i915: Initialize hardware status page at device load when possible.

Some chips were unstable with repeated setup/teardown of the hardware status
page.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 57 insertions, 29 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index aa9e8da9f716..f1b5aa92fa83 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -71,6 +71,52 @@ int i915_wait_ring(struct drm_device * dev, int n, const char *caller)
         return -EBUSY;
 }
 
+/**
+ * Sets up the hardware status page for devices that need a physical address
+ * in the register.
+ */
+int i915_init_phys_hws(struct drm_device *dev)
+{
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        /* Program Hardware Status Page */
+        dev_priv->status_page_dmah =
+                drm_pci_alloc(dev, PAGE_SIZE, PAGE_SIZE, 0xffffffff);
+
+        if (!dev_priv->status_page_dmah) {
+                DRM_ERROR("Can not allocate hardware status page\n");
+                return -ENOMEM;
+        }
+        dev_priv->hw_status_page = dev_priv->status_page_dmah->vaddr;
+        dev_priv->dma_status_page = dev_priv->status_page_dmah->busaddr;
+
+        memset(dev_priv->hw_status_page, 0, PAGE_SIZE);
+
+        I915_WRITE(HWS_PGA, dev_priv->dma_status_page);
+        DRM_DEBUG("Enabled hardware status page\n");
+        return 0;
+}
+
+/**
+ * Frees the hardware status page, whether it's a physical address or a virtual
+ * address set up by the X Server.
+ */
+void i915_free_hws(struct drm_device *dev)
+{
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        if (dev_priv->status_page_dmah) {
+                drm_pci_free(dev, dev_priv->status_page_dmah);
+                dev_priv->status_page_dmah = NULL;
+        }
+
+        if (dev_priv->status_gfx_addr) {
+                dev_priv->status_gfx_addr = 0;
+                drm_core_ioremapfree(&dev_priv->hws_map, dev);
+        }
+
+        /* Need to rewrite hardware status page */
+        I915_WRITE(HWS_PGA, 0x1ffff000);
+}
+
 void i915_kernel_lost_context(struct drm_device * dev)
 {
         drm_i915_private_t *dev_priv = dev->dev_private;
@@ -103,18 +149,9 @@ static int i915_dma_cleanup(struct drm_device * dev)
                 dev_priv->ring.map.size = 0;
         }
 
-        if (dev_priv->status_page_dmah) {
-                drm_pci_free(dev, dev_priv->status_page_dmah);
-                dev_priv->status_page_dmah = NULL;
-                /* Need to rewrite hardware status page */
-                I915_WRITE(HWS_PGA, 0x1ffff000);
-        }
-
-        if (dev_priv->status_gfx_addr) {
-                dev_priv->status_gfx_addr = 0;
-                drm_core_ioremapfree(&dev_priv->hws_map, dev);
-                I915_WRITE(HWS_PGA, 0x1ffff000);
-        }
+        /* Clear the HWS virtual address at teardown */
+        if (I915_NEED_GFX_HWS(dev))
+                i915_free_hws(dev);
 
         return 0;
 }
@@ -165,23 +202,6 @@ static int i915_initialize(struct drm_device * dev, drm_i915_init_t * init)
          */
         dev_priv->allow_batchbuffer = 1;
 
-        /* Program Hardware Status Page */
-        if (!I915_NEED_GFX_HWS(dev)) {
-                dev_priv->status_page_dmah =
-                        drm_pci_alloc(dev, PAGE_SIZE, PAGE_SIZE, 0xffffffff);
-
-                if (!dev_priv->status_page_dmah) {
-                        i915_dma_cleanup(dev);
-                        DRM_ERROR("Can not allocate hardware status page\n");
-                        return -ENOMEM;
-                }
-                dev_priv->hw_status_page = dev_priv->status_page_dmah->vaddr;
-                dev_priv->dma_status_page = dev_priv->status_page_dmah->busaddr;
-
-                memset(dev_priv->hw_status_page, 0, PAGE_SIZE);
-                I915_WRITE(HWS_PGA, dev_priv->dma_status_page);
-        }
-        DRM_DEBUG("Enabled hardware status page\n");
         return 0;
 }
 
@@ -773,6 +793,12 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
                          _DRM_KERNEL | _DRM_DRIVER,
                          &dev_priv->mmio_map);
 
+        /* Init HWS */
+        if (!I915_NEED_GFX_HWS(dev)) {
+                ret = i915_init_phys_hws(dev);
+                if (ret != 0)
+                        return ret;
+        }
 
         /* On the 945G/GM, the chipset reports the MSI capability on the
          * integrated graphics even though the support isn't actually there
@@ -796,6 +822,8 @@ int i915_driver_unload(struct drm_device *dev)
         if (dev->pdev->msi_enabled)
                 pci_disable_msi(dev->pdev);
 
+        i915_free_hws(dev);
+
         if (dev_priv->mmio_map)
                 drm_rmmap(dev, dev_priv->mmio_map);