drm/i915: framebuffer compression for pre-GM45
This patch adds framebuffer compression (good for about ~0.5W power
savings in the best case) support for pre-GM45 chips. GM45+ have a new,
more flexible FBC scheme that will be added in a separate patch.
FBC can't always be enabled: the compressed buffer must be physically
contiguous and reside in stolen space. So if you have a large display
and a small amount of stolen memory, you may not be able to take
advantage of FBC. In some cases, a BIOS setting controls how much
stolen space is available. Increasing this to 8 or 16M can help.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 9909505..5a6b731 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -921,7 +921,8 @@
* how much was set aside so we can use it for our own purposes.
*/
static int i915_probe_agp(struct drm_device *dev, uint32_t *aperture_size,
- uint32_t *preallocated_size)
+ uint32_t *preallocated_size,
+ uint32_t *start)
{
struct drm_i915_private *dev_priv = dev->dev_private;
u16 tmp = 0;
@@ -1008,11 +1009,148 @@
return -1;
}
*preallocated_size = stolen - overhead;
+ *start = overhead;
return 0;
}
+#define PTE_ADDRESS_MASK 0xfffff000
+#define PTE_ADDRESS_MASK_HIGH 0x000000f0 /* i915+ */
+#define PTE_MAPPING_TYPE_UNCACHED (0 << 1)
+#define PTE_MAPPING_TYPE_DCACHE (1 << 1) /* i830 only */
+#define PTE_MAPPING_TYPE_CACHED (3 << 1)
+#define PTE_MAPPING_TYPE_MASK (3 << 1)
+#define PTE_VALID (1 << 0)
+
+/**
+ * i915_gtt_to_phys - take a GTT address and turn it into a physical one
+ * @dev: drm device
+ * @gtt_addr: address to translate
+ *
+ * Some chip functions require allocations from stolen space but need the
+ * physical address of the memory in question. We use this routine
+ * to get a physical address suitable for register programming from a given
+ * GTT address.
+ */
+static unsigned long i915_gtt_to_phys(struct drm_device *dev,
+ unsigned long gtt_addr)
+{
+ unsigned long *gtt;
+ unsigned long entry, phys;
+ int gtt_bar = IS_I9XX(dev) ? 0 : 1;
+ int gtt_offset, gtt_size;
+
+ if (IS_I965G(dev)) {
+ if (IS_G4X(dev) || IS_IGDNG(dev)) {
+ gtt_offset = 2*1024*1024;
+ gtt_size = 2*1024*1024;
+ } else {
+ gtt_offset = 512*1024;
+ gtt_size = 512*1024;
+ }
+ } else {
+ gtt_bar = 3;
+ gtt_offset = 0;
+ gtt_size = pci_resource_len(dev->pdev, gtt_bar);
+ }
+
+ gtt = ioremap_wc(pci_resource_start(dev->pdev, gtt_bar) + gtt_offset,
+ gtt_size);
+ if (!gtt) {
+ DRM_ERROR("ioremap of GTT failed\n");
+ return 0;
+ }
+
+ entry = *(volatile u32 *)(gtt + (gtt_addr / 1024));
+
+ DRM_DEBUG("GTT addr: 0x%08lx, PTE: 0x%08lx\n", gtt_addr, entry);
+
+ /* Mask out these reserved bits on this hardware. */
+ if (!IS_I9XX(dev) || IS_I915G(dev) || IS_I915GM(dev) ||
+ IS_I945G(dev) || IS_I945GM(dev)) {
+ entry &= ~PTE_ADDRESS_MASK_HIGH;
+ }
+
+ /* If it's not a mapping type we know, then bail. */
+ if ((entry & PTE_MAPPING_TYPE_MASK) != PTE_MAPPING_TYPE_UNCACHED &&
+ (entry & PTE_MAPPING_TYPE_MASK) != PTE_MAPPING_TYPE_CACHED) {
+ iounmap(gtt);
+ return 0;
+ }
+
+ if (!(entry & PTE_VALID)) {
+ DRM_ERROR("bad GTT entry in stolen space\n");
+ iounmap(gtt);
+ return 0;
+ }
+
+ iounmap(gtt);
+
+ phys =(entry & PTE_ADDRESS_MASK) |
+ ((uint64_t)(entry & PTE_ADDRESS_MASK_HIGH) << (32 - 4));
+
+ DRM_DEBUG("GTT addr: 0x%08lx, phys addr: 0x%08lx\n", gtt_addr, phys);
+
+ return phys;
+}
+
+static void i915_warn_stolen(struct drm_device *dev)
+{
+ DRM_ERROR("not enough stolen space for compressed buffer, disabling\n");
+ DRM_ERROR("hint: you may be able to increase stolen memory size in the BIOS to avoid this\n");
+}
+
+static void i915_setup_compression(struct drm_device *dev, int size)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct drm_mm_node *compressed_fb, *compressed_llb;
+ unsigned long cfb_base, ll_base;
+
+ /* Leave 1M for line length buffer & misc. */
+ compressed_fb = drm_mm_search_free(&dev_priv->vram, size, 4096, 0);
+ if (!compressed_fb) {
+ i915_warn_stolen(dev);
+ return;
+ }
+
+ compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
+ if (!compressed_fb) {
+ i915_warn_stolen(dev);
+ return;
+ }
+
+ compressed_llb = drm_mm_search_free(&dev_priv->vram, 4096, 4096, 0);
+ if (!compressed_llb) {
+ i915_warn_stolen(dev);
+ return;
+ }
+
+ compressed_llb = drm_mm_get_block(compressed_fb, 4096, 4096);
+ if (!compressed_llb) {
+ i915_warn_stolen(dev);
+ return;
+ }
+
+ dev_priv->cfb_size = size;
+
+ cfb_base = i915_gtt_to_phys(dev, compressed_fb->start);
+ ll_base = i915_gtt_to_phys(dev, compressed_llb->start);
+ if (!cfb_base || !ll_base) {
+ DRM_ERROR("failed to get stolen phys addr, disabling FBC\n");
+ drm_mm_put_block(compressed_fb);
+ drm_mm_put_block(compressed_llb);
+ }
+
+ i8xx_disable_fbc(dev);
+
+ DRM_DEBUG("FBC base 0x%08lx, ll base 0x%08lx, size %dM\n", cfb_base,
+ ll_base, size >> 20);
+ I915_WRITE(FBC_CFB_BASE, cfb_base);
+ I915_WRITE(FBC_LL_BASE, ll_base);
+}
+
static int i915_load_modeset_init(struct drm_device *dev,
+ unsigned long prealloc_start,
unsigned long prealloc_size,
unsigned long agp_size)
{
@@ -1033,6 +1171,7 @@
/* Basic memrange allocator for stolen space (aka vram) */
drm_mm_init(&dev_priv->vram, 0, prealloc_size);
+ DRM_INFO("set up %ldM of stolen space\n", prealloc_size / (1024*1024));
/* Let GEM Manage from end of prealloc space to end of aperture.
*
@@ -1049,6 +1188,19 @@
if (ret)
goto out;
+ /* Try to set up FBC with a reasonable compressed buffer size */
+ if (IS_MOBILE(dev) && (IS_I9XX(dev) || IS_I965G(dev)) &&
+ i915_powersave) {
+ int cfb_size;
+
+ /* Try to get an 8M buffer... */
+ if (prealloc_size > (9*1024*1024))
+ cfb_size = 8*1024*1024;
+ else /* fall back to 7/8 of the stolen space */
+ cfb_size = prealloc_size * 7 / 8;
+ i915_setup_compression(dev, cfb_size);
+ }
+
/* Allow hardware batchbuffers unless told otherwise.
*/
dev_priv->allow_batchbuffer = 1;
@@ -1161,7 +1313,7 @@
struct drm_i915_private *dev_priv = dev->dev_private;
resource_size_t base, size;
int ret = 0, mmio_bar = IS_I9XX(dev) ? 0 : 1;
- uint32_t agp_size, prealloc_size;
+ uint32_t agp_size, prealloc_size, prealloc_start;
/* i915 has 4 more counters */
dev->counters += 4;
@@ -1215,7 +1367,7 @@
"performance may suffer.\n");
}
- ret = i915_probe_agp(dev, &agp_size, &prealloc_size);
+ ret = i915_probe_agp(dev, &agp_size, &prealloc_size, &prealloc_start);
if (ret)
goto out_iomapfree;
@@ -1282,7 +1434,8 @@
}
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
- ret = i915_load_modeset_init(dev, prealloc_size, agp_size);
+ ret = i915_load_modeset_init(dev, prealloc_start,
+ prealloc_size, agp_size);
if (ret < 0) {
DRM_ERROR("failed to init modeset\n");
goto out_workqueue_free;