src/gallium/drivers/iris/iris_formats.c

   1 /*
   2  * Copyright © 2017 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  15  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  20  * DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 /**
  24  * @file iris_formats.c
  25  *
  26  * Converts Gallium formats (PIPE_FORMAT_*) to hardware ones (ISL_FORMAT_*).
  27  * Provides information about which formats support what features.
  28  */
  29
  30 #include "util/bitscan.h"
  31 #include "util/macros.h"
  32 #include "util/format/u_format.h"
  33
  34 #include "iris_resource.h"
  35 #include "iris_screen.h"
  36
  37 struct iris_format_info
  38 iris_format_for_usage(const struct gen_device_info *devinfo,
  39                       enum pipe_format pformat,
  40                       isl_surf_usage_flags_t usage)
  41 {
  42    enum isl_format format = isl_format_for_pipe_format(pformat);
  43    const struct isl_format_layout *fmtl = isl_format_get_layout(format);
  44    struct isl_swizzle swizzle = ISL_SWIZZLE_IDENTITY;
  45
  46    if (!util_format_is_srgb(pformat)) {
  47       if (util_format_is_intensity(pformat)) {
  48          swizzle = ISL_SWIZZLE(RED, RED, RED, RED);
  49       } else if (util_format_is_luminance(pformat)) {
  50          swizzle = ISL_SWIZZLE(RED, RED, RED, ONE);
  51       } else if (util_format_is_luminance_alpha(pformat)) {
  52          swizzle = ISL_SWIZZLE(RED, RED, RED, GREEN);
  53       } else if (util_format_is_alpha(pformat)) {
  54          swizzle = ISL_SWIZZLE(ZERO, ZERO, ZERO, RED);
  55       }
  56    }
  57
  58    /* When faking RGBX pipe formats with RGBA ISL formats, override alpha. */
  59    if (!util_format_has_alpha(pformat) && fmtl->channels.a.type != ISL_VOID) {
  60       swizzle = ISL_SWIZZLE(RED, GREEN, BLUE, ONE);
  61    }
  62
  63    if ((usage & ISL_SURF_USAGE_RENDER_TARGET_BIT) &&
  64        pformat == PIPE_FORMAT_A8_UNORM) {
  65       /* Most of the hardware A/LA formats are not renderable, except
  66        * for A8_UNORM.  SURFACE_STATE's shader channel select fields
  67        * cannot be used to swap RGB and A channels when rendering (as
  68        * it could impact alpha blending), so we have to use the actual
  69        * A8_UNORM format when rendering.
  70        */
  71       format = ISL_FORMAT_A8_UNORM;
  72       swizzle = ISL_SWIZZLE_IDENTITY;
  73    }
  74
  75    /* We choose RGBA over RGBX for rendering the hardware doesn't support
  76     * rendering to RGBX. However, when this internal override is used on Gen9+,
  77     * fast clears don't work correctly.
  78     *
  79     * i965 fixes this by pretending to not support RGBX formats, and the higher
  80     * layers of Mesa pick the RGBA format instead. Gallium doesn't work that
  81     * way, and might choose a different format, like BGRX instead of RGBX,
  82     * which will also cause problems when sampling from a surface fast cleared
  83     * as RGBX. So we always choose RGBA instead of RGBX explicitly
  84     * here.
  85     */
  86    if (isl_format_is_rgbx(format) &&
  87        !isl_format_supports_rendering(devinfo, format)) {
  88       format = isl_format_rgbx_to_rgba(format);
  89       swizzle = ISL_SWIZZLE(RED, GREEN, BLUE, ONE);
  90    }
  91
  92    return (struct iris_format_info) { .fmt = format, .swizzle = swizzle };
  93 }
  94
  95 /**
  96  * The pscreen->is_format_supported() driver hook.
  97  *
  98  * Returns true if the given format is supported for the given usage
  99  * (PIPE_BIND_*) and sample count.
 100  */
 101 bool
 102 iris_is_format_supported(struct pipe_screen *pscreen,
 103                          enum pipe_format pformat,
 104                          enum pipe_texture_target target,
 105                          unsigned sample_count,
 106                          unsigned storage_sample_count,
 107                          unsigned usage)
 108 {
 109    struct iris_screen *screen = (struct iris_screen *) pscreen;
 110    const struct gen_device_info *devinfo = &screen->devinfo;
 111    uint32_t max_samples = devinfo->gen == 8 ? 8 : 16;
 112
 113    if (sample_count > max_samples ||
 114        !util_is_power_of_two_or_zero(sample_count))
 115       return false;
 116
 117    if (pformat == PIPE_FORMAT_NONE)
 118       return true;
 119
 120    enum isl_format format = isl_format_for_pipe_format(pformat);
 121
 122    if (format == ISL_FORMAT_UNSUPPORTED)
 123       return false;
 124
 125    const struct isl_format_layout *fmtl = isl_format_get_layout(format);
 126    const bool is_integer = isl_format_has_int_channel(format);
 127    bool supported = true;
 128
 129    if (sample_count > 1)
 130       supported &= isl_format_supports_multisampling(devinfo, format);
 131
 132    if (usage & PIPE_BIND_DEPTH_STENCIL) {
 133       supported &= format == ISL_FORMAT_R32_FLOAT_X8X24_TYPELESS ||
 134                    format == ISL_FORMAT_R32_FLOAT ||
 135                    format == ISL_FORMAT_R24_UNORM_X8_TYPELESS ||
 136                    format == ISL_FORMAT_R16_UNORM ||
 137                    format == ISL_FORMAT_R8_UINT;
 138    }
 139
 140    if (usage & PIPE_BIND_RENDER_TARGET) {
 141       /* Alpha and luminance-alpha formats other than A8_UNORM are not
 142        * renderable.  For texturing, we can use R or RG formats with
 143        * shader channel selects (SCS) to swizzle the data into the correct
 144        * channels.  But for render targets, the hardware prohibits using
 145        * SCS to move shader outputs between the RGB and A channels, as it
 146        * would alter what data is used for alpha blending.
 147        *
 148        * For BLORP, we can apply the swizzle in the shader.  But for
 149        * general rendering, this would mean recompiling the shader, which
 150        * we'd like to avoid doing.  So we mark these formats non-renderable.
 151        *
 152        * We do support A8_UNORM as it's required and is renderable.
 153        */
 154       if (pformat != PIPE_FORMAT_A8_UNORM &&
 155           (util_format_is_alpha(pformat) ||
 156            util_format_is_luminance_alpha(pformat)))
 157          supported = false;
 158
 159       enum isl_format rt_format = format;
 160
 161       if (isl_format_is_rgbx(format) &&
 162           !isl_format_supports_rendering(devinfo, format))
 163          rt_format = isl_format_rgbx_to_rgba(format);
 164
 165       supported &= isl_format_supports_rendering(devinfo, rt_format);
 166
 167       if (!is_integer)
 168          supported &= isl_format_supports_alpha_blending(devinfo, rt_format);
 169    }
 170
 171    if (usage & PIPE_BIND_SHADER_IMAGE) {
 172       /* Dataport doesn't support compression, and we can't resolve an MCS
 173        * compressed surface.  (Buffer images may have sample count of 0.)
 174        */
 175       supported &= sample_count == 0;
 176
 177       supported &= isl_format_supports_typed_writes(devinfo, format);
 178       supported &= isl_has_matching_typed_storage_image_format(devinfo, format);
 179    }
 180
 181    if (usage & PIPE_BIND_SAMPLER_VIEW) {
 182       supported &= isl_format_supports_sampling(devinfo, format);
 183       if (!is_integer)
 184          supported &= isl_format_supports_filtering(devinfo, format);
 185
 186       /* Don't advertise 3-component RGB formats for non-buffer textures.
 187        * This ensures that they are renderable from an API perspective since
 188        * the state tracker will fall back to RGBA or RGBX, which are
 189        * renderable.  We want to render internally for copies and blits,
 190        * even if the application doesn't.
 191        *
 192        * Buffer textures don't need to be renderable, so we support real RGB.
 193        * This is useful for PBO upload, and 32-bit RGB support is mandatory.
 194        */
 195       if (target != PIPE_BUFFER)
 196          supported &= fmtl->bpb != 24 && fmtl->bpb != 48 && fmtl->bpb != 96;
 197    }
 198
 199    if (usage & PIPE_BIND_VERTEX_BUFFER)
 200       supported &= isl_format_supports_vertex_fetch(devinfo, format);
 201
 202    if (usage & PIPE_BIND_INDEX_BUFFER) {
 203       supported &= format == ISL_FORMAT_R8_UINT ||
 204                    format == ISL_FORMAT_R16_UINT ||
 205                    format == ISL_FORMAT_R32_UINT;
 206    }
 207
 208    /* TODO: Support ASTC 5x5 on Gen9 properly.  This means implementing
 209     * a complex sampler workaround (see i965's gen9_apply_astc5x5_wa_flush).
 210     * Without it, st/mesa will emulate ASTC 5x5 via uncompressed textures.
 211     */
 212    if (devinfo->gen == 9 && (format == ISL_FORMAT_ASTC_LDR_2D_5X5_FLT16 ||
 213                              format == ISL_FORMAT_ASTC_LDR_2D_5X5_U8SRGB))
 214       return false;
 215
 216    return supported;
 217 }
 218