util: Use qemu_getauxval in linux qemu_cache_utils_init

With this we no longer pass down envp, and thus all systems can have
the same void prototype.  So also eliminate a useless thunk.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>

include/qemu/cache-utils.h

@@ -12,7 +12,7 @@ struct qemu_cache_conf {
 
 extern struct qemu_cache_conf qemu_cache_conf;
 
-void qemu_cache_utils_init(char **envp);
+void qemu_cache_utils_init(void);
 
 /* mildly adjusted code from tcg-dyngen.c */
 static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
@@ -38,7 +38,7 @@ static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
 }
 
 #else
-#define qemu_cache_utils_init(envp) do { (void) (envp); } while (0)
+#define qemu_cache_utils_init() do { } while (0)
 #endif
 
 #endif /* QEMU_CACHE_UTILS_H */

linux-user/main.c

@@ -3702,7 +3702,7 @@ int main(int argc, char **argv, char **envp)
     module_call_init(MODULE_INIT_QOM);
 
     qemu_init_auxval(envp);
-    qemu_cache_utils_init(envp);
+    qemu_cache_utils_init();
 
     if ((envlist = envlist_create()) == NULL) {
         (void) fprintf(stderr, "Unable to allocate envlist\n");

util/cache-utils.c

@@ -1,3 +1,4 @@
+#include "qemu-common.h"
 #include "qemu/cache-utils.h"
 
 #if defined(_ARCH_PPC)
@@ -9,31 +10,33 @@ struct qemu_cache_conf qemu_cache_conf = {
 #if defined _AIX
 #include <sys/systemcfg.h>
 
-static void ppc_init_cacheline_sizes(void)
+void qemu_cache_utils_init(void)
 {
     qemu_cache_conf.icache_bsize = _system_configuration.icache_line;
     qemu_cache_conf.dcache_bsize = _system_configuration.dcache_line;
 }
 
 #elif defined __linux__
+#include "qemu/osdep.h"
+#include "elf.h"
 
-#define QEMU_AT_NULL        0
-#define QEMU_AT_DCACHEBSIZE 19
-#define QEMU_AT_ICACHEBSIZE 20
-
-static void ppc_init_cacheline_sizes(char **envp)
+void qemu_cache_utils_init(void)
 {
-    unsigned long *auxv;
+    unsigned long dsize = qemu_getauxval(AT_DCACHEBSIZE);
+    unsigned long isize = qemu_getauxval(AT_ICACHEBSIZE);
 
-    while (*envp++);
-
-    for (auxv = (unsigned long *) envp; *auxv != QEMU_AT_NULL; auxv += 2) {
-        switch (*auxv) {
-        case QEMU_AT_DCACHEBSIZE: qemu_cache_conf.dcache_bsize = auxv[1]; break;
-        case QEMU_AT_ICACHEBSIZE: qemu_cache_conf.icache_bsize = auxv[1]; break;
-        default: break;
+    if (dsize == 0 || isize == 0) {
+        if (dsize == 0) {
+            fprintf(stderr, "getauxval AT_DCACHEBSIZE failed\n");
         }
+        if (isize == 0) {
+            fprintf(stderr, "getauxval AT_ICACHEBSIZE failed\n");
+        }
+        exit(1);
+
     }
+    qemu_cache_conf.dcache_bsize = dsize;
+    qemu_cache_conf.icache_bsize = isize;
 }
 
 #elif defined __APPLE__
@@ -41,7 +44,7 @@ static void ppc_init_cacheline_sizes(char **envp)
 #include <sys/types.h>
 #include <sys/sysctl.h>
 
-static void ppc_init_cacheline_sizes(void)
+void qemu_cache_utils_init(void)
 {
     size_t len;
     unsigned cacheline;
@@ -55,9 +58,8 @@ static void ppc_init_cacheline_sizes(void)
         qemu_cache_conf.icache_bsize = cacheline;
     }
 }
-#endif
 
-#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -65,7 +67,7 @@ static void ppc_init_cacheline_sizes(void)
 #include <sys/types.h>
 #include <sys/sysctl.h>
 
-static void ppc_init_cacheline_sizes(void)
+void qemu_cache_utils_init(void)
 {
     size_t len = 4;
     unsigned cacheline;
@@ -81,17 +83,4 @@ static void ppc_init_cacheline_sizes(void)
 }
 #endif
 
-#ifdef __linux__
-void qemu_cache_utils_init(char **envp)
-{
-    ppc_init_cacheline_sizes(envp);
-}
-#else
-void qemu_cache_utils_init(char **envp)
-{
-    (void) envp;
-    ppc_init_cacheline_sizes();
-}
-#endif
-
 #endif /* _ARCH_PPC */

vl.c

@@ -2895,7 +2895,7 @@ int main(int argc, char **argv, char **envp)
     rtc_clock = QEMU_CLOCK_HOST;
 
     qemu_init_auxval(envp);
-    qemu_cache_utils_init(envp);
+    qemu_cache_utils_init();
 
     QLIST_INIT (&vm_change_state_head);
     os_setup_early_signal_handling();