Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
 help / color / mirror / Atom feed
* [FFmpeg-devel] [PATCH] avutil: [LA] use getauxval to do runtime check.
@ 2023-02-14 12:25 Shiyou Yin
  2023-02-23  7:48 ` Steven Liu
  0 siblings, 1 reply; 6+ messages in thread
From: Shiyou Yin @ 2023-02-14 12:25 UTC (permalink / raw)
  To: ffmpeg-devel

Replace cpucfg with getauxval to avoid crash in case of
some processor capabilities are not supportted by kernel used.
---
 libavutil/loongarch/cpu.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/libavutil/loongarch/cpu.c b/libavutil/loongarch/cpu.c
index e4b240bc44..cad8504fde 100644
--- a/libavutil/loongarch/cpu.c
+++ b/libavutil/loongarch/cpu.c
@@ -21,26 +21,18 @@
 
 #include <stdint.h>
 #include "cpu.h"
+#include <sys/auxv.h>
 
-#define LOONGARCH_CFG2 0x2
-#define LOONGARCH_CFG2_LSX    (1 << 6)
-#define LOONGARCH_CFG2_LASX   (1 << 7)
-
-static int cpu_flags_cpucfg(void)
+#define LA_HWCAP_LSX    (1<<4)
+#define LA_HWCAP_LASX   (1<<5)
+static int cpu_flags_getauxval(void)
 {
     int flags = 0;
-    uint32_t cfg2 = 0;
-
-    __asm__ volatile(
-        "cpucfg %0, %1 \n\t"
-        : "+&r"(cfg2)
-        : "r"(LOONGARCH_CFG2)
-    );
+    int flag  = (int)getauxval(AT_HWCAP);
 
-    if (cfg2 & LOONGARCH_CFG2_LSX)
+    if (flag & LA_HWCAP_LSX)
         flags |= AV_CPU_FLAG_LSX;
-
-    if (cfg2 & LOONGARCH_CFG2_LASX)
+    if (flag & LA_HWCAP_LASX)
         flags |= AV_CPU_FLAG_LASX;
 
     return flags;
@@ -49,7 +41,7 @@ static int cpu_flags_cpucfg(void)
 int ff_get_cpu_flags_loongarch(void)
 {
 #if defined __linux__
-    return cpu_flags_cpucfg();
+    return cpu_flags_getauxval();
 #else
     /* Assume no SIMD ASE supported */
     return 0;
-- 
2.20.1

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2023-02-27  4:44 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-14 12:25 [FFmpeg-devel] [PATCH] avutil: [LA] use getauxval to do runtime check Shiyou Yin
2023-02-23  7:48 ` Steven Liu
2023-02-27  1:03   ` Shiyou Yin
2023-02-27  2:47     ` Steven Liu
2023-02-27  3:17       ` Steven Liu
2023-02-27  4:44         ` Steven Liu

Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://master.gitmailbox.com/ffmpegdev/0 ffmpegdev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 ffmpegdev ffmpegdev/ https://master.gitmailbox.com/ffmpegdev \
		ffmpegdev@gitmailbox.com
	public-inbox-index ffmpegdev

Example config snippet for mirrors.


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git