--- zzzz-none-000/linux-3.10.107/drivers/gpu/drm/i915/i915_gem_tiling.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/gpu/drm/i915/i915_gem_tiling.c 2021-02-04 17:41:59.000000000 +0000 @@ -31,174 +31,32 @@ #include #include "i915_drv.h" -/** @file i915_gem_tiling.c - * - * 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. +/** + * DOC: buffer object tiling * - * 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. + * i915_gem_set_tiling() and i915_gem_get_tiling() is the userspace interface to + * declare fence register requirements. * - * If we don't have interleaved memory, all tiling is safe and no swizzling is - * required. + * In principle GEM doesn't care at all about the internal data layout of an + * object, and hence it also doesn't care about tiling or swizzling. There's two + * exceptions: * - * 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! + * - For X and Y tiling the hardware provides detilers for CPU access, so called + * fences. Since there's only a limited amount of them the kernel must manage + * these, and therefore userspace must tell the kernel the object tiling if it + * wants to use fences for detiling. + * - On gen3 and gen4 platforms have a swizzling pattern for tiled objects which + * depends upon the physical page frame number. When swapping such objects the + * page frame number might change and the kernel must be able to fix this up + * and hence now the tiling. Note that on a subset of platforms with + * asymmetric memory channel population the swizzling pattern changes in an + * unknown way, and for those the kernel simply forbids swapping completely. * - * 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. + * Since neither of this applies for new tiling layouts on modern platforms like + * W, Ys and Yf tiling GEM only allows object tiling to be set to X or Y tiled. + * Anything else can be handled in userspace entirely without the kernel's + * invovlement. */ -void -i915_gem_detect_bit_6_swizzle(struct drm_device *dev) -{ - drm_i915_private_t *dev_priv = dev->dev_private; - uint32_t swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN; - uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN; - - if (IS_VALLEYVIEW(dev)) { - swizzle_x = I915_BIT_6_SWIZZLE_NONE; - swizzle_y = I915_BIT_6_SWIZZLE_NONE; - } else if (INTEL_INFO(dev)->gen >= 6) { - 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; - } - 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 @@ -268,33 +126,43 @@ return true; if (INTEL_INFO(obj->base.dev)->gen == 3) { - if (obj->gtt_offset & ~I915_FENCE_START_MASK) + if (i915_gem_obj_ggtt_offset(obj) & ~I915_FENCE_START_MASK) return false; } else { - if (obj->gtt_offset & ~I830_FENCE_START_MASK) + if (i915_gem_obj_ggtt_offset(obj) & ~I830_FENCE_START_MASK) return false; } size = i915_gem_get_gtt_size(obj->base.dev, obj->base.size, tiling_mode); - if (obj->gtt_space->size != size) + if (i915_gem_obj_ggtt_size(obj) != size) return false; - if (obj->gtt_offset & (size - 1)) + if (i915_gem_obj_ggtt_offset(obj) & (size - 1)) return false; return true; } /** + * i915_gem_set_tiling - IOCTL handler to set tiling mode + * @dev: DRM device + * @data: data pointer for the ioctl + * @file: DRM file for the ioctl call + * * Sets the tiling mode of an object, returning the required swizzling of * bit 6 of addresses in the object. + * + * Called by the user via ioctl. + * + * Returns: + * Zero on success, negative errno on failure. */ int i915_gem_set_tiling(struct drm_device *dev, void *data, struct drm_file *file) { struct drm_i915_gem_set_tiling *args = data; - drm_i915_private_t *dev_priv = dev->dev_private; + struct drm_i915_private *dev_priv = dev->dev_private; struct drm_i915_gem_object *obj; int ret = 0; @@ -308,9 +176,10 @@ return -EINVAL; } - if (obj->pin_count) { - drm_gem_object_unreference_unlocked(&obj->base); - return -EBUSY; + mutex_lock(&dev->struct_mutex); + if (obj->pin_display || obj->framebuffer_references) { + ret = -EBUSY; + goto err; } if (args->tiling_mode == I915_TILING_NONE) { @@ -342,7 +211,6 @@ } } - mutex_lock(&dev->struct_mutex); if (args->tiling_mode != obj->tiling_mode || args->stride != obj->stride) { /* We need to rebind the object if its current allocation @@ -357,25 +225,22 @@ * has to also include the unfenced register the GPU uses * whilst executing a fenced command for an untiled object. */ - - obj->map_and_fenceable = - obj->gtt_space == NULL || - (obj->gtt_offset + obj->base.size <= dev_priv->gtt.mappable_end && - i915_gem_object_fence_ok(obj, args->tiling_mode)); - - /* Rebind if we need a change of alignment */ - if (!obj->map_and_fenceable) { - u32 unfenced_alignment = - i915_gem_get_gtt_alignment(dev, obj->base.size, - args->tiling_mode, - false); - if (obj->gtt_offset & (unfenced_alignment - 1)) - ret = i915_gem_object_unbind(obj); - } + if (obj->map_and_fenceable && + !i915_gem_object_fence_ok(obj, args->tiling_mode)) + ret = i915_gem_object_ggtt_unbind(obj); if (ret == 0) { + if (obj->pages && + obj->madv == I915_MADV_WILLNEED && + dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) { + if (args->tiling_mode == I915_TILING_NONE) + i915_gem_object_unpin_pages(obj); + if (obj->tiling_mode == I915_TILING_NONE) + i915_gem_object_pin_pages(obj); + } + obj->fence_dirty = - obj->fenced_gpu_access || + obj->last_fenced_req || obj->fence_reg != I915_FENCE_REG_NONE; obj->tiling_mode = args->tiling_mode; @@ -392,7 +257,7 @@ /* Try to preallocate memory required to save swizzling on put-pages */ if (i915_gem_object_needs_bit17_swizzle(obj)) { if (obj->bit_17 == NULL) { - obj->bit_17 = kmalloc(BITS_TO_LONGS(obj->base.size >> PAGE_SHIFT) * + obj->bit_17 = kcalloc(BITS_TO_LONGS(obj->base.size >> PAGE_SHIFT), sizeof(long), GFP_KERNEL); } } else { @@ -400,6 +265,7 @@ obj->bit_17 = NULL; } +err: drm_gem_object_unreference(&obj->base); mutex_unlock(&dev->struct_mutex); @@ -407,14 +273,24 @@ } /** + * i915_gem_get_tiling - IOCTL handler to get tiling mode + * @dev: DRM device + * @data: data pointer for the ioctl + * @file: DRM file for the ioctl call + * * Returns the current tiling mode and required bit 6 swizzling for the object. + * + * Called by the user via ioctl. + * + * Returns: + * Zero on success, negative errno on failure. */ int i915_gem_get_tiling(struct drm_device *dev, void *data, struct drm_file *file) { struct drm_i915_gem_get_tiling *args = data; - drm_i915_private_t *dev_priv = dev->dev_private; + struct drm_i915_private *dev_priv = dev->dev_private; struct drm_i915_gem_object *obj; obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle)); @@ -439,6 +315,10 @@ } /* Hide bit 17 from the user -- see comment in i915_gem_set_tiling */ + if (dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) + args->phys_swizzle_mode = I915_BIT_6_SWIZZLE_UNKNOWN; + else + args->phys_swizzle_mode = args->swizzle_mode; if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_17) args->swizzle_mode = I915_BIT_6_SWIZZLE_9; if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17) @@ -449,75 +329,3 @@ 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 = kmalloc(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++; - } -}