drm/i915: Implement GPU reset on i965
This patch puts in place the machinery to attempt to reset the GPU. This
will be used when attempting to recover from a GPU hang.
Signed-off-by: Owain G. Ainsworth <oga@openbsd.org>
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index dbe568c..435082e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -127,6 +127,130 @@
return ret;
}
+/**
+ * i965_reset - reset chip after a hang
+ * @dev: drm device to reset
+ * @flags: reset domains
+ *
+ * Reset the chip. Useful if a hang is detected. Returns zero on successful
+ * reset or otherwise an error code.
+ *
+ * Procedure is fairly simple:
+ * - reset the chip using the reset reg
+ * - re-init context state
+ * - re-init hardware status page
+ * - re-init ring buffer
+ * - re-init interrupt state
+ * - re-init display
+ */
+int i965_reset(struct drm_device *dev, u8 flags)
+{
+ drm_i915_private_t *dev_priv = dev->dev_private;
+ unsigned long timeout;
+ u8 gdrst;
+ /*
+ * We really should only reset the display subsystem if we actually
+ * need to
+ */
+ bool need_display = true;
+
+ mutex_lock(&dev->struct_mutex);
+
+ /*
+ * Clear request list
+ */
+ i915_gem_retire_requests(dev);
+
+ if (need_display)
+ i915_save_display(dev);
+
+ if (IS_I965G(dev) || IS_G4X(dev)) {
+ /*
+ * Set the domains we want to reset, then the reset bit (bit 0).
+ * Clear the reset bit after a while and wait for hardware status
+ * bit (bit 1) to be set
+ */
+ pci_read_config_byte(dev->pdev, GDRST, &gdrst);
+ pci_write_config_byte(dev->pdev, GDRST, gdrst | flags | ((flags == GDRST_FULL) ? 0x1 : 0x0));
+ udelay(50);
+ pci_write_config_byte(dev->pdev, GDRST, gdrst & 0xfe);
+
+ /* ...we don't want to loop forever though, 500ms should be plenty */
+ timeout = jiffies + msecs_to_jiffies(500);
+ do {
+ udelay(100);
+ pci_read_config_byte(dev->pdev, GDRST, &gdrst);
+ } while ((gdrst & 0x1) && time_after(timeout, jiffies));
+
+ if (gdrst & 0x1) {
+ WARN(true, "i915: Failed to reset chip\n");
+ mutex_unlock(&dev->struct_mutex);
+ return -EIO;
+ }
+ } else {
+ DRM_ERROR("Error occurred. Don't know how to reset this chip.\n");
+ return -ENODEV;
+ }
+
+ /* Ok, now get things going again... */
+
+ /*
+ * Everything depends on having the GTT running, so we need to start
+ * there. Fortunately we don't need to do this unless we reset the
+ * chip at a PCI level.
+ *
+ * Next we need to restore the context, but we don't use those
+ * yet either...
+ *
+ * Ring buffer needs to be re-initialized in the KMS case, or if X
+ * was running at the time of the reset (i.e. we weren't VT
+ * switched away).
+ */
+ if (drm_core_check_feature(dev, DRIVER_MODESET) ||
+ !dev_priv->mm.suspended) {
+ drm_i915_ring_buffer_t *ring = &dev_priv->ring;
+ struct drm_gem_object *obj = ring->ring_obj;
+ struct drm_i915_gem_object *obj_priv = obj->driver_private;
+ dev_priv->mm.suspended = 0;
+
+ /* Stop the ring if it's running. */
+ I915_WRITE(PRB0_CTL, 0);
+ I915_WRITE(PRB0_TAIL, 0);
+ I915_WRITE(PRB0_HEAD, 0);
+
+ /* Initialize the ring. */
+ I915_WRITE(PRB0_START, obj_priv->gtt_offset);
+ I915_WRITE(PRB0_CTL,
+ ((obj->size - 4096) & RING_NR_PAGES) |
+ RING_NO_REPORT |
+ RING_VALID);
+ if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ i915_kernel_lost_context(dev);
+ else {
+ ring->head = I915_READ(PRB0_HEAD) & HEAD_ADDR;
+ ring->tail = I915_READ(PRB0_TAIL) & TAIL_ADDR;
+ ring->space = ring->head - (ring->tail + 8);
+ if (ring->space < 0)
+ ring->space += ring->Size;
+ }
+
+ mutex_unlock(&dev->struct_mutex);
+ drm_irq_uninstall(dev);
+ drm_irq_install(dev);
+ mutex_lock(&dev->struct_mutex);
+ }
+
+ /*
+ * Display needs restore too...
+ */
+ if (need_display)
+ i915_restore_display(dev);
+
+ mutex_unlock(&dev->struct_mutex);
+ return 0;
+}
+
+
static int __devinit
i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{