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    struct isl_swizzle swizzle = ISL_SWIZZLE_IDENTITY;
  44
  45    if (format == ISL_FORMAT_UNSUPPORTED)
  46       return (struct iris_format_info) { .fmt = format, .swizzle = swizzle };
  47
  48    const struct isl_format_layout *fmtl = isl_format_get_layout(format);
  49
  50    if (!util_format_is_srgb(pformat)) {
  51       if (util_format_is_intensity(pformat)) {
  52          swizzle = ISL_SWIZZLE(RED, RED, RED, RED);
  53       } else if (util_format_is_luminance(pformat)) {
  54          swizzle = ISL_SWIZZLE(RED, RED, RED, ONE);
  55       } else if (util_format_is_luminance_alpha(pformat)) {
  56          swizzle = ISL_SWIZZLE(RED, RED, RED, GREEN);
  57       } else if (util_format_is_alpha(pformat)) {
  58          swizzle = ISL_SWIZZLE(ZERO, ZERO, ZERO, RED);
  59       }
  60    }
  61
  62    /* When faking RGBX pipe formats with RGBA ISL formats, override alpha. */
  63    if (!util_format_has_alpha(pformat) && fmtl->channels.a.type != ISL_VOID) {
  64       swizzle = ISL_SWIZZLE(RED, GREEN, BLUE, ONE);
  65    }
  66
  67    if ((usage & ISL_SURF_USAGE_RENDER_TARGET_BIT) &&
  68        pformat == PIPE_FORMAT_A8_UNORM) {
  69       /* Most of the hardware A/LA formats are not renderable, except
  70        * for A8_UNORM.  SURFACE_STATE's shader channel select fields
  71        * cannot be used to swap RGB and A channels when rendering (as
  72        * it could impact alpha blending), so we have to use the actual
  73        * A8_UNORM format when rendering.
  74        */
  75       format = ISL_FORMAT_A8_UNORM;
  76       swizzle = ISL_SWIZZLE_IDENTITY;
  77    }
  78
  79    /* We choose RGBA over RGBX for rendering the hardware doesn't support
  80     * rendering to RGBX. However, when this internal override is used on Gen9+,
  81     * fast clears don't work correctly.
  82     *
  83     * i965 fixes this by pretending to not support RGBX formats, and the higher
  84     * layers of Mesa pick the RGBA format instead. Gallium doesn't work that
  85     * way, and might choose a different format, like BGRX instead of RGBX,
  86     * which will also cause problems when sampling from a surface fast cleared
  87     * as RGBX. So we always choose RGBA instead of RGBX explicitly
  88     * here.
  89     */
  90    if (isl_format_is_rgbx(format) &&
  91        !isl_format_supports_rendering(devinfo, format)) {
  92       format = isl_format_rgbx_to_rgba(format);
  93       swizzle = ISL_SWIZZLE(RED, GREEN, BLUE, ONE);
  94    }
  95
  96    return (struct iris_format_info) { .fmt = format, .swizzle = swizzle };
  97 }
  98
  99 /**
 100  * The pscreen->is_format_supported() driver hook.
 101  *
 102  * Returns true if the given format is supported for the given usage
 103  * (PIPE_BIND_*) and sample count.
 104  */
 105 bool
 106 iris_is_format_supported(struct pipe_screen *pscreen,
 107                          enum pipe_format pformat,
 108                          enum pipe_texture_target target,
 109                          unsigned sample_count,
 110                          unsigned storage_sample_count,
 111                          unsigned usage)
 112 {
 113    struct iris_screen *screen = (struct iris_screen *) pscreen;
 114    const struct gen_device_info *devinfo = &screen->devinfo;
 115    uint32_t max_samples = devinfo->gen == 8 ? 8 : 16;
 116
 117    if (sample_count > max_samples ||
 118        !util_is_power_of_two_or_zero(sample_count))
 119       return false;
 120
 121    if (pformat == PIPE_FORMAT_NONE)
 122       return true;
 123
 124    enum isl_format format = isl_format_for_pipe_format(pformat);
 125
 126    if (format == ISL_FORMAT_UNSUPPORTED)
 127       return false;
 128
 129    const struct isl_format_layout *fmtl = isl_format_get_layout(format);
 130    const bool is_integer = isl_format_has_int_channel(format);
 131    bool supported = true;
 132
 133    if (sample_count > 1)
 134       supported &= isl_format_supports_multisampling(devinfo, format);
 135
 136    if (usage & PIPE_BIND_DEPTH_STENCIL) {
 137       supported &= format == ISL_FORMAT_R32_FLOAT_X8X24_TYPELESS ||
 138                    format == ISL_FORMAT_R32_FLOAT ||
 139                    format == ISL_FORMAT_R24_UNORM_X8_TYPELESS ||
 140                    format == ISL_FORMAT_R16_UNORM ||
 141                    format == ISL_FORMAT_R8_UINT;
 142    }
 143
 144    if (usage & PIPE_BIND_RENDER_TARGET) {
 145       /* Alpha and luminance-alpha formats other than A8_UNORM are not
 146        * renderable.  For texturing, we can use R or RG formats with
 147        * shader channel selects (SCS) to swizzle the data into the correct
 148        * channels.  But for render targets, the hardware prohibits using
 149        * SCS to move shader outputs between the RGB and A channels, as it
 150        * would alter what data is used for alpha blending.
 151        *
 152        * For BLORP, we can apply the swizzle in the shader.  But for
 153        * general rendering, this would mean recompiling the shader, which
 154        * we'd like to avoid doing.  So we mark these formats non-renderable.
 155        *
 156        * We do support A8_UNORM as it's required and is renderable.
 157        */
 158       if (pformat != PIPE_FORMAT_A8_UNORM &&
 159           (util_format_is_alpha(pformat) ||
 160            util_format_is_luminance_alpha(pformat)))
 161          supported = false;
 162
 163       enum isl_format rt_format = format;
 164
 165       if (isl_format_is_rgbx(format) &&
 166           !isl_format_supports_rendering(devinfo, format))
 167          rt_format = isl_format_rgbx_to_rgba(format);
 168
 169       supported &= isl_format_supports_rendering(devinfo, rt_format);
 170
 171       if (!is_integer)
 172          supported &= isl_format_supports_alpha_blending(devinfo, rt_format);
 173    }
 174
 175    if (usage & PIPE_BIND_SHADER_IMAGE) {
 176       /* Dataport doesn't support compression, and we can't resolve an MCS
 177        * compressed surface.  (Buffer images may have sample count of 0.)
 178        */
 179       supported &= sample_count == 0;
 180
 181       supported &= isl_format_supports_typed_writes(devinfo, format);
 182       supported &= isl_has_matching_typed_storage_image_format(devinfo, format);
 183    }
 184
 185    if (usage & PIPE_BIND_SAMPLER_VIEW) {
 186       supported &= isl_format_supports_sampling(devinfo, format);
 187       if (!is_integer)
 188          supported &= isl_format_supports_filtering(devinfo, format);
 189
 190       /* Don't advertise 3-component RGB formats for non-buffer textures.
 191        * This ensures that they are renderable from an API perspective since
 192        * gallium frontends will fall back to RGBA or RGBX, which are
 193        * renderable.  We want to render internally for copies and blits,
 194        * even if the application doesn't.
 195        *
 196        * Buffer textures don't need to be renderable, so we support real RGB.
 197        * This is useful for PBO upload, and 32-bit RGB support is mandatory.
 198        */
 199       if (target != PIPE_BUFFER)
 200          supported &= fmtl->bpb != 24 && fmtl->bpb != 48 && fmtl->bpb != 96;
 201    }
 202
 203    if (usage & PIPE_BIND_VERTEX_BUFFER)
 204       supported &= isl_format_supports_vertex_fetch(devinfo, format);
 205
 206    if (usage & PIPE_BIND_INDEX_BUFFER) {
 207       supported &= format == ISL_FORMAT_R8_UINT ||
 208                    format == ISL_FORMAT_R16_UINT ||
 209                    format == ISL_FORMAT_R32_UINT;
 210    }
 211
 212    /* TODO: Support ASTC 5x5 on Gen9 properly.  This means implementing
 213     * a complex sampler workaround (see i965's gen9_apply_astc5x5_wa_flush).
 214     * Without it, st/mesa will emulate ASTC 5x5 via uncompressed textures.
 215     */
 216    if (devinfo->gen == 9 && (format == ISL_FORMAT_ASTC_LDR_2D_5X5_FLT16 ||
 217                              format == ISL_FORMAT_ASTC_LDR_2D_5X5_U8SRGB))
 218       return false;
 219
 220    return supported;
 221 }
 222