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/u_format.h"
29#include "util/u_mm.h"
30
31/*
32  HiZ rules - taken from various docs
33   1. HiZ only works on depth values
34   2. Cannot HiZ if stencil fail or zfail is !KEEP
35   3. on R300/400, HiZ is disabled if depth test is EQUAL
36   4. comparison changes without clears usually mean disabling HiZ
37*/
38/*****************************************************************************/
39/* The HyperZ setup                                                          */
40/*****************************************************************************/
41
42static enum r300_hiz_func r300_get_hiz_func(struct r300_context *r300)
43{
44    struct r300_dsa_state *dsa = r300->dsa_state.state;
45
46    switch (dsa->dsa.depth.func) {
47    case PIPE_FUNC_NEVER:
48    case PIPE_FUNC_EQUAL:
49    case PIPE_FUNC_NOTEQUAL:
50    case PIPE_FUNC_ALWAYS:
51    default:
52        /* Guess MAX for uncertain cases. */
53    case PIPE_FUNC_LESS:
54    case PIPE_FUNC_LEQUAL:
55        return HIZ_FUNC_MAX;
56
57    case PIPE_FUNC_GREATER:
58    case PIPE_FUNC_GEQUAL:
59        return HIZ_FUNC_MIN;
60    }
61}
62
63/* Return what's used for the depth test (either minimum or maximum). */
64static unsigned r300_get_sc_hz_max(struct r300_context *r300)
65{
66    struct r300_dsa_state *dsa = r300->dsa_state.state;
67    unsigned func = dsa->dsa.depth.func;
68
69    return func >= PIPE_FUNC_GREATER ? R300_SC_HYPERZ_MAX : R300_SC_HYPERZ_MIN;
70}
71
72static boolean r300_is_hiz_func_valid(struct r300_context *r300)
73{
74    struct r300_dsa_state *dsa = r300->dsa_state.state;
75    unsigned func = dsa->dsa.depth.func;
76
77    if (r300->hiz_func == HIZ_FUNC_NONE)
78        return TRUE;
79
80    /* func1 is less/lessthan */
81    if (r300->hiz_func == HIZ_FUNC_MAX &&
82        (func == PIPE_FUNC_GEQUAL || func == PIPE_FUNC_GREATER))
83        return FALSE;
84
85    /* func1 is greater/greaterthan */
86    if (r300->hiz_func == HIZ_FUNC_MIN &&
87        (func == PIPE_FUNC_LESS   || func == PIPE_FUNC_LEQUAL))
88        return FALSE;
89
90    return TRUE;
91}
92
93static boolean r300_dsa_stencil_op_not_keep(struct pipe_stencil_state *s)
94{
95    return s->enabled && (s->fail_op != PIPE_STENCIL_OP_KEEP ||
96                          s->zfail_op != PIPE_STENCIL_OP_KEEP);
97}
98
99static boolean r300_hiz_allowed(struct r300_context *r300)
100{
101    struct r300_dsa_state *dsa = r300->dsa_state.state;
102    struct r300_screen *r300screen = r300->screen;
103
104    if (r300_fragment_shader_writes_depth(r300_fs(r300)))
105        return FALSE;
106
107    if (r300->query_current)
108        return FALSE;
109
110    /* If the depth function is inverted, HiZ must be disabled. */
111    if (!r300_is_hiz_func_valid(r300))
112        return FALSE;
113
114    /* if stencil fail/zfail op is not KEEP */
115    if (r300_dsa_stencil_op_not_keep(&dsa->dsa.stencil[0]) ||
116        r300_dsa_stencil_op_not_keep(&dsa->dsa.stencil[1]))
117        return FALSE;
118
119    if (dsa->dsa.depth.enabled) {
120        /* if depth func is EQUAL pre-r500 */
121        if (dsa->dsa.depth.func == PIPE_FUNC_EQUAL && !r300screen->caps.is_r500)
122            return FALSE;
123
124        /* if depth func is NOTEQUAL */
125        if (dsa->dsa.depth.func == PIPE_FUNC_NOTEQUAL)
126            return FALSE;
127    }
128    return TRUE;
129}
130
131static void r300_update_hyperz(struct r300_context* r300)
132{
133    struct r300_hyperz_state *z =
134        (struct r300_hyperz_state*)r300->hyperz_state.state;
135    struct pipe_framebuffer_state *fb =
136        (struct pipe_framebuffer_state*)r300->fb_state.state;
137    struct r300_dsa_state *dsa = r300->dsa_state.state;
138    struct r300_resource *zstex =
139            fb->zsbuf ? r300_resource(fb->zsbuf->texture) : NULL;
140
141    z->gb_z_peq_config = 0;
142    z->zb_bw_cntl = 0;
143    z->sc_hyperz = R300_SC_HYPERZ_ADJ_2;
144    z->flush = 0;
145
146    if (r300->cbzb_clear) {
147        z->zb_bw_cntl |= R300_ZB_CB_CLEAR_CACHE_LINE_WRITE_ONLY;
148        return;
149    }
150
151    if (!zstex || !r300->hyperz_enabled)
152        return;
153
154    /* Set the size of ZMASK tiles. */
155    if (zstex->tex.zcomp8x8[fb->zsbuf->u.tex.level]) {
156        z->gb_z_peq_config |= R300_GB_Z_PEQ_CONFIG_Z_PEQ_SIZE_8_8;
157    }
158
159    /* R500-specific features and optimizations. */
160    if (r300->screen->caps.is_r500) {
161        z->zb_bw_cntl |= R500_PEQ_PACKING_ENABLE |
162                         R500_COVERED_PTR_MASKING_ENABLE;
163    }
164
165    /* Setup decompression if needed. No other HyperZ setting is required. */
166    if (r300->zmask_decompress) {
167        z->zb_bw_cntl |= R300_FAST_FILL_ENABLE |
168                         R300_RD_COMP_ENABLE;
169        return;
170    }
171
172    /* Do not set anything if depth and stencil tests are off. */
173    if (!dsa->dsa.depth.enabled &&
174        !dsa->dsa.stencil[0].enabled &&
175        !dsa->dsa.stencil[1].enabled) {
176        assert(!dsa->dsa.depth.writemask);
177        return;
178    }
179
180    /* Zbuffer compression. */
181    if (r300->zmask_in_use && !r300->locked_zbuffer) {
182        z->zb_bw_cntl |= R300_FAST_FILL_ENABLE |
183                         R300_RD_COMP_ENABLE |
184                         R300_WR_COMP_ENABLE;
185    }
186
187    /* HiZ. */
188    if (r300->hiz_in_use && !r300->locked_zbuffer) {
189        /* HiZ cannot be used under some circumstances. */
190        if (!r300_hiz_allowed(r300)) {
191            /* If writemask is disabled, the HiZ memory will not be changed,
192             * so we can keep its content for later. */
193            if (dsa->dsa.depth.writemask) {
194                r300->hiz_in_use = FALSE;
195            }
196            return;
197        }
198        DBG(r300, DBG_HYPERZ, "r300: Z-func: %i\n", dsa->dsa.depth.func);
199
200        /* Set the HiZ function if needed. */
201        if (r300->hiz_func == HIZ_FUNC_NONE) {
202            r300->hiz_func = r300_get_hiz_func(r300);
203        }
204
205        /* Setup the HiZ bits. */
206        z->zb_bw_cntl |= R300_HIZ_ENABLE |
207                (r300->hiz_func == HIZ_FUNC_MIN ? R300_HIZ_MIN : R300_HIZ_MAX);
208
209        z->sc_hyperz |= R300_SC_HYPERZ_ENABLE |
210                        r300_get_sc_hz_max(r300);
211
212        if (r300->screen->caps.is_r500) {
213            z->zb_bw_cntl |= R500_HIZ_EQUAL_REJECT_ENABLE;
214        }
215    }
216}
217
218/*****************************************************************************/
219/* The ZTOP state                                                            */
220/*****************************************************************************/
221
222static boolean r300_dsa_writes_stencil(
223        struct pipe_stencil_state *s)
224{
225    return s->enabled && s->writemask &&
226           (s->fail_op  != PIPE_STENCIL_OP_KEEP ||
227            s->zfail_op != PIPE_STENCIL_OP_KEEP ||
228            s->zpass_op != PIPE_STENCIL_OP_KEEP);
229}
230
231static boolean r300_dsa_writes_depth_stencil(
232        struct pipe_depth_stencil_alpha_state *dsa)
233{
234    /* We are interested only in the cases when a depth or stencil value
235     * can be changed. */
236
237    if (dsa->depth.enabled && dsa->depth.writemask &&
238        dsa->depth.func != PIPE_FUNC_NEVER)
239        return TRUE;
240
241    if (r300_dsa_writes_stencil(&dsa->stencil[0]) ||
242        r300_dsa_writes_stencil(&dsa->stencil[1]))
243        return TRUE;
244
245    return FALSE;
246}
247
248static boolean r300_dsa_alpha_test_enabled(
249        struct pipe_depth_stencil_alpha_state *dsa)
250{
251    /* We are interested only in the cases when alpha testing can kill
252     * a fragment. */
253
254    return dsa->alpha.enabled && dsa->alpha.func != PIPE_FUNC_ALWAYS;
255}
256
257static void r300_update_ztop(struct r300_context* r300)
258{
259    struct r300_ztop_state* ztop_state =
260        (struct r300_ztop_state*)r300->ztop_state.state;
261    uint32_t old_ztop = ztop_state->z_buffer_top;
262
263    /* This is important enough that I felt it warranted a comment.
264     *
265     * According to the docs, these are the conditions where ZTOP must be
266     * disabled:
267     * 1) Alpha testing enabled
268     * 2) Texture kill instructions in fragment shader
269     * 3) Chroma key culling enabled
270     * 4) W-buffering enabled
271     *
272     * The docs claim that for the first three cases, if no ZS writes happen,
273     * then ZTOP can be used.
274     *
275     * (3) will never apply since we do not support chroma-keyed operations.
276     * (4) will need to be re-examined (and this comment updated) if/when
277     * Hyper-Z becomes supported.
278     *
279     * Additionally, the following conditions require disabled ZTOP:
280     * 5) Depth writes in fragment shader
281     * 6) Outstanding occlusion queries
282     *
283     * This register causes stalls all the way from SC to CB when changed,
284     * but it is buffered on-chip so it does not hurt to write it if it has
285     * not changed.
286     *
287     * ~C.
288     */
289
290    /* ZS writes */
291    if (r300_dsa_writes_depth_stencil(r300->dsa_state.state) &&
292           (r300_dsa_alpha_test_enabled(r300->dsa_state.state) ||  /* (1) */
293            r300_fs(r300)->shader->info.uses_kill)) {              /* (2) */
294        ztop_state->z_buffer_top = R300_ZTOP_DISABLE;
295    } else if (r300_fragment_shader_writes_depth(r300_fs(r300))) { /* (5) */
296        ztop_state->z_buffer_top = R300_ZTOP_DISABLE;
297    } else if (r300->query_current) {                              /* (6) */
298        ztop_state->z_buffer_top = R300_ZTOP_DISABLE;
299    } else {
300        ztop_state->z_buffer_top = R300_ZTOP_ENABLE;
301    }
302    if (ztop_state->z_buffer_top != old_ztop)
303        r300_mark_atom_dirty(r300, &r300->ztop_state);
304}
305
306void r300_update_hyperz_state(struct r300_context* r300)
307{
308    r300_update_ztop(r300);
309
310    if (r300->hyperz_state.dirty) {
311        r300_update_hyperz(r300);
312    }
313}
314