src/gallium/drivers/r300/r300_hyperz.c

   1 /*
   2  * Copyright 2008 Corbin Simpson <MostAwesomeDude@gmail.com>
   3  * Copyright 2009 Marek Olšák <maraeo@gmail.com>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  22  * USE OR OTHER DEALINGS IN THE SOFTWARE. */
  23
  24 #include "r300_context.h"
  25 #include "r300_reg.h"
  26 #include "r300_fs.h"
  27
  28 #include "util/format/u_format.h"
  29
  30 /*
  31   HiZ rules - taken from various docs
  32    1. HiZ only works on depth values
  33    2. Cannot HiZ if stencil fail or zfail is !KEEP
  34    3. on R300/400, HiZ is disabled if depth test is EQUAL
  35    4. comparison changes without clears usually mean disabling HiZ
  36 */
  37 /*****************************************************************************/
  38 /* The HyperZ setup                                                          */
  39 /*****************************************************************************/
  40
  41 static enum r300_hiz_func r300_get_hiz_func(struct r300_context *r300)
  42 {
  43     struct r300_dsa_state *dsa = r300->dsa_state.state;
  44
  45     switch (dsa->dsa.depth.func) {
  46     case PIPE_FUNC_NEVER:
  47     case PIPE_FUNC_EQUAL:
  48     case PIPE_FUNC_NOTEQUAL:
  49     case PIPE_FUNC_ALWAYS:
  50     default:
  51         /* Guess MAX for uncertain cases. */
  52     case PIPE_FUNC_LESS:
  53     case PIPE_FUNC_LEQUAL:
  54         return HIZ_FUNC_MAX;
  55
  56     case PIPE_FUNC_GREATER:
  57     case PIPE_FUNC_GEQUAL:
  58         return HIZ_FUNC_MIN;
  59     }
  60 }
  61
  62 /* Return what's used for the depth test (either minimum or maximum). */
  63 static unsigned r300_get_sc_hz_max(struct r300_context *r300)
  64 {
  65     struct r300_dsa_state *dsa = r300->dsa_state.state;
  66     unsigned func = dsa->dsa.depth.func;
  67
  68     return func >= PIPE_FUNC_GREATER ? R300_SC_HYPERZ_MAX : R300_SC_HYPERZ_MIN;
  69 }
  70
  71 static boolean r300_is_hiz_func_valid(struct r300_context *r300)
  72 {
  73     struct r300_dsa_state *dsa = r300->dsa_state.state;
  74     unsigned func = dsa->dsa.depth.func;
  75
  76     if (r300->hiz_func == HIZ_FUNC_NONE)
  77         return TRUE;
  78
  79     /* func1 is less/lessthan */
  80     if (r300->hiz_func == HIZ_FUNC_MAX &&
  81         (func == PIPE_FUNC_GEQUAL || func == PIPE_FUNC_GREATER))
  82         return FALSE;
  83
  84     /* func1 is greater/greaterthan */
  85     if (r300->hiz_func == HIZ_FUNC_MIN &&
  86         (func == PIPE_FUNC_LESS   || func == PIPE_FUNC_LEQUAL))
  87         return FALSE;
  88
  89     return TRUE;
  90 }
  91
  92 static boolean r300_dsa_stencil_op_not_keep(struct pipe_stencil_state *s)
  93 {
  94     return s->enabled && (s->fail_op != PIPE_STENCIL_OP_KEEP ||
  95                           s->zfail_op != PIPE_STENCIL_OP_KEEP);
  96 }
  97
  98 static boolean r300_hiz_allowed(struct r300_context *r300)
  99 {
 100     struct r300_dsa_state *dsa = r300->dsa_state.state;
 101     struct r300_screen *r300screen = r300->screen;
 102
 103     if (r300_fragment_shader_writes_depth(r300_fs(r300)))
 104         return FALSE;
 105
 106     if (r300->query_current)
 107         return FALSE;
 108
 109     /* If the depth function is inverted, HiZ must be disabled. */
 110     if (!r300_is_hiz_func_valid(r300))
 111         return FALSE;
 112
 113     /* if stencil fail/zfail op is not KEEP */
 114     if (r300_dsa_stencil_op_not_keep(&dsa->dsa.stencil[0]) ||
 115         r300_dsa_stencil_op_not_keep(&dsa->dsa.stencil[1]))
 116         return FALSE;
 117
 118     if (dsa->dsa.depth.enabled) {
 119         /* if depth func is EQUAL pre-r500 */
 120         if (dsa->dsa.depth.func == PIPE_FUNC_EQUAL && !r300screen->caps.is_r500)
 121             return FALSE;
 122
 123         /* if depth func is NOTEQUAL */
 124         if (dsa->dsa.depth.func == PIPE_FUNC_NOTEQUAL)
 125             return FALSE;
 126     }
 127     return TRUE;
 128 }
 129
 130 static void r300_update_hyperz(struct r300_context* r300)
 131 {
 132     struct r300_hyperz_state *z =
 133         (struct r300_hyperz_state*)r300->hyperz_state.state;
 134     struct pipe_framebuffer_state *fb =
 135         (struct pipe_framebuffer_state*)r300->fb_state.state;
 136     struct r300_dsa_state *dsa = r300->dsa_state.state;
 137     struct r300_resource *zstex =
 138             fb->zsbuf ? r300_resource(fb->zsbuf->texture) : NULL;
 139
 140     z->gb_z_peq_config = 0;
 141     z->zb_bw_cntl = 0;
 142     z->sc_hyperz = R300_SC_HYPERZ_ADJ_2;
 143     z->flush = 0;
 144
 145     if (r300->cbzb_clear) {
 146         z->zb_bw_cntl |= R300_ZB_CB_CLEAR_CACHE_LINE_WRITE_ONLY;
 147         return;
 148     }
 149
 150     if (!zstex || !r300->hyperz_enabled)
 151         return;
 152
 153     /* Set the size of ZMASK tiles. */
 154     if (zstex->tex.zcomp8x8[fb->zsbuf->u.tex.level]) {
 155         z->gb_z_peq_config |= R300_GB_Z_PEQ_CONFIG_Z_PEQ_SIZE_8_8;
 156     }
 157
 158     /* R500-specific features and optimizations. */
 159     if (r300->screen->caps.is_r500) {
 160         z->zb_bw_cntl |= R500_PEQ_PACKING_ENABLE |
 161                          R500_COVERED_PTR_MASKING_ENABLE;
 162     }
 163
 164     /* Setup decompression if needed. No other HyperZ setting is required. */
 165     if (r300->zmask_decompress) {
 166         z->zb_bw_cntl |= R300_FAST_FILL_ENABLE |
 167                          R300_RD_COMP_ENABLE;
 168         return;
 169     }
 170
 171     /* Do not set anything if depth and stencil tests are off. */
 172     if (!dsa->dsa.depth.enabled &&
 173         !dsa->dsa.stencil[0].enabled &&
 174         !dsa->dsa.stencil[1].enabled) {
 175         assert(!dsa->dsa.depth.writemask);
 176         return;
 177     }
 178
 179     /* Zbuffer compression. */
 180     if (r300->zmask_in_use && !r300->locked_zbuffer) {
 181         z->zb_bw_cntl |= R300_FAST_FILL_ENABLE |
 182                          R300_RD_COMP_ENABLE |
 183                          R300_WR_COMP_ENABLE;
 184     }
 185
 186     /* HiZ. */
 187     if (r300->hiz_in_use && !r300->locked_zbuffer) {
 188         /* HiZ cannot be used under some circumstances. */
 189         if (!r300_hiz_allowed(r300)) {
 190             /* If writemask is disabled, the HiZ memory will not be changed,
 191              * so we can keep its content for later. */
 192             if (dsa->dsa.depth.writemask) {
 193                 r300->hiz_in_use = FALSE;
 194             }
 195             return;
 196         }
 197         DBG(r300, DBG_HYPERZ, "r300: Z-func: %i\n", dsa->dsa.depth.func);
 198
 199         /* Set the HiZ function if needed. */
 200         if (r300->hiz_func == HIZ_FUNC_NONE) {
 201             r300->hiz_func = r300_get_hiz_func(r300);
 202         }
 203
 204         /* Setup the HiZ bits. */
 205         z->zb_bw_cntl |= R300_HIZ_ENABLE |
 206                 (r300->hiz_func == HIZ_FUNC_MIN ? R300_HIZ_MIN : R300_HIZ_MAX);
 207
 208         z->sc_hyperz |= R300_SC_HYPERZ_ENABLE |
 209                         r300_get_sc_hz_max(r300);
 210
 211         if (r300->screen->caps.is_r500) {
 212             z->zb_bw_cntl |= R500_HIZ_EQUAL_REJECT_ENABLE;
 213         }
 214     }
 215 }
 216
 217 /*****************************************************************************/
 218 /* The ZTOP state                                                            */
 219 /*****************************************************************************/
 220
 221 static boolean r300_dsa_writes_stencil(
 222         struct pipe_stencil_state *s)
 223 {
 224     return s->enabled && s->writemask &&
 225            (s->fail_op  != PIPE_STENCIL_OP_KEEP ||
 226             s->zfail_op != PIPE_STENCIL_OP_KEEP ||
 227             s->zpass_op != PIPE_STENCIL_OP_KEEP);
 228 }
 229
 230 static boolean r300_dsa_writes_depth_stencil(
 231         struct pipe_depth_stencil_alpha_state *dsa)
 232 {
 233     /* We are interested only in the cases when a depth or stencil value
 234      * can be changed. */
 235
 236     if (dsa->depth.enabled && dsa->depth.writemask &&
 237         dsa->depth.func != PIPE_FUNC_NEVER)
 238         return TRUE;
 239
 240     if (r300_dsa_writes_stencil(&dsa->stencil[0]) ||
 241         r300_dsa_writes_stencil(&dsa->stencil[1]))
 242         return TRUE;
 243
 244     return FALSE;
 245 }
 246
 247 static boolean r300_dsa_alpha_test_enabled(
 248         struct pipe_depth_stencil_alpha_state *dsa)
 249 {
 250     /* We are interested only in the cases when alpha testing can kill
 251      * a fragment. */
 252
 253     return dsa->alpha.enabled && dsa->alpha.func != PIPE_FUNC_ALWAYS;
 254 }
 255
 256 static void r300_update_ztop(struct r300_context* r300)
 257 {
 258     struct r300_ztop_state* ztop_state =
 259         (struct r300_ztop_state*)r300->ztop_state.state;
 260     uint32_t old_ztop = ztop_state->z_buffer_top;
 261
 262     /* This is important enough that I felt it warranted a comment.
 263      *
 264      * According to the docs, these are the conditions where ZTOP must be
 265      * disabled:
 266      * 1) Alpha testing enabled
 267      * 2) Texture kill instructions in fragment shader
 268      * 3) Chroma key culling enabled
 269      * 4) W-buffering enabled
 270      *
 271      * The docs claim that for the first three cases, if no ZS writes happen,
 272      * then ZTOP can be used.
 273      *
 274      * (3) will never apply since we do not support chroma-keyed operations.
 275      * (4) will need to be re-examined (and this comment updated) if/when
 276      * Hyper-Z becomes supported.
 277      *
 278      * Additionally, the following conditions require disabled ZTOP:
 279      * 5) Depth writes in fragment shader
 280      * 6) Outstanding occlusion queries
 281      *
 282      * This register causes stalls all the way from SC to CB when changed,
 283      * but it is buffered on-chip so it does not hurt to write it if it has
 284      * not changed.
 285      *
 286      * ~C.
 287      */
 288
 289     /* ZS writes */
 290     if (r300_dsa_writes_depth_stencil(r300->dsa_state.state) &&
 291            (r300_dsa_alpha_test_enabled(r300->dsa_state.state) ||  /* (1) */
 292             r300_fs(r300)->shader->info.uses_kill)) {              /* (2) */
 293         ztop_state->z_buffer_top = R300_ZTOP_DISABLE;
 294     } else if (r300_fragment_shader_writes_depth(r300_fs(r300))) { /* (5) */
 295         ztop_state->z_buffer_top = R300_ZTOP_DISABLE;
 296     } else if (r300->query_current) {                              /* (6) */
 297         ztop_state->z_buffer_top = R300_ZTOP_DISABLE;
 298     } else {
 299         ztop_state->z_buffer_top = R300_ZTOP_ENABLE;
 300     }
 301     if (ztop_state->z_buffer_top != old_ztop)
 302         r300_mark_atom_dirty(r300, &r300->ztop_state);
 303 }
 304
 305 void r300_update_hyperz_state(struct r300_context* r300)
 306 {
 307     r300_update_ztop(r300);
 308
 309     if (r300->hyperz_state.dirty) {
 310         r300_update_hyperz(r300);
 311     }
 312 }