[Mesa-dev] [PATCH 4/4] i965: Implemente a tiled fast-path for glReadPixels and glGetTexImage
Jason Ekstrand
jason at jlekstrand.net
Sat Jan 3 11:54:15 PST 2015
From: Sisinty Sasmita Patra <sisinty.patra at intel.com>
Added intel_readpixels_tiled_mempcpy and intel_gettexsubimage_tiled_mempcpy
functions. These are the fast paths for glReadPixels and glGetTexImage.
v2: Jason Ekstrand <jason.ekstrand at intel.com>
- Refactor to make the functions look more like the old
intel_tex_subimage_tiled_memcpy
- Don't export the readpixels_tiled_memcpy function
- Fix some pointer arithmatic bugs in partial image downloads (using
ReadPixels with a non-zero x or y offset)
- Fix a bug when ReadPixels is performed on an FBO wrapping a texture
miplevel other than zero.
Signed-off-by: Jason Ekstrand <jason.ekstrand at intel.com>
---
src/mesa/drivers/dri/i965/intel_pixel_read.c | 134 +++++++++++++++++++++++++-
src/mesa/drivers/dri/i965/intel_tex.h | 9 ++
src/mesa/drivers/dri/i965/intel_tex_image.c | 137 ++++++++++++++++++++++++++-
3 files changed, 277 insertions(+), 3 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/intel_pixel_read.c b/src/mesa/drivers/dri/i965/intel_pixel_read.c
index beb3152..d1e7798 100644
--- a/src/mesa/drivers/dri/i965/intel_pixel_read.c
+++ b/src/mesa/drivers/dri/i965/intel_pixel_read.c
@@ -38,14 +38,16 @@
#include "brw_context.h"
#include "intel_screen.h"
+#include "intel_batchbuffer.h"
#include "intel_blit.h"
#include "intel_buffers.h"
#include "intel_fbo.h"
#include "intel_mipmap_tree.h"
#include "intel_pixel.h"
#include "intel_buffer_objects.h"
+#include "intel_tiled_memcpy.h"
-#define FILE_DEBUG_FLAG DEBUG_PIXEL
+#define FILE_DEBUG_FLAG DEBUG_TEXTURE
/* For many applications, the new ability to pull the source buffers
* back out of the GTT and then do the packing/conversion operations
@@ -161,17 +163,147 @@ do_blit_readpixels(struct gl_context * ctx,
return true;
}
+/**
+ * \brief A fast path for glReadPixels
+ *
+ * This fast path is taken when the source format is BGRA, RGBA,
+ * A or L and when the texture memory is X- or Y-tiled. It downloads
+ * the source data by mapping the memory without a GTT fence, thus
+ * acquiring a linear view of the memory.
+ *
+ * This is a performance win over the conventional texture download path.
+ * In the conventional texture download path,
+ *
+ */
+
+static bool
+intel_readpixels_tiled_memcpy(struct gl_context * ctx,
+ GLint xoffset, GLint yoffset,
+ GLsizei width, GLsizei height,
+ GLenum format, GLenum type,
+ GLvoid * pixels,
+ const struct gl_pixelstore_attrib *pack)
+{
+ struct brw_context *brw = brw_context(ctx);
+ struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
+
+ /* This path supports reading from color buffers only */
+ if (rb == NULL)
+ return false;
+
+ struct intel_renderbuffer *irb = intel_renderbuffer(rb);
+ int dst_pitch;
+
+ /* The miptree's buffer. */
+ drm_intel_bo *bo;
+
+ int error = 0;
+
+ uint32_t cpp;
+ mem_copy_fn mem_copy = NULL;
+
+ /* This fastpath is restricted to specific renderbuffer types:
+ * a 2D BGRA, RGBA, L8 or A8 texture. It could be generalized to support
+ * more types.
+ */
+ if (!brw->has_llc ||
+ !(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) ||
+ pixels == NULL ||
+ _mesa_is_bufferobj(pack->BufferObj) ||
+ pack->Alignment > 4 ||
+ pack->SkipPixels > 0 ||
+ pack->SkipRows > 0 ||
+ (pack->RowLength != 0 && pack->RowLength != width) ||
+ pack->SwapBytes ||
+ pack->LsbFirst ||
+ pack->Invert)
+ return false;
+
+ if (!intel_get_memcpy(rb->Format, format, type, &mem_copy, &cpp))
+ return false;
+
+ if (!irb->mt ||
+ (irb->mt->tiling != I915_TILING_X &&
+ irb->mt->tiling != I915_TILING_Y)) {
+ /* The algorithm is written only for X- or Y-tiled memory. */
+ return false;
+ }
+
+ /* Since we are going to read raw data to the miptree, we need to resolve
+ * any pending fast color clears before we start.
+ */
+ intel_miptree_resolve_color(brw, irb->mt);
+
+ bo = irb->mt->bo;
+
+ if (drm_intel_bo_references(brw->batch.bo, bo)) {
+ perf_debug("Flushing before mapping a referenced bo.\n");
+ intel_batchbuffer_flush(brw);
+ }
+
+ error = brw_bo_map(brw, bo, false /* write enable */, "miptree");
+ if (error || bo->virtual == NULL) {
+ DBG("%s: failed to map bo\n", __FUNCTION__);
+ return false;
+ }
+
+ dst_pitch = _mesa_image_row_stride(pack, width, format, type);
+
+ /* We postponed printing this message until having committed to executing
+ * the function.
+ */
+ DBG("%s: x,y=(%d,%d) (w,h)=(%d,%d) format=0x%x type=0x%x "
+ "mesa_format=0x%x tiling=%d "
+ "pack=(alignment=%d row_length=%d skip_pixels=%d skip_rows=%d)\n",
+ __FUNCTION__, xoffset, yoffset, width, height,
+ format, type, rb->Format, irb->mt->tiling,
+ pack->Alignment, pack->RowLength, pack->SkipPixels,
+ pack->SkipRows);
+
+ /* This renderbuffer can come from a texture which may not be miplevel 0.
+ * We need to adjust accordingly.
+ */
+ if (rb->TexImage) {
+ int level = rb->TexImage->Level + rb->TexImage->TexObject->MinLevel;
+
+ /* Adjust x and y offset based on miplevel */
+ xoffset += irb->mt->level[level].level_x;
+ yoffset += irb->mt->level[level].level_y;
+ }
+
+ tiled_to_linear(
+ xoffset * cpp, (xoffset + width) * cpp,
+ yoffset, yoffset + height,
+ pixels - (ptrdiff_t) yoffset * dst_pitch - (ptrdiff_t) xoffset * cpp,
+ bo->virtual,
+ dst_pitch, irb->mt->pitch,
+ brw->has_swizzling,
+ irb->mt->tiling,
+ mem_copy
+ );
+
+ drm_intel_bo_unmap(bo);
+ return true;
+}
+
void
intelReadPixels(struct gl_context * ctx,
GLint x, GLint y, GLsizei width, GLsizei height,
GLenum format, GLenum type,
const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
{
+ bool ok;
+
struct brw_context *brw = brw_context(ctx);
bool dirty;
DBG("%s\n", __FUNCTION__);
+ ok = intel_readpixels_tiled_memcpy(ctx, x, y, width, height,
+ format, type, pixels, pack);
+ if(ok)
+ return;
+
if (_mesa_is_bufferobj(pack->BufferObj)) {
/* Using PBOs, so try the BLT based path. */
if (do_blit_readpixels(ctx, x, y, width, height, format, type, pack,
diff --git a/src/mesa/drivers/dri/i965/intel_tex.h b/src/mesa/drivers/dri/i965/intel_tex.h
index 27f7f11..f048e84 100644
--- a/src/mesa/drivers/dri/i965/intel_tex.h
+++ b/src/mesa/drivers/dri/i965/intel_tex.h
@@ -68,4 +68,13 @@ intel_texsubimage_tiled_memcpy(struct gl_context *ctx,
const struct gl_pixelstore_attrib *packing,
bool for_glTexImage);
+bool
+intel_gettexsubimage_tiled_memcpy(struct gl_context *ctx,
+ struct gl_texture_image *texImage,
+ GLint xoffset, GLint yofset,
+ GLsizei width, GLsizei height,
+ GLenum format, GLenum type,
+ GLvoid *pixels,
+ const struct gl_pixelstore_attrib *packing);
+
#endif
diff --git a/src/mesa/drivers/dri/i965/intel_tex_image.c b/src/mesa/drivers/dri/i965/intel_tex_image.c
index 3317779..075315d 100644
--- a/src/mesa/drivers/dri/i965/intel_tex_image.c
+++ b/src/mesa/drivers/dri/i965/intel_tex_image.c
@@ -24,7 +24,7 @@
#include "intel_blit.h"
#include "intel_fbo.h"
#include "intel_image.h"
-
+#include "intel_tiled_memcpy.h"
#include "brw_context.h"
#define FILE_DEBUG_FLAG DEBUG_TEXTURE
@@ -507,12 +507,145 @@ blit_texture_to_pbo(struct gl_context *ctx,
return true;
}
+/**
+ * \brief A fast path for glGetTexImage.
+ *
+ *
+ * This fast path is taken when the texture format is BGRA, RGBA,
+ * A or L and when the texture memory is X- or Y-tiled. It downloads
+ * the texture data by mapping the texture memory without a GTT fence, thus
+ * acquiring a linear view of the memory.
+ *
+ * This is a performance win over the conventional texture download path.
+ * In the conventional texture download path,
+ *
+ */
+
+bool
+intel_gettexsubimage_tiled_memcpy(struct gl_context *ctx,
+ struct gl_texture_image *texImage,
+ GLint xoffset, GLint yoffset,
+ GLsizei width, GLsizei height,
+ GLenum format, GLenum type,
+ GLvoid *pixels,
+ const struct gl_pixelstore_attrib *packing)
+{
+ struct brw_context *brw = brw_context(ctx);
+ struct intel_texture_image *image = intel_texture_image(texImage);
+ int dst_pitch;
+
+ /* The miptree's buffer. */
+ drm_intel_bo *bo;
+
+ int error = 0;
+
+ uint32_t cpp;
+ mem_copy_fn mem_copy = NULL;
+
+ /* This fastpath is restricted to specific texture types:
+ * a 2D BGRA, RGBA, L8 or A8 texture. It could be generalized to support
+ * more types.
+ *
+ * FINISHME: The restrictions below on packing alignment and packing row
+ * length are likely unneeded now because we calculate the destination stride
+ * with _mesa_image_row_stride. However, before removing the restrictions
+ * we need tests.
+ */
+ if (!brw->has_llc ||
+ !(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) ||
+ !(texImage->TexObject->Target == GL_TEXTURE_2D ||
+ texImage->TexObject->Target == GL_TEXTURE_RECTANGLE) ||
+ pixels == NULL ||
+ _mesa_is_bufferobj(packing->BufferObj) ||
+ packing->Alignment > 4 ||
+ packing->SkipPixels > 0 ||
+ packing->SkipRows > 0 ||
+ (packing->RowLength != 0 && packing->RowLength != width) ||
+ packing->SwapBytes ||
+ packing->LsbFirst ||
+ packing->Invert)
+ return false;
+
+ if (!intel_get_memcpy(texImage->TexFormat, format, type, &mem_copy, &cpp))
+ return false;
+
+ /* If this is a nontrivial texture view, let another path handle it instead. */
+ if (texImage->TexObject->MinLayer)
+ return false;
+
+ if (!image->mt ||
+ (image->mt->tiling != I915_TILING_X &&
+ image->mt->tiling != I915_TILING_Y)) {
+ /* The algorithm is written only for X- or Y-tiled memory. */
+ return false;
+ }
+
+ /* Since we are going to write raw data to the miptree, we need to resolve
+ * any pending fast color clears before we start.
+ */
+ intel_miptree_resolve_color(brw, image->mt);
+
+ bo = image->mt->bo;
+
+ if (drm_intel_bo_references(brw->batch.bo, bo)) {
+ perf_debug("Flushing before mapping a referenced bo.\n");
+ intel_batchbuffer_flush(brw);
+ }
+
+ error = brw_bo_map(brw, bo, false /* write enable */, "miptree");
+ if (error || bo->virtual == NULL) {
+ DBG("%s: failed to map bo\n", __FUNCTION__);
+ return false;
+ }
+
+ dst_pitch = _mesa_image_row_stride(packing, width, format, type);
+
+ DBG("%s: level=%d x,y=(%d,%d) (w,h)=(%d,%d) format=0x%x type=0x%x "
+ "mesa_format=0x%x tiling=%d "
+ "packing=(alignment=%d row_length=%d skip_pixels=%d skip_rows=%d)\n",
+ __FUNCTION__, texImage->Level, xoffset, yoffset, width, height,
+ format, type, texImage->TexFormat, image->mt->tiling,
+ packing->Alignment, packing->RowLength, packing->SkipPixels,
+ packing->SkipRows);
+
+ int level = texImage->Level + texImage->TexObject->MinLevel;
+
+ /* Adjust x and y offset based on miplevel */
+ xoffset += image->mt->level[level].level_x;
+ yoffset += image->mt->level[level].level_y;
+
+ tiled_to_linear(
+ xoffset * cpp, (xoffset + width) * cpp,
+ yoffset, yoffset + height,
+ pixels - (ptrdiff_t) yoffset * dst_pitch - (ptrdiff_t) xoffset * cpp,
+ bo->virtual,
+ dst_pitch, image->mt->pitch,
+ brw->has_swizzling,
+ image->mt->tiling,
+ mem_copy
+ );
+
+ drm_intel_bo_unmap(bo);
+ return true;
+}
+
+
static void
intel_get_tex_image(struct gl_context *ctx,
GLenum format, GLenum type, GLvoid *pixels,
- struct gl_texture_image *texImage) {
+ struct gl_texture_image *texImage)
+{
+ bool ok;
+
DBG("%s\n", __FUNCTION__);
+ ok = intel_gettexsubimage_tiled_memcpy(ctx, texImage, 0, 0,
+ texImage->Width, texImage->Height,
+ format, type, pixels, &ctx->Pack);
+
+ if(ok)
+ return;
+
if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
/* Using PBOs, so try the BLT based path. */
if (blit_texture_to_pbo(ctx, format, type, pixels, texImage))
--
2.2.0
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