}
}
}
+
+/**
+ *
+ * Support for managing tiling state of buffer objects.
+ *
+ * The idea behind tiling is to increase cache hit rates by rearranging
+ * pixel data so that a group of pixel accesses are in the same cacheline.
+ * Performance improvement from doing this on the back/depth buffer are on
+ * the order of 30%.
+ *
+ * Intel architectures make this somewhat more complicated, though, by
+ * adjustments made to addressing of data when the memory is in interleaved
+ * mode (matched pairs of DIMMS) to improve memory bandwidth.
+ * For interleaved memory, the CPU sends every sequential 64 bytes
+ * to an alternate memory channel so it can get the bandwidth from both.
+ *
+ * The GPU also rearranges its accesses for increased bandwidth to interleaved
+ * memory, and it matches what the CPU does for non-tiled. However, when tiled
+ * it does it a little differently, since one walks addresses not just in the
+ * X direction but also Y. So, along with alternating channels when bit
+ * 6 of the address flips, it also alternates when other bits flip -- Bits 9
+ * (every 512 bytes, an X tile scanline) and 10 (every two X tile scanlines)
+ * are common to both the 915 and 965-class hardware.
+ *
+ * The CPU also sometimes XORs in higher bits as well, to improve
+ * bandwidth doing strided access like we do so frequently in graphics. This
+ * is called "Channel XOR Randomization" in the MCH documentation. The result
+ * is that the CPU is XORing in either bit 11 or bit 17 to bit 6 of its address
+ * decode.
+ *
+ * All of this bit 6 XORing has an effect on our memory management,
+ * as we need to make sure that the 3d driver can correctly address object
+ * contents.
+ *
+ * If we don't have interleaved memory, all tiling is safe and no swizzling is
+ * required.
+ *
+ * When bit 17 is XORed in, we simply refuse to tile at all. Bit
+ * 17 is not just a page offset, so as we page an objet out and back in,
+ * individual pages in it will have different bit 17 addresses, resulting in
+ * each 64 bytes being swapped with its neighbor!
+ *
+ * Otherwise, if interleaved, we have to tell the 3d driver what the address
+ * swizzling it needs to do is, since it's writing with the CPU to the pages
+ * (bit 6 and potentially bit 11 XORed in), and the GPU is reading from the
+ * pages (bit 6, 9, and 10 XORed in), resulting in a cumulative bit swizzling
+ * required by the CPU of XORing in bit 6, 9, 10, and potentially 11, in order
+ * to match what the GPU expects.
+ */
+
+/**
+ * Detects bit 6 swizzling of address lookup between IGD access and CPU
+ * access through main memory.
+ */
+void
+i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ uint32_t swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
+ uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
+
+ if (INTEL_INFO(dev)->gen >= 8 || IS_VALLEYVIEW(dev)) {
+ /*
+ * On BDW+, swizzling is not used. We leave the CPU memory
+ * controller in charge of optimizing memory accesses without
+ * the extra address manipulation GPU side.
+ *
+ * VLV and CHV don't have GPU swizzling.
+ */
+ swizzle_x = I915_BIT_6_SWIZZLE_NONE;
+ swizzle_y = I915_BIT_6_SWIZZLE_NONE;
+ } else if (INTEL_INFO(dev)->gen >= 6) {
+ if (dev_priv->preserve_bios_swizzle) {
+ if (I915_READ(DISP_ARB_CTL) &
+ DISP_TILE_SURFACE_SWIZZLING) {
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10;
+ swizzle_y = I915_BIT_6_SWIZZLE_9;
+ } else {
+ swizzle_x = I915_BIT_6_SWIZZLE_NONE;
+ swizzle_y = I915_BIT_6_SWIZZLE_NONE;
+ }
+ } else {
+ uint32_t dimm_c0, dimm_c1;
+ dimm_c0 = I915_READ(MAD_DIMM_C0);
+ dimm_c1 = I915_READ(MAD_DIMM_C1);
+ dimm_c0 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK;
+ dimm_c1 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK;
+ /* Enable swizzling when the channels are populated
+ * with identically sized dimms. We don't need to check
+ * the 3rd channel because no cpu with gpu attached
+ * ships in that configuration. Also, swizzling only
+ * makes sense for 2 channels anyway. */
+ if (dimm_c0 == dimm_c1) {
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10;
+ swizzle_y = I915_BIT_6_SWIZZLE_9;
+ } else {
+ swizzle_x = I915_BIT_6_SWIZZLE_NONE;
+ swizzle_y = I915_BIT_6_SWIZZLE_NONE;
+ }
+ }
+ } else if (IS_GEN5(dev)) {
+ /* On Ironlake whatever DRAM config, GPU always do
+ * same swizzling setup.
+ */
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10;
+ swizzle_y = I915_BIT_6_SWIZZLE_9;
+ } else if (IS_GEN2(dev)) {
+ /* As far as we know, the 865 doesn't have these bit 6
+ * swizzling issues.
+ */
+ swizzle_x = I915_BIT_6_SWIZZLE_NONE;
+ swizzle_y = I915_BIT_6_SWIZZLE_NONE;
+ } else if (IS_MOBILE(dev) || (IS_GEN3(dev) && !IS_G33(dev))) {
+ uint32_t dcc;
+
+ /* On 9xx chipsets, channel interleave by the CPU is
+ * determined by DCC. For single-channel, neither the CPU
+ * nor the GPU do swizzling. For dual channel interleaved,
+ * the GPU's interleave is bit 9 and 10 for X tiled, and bit
+ * 9 for Y tiled. The CPU's interleave is independent, and
+ * can be based on either bit 11 (haven't seen this yet) or
+ * bit 17 (common).
+ */
+ dcc = I915_READ(DCC);
+ switch (dcc & DCC_ADDRESSING_MODE_MASK) {
+ case DCC_ADDRESSING_MODE_SINGLE_CHANNEL:
+ case DCC_ADDRESSING_MODE_DUAL_CHANNEL_ASYMMETRIC:
+ swizzle_x = I915_BIT_6_SWIZZLE_NONE;
+ swizzle_y = I915_BIT_6_SWIZZLE_NONE;
+ break;
+ case DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED:
+ if (dcc & DCC_CHANNEL_XOR_DISABLE) {
+ /* This is the base swizzling by the GPU for
+ * tiled buffers.
+ */
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10;
+ swizzle_y = I915_BIT_6_SWIZZLE_9;
+ } else if ((dcc & DCC_CHANNEL_XOR_BIT_17) == 0) {
+ /* Bit 11 swizzling by the CPU in addition. */
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10_11;
+ swizzle_y = I915_BIT_6_SWIZZLE_9_11;
+ } else {
+ /* Bit 17 swizzling by the CPU in addition. */
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10_17;
+ swizzle_y = I915_BIT_6_SWIZZLE_9_17;
+ }
+ break;
+ }
+
+ /* check for L-shaped memory aka modified enhanced addressing */
+ if (IS_GEN4(dev)) {
+ uint32_t ddc2 = I915_READ(DCC2);
+
+ if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE))
+ dev_priv->quirks |= QUIRK_PIN_SWIZZLED_PAGES;
+ }
+
+ if (dcc == 0xffffffff) {
+ DRM_ERROR("Couldn't read from MCHBAR. "
+ "Disabling tiling.\n");
+ swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
+ swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
+ }
+ } else {
+ /* The 965, G33, and newer, have a very flexible memory
+ * configuration. It will enable dual-channel mode
+ * (interleaving) on as much memory as it can, and the GPU
+ * will additionally sometimes enable different bit 6
+ * swizzling for tiled objects from the CPU.
+ *
+ * Here's what I found on the G965:
+ * slot fill memory size swizzling
+ * 0A 0B 1A 1B 1-ch 2-ch
+ * 512 0 0 0 512 0 O
+ * 512 0 512 0 16 1008 X
+ * 512 0 0 512 16 1008 X
+ * 0 512 0 512 16 1008 X
+ * 1024 1024 1024 0 2048 1024 O
+ *
+ * We could probably detect this based on either the DRB
+ * matching, which was the case for the swizzling required in
+ * the table above, or from the 1-ch value being less than
+ * the minimum size of a rank.
+ */
+ if (I915_READ16(C0DRB3) != I915_READ16(C1DRB3)) {
+ swizzle_x = I915_BIT_6_SWIZZLE_NONE;
+ swizzle_y = I915_BIT_6_SWIZZLE_NONE;
+ } else {
+ swizzle_x = I915_BIT_6_SWIZZLE_9_10;
+ swizzle_y = I915_BIT_6_SWIZZLE_9;
+ }
+ }
+
+ dev_priv->mm.bit_6_swizzle_x = swizzle_x;
+ dev_priv->mm.bit_6_swizzle_y = swizzle_y;
+}
+
+/**
+ * Swap every 64 bytes of this page around, to account for it having a new
+ * bit 17 of its physical address and therefore being interpreted differently
+ * by the GPU.
+ */
+static void
+i915_gem_swizzle_page(struct page *page)
+{
+ char temp[64];
+ char *vaddr;
+ int i;
+
+ vaddr = kmap(page);
+
+ for (i = 0; i < PAGE_SIZE; i += 128) {
+ memcpy(temp, &vaddr[i], 64);
+ memcpy(&vaddr[i], &vaddr[i + 64], 64);
+ memcpy(&vaddr[i + 64], temp, 64);
+ }
+
+ kunmap(page);
+}
+
+void
+i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj)
+{
+ struct sg_page_iter sg_iter;
+ int i;
+
+ if (obj->bit_17 == NULL)
+ return;
+
+ i = 0;
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
+ struct page *page = sg_page_iter_page(&sg_iter);
+ char new_bit_17 = page_to_phys(page) >> 17;
+ if ((new_bit_17 & 0x1) !=
+ (test_bit(i, obj->bit_17) != 0)) {
+ i915_gem_swizzle_page(page);
+ set_page_dirty(page);
+ }
+ i++;
+ }
+}
+
+void
+i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj)
+{
+ struct sg_page_iter sg_iter;
+ int page_count = obj->base.size >> PAGE_SHIFT;
+ int i;
+
+ if (obj->bit_17 == NULL) {
+ obj->bit_17 = kcalloc(BITS_TO_LONGS(page_count),
+ sizeof(long), GFP_KERNEL);
+ if (obj->bit_17 == NULL) {
+ DRM_ERROR("Failed to allocate memory for bit 17 "
+ "record\n");
+ return;
+ }
+ }
+
+ i = 0;
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
+ if (page_to_phys(sg_page_iter_page(&sg_iter)) & (1 << 17))
+ __set_bit(i, obj->bit_17);
+ else
+ __clear_bit(i, obj->bit_17);
+ i++;
+ }
+}
* to match what the GPU expects.
*/
-/**
- * Detects bit 6 swizzling of address lookup between IGD access and CPU
- * access through main memory.
- */
-void
-i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
-{
- struct drm_i915_private *dev_priv = dev->dev_private;
- uint32_t swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
- uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
-
- if (INTEL_INFO(dev)->gen >= 8 || IS_VALLEYVIEW(dev)) {
- /*
- * On BDW+, swizzling is not used. We leave the CPU memory
- * controller in charge of optimizing memory accesses without
- * the extra address manipulation GPU side.
- *
- * VLV and CHV don't have GPU swizzling.
- */
- swizzle_x = I915_BIT_6_SWIZZLE_NONE;
- swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- } else if (INTEL_INFO(dev)->gen >= 6) {
- if (dev_priv->preserve_bios_swizzle) {
- if (I915_READ(DISP_ARB_CTL) &
- DISP_TILE_SURFACE_SWIZZLING) {
- swizzle_x = I915_BIT_6_SWIZZLE_9_10;
- swizzle_y = I915_BIT_6_SWIZZLE_9;
- } else {
- swizzle_x = I915_BIT_6_SWIZZLE_NONE;
- swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- }
- } else {
- uint32_t dimm_c0, dimm_c1;
- dimm_c0 = I915_READ(MAD_DIMM_C0);
- dimm_c1 = I915_READ(MAD_DIMM_C1);
- dimm_c0 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK;
- dimm_c1 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK;
- /* Enable swizzling when the channels are populated
- * with identically sized dimms. We don't need to check
- * the 3rd channel because no cpu with gpu attached
- * ships in that configuration. Also, swizzling only
- * makes sense for 2 channels anyway. */
- if (dimm_c0 == dimm_c1) {
- swizzle_x = I915_BIT_6_SWIZZLE_9_10;
- swizzle_y = I915_BIT_6_SWIZZLE_9;
- } else {
- swizzle_x = I915_BIT_6_SWIZZLE_NONE;
- swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- }
- }
- } else if (IS_GEN5(dev)) {
- /* On Ironlake whatever DRAM config, GPU always do
- * same swizzling setup.
- */
- swizzle_x = I915_BIT_6_SWIZZLE_9_10;
- swizzle_y = I915_BIT_6_SWIZZLE_9;
- } else if (IS_GEN2(dev)) {
- /* As far as we know, the 865 doesn't have these bit 6
- * swizzling issues.
- */
- swizzle_x = I915_BIT_6_SWIZZLE_NONE;
- swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- } else if (IS_MOBILE(dev) || (IS_GEN3(dev) && !IS_G33(dev))) {
- uint32_t dcc;
-
- /* On 9xx chipsets, channel interleave by the CPU is
- * determined by DCC. For single-channel, neither the CPU
- * nor the GPU do swizzling. For dual channel interleaved,
- * the GPU's interleave is bit 9 and 10 for X tiled, and bit
- * 9 for Y tiled. The CPU's interleave is independent, and
- * can be based on either bit 11 (haven't seen this yet) or
- * bit 17 (common).
- */
- dcc = I915_READ(DCC);
- switch (dcc & DCC_ADDRESSING_MODE_MASK) {
- case DCC_ADDRESSING_MODE_SINGLE_CHANNEL:
- case DCC_ADDRESSING_MODE_DUAL_CHANNEL_ASYMMETRIC:
- swizzle_x = I915_BIT_6_SWIZZLE_NONE;
- swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- break;
- case DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED:
- if (dcc & DCC_CHANNEL_XOR_DISABLE) {
- /* This is the base swizzling by the GPU for
- * tiled buffers.
- */
- swizzle_x = I915_BIT_6_SWIZZLE_9_10;
- swizzle_y = I915_BIT_6_SWIZZLE_9;
- } else if ((dcc & DCC_CHANNEL_XOR_BIT_17) == 0) {
- /* Bit 11 swizzling by the CPU in addition. */
- swizzle_x = I915_BIT_6_SWIZZLE_9_10_11;
- swizzle_y = I915_BIT_6_SWIZZLE_9_11;
- } else {
- /* Bit 17 swizzling by the CPU in addition. */
- swizzle_x = I915_BIT_6_SWIZZLE_9_10_17;
- swizzle_y = I915_BIT_6_SWIZZLE_9_17;
- }
- break;
- }
-
- /* check for L-shaped memory aka modified enhanced addressing */
- if (IS_GEN4(dev)) {
- uint32_t ddc2 = I915_READ(DCC2);
-
- if (!(ddc2 & DCC2_MODIFIED_ENHANCED_DISABLE))
- dev_priv->quirks |= QUIRK_PIN_SWIZZLED_PAGES;
- }
-
- if (dcc == 0xffffffff) {
- DRM_ERROR("Couldn't read from MCHBAR. "
- "Disabling tiling.\n");
- swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
- swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
- }
- } else {
- /* The 965, G33, and newer, have a very flexible memory
- * configuration. It will enable dual-channel mode
- * (interleaving) on as much memory as it can, and the GPU
- * will additionally sometimes enable different bit 6
- * swizzling for tiled objects from the CPU.
- *
- * Here's what I found on the G965:
- * slot fill memory size swizzling
- * 0A 0B 1A 1B 1-ch 2-ch
- * 512 0 0 0 512 0 O
- * 512 0 512 0 16 1008 X
- * 512 0 0 512 16 1008 X
- * 0 512 0 512 16 1008 X
- * 1024 1024 1024 0 2048 1024 O
- *
- * We could probably detect this based on either the DRB
- * matching, which was the case for the swizzling required in
- * the table above, or from the 1-ch value being less than
- * the minimum size of a rank.
- */
- if (I915_READ16(C0DRB3) != I915_READ16(C1DRB3)) {
- swizzle_x = I915_BIT_6_SWIZZLE_NONE;
- swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- } else {
- swizzle_x = I915_BIT_6_SWIZZLE_9_10;
- swizzle_y = I915_BIT_6_SWIZZLE_9;
- }
- }
-
- dev_priv->mm.bit_6_swizzle_x = swizzle_x;
- dev_priv->mm.bit_6_swizzle_y = swizzle_y;
-}
-
/* Check pitch constriants for all chips & tiling formats */
static bool
i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
return 0;
}
-
-/**
- * Swap every 64 bytes of this page around, to account for it having a new
- * bit 17 of its physical address and therefore being interpreted differently
- * by the GPU.
- */
-static void
-i915_gem_swizzle_page(struct page *page)
-{
- char temp[64];
- char *vaddr;
- int i;
-
- vaddr = kmap(page);
-
- for (i = 0; i < PAGE_SIZE; i += 128) {
- memcpy(temp, &vaddr[i], 64);
- memcpy(&vaddr[i], &vaddr[i + 64], 64);
- memcpy(&vaddr[i + 64], temp, 64);
- }
-
- kunmap(page);
-}
-
-void
-i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj)
-{
- struct sg_page_iter sg_iter;
- int i;
-
- if (obj->bit_17 == NULL)
- return;
-
- i = 0;
- for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
- struct page *page = sg_page_iter_page(&sg_iter);
- char new_bit_17 = page_to_phys(page) >> 17;
- if ((new_bit_17 & 0x1) !=
- (test_bit(i, obj->bit_17) != 0)) {
- i915_gem_swizzle_page(page);
- set_page_dirty(page);
- }
- i++;
- }
-}
-
-void
-i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj)
-{
- struct sg_page_iter sg_iter;
- int page_count = obj->base.size >> PAGE_SHIFT;
- int i;
-
- if (obj->bit_17 == NULL) {
- obj->bit_17 = kcalloc(BITS_TO_LONGS(page_count),
- sizeof(long), GFP_KERNEL);
- if (obj->bit_17 == NULL) {
- DRM_ERROR("Failed to allocate memory for bit 17 "
- "record\n");
- return;
- }
- }
-
- i = 0;
- for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
- if (page_to_phys(sg_page_iter_page(&sg_iter)) & (1 << 17))
- __set_bit(i, obj->bit_17);
- else
- __clear_bit(i, obj->bit_17);
- i++;
- }
-}