gpu: nvgpu: support per-channel wdt timeouts

Replace the padding in nvgpu_channel_wdt_args with a timeout value in
milliseconds, and add NVGPU_IOCTL_CHANNEL_WDT_FLAG_SET_TIMEOUT to
signify the existence of this new field. When the new flag is included
in the value of wdt_status, the field is used to set a per-channel
timeout to override the per-GPU default.

Add NVGPU_IOCTL_CHANNEL_WDT_FLAG_DISABLE_DUMP to disable the long debug
dump when a timed out channel gets recovered by the watchdog. Printing
the dump to serial console takes easily several seconds. (Note that
there is NVGPU_TIMEOUT_FLAG_DISABLE_DUMP about ctxsw timeout separately
for NVGPU_IOCTL_CHANNEL_SET_TIMEOUT_EX as well.)

The behaviour of NVGPU_IOCTL_CHANNEL_WDT is changed so that either
NVGPU_IOCTL_CHANNEL_ENABLE_WDT or NVGPU_IOCTL_CHANNEL_DISABLE_WDT has to
be set. The old behaviour was that other values were silently ignored.

The usage of the global default debugfs-controlled ch_wdt_timeout_ms is
changed so that its value takes effect only for newly opened channels
instead of in realtime. Also, zero value no longer means that the
watchdog is disabled; there is a separate flag for that after all.

gk20a_fifo_recover_tsg used to ignore the value of "verbose" when no
engines were found. Correct this.

Bug 1982826
Bug 1985845
Jira NVGPU-73

Change-Id: Iea6213a646a66cb7c631ed7d7c91d8c2ba8a92a4
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1510898
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/include/uapi/linux/nvgpu.h b/include/uapi/linux/nvgpu.h
index cf75595a..8a578102 100644
--- a/include/uapi/linux/nvgpu.h
+++ b/include/uapi/linux/nvgpu.h
@@ -1577,13 +1577,15 @@ struct nvgpu_cycle_stats_snapshot_args {
 #define NVGPU_IOCTL_CHANNEL_CYCLE_STATS_SNAPSHOT_CMD_ATTACH  1
 #define NVGPU_IOCTL_CHANNEL_CYCLE_STATS_SNAPSHOT_CMD_DETACH  2
 
-/* disable watchdog per-channel */
+/* configure watchdog per-channel */
 struct nvgpu_channel_wdt_args {
         __u32 wdt_status;
-        __u32 padding;
+        __u32 timeout_ms;
 };
-#define NVGPU_IOCTL_CHANNEL_DISABLE_WDT         1
-#define NVGPU_IOCTL_CHANNEL_ENABLE_WDT          2
+#define NVGPU_IOCTL_CHANNEL_DISABLE_WDT           (1 << 0)
+#define NVGPU_IOCTL_CHANNEL_ENABLE_WDT            (1 << 1)
+#define NVGPU_IOCTL_CHANNEL_WDT_FLAG_SET_TIMEOUT  (1 << 2)
+#define NVGPU_IOCTL_CHANNEL_WDT_FLAG_DISABLE_DUMP (1 << 3)
 
 /*
  * Interleaving channels in a runlist is an approach to improve