[PATCH 1/2] selftests/powerpc: Refactor the AUXV routines

@@ -24,7 +24,11 @@ typedef uint8_t u8;
 
 void test_harness_set_timeout(uint64_t time);
 int test_harness(int (test_function)(void), char *name);
-extern void *get_auxv_entry(int type);
+
+int read_auxv(char *buf, ssize_t buf_size);
+void *find_auxv_entry(int type, char *auxv);
+void *get_auxv_entry(int type);
+
 int pick_online_cpu(void);
 
 static inline bool have_hwcap(unsigned long ftr)

@@ -19,45 +19,64 @@
 
 static char auxv[4096];
 
-void *get_auxv_entry(int type)
+int read_auxv(char *buf, ssize_t buf_size)
 {
-	ElfW(auxv_t) *p;
-	void *result;
 	ssize_t num;
-	int fd;
+	int rc, fd;
 
 	fd = open("/proc/self/auxv", O_RDONLY);
 	if (fd == -1) {
 		perror("open");
-		return NULL;
+		return -errno;
 	}
 
-	result = NULL;
-
-	num = read(fd, auxv, sizeof(auxv));
+	num = read(fd, buf, buf_size);
 	if (num < 0) {
 		perror("read");
+		rc = -EIO;
 		goto out;
 	}
 
-	if (num > sizeof(auxv)) {
-		printf("Overflowed auxv buffer\n");
+	if (num > buf_size) {
+		printf("overflowed auxv buffer\n");
+		rc = -EOVERFLOW;
 		goto out;
 	}
 
+	rc = 0;
+out:
+	close(fd);
+	return rc;
+}
+
+void *find_auxv_entry(int type, char *auxv)
+{
+	ElfW(auxv_t) *p;
+
 	p = (ElfW(auxv_t) *)auxv;
 
 	while (p->a_type != AT_NULL) {
-		if (p->a_type == type) {
-			result = (void *)p->a_un.a_val;
-			break;
-		}
+		if (p->a_type == type)
+			return p;
 
 		p++;
 	}
-out:
-	close(fd);
-	return result;
+
+	return NULL;
+}
+
+void *get_auxv_entry(int type)
+{
+	ElfW(auxv_t) *p;
+
+	if (read_auxv(auxv, sizeof(auxv)))
+		return NULL;
+
+	p = find_auxv_entry(type, auxv);
+	if (p)
+		return (void *)p->a_un.a_val;
+
+	return NULL;
 }
 
 int pick_online_cpu(void)

@@ -14,6 +14,7 @@ export CFLAGS
 
 SUB_DIRS = alignment		\
 	   benchmarks		\
+	   cache_shape		\
 	   copyloops		\
 	   context_switch	\
 	   dscr			\

@@ -0,0 +1 @@
+cache_shape

@@ -0,0 +1,10 @@
+TEST_PROGS := cache_shape
+
+all: $(TEST_PROGS)
+
+$(TEST_PROGS): ../harness.c ../utils.c
+
+include ../../lib.mk
+
+clean:
+	rm -f $(TEST_PROGS) *.o

@@ -0,0 +1,125 @@
+/*
+ * Copyright 2017, Michael Ellerman, IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <link.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+#ifndef AT_L1I_CACHESIZE
+#define AT_L1I_CACHESIZE	40
+#define AT_L1I_CACHEGEOMETRY	41
+#define AT_L1D_CACHESIZE	42
+#define AT_L1D_CACHEGEOMETRY	43
+#define AT_L2_CACHESIZE		44
+#define AT_L2_CACHEGEOMETRY	45
+#define AT_L3_CACHESIZE		46
+#define AT_L3_CACHEGEOMETRY	47
+#endif
+
+static void print_size(const char *label, uint32_t val)
+{
+	printf("%s cache size: %#10x %10dB %10dK\n", label, val, val, val / 1024);
+}
+
+static void print_geo(const char *label, uint32_t val)
+{
+	uint16_t assoc;
+
+	printf("%s line size:  %#10x       ", label, val & 0xFFFF);
+
+	assoc = val >> 16;
+	if (assoc)
+		printf("%u-way", assoc);
+	else
+		printf("fully");
+
+	printf(" associative\n");
+}
+
+static int test_cache_shape()
+{
+	static char buffer[4096];
+	ElfW(auxv_t) *p;
+	int found;
+
+	FAIL_IF(read_auxv(buffer, sizeof(buffer)));
+
+	found = 0;
+
+	p = find_auxv_entry(AT_L1I_CACHESIZE, buffer);
+	if (p) {
+		found++;
+		print_size("L1I ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L1I_CACHEGEOMETRY, buffer);
+	if (p) {
+		found++;
+		print_geo("L1I ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L1D_CACHESIZE, buffer);
+	if (p) {
+		found++;
+		print_size("L1D ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L1D_CACHEGEOMETRY, buffer);
+	if (p) {
+		found++;
+		print_geo("L1D ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L2_CACHESIZE, buffer);
+	if (p) {
+		found++;
+		print_size("L2  ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L2_CACHEGEOMETRY, buffer);
+	if (p) {
+		found++;
+		print_geo("L2  ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L3_CACHESIZE, buffer);
+	if (p) {
+		found++;
+		print_size("L3  ", (uint32_t)p->a_un.a_val);
+	}
+
+	p = find_auxv_entry(AT_L3_CACHEGEOMETRY, buffer);
+	if (p) {
+		found++;
+		print_geo("L3  ", (uint32_t)p->a_un.a_val);
+	}
+
+	/* If we found none we're probably on a system where they don't exist */
+	SKIP_IF(found == 0);
+
+	/* But if we found any, we expect to find them all */
+	FAIL_IF(found != 8);
+
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(test_cache_shape, "cache_shape");
+}