xfeature_uncompacted_offset(int xfeature_nr) { u32 eax, ebx, ecx, edx; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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