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Commit a30469e7 authored by Suresh Siddha's avatar Suresh Siddha Committed by Ingo Molnar
Browse files

x86: add linux kernel support for YMM state 

Impact: save/restore Intel-AVX state properly between tasks

Intel Advanced Vector Extensions (AVX) introduce 256-bit vector processing
capability. More about AVX at http://software.intel.com/sites/avx



Add OS support for YMM state management using xsave/xrstor infrastructure
to support AVX.

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1239402084.27006.8057.camel@localhost.localdomain>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 1ee4bd92

arch/x86/include/asm/processor.h

+6 −0
Original line number Diff line number Diff line
@@ -352,6 +352,11 @@ struct i387_soft_struct { 
	u32			entry_eip;

};



struct ymmh_struct {

	/* 16 * 16 bytes for each YMMH-reg = 256 bytes */

	u32 ymmh_space[64];

};



struct xsave_hdr_struct {

	u64 xstate_bv;

	u64 reserved1[2];
@@ -361,6 +366,7 @@ struct xsave_hdr_struct { 
struct xsave_struct {

	struct i387_fxsave_struct i387;

	struct xsave_hdr_struct xsave_hdr;

	struct ymmh_struct ymmh;

	/* new processor state extensions will go here */

} __attribute__ ((packed, aligned (64)));

arch/x86/include/asm/sigcontext.h

+6 −0
Original line number Diff line number Diff line
@@ -269,6 +269,11 @@ struct _xsave_hdr { 
	__u64 reserved2[5];

};



struct _ymmh_state {

	/* 16 * 16 bytes for each YMMH-reg */

	__u32 ymmh_space[64];

};



/*

 * Extended state pointed by the fpstate pointer in the sigcontext.

 * In addition to the fpstate, information encoded in the xstate_hdr
@@ -278,6 +283,7 @@ struct _xsave_hdr { 
struct _xstate {

	struct _fpstate fpstate;

	struct _xsave_hdr xstate_hdr;

	struct _ymmh_state ymmh;

	/* new processor state extensions go here */

};

arch/x86/include/asm/xsave.h

+2 −1
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


#define XSTATE_FP	0x1

#define XSTATE_SSE	0x2

#define XSTATE_YMM	0x4



#define XSTATE_FPSSE	(XSTATE_FP | XSTATE_SSE)
@@ -15,7 +16,7 @@ 
/*

 * These are the features that the OS can handle currently.

 */

#define XCNTXT_MASK	(XSTATE_FP | XSTATE_SSE)

#define XCNTXT_MASK	(XSTATE_FP | XSTATE_SSE | XSTATE_YMM)



#ifdef CONFIG_X86_64

#define REX_PREFIX	"0x48, "

arch/x86/kernel/xsave.c

+1 −1
Original line number Diff line number Diff line
@@ -324,7 +324,7 @@ void __ref xsave_cntxt_init(void) 
	}



	/*

	 * for now OS knows only about FP/SSE

	 * Support only the state known to OS.

	 */

	pcntxt_mask = pcntxt_mask & XCNTXT_MASK;

	xsave_init();