x86/fpu: Add C structures for AVX-512 state components

AVX-512 has 3 separate state components:

  1. opmask registers
  2. zmm upper half of registers 0-15
  3. new zmm registers (16-31)

This patch adds C structures for the three components along with
a few comments mostly lifted from the SDM to explain what they
do.  This will allow us to check our structures against what the
hardware tells us about the sizes of the components.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: dave@sr71.net
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20150902233129.F2433B98@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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

@@ -131,6 +131,12 @@ enum xfeature {
 struct reg_128_bit {
 	u8      regbytes[128/8];
 };
+struct reg_256_bit {
+	u8	regbytes[256/8];
+};
+struct reg_512_bit {
+	u8	regbytes[512/8];
+};
 
 /*
  * State component 2:
@@ -179,6 +185,33 @@ struct mpx_bndcsr_state {
 	};
 } __packed;
 
+/* AVX-512 Components: */
+
+/*
+ * State component 5 is used for the 8 64-bit opmask registers
+ * k0-k7 (opmask state).
+ */
+struct avx_512_opmask_state {
+	u64				opmask_reg[8];
+} __packed;
+
+/*
+ * State component 6 is used for the upper 256 bits of the
+ * registers ZMM0-ZMM15. These 16 256-bit values are denoted
+ * ZMM0_H-ZMM15_H (ZMM_Hi256 state).
+ */
+struct avx_512_zmm_uppers_state {
+	struct reg_256_bit		zmm_upper[16];
+} __packed;
+
+/*
+ * State component 7 is used for the 16 512-bit registers
+ * ZMM16-ZMM31 (Hi16_ZMM state).
+ */
+struct avx_512_hi16_state {
+	struct reg_512_bit		hi16_zmm[16];
+} __packed;
+
 struct xstate_header {
 	u64				xfeatures;
 	u64				xcomp_bv;