x86: Add PTWRITE feature detection [BZ #27346]

1. Add CPUID_INDEX_14_ECX_0 for CPUID leaf 0x14 to detect PTWRITE feature
in EBX of CPUID leaf 0x14 with ECX == 0.
2. Add PTWRITE detection to CPU feature tests.
3. Add 2 static CPU feature tests.

manual/platform.texi

@@ -487,6 +487,9 @@ extended state management using XSAVE/XRSTOR.
 @item
 @code{PSN} -- Processor Serial Number.
 
+@item
+@code{PTWRITE} -- PTWRITE instruction.
+
 @item
 @code{RDPID} -- RDPID instruction.
 

sysdeps/x86/Makefile

@@ -8,8 +8,11 @@ sysdep-dl-routines += dl-get-cpu-features
 sysdep_headers += sys/platform/x86.h
 
 tests += tst-get-cpu-features tst-get-cpu-features-static \
-	 tst-cpu-features-cpuinfo tst-cpu-features-supports
+	 tst-cpu-features-cpuinfo tst-cpu-features-cpuinfo-static \
-tests-static += tst-get-cpu-features-static
+	 tst-cpu-features-supports tst-cpu-features-supports-static
+tests-static += tst-get-cpu-features-static \
+		tst-cpu-features-cpuinfo-static \
+		tst-cpu-features-supports-static
 ifeq (yes,$(have-ifunc))
 tests += \
   tst-ifunc-isa-1 \

sysdeps/x86/bits/platform/x86.h

@@ -29,7 +29,8 @@ enum
   CPUID_INDEX_80000007,
   CPUID_INDEX_80000008,
   CPUID_INDEX_7_ECX_1,
-  CPUID_INDEX_19
+  CPUID_INDEX_19,
+  CPUID_INDEX_14_ECX_0
 };
 
 struct cpuid_feature
@@ -295,5 +296,11 @@ enum
        + cpuid_register_index_ebx * 8 * sizeof (unsigned int)),
 
   x86_cpu_AESKLE		= x86_cpu_index_19_ebx,
-  x86_cpu_WIDE_KL		= x86_cpu_index_19_ebx + 2
+  x86_cpu_WIDE_KL		= x86_cpu_index_19_ebx + 2,
+
+  x86_cpu_index_14_ecx_0_ebx
+    = (CPUID_INDEX_14_ECX_0 * 8 * 4 * sizeof (unsigned int)
+       + cpuid_register_index_ebx * 8 * sizeof (unsigned int)),
+
+  x86_cpu_PTWRITE		= x86_cpu_index_14_ecx_0_ebx + 4
 };

sysdeps/x86/cpu-features.c

@@ -97,6 +97,7 @@ update_usable (struct cpu_features *cpu_features)
   CPU_FEATURE_SET_USABLE (cpu_features, FZLRM);
   CPU_FEATURE_SET_USABLE (cpu_features, FSRS);
   CPU_FEATURE_SET_USABLE (cpu_features, FSRCS);
+  CPU_FEATURE_SET_USABLE (cpu_features, PTWRITE);
 
   /* Can we call xgetbv?  */
   if (CPU_FEATURES_CPU_P (cpu_features, OSXSAVE))
@@ -359,6 +360,13 @@ get_common_indices (struct cpu_features *cpu_features,
 		   cpu_features->features[CPUID_INDEX_D_ECX_1].cpuid.ecx,
 		   cpu_features->features[CPUID_INDEX_D_ECX_1].cpuid.edx);
 
+  if (cpu_features->basic.max_cpuid >= 0x14)
+    __cpuid_count (0x14, 0,
+		   cpu_features->features[CPUID_INDEX_14_ECX_0].cpuid.eax,
+		   cpu_features->features[CPUID_INDEX_14_ECX_0].cpuid.ebx,
+		   cpu_features->features[CPUID_INDEX_14_ECX_0].cpuid.ecx,
+		   cpu_features->features[CPUID_INDEX_14_ECX_0].cpuid.edx);
+
   if (cpu_features->basic.max_cpuid >= 0x19)
     __cpuid_count (0x19, 0,
 		   cpu_features->features[CPUID_INDEX_19].cpuid.eax,

sysdeps/x86/include/cpu-features.h

@@ -29,7 +29,7 @@
 
 enum
 {
-  CPUID_INDEX_MAX = CPUID_INDEX_19 + 1
+  CPUID_INDEX_MAX = CPUID_INDEX_14_ECX_0 + 1
 };
 
 enum
@@ -307,6 +307,11 @@ enum
 #define bit_cpu_AESKLE		(1u << 0)
 #define bit_cpu_WIDE_KL		(1u << 2)
 
+/* CPUID_INDEX_14_ECX_0.  */
+
+/* EBX.  */
+#define bit_cpu_PTWRITE		(1u << 4)
+
 /* CPUID_INDEX_1.  */
 
 /* ECX.  */
@@ -532,6 +537,11 @@ enum
 #define index_cpu_AESKLE	CPUID_INDEX_19
 #define index_cpu_WIDE_KL	CPUID_INDEX_19
 
+/* CPUID_INDEX_14_ECX_0.  */
+
+/* EBX.  */
+#define index_cpu_PTWRITE	CPUID_INDEX_14_ECX_0
+
 /* CPUID_INDEX_1.  */
 
 /* ECX.  */
@@ -757,6 +767,11 @@ enum
 #define reg_AESKLE		ebx
 #define reg_WIDE_KL		ebx
 
+/* CPUID_INDEX_14_ECX_0.  */
+
+/* EBX.  */
+#define reg_PTWRITE		ebx
+
 /* PREFERRED_FEATURE_INDEX_1.  */
 #define bit_arch_I586				(1u << 0)
 #define bit_arch_I686				(1u << 1)

sysdeps/x86/tst-cpu-features-cpuinfo-static.c

@@ -0,0 +1 @@
+#include "tst-cpu-features-cpuinfo.c"

sysdeps/x86/tst-cpu-features-cpuinfo.c

@@ -199,6 +199,7 @@ do_test (int argc, char **argv)
   fails += CHECK_PROC (popcnt, POPCNT);
   fails += CHECK_PROC (3dnowprefetch, PREFETCHW);
   fails += CHECK_PROC (prefetchwt1, PREFETCHWT1);
+  fails += CHECK_PROC (ptwrite, PTWRITE);
   fails += CHECK_PROC (pse, PSE);
   fails += CHECK_PROC (pse36, PSE_36);
   fails += CHECK_PROC (psn, PSN);

sysdeps/x86/tst-cpu-features-supports-static.c

@@ -0,0 +1 @@
+#include "tst-cpu-features-supports.c"

sysdeps/x86/tst-cpu-features-supports.c

@@ -149,6 +149,7 @@ do_test (int argc, char **argv)
   fails += CHECK_SUPPORTS (popcnt, POPCNT);
 #if __GNUC_PREREQ (11, 0)
   fails += CHECK_SUPPORTS (prefetchwt1, PREFETCHWT1);
+  fails += CHECK_SUPPORTS (ptwrite, PTWRITE);
   fails += CHECK_SUPPORTS (rdpid, RDPID);
   fails += CHECK_SUPPORTS (rdrnd, RDRAND);
   fails += CHECK_SUPPORTS (rdseed, RDSEED);

sysdeps/x86/tst-get-cpu-features.c

@@ -203,6 +203,7 @@ do_test (void)
   CHECK_CPU_FEATURE (LAM);
   CHECK_CPU_FEATURE (AESKLE);
   CHECK_CPU_FEATURE (WIDE_KL);
+  CHECK_CPU_FEATURE (PTWRITE);
 
   printf ("Usable CPU features:\n");
   CHECK_CPU_FEATURE_USABLE (SSE3);
@@ -364,6 +365,7 @@ do_test (void)
   CHECK_CPU_FEATURE_USABLE (FSRCS);
   CHECK_CPU_FEATURE_USABLE (AESKLE);
   CHECK_CPU_FEATURE_USABLE (WIDE_KL);
+  CHECK_CPU_FEATURE_USABLE (PTWRITE);
 
   return 0;
 }