From 19d4f90c44c3a5bd244c188997fa5a5c57c6fcc0 Mon Sep 17 00:00:00 2001
From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Sun, 31 Jul 2022 18:17:07 +0100
Subject: [PATCH] Use auvx to detect CPUCFG on mips/loongson

It's safer and easier than SIGILL.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 driver/others/dynamic_mips64.c | 80 +++++++++-------------------------
 1 file changed, 21 insertions(+), 59 deletions(-)

diff --git a/driver/others/dynamic_mips64.c b/driver/others/dynamic_mips64.c
index 9fd19d739..d50b2dc27 100644
--- a/driver/others/dynamic_mips64.c
+++ b/driver/others/dynamic_mips64.c
@@ -38,6 +38,15 @@ USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <sys/resource.h>
 #include "common.h"
 
+#if (defined OS_LINUX || defined OS_ANDROID)
+#include <asm/hwcap.h>
+#include <sys/auxv.h>
+
+#ifndef HWCAP_LOONGSON_CPUCFG
+#define HWCAP_LOONGSON_CPUCFG (1 << 14)
+#endif
+#endif
+
 extern gotoblas_t  gotoblas_LOONGSON3R3;
 extern gotoblas_t  gotoblas_LOONGSON3R4;
 
@@ -81,59 +90,10 @@ static gotoblas_t *force_coretype(char *coretype) {
   return NULL;
 }
 
+#if (defined OS_LINUX || defined OS_ANDROID)
 #define MMI_MASK    0x00000010
 #define MSA_MASK    0x00000020
 
-int fd[2];
-int support_cpucfg;
-
-static void handler(int signum)
-{
-    close(fd[1]);
-    exit(1);
-}
-
-/* Brief :  Function to check if cpucfg supported on loongson
- * Return:  1   supported
- *          0   not supported
- */
-static int cpucfg_test(void) {
-    pid_t pid;
-    int status = 0;
-
-    support_cpucfg = 0;
-    pipe(fd);
-    pid = fork();
-    if (pid == 0) { /* Subprocess */
-        struct sigaction act;
-        close(fd[0]);
-        /* Set signal action for SIGILL. */
-        act.sa_handler = handler;
-        sigaction(SIGILL,&act,NULL);
-
-        /* Execute cpucfg in subprocess. */
-        __asm__ volatile(
-            ".insn              \n\t"
-            ".word (0xc8080118) \n\t"
-            :::
-        );
-        support_cpucfg = 1;
-        write(fd[1],&support_cpucfg,sizeof(support_cpucfg));
-        close(fd[1]);
-        exit(0);
-    } else if (pid > 0){ /* Parent process*/
-        close(fd[1]);
-        if ((waitpid(pid,&status,0) <= 0) ||
-            (read(fd[0],&support_cpucfg,sizeof(support_cpucfg)) <= 0))
-            support_cpucfg = 0;
-        close(fd[0]);
-    } else {
-        support_cpucfg = 0;
-    }
-
-    return support_cpucfg;
-}
-
 static gotoblas_t *get_coretype_from_cpucfg(void) {
     int flag = 0;
     __asm__ volatile(
@@ -153,7 +113,7 @@ static gotoblas_t *get_coretype_from_cpucfg(void) {
 }
 
 static gotoblas_t *get_coretype_from_cpuinfo(void) {
-#ifdef linux
+#ifdef __linux
   FILE *infile;
   char buffer[512], *p;
 
@@ -176,17 +136,19 @@ static gotoblas_t *get_coretype_from_cpuinfo(void) {
      return NULL;
   }
 #endif
-    return NULL;
+  return NULL;
 }
+#endif
 
 static gotoblas_t *get_coretype(void) {
-    int ret = 0;
-
-    ret = cpucfg_test();
-    if (ret == 1)
-        return get_coretype_from_cpucfg();
-    else
-        return get_coretype_from_cpuinfo();
+#if (!defined OS_LINUX && !defined OS_ANDROID)
+  return NULL;
+#else
+  if (!(getauxval(AT_HWCAP) & HWCAP_LOONGSON_CPUCFG))
+    return get_coretype_from_cpucfg();
+  else
+    return get_coretype_from_cpuinfo();
+#endif
 }
 
 void gotoblas_dynamic_init(void) {