xref: /linux/drivers/gpu/drm/i915/display/intel_wm.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i9xx_wm.h"
8 #include "intel_display_types.h"
9 #include "intel_wm.h"
10 #include "skl_watermark.h"
11 
12 /**
13  * intel_update_watermarks - update FIFO watermark values based on current modes
14  * @i915: i915 device
15  *
16  * Calculate watermark values for the various WM regs based on current mode
17  * and plane configuration.
18  *
19  * There are several cases to deal with here:
20  *   - normal (i.e. non-self-refresh)
21  *   - self-refresh (SR) mode
22  *   - lines are large relative to FIFO size (buffer can hold up to 2)
23  *   - lines are small relative to FIFO size (buffer can hold more than 2
24  *     lines), so need to account for TLB latency
25  *
26  *   The normal calculation is:
27  *     watermark = dotclock * bytes per pixel * latency
28  *   where latency is platform & configuration dependent (we assume pessimal
29  *   values here).
30  *
31  *   The SR calculation is:
32  *     watermark = (trunc(latency/line time)+1) * surface width *
33  *       bytes per pixel
34  *   where
35  *     line time = htotal / dotclock
36  *     surface width = hdisplay for normal plane and 64 for cursor
37  *   and latency is assumed to be high, as above.
38  *
39  * The final value programmed to the register should always be rounded up,
40  * and include an extra 2 entries to account for clock crossings.
41  *
42  * We don't use the sprite, so we can ignore that.  And on Crestline we have
43  * to set the non-SR watermarks to 8.
44  */
45 void intel_update_watermarks(struct drm_i915_private *i915)
46 {
47 	if (i915->display.funcs.wm->update_wm)
48 		i915->display.funcs.wm->update_wm(i915);
49 }
50 
51 int intel_compute_pipe_wm(struct intel_atomic_state *state,
52 			  struct intel_crtc *crtc)
53 {
54 	struct drm_i915_private *i915 = to_i915(state->base.dev);
55 
56 	if (i915->display.funcs.wm->compute_pipe_wm)
57 		return i915->display.funcs.wm->compute_pipe_wm(state, crtc);
58 
59 	return 0;
60 }
61 
62 int intel_compute_intermediate_wm(struct intel_atomic_state *state,
63 				  struct intel_crtc *crtc)
64 {
65 	struct drm_i915_private *i915 = to_i915(state->base.dev);
66 
67 	if (!i915->display.funcs.wm->compute_intermediate_wm)
68 		return 0;
69 
70 	if (drm_WARN_ON(&i915->drm, !i915->display.funcs.wm->compute_pipe_wm))
71 		return 0;
72 
73 	return i915->display.funcs.wm->compute_intermediate_wm(state, crtc);
74 }
75 
76 bool intel_initial_watermarks(struct intel_atomic_state *state,
77 			      struct intel_crtc *crtc)
78 {
79 	struct drm_i915_private *i915 = to_i915(state->base.dev);
80 
81 	if (i915->display.funcs.wm->initial_watermarks) {
82 		i915->display.funcs.wm->initial_watermarks(state, crtc);
83 		return true;
84 	}
85 
86 	return false;
87 }
88 
89 void intel_atomic_update_watermarks(struct intel_atomic_state *state,
90 				    struct intel_crtc *crtc)
91 {
92 	struct drm_i915_private *i915 = to_i915(state->base.dev);
93 
94 	if (i915->display.funcs.wm->atomic_update_watermarks)
95 		i915->display.funcs.wm->atomic_update_watermarks(state, crtc);
96 }
97 
98 void intel_optimize_watermarks(struct intel_atomic_state *state,
99 			       struct intel_crtc *crtc)
100 {
101 	struct drm_i915_private *i915 = to_i915(state->base.dev);
102 
103 	if (i915->display.funcs.wm->optimize_watermarks)
104 		i915->display.funcs.wm->optimize_watermarks(state, crtc);
105 }
106 
107 int intel_compute_global_watermarks(struct intel_atomic_state *state)
108 {
109 	struct drm_i915_private *i915 = to_i915(state->base.dev);
110 
111 	if (i915->display.funcs.wm->compute_global_watermarks)
112 		return i915->display.funcs.wm->compute_global_watermarks(state);
113 
114 	return 0;
115 }
116 
117 void intel_wm_get_hw_state(struct drm_i915_private *i915)
118 {
119 	if (i915->display.funcs.wm->get_hw_state)
120 		return i915->display.funcs.wm->get_hw_state(i915);
121 }
122 
123 bool intel_wm_plane_visible(const struct intel_crtc_state *crtc_state,
124 			    const struct intel_plane_state *plane_state)
125 {
126 	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
127 
128 	/* FIXME check the 'enable' instead */
129 	if (!crtc_state->hw.active)
130 		return false;
131 
132 	/*
133 	 * Treat cursor with fb as always visible since cursor updates
134 	 * can happen faster than the vrefresh rate, and the current
135 	 * watermark code doesn't handle that correctly. Cursor updates
136 	 * which set/clear the fb or change the cursor size are going
137 	 * to get throttled by intel_legacy_cursor_update() to work
138 	 * around this problem with the watermark code.
139 	 */
140 	if (plane->id == PLANE_CURSOR)
141 		return plane_state->hw.fb != NULL;
142 	else
143 		return plane_state->uapi.visible;
144 }
145 
146 void intel_print_wm_latency(struct drm_i915_private *dev_priv,
147 			    const char *name, const u16 wm[])
148 {
149 	int level;
150 
151 	for (level = 0; level < dev_priv->display.wm.num_levels; level++) {
152 		unsigned int latency = wm[level];
153 
154 		if (latency == 0) {
155 			drm_dbg_kms(&dev_priv->drm,
156 				    "%s WM%d latency not provided\n",
157 				    name, level);
158 			continue;
159 		}
160 
161 		/*
162 		 * - latencies are in us on gen9.
163 		 * - before then, WM1+ latency values are in 0.5us units
164 		 */
165 		if (DISPLAY_VER(dev_priv) >= 9)
166 			latency *= 10;
167 		else if (level > 0)
168 			latency *= 5;
169 
170 		drm_dbg_kms(&dev_priv->drm,
171 			    "%s WM%d latency %u (%u.%u usec)\n", name, level,
172 			    wm[level], latency / 10, latency % 10);
173 	}
174 }
175 
176 void intel_wm_init(struct drm_i915_private *i915)
177 {
178 	if (DISPLAY_VER(i915) >= 9)
179 		skl_wm_init(i915);
180 	else
181 		i9xx_wm_init(i915);
182 }
183 
184 static void wm_latency_show(struct seq_file *m, const u16 wm[8])
185 {
186 	struct drm_i915_private *dev_priv = m->private;
187 	int level;
188 
189 	drm_modeset_lock_all(&dev_priv->drm);
190 
191 	for (level = 0; level < dev_priv->display.wm.num_levels; level++) {
192 		unsigned int latency = wm[level];
193 
194 		/*
195 		 * - WM1+ latency values in 0.5us units
196 		 * - latencies are in us on gen9/vlv/chv
197 		 */
198 		if (DISPLAY_VER(dev_priv) >= 9 ||
199 		    IS_VALLEYVIEW(dev_priv) ||
200 		    IS_CHERRYVIEW(dev_priv) ||
201 		    IS_G4X(dev_priv))
202 			latency *= 10;
203 		else if (level > 0)
204 			latency *= 5;
205 
206 		seq_printf(m, "WM%d %u (%u.%u usec)\n",
207 			   level, wm[level], latency / 10, latency % 10);
208 	}
209 
210 	drm_modeset_unlock_all(&dev_priv->drm);
211 }
212 
213 static int pri_wm_latency_show(struct seq_file *m, void *data)
214 {
215 	struct drm_i915_private *dev_priv = m->private;
216 	const u16 *latencies;
217 
218 	if (DISPLAY_VER(dev_priv) >= 9)
219 		latencies = dev_priv->display.wm.skl_latency;
220 	else
221 		latencies = dev_priv->display.wm.pri_latency;
222 
223 	wm_latency_show(m, latencies);
224 
225 	return 0;
226 }
227 
228 static int spr_wm_latency_show(struct seq_file *m, void *data)
229 {
230 	struct drm_i915_private *dev_priv = m->private;
231 	const u16 *latencies;
232 
233 	if (DISPLAY_VER(dev_priv) >= 9)
234 		latencies = dev_priv->display.wm.skl_latency;
235 	else
236 		latencies = dev_priv->display.wm.spr_latency;
237 
238 	wm_latency_show(m, latencies);
239 
240 	return 0;
241 }
242 
243 static int cur_wm_latency_show(struct seq_file *m, void *data)
244 {
245 	struct drm_i915_private *dev_priv = m->private;
246 	const u16 *latencies;
247 
248 	if (DISPLAY_VER(dev_priv) >= 9)
249 		latencies = dev_priv->display.wm.skl_latency;
250 	else
251 		latencies = dev_priv->display.wm.cur_latency;
252 
253 	wm_latency_show(m, latencies);
254 
255 	return 0;
256 }
257 
258 static int pri_wm_latency_open(struct inode *inode, struct file *file)
259 {
260 	struct drm_i915_private *dev_priv = inode->i_private;
261 
262 	if (DISPLAY_VER(dev_priv) < 5 && !IS_G4X(dev_priv))
263 		return -ENODEV;
264 
265 	return single_open(file, pri_wm_latency_show, dev_priv);
266 }
267 
268 static int spr_wm_latency_open(struct inode *inode, struct file *file)
269 {
270 	struct drm_i915_private *dev_priv = inode->i_private;
271 
272 	if (HAS_GMCH(dev_priv))
273 		return -ENODEV;
274 
275 	return single_open(file, spr_wm_latency_show, dev_priv);
276 }
277 
278 static int cur_wm_latency_open(struct inode *inode, struct file *file)
279 {
280 	struct drm_i915_private *dev_priv = inode->i_private;
281 
282 	if (HAS_GMCH(dev_priv))
283 		return -ENODEV;
284 
285 	return single_open(file, cur_wm_latency_show, dev_priv);
286 }
287 
288 static ssize_t wm_latency_write(struct file *file, const char __user *ubuf,
289 				size_t len, loff_t *offp, u16 wm[8])
290 {
291 	struct seq_file *m = file->private_data;
292 	struct drm_i915_private *dev_priv = m->private;
293 	u16 new[8] = {};
294 	int level;
295 	int ret;
296 	char tmp[32];
297 
298 	if (len >= sizeof(tmp))
299 		return -EINVAL;
300 
301 	if (copy_from_user(tmp, ubuf, len))
302 		return -EFAULT;
303 
304 	tmp[len] = '\0';
305 
306 	ret = sscanf(tmp, "%hu %hu %hu %hu %hu %hu %hu %hu",
307 		     &new[0], &new[1], &new[2], &new[3],
308 		     &new[4], &new[5], &new[6], &new[7]);
309 	if (ret != dev_priv->display.wm.num_levels)
310 		return -EINVAL;
311 
312 	drm_modeset_lock_all(&dev_priv->drm);
313 
314 	for (level = 0; level < dev_priv->display.wm.num_levels; level++)
315 		wm[level] = new[level];
316 
317 	drm_modeset_unlock_all(&dev_priv->drm);
318 
319 	return len;
320 }
321 
322 static ssize_t pri_wm_latency_write(struct file *file, const char __user *ubuf,
323 				    size_t len, loff_t *offp)
324 {
325 	struct seq_file *m = file->private_data;
326 	struct drm_i915_private *dev_priv = m->private;
327 	u16 *latencies;
328 
329 	if (DISPLAY_VER(dev_priv) >= 9)
330 		latencies = dev_priv->display.wm.skl_latency;
331 	else
332 		latencies = dev_priv->display.wm.pri_latency;
333 
334 	return wm_latency_write(file, ubuf, len, offp, latencies);
335 }
336 
337 static ssize_t spr_wm_latency_write(struct file *file, const char __user *ubuf,
338 				    size_t len, loff_t *offp)
339 {
340 	struct seq_file *m = file->private_data;
341 	struct drm_i915_private *dev_priv = m->private;
342 	u16 *latencies;
343 
344 	if (DISPLAY_VER(dev_priv) >= 9)
345 		latencies = dev_priv->display.wm.skl_latency;
346 	else
347 		latencies = dev_priv->display.wm.spr_latency;
348 
349 	return wm_latency_write(file, ubuf, len, offp, latencies);
350 }
351 
352 static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf,
353 				    size_t len, loff_t *offp)
354 {
355 	struct seq_file *m = file->private_data;
356 	struct drm_i915_private *dev_priv = m->private;
357 	u16 *latencies;
358 
359 	if (DISPLAY_VER(dev_priv) >= 9)
360 		latencies = dev_priv->display.wm.skl_latency;
361 	else
362 		latencies = dev_priv->display.wm.cur_latency;
363 
364 	return wm_latency_write(file, ubuf, len, offp, latencies);
365 }
366 
367 static const struct file_operations i915_pri_wm_latency_fops = {
368 	.owner = THIS_MODULE,
369 	.open = pri_wm_latency_open,
370 	.read = seq_read,
371 	.llseek = seq_lseek,
372 	.release = single_release,
373 	.write = pri_wm_latency_write
374 };
375 
376 static const struct file_operations i915_spr_wm_latency_fops = {
377 	.owner = THIS_MODULE,
378 	.open = spr_wm_latency_open,
379 	.read = seq_read,
380 	.llseek = seq_lseek,
381 	.release = single_release,
382 	.write = spr_wm_latency_write
383 };
384 
385 static const struct file_operations i915_cur_wm_latency_fops = {
386 	.owner = THIS_MODULE,
387 	.open = cur_wm_latency_open,
388 	.read = seq_read,
389 	.llseek = seq_lseek,
390 	.release = single_release,
391 	.write = cur_wm_latency_write
392 };
393 
394 void intel_wm_debugfs_register(struct drm_i915_private *i915)
395 {
396 	struct drm_minor *minor = i915->drm.primary;
397 
398 	debugfs_create_file("i915_pri_wm_latency", 0644, minor->debugfs_root,
399 			    i915, &i915_pri_wm_latency_fops);
400 
401 	debugfs_create_file("i915_spr_wm_latency", 0644, minor->debugfs_root,
402 			    i915, &i915_spr_wm_latency_fops);
403 
404 	debugfs_create_file("i915_cur_wm_latency", 0644, minor->debugfs_root,
405 			    i915, &i915_cur_wm_latency_fops);
406 
407 	skl_watermark_debugfs_register(i915);
408 }
409