1 files changed, 83 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
new file mode 100644
index 0000000000..39eba0186f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c
@@ -0,0 +1,83 @@
+/* Initialize CPU feature data.  AArch64 version.
+   This file is part of the GNU C Library.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <cpu-features.h>
+#include <sys/auxv.h>
+#include <elf/dl-hwcaps.h>
+
+#define DCZID_DZP_MASK (1 << 4)
+#define DCZID_BS_MASK (0xf)
+
+#if HAVE_TUNABLES
+struct cpu_list
+{
+  const char *name;
+  uint64_t midr;
+};
+
+static struct cpu_list cpu_list[] = {
+      {"falkor",	 0x510FC000},
+      {"thunderxt88",	 0x430F0A10},
+      {"thunderx2t99",   0x431F0AF0},
+      {"thunderx2t99p1", 0x420F5160},
+      {"phecda",	 0x680F0000},
+      {"generic", 	 0x0}
+};
+
+static uint64_t
+get_midr_from_mcpu (const char *mcpu)
+{
+  for (int i = 0; i < sizeof (cpu_list) / sizeof (struct cpu_list); i++)
+    if (strcmp (mcpu, cpu_list[i].name) == 0)
+      return cpu_list[i].midr;
+
+  return UINT64_MAX;
+}
+#endif
+
+static inline void
+init_cpu_features (struct cpu_features *cpu_features)
+{
+  register uint64_t midr = UINT64_MAX;
+
+#if HAVE_TUNABLES
+  /* Get the tunable override.  */
+  const char *mcpu = TUNABLE_GET (glibc, tune, cpu, const char *, NULL);
+  if (mcpu != NULL)
+    midr = get_midr_from_mcpu (mcpu);
+#endif
+
+  /* If there was no useful tunable override, query the MIDR if the kernel
+     allows it.  */
+  if (midr == UINT64_MAX)
+    {
+      if (GLRO (dl_hwcap) & HWCAP_CPUID)
+	asm volatile ("mrs %0, midr_el1" : "=r"(midr));
+      else
+	midr = 0;
+    }
+
+  cpu_features->midr_el1 = midr;
+
+  /* Check if ZVA is enabled.  */
+  unsigned dczid;
+  asm volatile ("mrs %0, dczid_el0" : "=r"(dczid));
+
+  if ((dczid & DCZID_DZP_MASK) == 0)
+    cpu_features->zva_size = 4 << (dczid & DCZID_BS_MASK);
+}