gpu: nvgpu: add ioctl to force reset channel

Add below ioctl to force channel reset/recovery.
NVHOST_IOCTL_CHANNEL_FORCE_RESET

This recovery/reset is initiated by triggering
mmu fault on channel so as to force the channel
out (as oppose to waiting until channel is
preempted)

Bug 200027958

Change-Id: Idd3c10ef5fa691d746e34a8b890bd79aca815a20
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/456084
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index f7cafc52..45757884 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -2306,6 +2306,19 @@ long gk20a_channel_ioctl(struct file *filp,
                 err = gk20a_fifo_preempt_channel(ch->g, ch->hw_chid);
                 gk20a_idle(dev);
                 break;
+        case NVHOST_IOCTL_CHANNEL_FORCE_RESET:
+                err = gk20a_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
+                gk20a_set_error_notifier(ch,
+                        NVHOST_CHANNEL_RESETCHANNEL_VERIF_ERROR);
+                gk20a_fifo_recover_ch(ch->g, ch->hw_chid, true);
+                gk20a_idle(dev);
+                break;
         default:
                 dev_err(&dev->dev, "unrecognized ioctl cmd: 0x%x", cmd);
                 err = -ENOTTY;