Commit e783e816 authored Apr 24, 2015 by Ingo Molnar

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 <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 678eaf60

arch/x86/include/asm/fpu/types.h

+9 −2

Original line number	Diff line number	Diff line
		@@ -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: */