From e783e8167ddf275782ef448eb139fafff3ac3af2 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 24 Apr 2015 11:43:47 +0200 Subject: [PATCH] x86/fpu: Explain the AVX register layout in the xsave area The previous explanation was rather cryptic. Also transform "u32 [64]" to the more readable "u8[256]" form. No change in implementation. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/types.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 9bd2cd1a19fd..8a5120a3b48b 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -78,9 +78,16 @@ struct i387_soft_struct { u32 entry_eip; }; +/* + * There are 16x 256-bit AVX registers named YMM0-YMM15. + * The low 128 bits are aliased to the 16 SSE registers (XMM0-XMM15) + * and are stored in 'struct i387_fxsave_struct::xmm_space[]'. + * + * The high 128 bits are stored here: + * 16x 128 bits == 256 bytes. + */ struct ymmh_struct { - /* 16 * 16 bytes for each YMMH-reg = 256 bytes */ - u32 ymmh_space[64]; + u8 ymmh_space[256]; }; /* We don't support LWP yet: */ -- 2.39.5