x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS features

AVX512_4VNNIW  - Vector instructions for deep learning enhanced word
variable precision.
AVX512_4FMAPS - Vector instructions for deep learning floating-point
single precision.

These new instructions are to be used in future Intel Xeon & Xeon Phi
processors. The bits 2&3 of CPUID[level:0x07, EDX] inform that new
instructions are supported by a processor.

The spec can be found in the Intel Software Developer Manual (SDM) or in
the Instruction Set Extensions Programming Reference (ISE).

Define new feature flags to enumerate the new instructions in /proc/cpuinfo
accordingly to CPUID bits and add the required xsave extensions which are
required for proper operation.

Signed-off-by: Piotr Luc <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

arch/x86/include/asm/cpufeatures.h

@@ -194,6 +194,8 @@
 #define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */
 
 #define X86_FEATURE_INTEL_PT	( 7*32+15) /* Intel Processor Trace */
+#define X86_FEATURE_AVX512_4VNNIW (7*32+16) /* AVX-512 Neural Network Instructions */
+#define X86_FEATURE_AVX512_4FMAPS (7*32+17) /* AVX-512 Multiply Accumulation Single precision */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW  ( 8*32+ 0) /* Intel TPR Shadow */

arch/x86/kernel/cpu/scattered.c

@@ -32,6 +32,8 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c)
 
 	static const struct cpuid_bit cpuid_bits[] = {
 		{ X86_FEATURE_INTEL_PT,		CR_EBX,25, 0x00000007, 0 },
+		{ X86_FEATURE_AVX512_4VNNIW,	CR_EDX, 2, 0x00000007, 0 },
+		{ X86_FEATURE_AVX512_4FMAPS,	CR_EDX, 3, 0x00000007, 0 },
 		{ X86_FEATURE_APERFMPERF,	CR_ECX, 0, 0x00000006, 0 },
 		{ X86_FEATURE_EPB,		CR_ECX, 3, 0x00000006, 0 },
 		{ X86_FEATURE_HW_PSTATE,	CR_EDX, 7, 0x80000007, 0 },

arch/x86/kernel/fpu/xstate.c

@@ -74,6 +74,8 @@ void fpu__xstate_clear_all_cpu_caps(void)
 	setup_clear_cpu_cap(X86_FEATURE_MPX);
 	setup_clear_cpu_cap(X86_FEATURE_XGETBV1);
 	setup_clear_cpu_cap(X86_FEATURE_PKU);
+	setup_clear_cpu_cap(X86_FEATURE_AVX512_4VNNIW);
+	setup_clear_cpu_cap(X86_FEATURE_AVX512_4FMAPS);
 }
 
 /*

tools/arch/x86/include/asm/cpufeatures.h

@@ -194,6 +194,8 @@
 #define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */
 
 #define X86_FEATURE_INTEL_PT	( 7*32+15) /* Intel Processor Trace */
+#define X86_FEATURE_AVX512_4VNNIW (7*32+16) /* AVX-512 Neural Network Instructions */
+#define X86_FEATURE_AVX512_4FMAPS (7*32+17) /* AVX-512 Multiply Accumulation Single precision */
 
 /* Virtualization flags: Linux defined, word 8 */
 #define X86_FEATURE_TPR_SHADOW  ( 8*32+ 0) /* Intel TPR Shadow */