common/arch/arm: Improve CPU feature check.

Signed-off-by: Adam Kupczyk <[email protected]>
knoppixmeister · May 24, 2018 · d998580 · d998580
1 parent 90b1c1f
commit d998580
Showing 1 changed file with 10 additions and 31 deletions.
diff --git a/src/arch/arm.c b/src/arch/arm.c
@@ -12,47 +12,26 @@ int ceph_arch_aarch64_pmull = 0;
 
 #include <elf.h>
 #include <link.h> // ElfW macro
+#include <sys/auxv.h>
 
 #if __arm__ || __aarch64__
 #include <asm/hwcap.h>
 #endif // __arm__
 
-static unsigned long get_auxval(unsigned long type)
-{
-	unsigned long result = 0;
-	FILE *f = fopen("/proc/self/auxv", "r");
-	if (f) {
-		ElfW(auxv_t) entry;
-		while (fread(&entry, sizeof(entry), 1, f) == 1) {
-			if (entry.a_type == type) {
-				result = entry.a_un.a_val;
-				break;
-			}
-		}
-		fclose(f);
-	}
-	return result;
-}
-
-static unsigned long get_hwcap(void)
-{
-	return get_auxval(AT_HWCAP);
-}
-
 #endif // __linux__
 
 int ceph_arch_arm_probe(void)
 {
-#if __arm__ && __linux__
-	ceph_arch_neon = (get_hwcap() & HWCAP_NEON) == HWCAP_NEON;
-#elif __aarch64__ && __linux__
-	ceph_arch_neon = (get_hwcap() & HWCAP_ASIMD) == HWCAP_ASIMD;
-	ceph_arch_aarch64_crc32 = (get_hwcap() & HWCAP_CRC32) == HWCAP_CRC32;
-        ceph_arch_aarch64_pmull = (get_hwcap() & HWCAP_PMULL) == HWCAP_PMULL;
-#else
-	if (0)
-		get_hwcap();  // make compiler shut up
+#if __linux__
+	unsigned long hwcap = getauxval(AT_HWCAP);
+#if __arm__
+	ceph_arch_neon = (hwcap & HWCAP_NEON) == HWCAP_NEON;
+#elif __aarch64__
+	ceph_arch_neon = (hwcap & HWCAP_ASIMD) == HWCAP_ASIMD;
+	ceph_arch_aarch64_crc32 = (hwcap & HWCAP_CRC32) == HWCAP_CRC32;
+	ceph_arch_aarch64_pmull = (hwcap & HWCAP_PMULL) == HWCAP_PMULL;
 #endif
+#endif // __linux__
 	return 0;
 }