1 files changed, 86 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 3ae51ada1abf..845c8f3063fe 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -1777,6 +1777,92 @@ int r100_rb2d_reset(struct radeon_device *rdev)
         return -1;
 }
 
+void r100_gpu_lockup_update(struct r100_gpu_lockup *lockup, struct radeon_cp *cp)
+{
+        lockup->last_cp_rptr = cp->rptr;
+        lockup->last_jiffies = jiffies;
+}
+
+/**
+ * r100_gpu_cp_is_lockup() - check if CP is lockup by recording information
+ * @rdev:       radeon device structure
+ * @lockup:     r100_gpu_lockup structure holding CP lockup tracking informations
+ * @cp:         radeon_cp structure holding CP information
+ *
+ * We don't need to initialize the lockup tracking information as we will either
+ * have CP rptr to a different value of jiffies wrap around which will force
+ * initialization of the lockup tracking informations.
+ *
+ * A possible false positivie is if we get call after while and last_cp_rptr ==
+ * the current CP rptr, even if it's unlikely it might happen. To avoid this
+ * if the elapsed time since last call is bigger than 2 second than we return
+ * false and update the tracking information. Due to this the caller must call
+ * r100_gpu_cp_is_lockup several time in less than 2sec for lockup to be reported
+ * the fencing code should be cautious about that.
+ *
+ * Caller should write to the ring to force CP to do something so we don't get
+ * false positive when CP is just gived nothing to do.
+ *
+ **/
+bool r100_gpu_cp_is_lockup(struct radeon_device *rdev, struct r100_gpu_lockup *lockup, struct radeon_cp *cp)
+{
+        unsigned long cjiffies, elapsed;
+
+        cjiffies = jiffies;
+        if (!time_after(cjiffies, lockup->last_jiffies)) {
+                /* likely a wrap around */
+                lockup->last_cp_rptr = cp->rptr;
+                lockup->last_jiffies = jiffies;
+                return false;
+        }
+        if (cp->rptr != lockup->last_cp_rptr) {
+                /* CP is still working no lockup */
+                lockup->last_cp_rptr = cp->rptr;
+                lockup->last_jiffies = jiffies;
+                return false;
+        }
+        elapsed = jiffies_to_msecs(cjiffies - lockup->last_jiffies);
+        if (elapsed >= 3000) {
+                /* very likely the improbable case where current
+                 * rptr is equal to last recorded, a while ago, rptr
+                 * this is more likely a false positive update tracking
+                 * information which should force us to be recall at
+                 * latter point
+                 */
+                lockup->last_cp_rptr = cp->rptr;
+                lockup->last_jiffies = jiffies;
+                return false;
+        }
+        if (elapsed >= 1000) {
+                dev_err(rdev->dev, "GPU lockup CP stall for more than %lumsec\n", elapsed);
+                return true;
+        }
+        /* give a chance to the GPU ... */
+        return false;
+}
+
+bool r100_gpu_is_lockup(struct radeon_device *rdev)
+{
+        u32 rbbm_status;
+        int r;
+
+        rbbm_status = RREG32(R_000E40_RBBM_STATUS);
+        if (!G_000E40_GUI_ACTIVE(rbbm_status)) {
+                r100_gpu_lockup_update(&rdev->config.r100.lockup, &rdev->cp);
+                return false;
+        }
+        /* force CP activities */
+        r = radeon_ring_lock(rdev, 2);
+        if (!r) {
+                /* PACKET2 NOP */
+                radeon_ring_write(rdev, 0x80000000);
+                radeon_ring_write(rdev, 0x80000000);
+                radeon_ring_unlock_commit(rdev);
+        }
+        rdev->cp.rptr = RREG32(RADEON_CP_RB_RPTR);
+        return r100_gpu_cp_is_lockup(rdev, &rdev->config.r100.lockup, &rdev->cp);
+}
+
 int r100_gpu_reset(struct radeon_device *rdev)
 {
         uint32_t status;