1 /* 2 * Copyright 2003 VMware, Inc. 3 * All Rights Reserved. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a 6 * copy of this software and associated documentation files (the 7 * "Software"), to deal in the Software without restriction, including 8 * without limitation the rights to use, copy, modify, merge, publish, 9 * distribute, sublicense, and/or sell copies of the Software, and to 10 * permit persons to whom the Software is furnished to do so, subject to 11 * the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the 14 * next paragraph) shall be included in all copies or substantial portions 15 * of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 20 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR 21 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 24 */ 25 26 #include "main/enums.h" 27 #include "main/mtypes.h" 28 #include "main/macros.h" 29 #include "main/fbobject.h" 30 #include "main/image.h" 31 #include "main/bufferobj.h" 32 #include "main/readpix.h" 33 #include "main/state.h" 34 #include "main/glformats.h" 35 #include "drivers/common/meta.h" 36 37 #include "brw_context.h" 38 #include "intel_screen.h" 39 #include "intel_batchbuffer.h" 40 #include "intel_blit.h" 41 #include "intel_buffers.h" 42 #include "intel_fbo.h" 43 #include "intel_mipmap_tree.h" 44 #include "intel_pixel.h" 45 #include "intel_buffer_objects.h" 46 #include "intel_tiled_memcpy.h" 47 48 #define FILE_DEBUG_FLAG DEBUG_PIXEL 49 50 /** 51 * \brief A fast path for glReadPixels 52 * 53 * This fast path is taken when the source format is BGRA, RGBA, 54 * A or L and when the texture memory is X- or Y-tiled. It downloads 55 * the source data by directly mapping the memory without a GTT fence. 56 * This then needs to be de-tiled on the CPU before presenting the data to 57 * the user in the linear fasion. 58 * 59 * This is a performance win over the conventional texture download path. 60 * In the conventional texture download path, the texture is either mapped 61 * through the GTT or copied to a linear buffer with the blitter before 62 * handing off to a software path. This allows us to avoid round-tripping 63 * through the GPU (in the case where we would be blitting) and do only a 64 * single copy operation. 65 */ 66 static bool 67 intel_readpixels_tiled_memcpy(struct gl_context * ctx, 68 GLint xoffset, GLint yoffset, 69 GLsizei width, GLsizei height, 70 GLenum format, GLenum type, 71 GLvoid * pixels, 72 const struct gl_pixelstore_attrib *pack) 73 { 74 struct brw_context *brw = brw_context(ctx); 75 struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer; 76 77 /* This path supports reading from color buffers only */ 78 if (rb == NULL) 79 return false; 80 81 struct intel_renderbuffer *irb = intel_renderbuffer(rb); 82 int dst_pitch; 83 84 /* The miptree's buffer. */ 85 drm_intel_bo *bo; 86 87 int error = 0; 88 89 uint32_t cpp; 90 mem_copy_fn mem_copy = NULL; 91 92 /* This fastpath is restricted to specific renderbuffer types: 93 * a 2D BGRA, RGBA, L8 or A8 texture. It could be generalized to support 94 * more types. 95 */ 96 if (!brw->has_llc || 97 !(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) || 98 pixels == NULL || 99 _mesa_is_bufferobj(pack->BufferObj) || 100 pack->Alignment > 4 || 101 pack->SkipPixels > 0 || 102 pack->SkipRows > 0 || 103 (pack->RowLength != 0 && pack->RowLength != width) || 104 pack->SwapBytes || 105 pack->LsbFirst || 106 pack->Invert) 107 return false; 108 109 /* Only a simple blit, no scale, bias or other mapping. */ 110 if (ctx->_ImageTransferState) 111 return false; 112 113 /* It is possible that the renderbuffer (or underlying texture) is 114 * multisampled. Since ReadPixels from a multisampled buffer requires a 115 * multisample resolve, we can't handle this here 116 */ 117 if (rb->NumSamples > 1) 118 return false; 119 120 /* We can't handle copying from RGBX or BGRX because the tiled_memcpy 121 * function doesn't set the last channel to 1. Note this checks BaseFormat 122 * rather than TexFormat in case the RGBX format is being simulated with an 123 * RGBA format. 124 */ 125 if (rb->_BaseFormat == GL_RGB) 126 return false; 127 128 if (!intel_get_memcpy(rb->Format, format, type, &mem_copy, &cpp)) 129 return false; 130 131 if (!irb->mt || 132 (irb->mt->tiling != I915_TILING_X && 133 irb->mt->tiling != I915_TILING_Y)) { 134 /* The algorithm is written only for X- or Y-tiled memory. */ 135 return false; 136 } 137 138 /* Since we are going to read raw data to the miptree, we need to resolve 139 * any pending fast color clears before we start. 140 */ 141 intel_miptree_all_slices_resolve_color(brw, irb->mt, 0); 142 143 bo = irb->mt->bo; 144 145 if (drm_intel_bo_references(brw->batch.bo, bo)) { 146 perf_debug("Flushing before mapping a referenced bo.\n"); 147 intel_batchbuffer_flush(brw); 148 } 149 150 error = brw_bo_map(brw, bo, false /* write enable */, "miptree"); 151 if (error) { 152 DBG("%s: failed to map bo\n", __func__); 153 return false; 154 } 155 156 xoffset += irb->mt->level[irb->mt_level].slice[irb->mt_layer].x_offset; 157 yoffset += irb->mt->level[irb->mt_level].slice[irb->mt_layer].y_offset; 158 159 dst_pitch = _mesa_image_row_stride(pack, width, format, type); 160 161 /* For a window-system renderbuffer, the buffer is actually flipped 162 * vertically, so we need to handle that. Since the detiling function 163 * can only really work in the forwards direction, we have to be a 164 * little creative. First, we compute the Y-offset of the first row of 165 * the renderbuffer (in renderbuffer coordinates). We then match that 166 * with the last row of the client's data. Finally, we give 167 * tiled_to_linear a negative pitch so that it walks through the 168 * client's data backwards as it walks through the renderbufer forwards. 169 */ 170 if (rb->Name == 0) { 171 yoffset = rb->Height - yoffset - height; 172 pixels += (ptrdiff_t) (height - 1) * dst_pitch; 173 dst_pitch = -dst_pitch; 174 } 175 176 /* We postponed printing this message until having committed to executing 177 * the function. 178 */ 179 DBG("%s: x,y=(%d,%d) (w,h)=(%d,%d) format=0x%x type=0x%x " 180 "mesa_format=0x%x tiling=%d " 181 "pack=(alignment=%d row_length=%d skip_pixels=%d skip_rows=%d)\n", 182 __func__, xoffset, yoffset, width, height, 183 format, type, rb->Format, irb->mt->tiling, 184 pack->Alignment, pack->RowLength, pack->SkipPixels, 185 pack->SkipRows); 186 187 tiled_to_linear( 188 xoffset * cpp, (xoffset + width) * cpp, 189 yoffset, yoffset + height, 190 pixels - (ptrdiff_t) yoffset * dst_pitch - (ptrdiff_t) xoffset * cpp, 191 bo->virtual + irb->mt->offset, 192 dst_pitch, irb->mt->pitch, 193 brw->has_swizzling, 194 irb->mt->tiling, 195 mem_copy 196 ); 197 198 drm_intel_bo_unmap(bo); 199 return true; 200 } 201 202 void 203 intelReadPixels(struct gl_context * ctx, 204 GLint x, GLint y, GLsizei width, GLsizei height, 205 GLenum format, GLenum type, 206 const struct gl_pixelstore_attrib *pack, GLvoid * pixels) 207 { 208 bool ok; 209 210 struct brw_context *brw = brw_context(ctx); 211 bool dirty; 212 213 DBG("%s\n", __func__); 214 215 if (_mesa_is_bufferobj(pack->BufferObj)) { 216 if (_mesa_meta_pbo_GetTexSubImage(ctx, 2, NULL, x, y, 0, width, height, 1, 217 format, type, pixels, pack)) { 218 /* _mesa_meta_pbo_GetTexSubImage() implements PBO transfers by 219 * binding the user-provided BO as a fake framebuffer and rendering 220 * to it. This breaks the invariant of the GL that nothing is able 221 * to render to a BO, causing nondeterministic corruption issues 222 * because the render cache is not coherent with a number of other 223 * caches that the BO could potentially be bound to afterwards. 224 * 225 * This could be solved in the same way that we guarantee texture 226 * coherency after a texture is attached to a framebuffer and 227 * rendered to, but that would involve checking *all* BOs bound to 228 * the pipeline for the case we need to emit a cache flush due to 229 * previous rendering to any of them -- Including vertex, index, 230 * uniform, atomic counter, shader image, transform feedback, 231 * indirect draw buffers, etc. 232 * 233 * That would increase the per-draw call overhead even though it's 234 * very unlikely that any of the BOs bound to the pipeline has been 235 * rendered to via a PBO at any point, so it seems better to just 236 * flush here unconditionally. 237 */ 238 brw_emit_mi_flush(brw); 239 return; 240 } 241 242 perf_debug("%s: fallback to CPU mapping in PBO case\n", __func__); 243 } 244 245 /* Reading pixels wont dirty the front buffer, so reset the dirty 246 * flag after calling intel_prepare_render(). */ 247 dirty = brw->front_buffer_dirty; 248 intel_prepare_render(brw); 249 brw->front_buffer_dirty = dirty; 250 251 ok = intel_readpixels_tiled_memcpy(ctx, x, y, width, height, 252 format, type, pixels, pack); 253 if(ok) 254 return; 255 256 /* Update Mesa state before calling _mesa_readpixels(). 257 * XXX this may not be needed since ReadPixels no longer uses the 258 * span code. 259 */ 260 261 if (ctx->NewState) 262 _mesa_update_state(ctx); 263 264 _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels); 265 266 /* There's an intel_prepare_render() call in intelSpanRenderStart(). */ 267 brw->front_buffer_dirty = dirty; 268 } 269