[PATCH 153/208] x86/fpu: Enumerate xfeature bits

From: Ingo Molnar
Date: Tue May 05 2015 - 13:56:59 EST


Transform the xstate masks into an enumerated list of xfeature bits.

This removes the hard coding of XFEATURES_NR_MAX.

Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/fpu/xstate.h | 38 ++++++++++++++++++++++++++------------
1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 2f2ed322263f..9b2869dea490 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -4,25 +4,39 @@
#include <linux/types.h>
#include <asm/processor.h>

-#define XSTATE_CPUID 0x0000000d
-
-#define XSTATE_FP 0x1
-#define XSTATE_SSE 0x2
-#define XSTATE_YMM 0x4
-#define XSTATE_BNDREGS 0x8
-#define XSTATE_BNDCSR 0x10
-#define XSTATE_OPMASK 0x20
-#define XSTATE_ZMM_Hi256 0x40
-#define XSTATE_Hi16_ZMM 0x80
+/*
+ * List of XSAVE features Linux knows about:
+ */
+enum xfeature_bit {
+ XSTATE_BIT_FP,
+ XSTATE_BIT_SSE,
+ XSTATE_BIT_YMM,
+ XSTATE_BIT_BNDREGS,
+ XSTATE_BIT_BNDCSR,
+ XSTATE_BIT_OPMASK,
+ XSTATE_BIT_ZMM_Hi256,
+ XSTATE_BIT_Hi16_ZMM,
+
+ XFEATURES_NR_MAX,
+};
+
+#define XSTATE_FP (1 << XSTATE_BIT_FP)
+#define XSTATE_SSE (1 << XSTATE_BIT_SSE)
+#define XSTATE_YMM (1 << XSTATE_BIT_YMM)
+#define XSTATE_BNDREGS (1 << XSTATE_BIT_BNDREGS)
+#define XSTATE_BNDCSR (1 << XSTATE_BIT_BNDCSR)
+#define XSTATE_OPMASK (1 << XSTATE_BIT_OPMASK)
+#define XSTATE_ZMM_Hi256 (1 << XSTATE_BIT_ZMM_Hi256)
+#define XSTATE_Hi16_ZMM (1 << XSTATE_BIT_Hi16_ZMM)

-/* The highest xstate bit above (of XSTATE_Hi16_ZMM): */
-#define XFEATURES_NR_MAX 8

#define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE)
#define XSTATE_AVX512 (XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM)
/* Bit 63 of XCR0 is reserved for future expansion */
#define XSTATE_EXTEND_MASK (~(XSTATE_FPSSE | (1ULL << 63)))

+#define XSTATE_CPUID 0x0000000d
+
#define FXSAVE_SIZE 512

#define XSAVE_HDR_SIZE 64
--
2.1.0

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