[PATCH v2] lib/eal/ppc fix compilation for musl

[Duncan Bellamy]

musl lacks __ppc_get_timebase() but has __builtin_ppc_get_timebase()

the __ppc_get_timebase_freq() is taken from:
https://git.alpinelinux.org/aports/commit/?id=06b03f70fb94972286c0c9f6278df89e53903833

Signed-off-by: Duncan Bellamy <dunk at denkimushi.com>
---
 lib/eal/ppc/include/rte_cycles.h |  6 ++++++
 lib/eal/ppc/rte_cycles.c         | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/lib/eal/ppc/include/rte_cycles.h b/lib/eal/ppc/include/rte_cycles.h
index 5585f9273c..98ffbd2592 100644
--- a/lib/eal/ppc/include/rte_cycles.h
+++ b/lib/eal/ppc/include/rte_cycles.h
@@ -10,7 +10,9 @@
 extern "C" {
 #endif
 
+#if defined(__GLIBC__)
 #include <sys/platform/ppc.h>
+#endif
 
 #include "generic/rte_cycles.h"
 
@@ -26,7 +28,11 @@ extern "C" {
 static inline uint64_t
 rte_rdtsc(void)
 {
+#if defined(__GLIBC__)
 	return __ppc_get_timebase();
+#else
+	return __builtin_ppc_get_timebase();
+#endif
 }
 
 static inline uint64_t
diff --git a/lib/eal/ppc/rte_cycles.c b/lib/eal/ppc/rte_cycles.c
index 3180adb0ff..154eba722c 100644
--- a/lib/eal/ppc/rte_cycles.c
+++ b/lib/eal/ppc/rte_cycles.c
@@ -2,12 +2,44 @@
  * Copyright (C) IBM Corporation 2019.
  */
 
+#if defined(__GLIBC__)
 #include <sys/platform/ppc.h>
+#else
+#include <string.h>
+#include <stdio.h>
+#endif
 
 #include "eal_private.h"
 
 uint64_t
 get_tsc_freq_arch(void)
 {
+#if defined(__GLIBC__)
 	return __ppc_get_timebase_freq();
+#else
+	static uint64_t base;
+	if (!base) {
+		FILE *f = fopen("/proc/cpuinfo", "rb");
+		if (f) {
+			ssize_t nr;
+			/* virtually always big enough to hold the line */
+			char buf[512];
+			while (fgets(buf, sizeof(buf), f)) {
+				char *ret = strstr(buf, "timebase");
+				if (!ret) {
+					continue;
+				}
+				ret += sizeof("timebase") - 1;
+				ret = strchr(ret, ':');
+				if (!ret) {
+					continue;
+				}
+				base = strtoul(ret + 1, 0, 10);
+				break;
+			}
+			fclose(f);
+		}
+	}
+	return base;;
+#endif
 }
-- 
2.32.0