1 /*
2  * Copyright 1993-2003 NVIDIA, Corporation
3  * Copyright 2007-2009 Stuart Bennett
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  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
19  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
20  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  */
23 
24 #include "drmP.h"
25 #include "nouveau_drv.h"
26 #include "nouveau_hw.h"
27 
28 /****************************************************************************\
29 *                                                                            *
30 * The video arbitration routines calculate some "magic" numbers.  Fixes      *
31 * the snow seen when accessing the framebuffer without it.                   *
32 * It just works (I hope).                                                    *
33 *                                                                            *
34 \****************************************************************************/
35 
36 struct nv_fifo_info {
37 	int lwm;
38 	int burst;
39 };
40 
41 struct nv_sim_state {
42 	int pclk_khz;
43 	int mclk_khz;
44 	int nvclk_khz;
45 	int bpp;
46 	int mem_page_miss;
47 	int mem_latency;
48 	int memory_type;
49 	int memory_width;
50 	int two_heads;
51 };
52 
53 static void
nv04_calc_arb(struct nv_fifo_info * fifo,struct nv_sim_state * arb)54 nv04_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
55 {
56 	int pagemiss, cas, width, bpp;
57 	int nvclks, mclks, pclks, crtpagemiss;
58 	int found, mclk_extra, mclk_loop, cbs, m1, p1;
59 	int mclk_freq, pclk_freq, nvclk_freq;
60 	int us_m, us_n, us_p, crtc_drain_rate;
61 	int cpm_us, us_crt, clwm;
62 
63 	pclk_freq = arb->pclk_khz;
64 	mclk_freq = arb->mclk_khz;
65 	nvclk_freq = arb->nvclk_khz;
66 	pagemiss = arb->mem_page_miss;
67 	cas = arb->mem_latency;
68 	width = arb->memory_width >> 6;
69 	bpp = arb->bpp;
70 	cbs = 128;
71 
72 	pclks = 2;
73 	nvclks = 10;
74 	mclks = 13 + cas;
75 	mclk_extra = 3;
76 	found = 0;
77 
78 	while (!found) {
79 		found = 1;
80 
81 		mclk_loop = mclks + mclk_extra;
82 		us_m = mclk_loop * 1000 * 1000 / mclk_freq;
83 		us_n = nvclks * 1000 * 1000 / nvclk_freq;
84 		us_p = nvclks * 1000 * 1000 / pclk_freq;
85 
86 		crtc_drain_rate = pclk_freq * bpp / 8;
87 		crtpagemiss = 2;
88 		crtpagemiss += 1;
89 		cpm_us = crtpagemiss * pagemiss * 1000 * 1000 / mclk_freq;
90 		us_crt = cpm_us + us_m + us_n + us_p;
91 		clwm = us_crt * crtc_drain_rate / (1000 * 1000);
92 		clwm++;
93 
94 		m1 = clwm + cbs - 512;
95 		p1 = m1 * pclk_freq / mclk_freq;
96 		p1 = p1 * bpp / 8;
97 		if ((p1 < m1 && m1 > 0) || clwm > 519) {
98 			found = !mclk_extra;
99 			mclk_extra--;
100 		}
101 		if (clwm < 384)
102 			clwm = 384;
103 
104 		fifo->lwm = clwm;
105 		fifo->burst = cbs;
106 	}
107 }
108 
109 static void
nv10_calc_arb(struct nv_fifo_info * fifo,struct nv_sim_state * arb)110 nv10_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
111 {
112 	int fill_rate, drain_rate;
113 	int pclks, nvclks, mclks, xclks;
114 	int pclk_freq, nvclk_freq, mclk_freq;
115 	int fill_lat, extra_lat;
116 	int max_burst_o, max_burst_l;
117 	int fifo_len, min_lwm, max_lwm;
118 	const int burst_lat = 80; /* Maximum allowable latency due
119 				   * to the CRTC FIFO burst. (ns) */
120 
121 	pclk_freq = arb->pclk_khz;
122 	nvclk_freq = arb->nvclk_khz;
123 	mclk_freq = arb->mclk_khz;
124 
125 	fill_rate = mclk_freq * arb->memory_width / 8; /* kB/s */
126 	drain_rate = pclk_freq * arb->bpp / 8; /* kB/s */
127 
128 	fifo_len = arb->two_heads ? 1536 : 1024; /* B */
129 
130 	/* Fixed FIFO refill latency. */
131 
132 	pclks = 4;	/* lwm detect. */
133 
134 	nvclks = 3	/* lwm -> sync. */
135 		+ 2	/* fbi bus cycles (1 req + 1 busy) */
136 		+ 1	/* 2 edge sync.  may be very close to edge so
137 			 * just put one. */
138 		+ 1	/* fbi_d_rdv_n */
139 		+ 1	/* Fbi_d_rdata */
140 		+ 1;	/* crtfifo load */
141 
142 	mclks = 1	/* 2 edge sync.  may be very close to edge so
143 			 * just put one. */
144 		+ 1	/* arb_hp_req */
145 		+ 5	/* tiling pipeline */
146 		+ 2	/* latency fifo */
147 		+ 2	/* memory request to fbio block */
148 		+ 7;	/* data returned from fbio block */
149 
150 	/* Need to accumulate 256 bits for read */
151 	mclks += (arb->memory_type == 0 ? 2 : 1)
152 		* arb->memory_width / 32;
153 
154 	fill_lat = mclks * 1000 * 1000 / mclk_freq   /* minimum mclk latency */
155 		+ nvclks * 1000 * 1000 / nvclk_freq  /* nvclk latency */
156 		+ pclks * 1000 * 1000 / pclk_freq;   /* pclk latency */
157 
158 	/* Conditional FIFO refill latency. */
159 
160 	xclks = 2 * arb->mem_page_miss + mclks /* Extra latency due to
161 						* the overlay. */
162 		+ 2 * arb->mem_page_miss       /* Extra pagemiss latency. */
163 		+ (arb->bpp == 32 ? 8 : 4);    /* Margin of error. */
164 
165 	extra_lat = xclks * 1000 * 1000 / mclk_freq;
166 
167 	if (arb->two_heads)
168 		/* Account for another CRTC. */
169 		extra_lat += fill_lat + extra_lat + burst_lat;
170 
171 	/* FIFO burst */
172 
173 	/* Max burst not leading to overflows. */
174 	max_burst_o = (1 + fifo_len - extra_lat * drain_rate / (1000 * 1000))
175 		* (fill_rate / 1000) / ((fill_rate - drain_rate) / 1000);
176 	fifo->burst = min(max_burst_o, 1024);
177 
178 	/* Max burst value with an acceptable latency. */
179 	max_burst_l = burst_lat * fill_rate / (1000 * 1000);
180 	fifo->burst = min(max_burst_l, fifo->burst);
181 
182 	fifo->burst = rounddown_pow_of_two(fifo->burst);
183 
184 	/* FIFO low watermark */
185 
186 	min_lwm = (fill_lat + extra_lat) * drain_rate / (1000 * 1000) + 1;
187 	max_lwm = fifo_len - fifo->burst
188 		+ fill_lat * drain_rate / (1000 * 1000)
189 		+ fifo->burst * drain_rate / fill_rate;
190 
191 	fifo->lwm = min_lwm + 10 * (max_lwm - min_lwm) / 100; /* Empirical. */
192 }
193 
194 static void
nv04_update_arb(struct drm_device * dev,int VClk,int bpp,int * burst,int * lwm)195 nv04_update_arb(struct drm_device *dev, int VClk, int bpp,
196 		int *burst, int *lwm)
197 {
198 	struct drm_nouveau_private *dev_priv = dev->dev_private;
199 	struct nv_fifo_info fifo_data;
200 	struct nv_sim_state sim_data;
201 	int MClk = nouveau_hw_get_clock(dev, PLL_MEMORY);
202 	int NVClk = nouveau_hw_get_clock(dev, PLL_CORE);
203 	uint32_t cfg1 = nvReadFB(dev, NV04_PFB_CFG1);
204 
205 	sim_data.pclk_khz = VClk;
206 	sim_data.mclk_khz = MClk;
207 	sim_data.nvclk_khz = NVClk;
208 	sim_data.bpp = bpp;
209 	sim_data.two_heads = nv_two_heads(dev);
210 	if ((dev->pci_device & 0xffff) == 0x01a0 /*CHIPSET_NFORCE*/ ||
211 	    (dev->pci_device & 0xffff) == 0x01f0 /*CHIPSET_NFORCE2*/) {
212 		uint32_t type;
213 
214 		pci_read_config_dword(pci_get_bus_and_slot(0, 1), 0x7c, &type);
215 
216 		sim_data.memory_type = (type >> 12) & 1;
217 		sim_data.memory_width = 64;
218 		sim_data.mem_latency = 3;
219 		sim_data.mem_page_miss = 10;
220 	} else {
221 		sim_data.memory_type = nvReadFB(dev, NV04_PFB_CFG0) & 0x1;
222 		sim_data.memory_width = (nvReadEXTDEV(dev, NV_PEXTDEV_BOOT_0) & 0x10) ? 128 : 64;
223 		sim_data.mem_latency = cfg1 & 0xf;
224 		sim_data.mem_page_miss = ((cfg1 >> 4) & 0xf) + ((cfg1 >> 31) & 0x1);
225 	}
226 
227 	if (dev_priv->card_type == NV_04)
228 		nv04_calc_arb(&fifo_data, &sim_data);
229 	else
230 		nv10_calc_arb(&fifo_data, &sim_data);
231 
232 	*burst = ilog2(fifo_data.burst >> 4);
233 	*lwm = fifo_data.lwm >> 3;
234 }
235 
236 static void
nv20_update_arb(int * burst,int * lwm)237 nv20_update_arb(int *burst, int *lwm)
238 {
239 	unsigned int fifo_size, burst_size, graphics_lwm;
240 
241 	fifo_size = 2048;
242 	burst_size = 512;
243 	graphics_lwm = fifo_size - burst_size;
244 
245 	*burst = ilog2(burst_size >> 5);
246 	*lwm = graphics_lwm >> 3;
247 }
248 
249 void
nouveau_calc_arb(struct drm_device * dev,int vclk,int bpp,int * burst,int * lwm)250 nouveau_calc_arb(struct drm_device *dev, int vclk, int bpp, int *burst, int *lwm)
251 {
252 	struct drm_nouveau_private *dev_priv = dev->dev_private;
253 
254 	if (dev_priv->card_type < NV_20)
255 		nv04_update_arb(dev, vclk, bpp, burst, lwm);
256 	else if ((dev->pci_device & 0xfff0) == 0x0240 /*CHIPSET_C51*/ ||
257 		 (dev->pci_device & 0xfff0) == 0x03d0 /*CHIPSET_C512*/) {
258 		*burst = 128;
259 		*lwm = 0x0480;
260 	} else
261 		nv20_update_arb(burst, lwm);
262 }
263 
264 static int
getMNP_single(struct drm_device * dev,struct pll_lims * pll_lim,int clk,struct nouveau_pll_vals * bestpv)265 getMNP_single(struct drm_device *dev, struct pll_lims *pll_lim, int clk,
266 	      struct nouveau_pll_vals *bestpv)
267 {
268 	/* Find M, N and P for a single stage PLL
269 	 *
270 	 * Note that some bioses (NV3x) have lookup tables of precomputed MNP
271 	 * values, but we're too lazy to use those atm
272 	 *
273 	 * "clk" parameter in kHz
274 	 * returns calculated clock
275 	 */
276 	struct drm_nouveau_private *dev_priv = dev->dev_private;
277 	int cv = dev_priv->vbios.chip_version;
278 	int minvco = pll_lim->vco1.minfreq, maxvco = pll_lim->vco1.maxfreq;
279 	int minM = pll_lim->vco1.min_m, maxM = pll_lim->vco1.max_m;
280 	int minN = pll_lim->vco1.min_n, maxN = pll_lim->vco1.max_n;
281 	int minU = pll_lim->vco1.min_inputfreq;
282 	int maxU = pll_lim->vco1.max_inputfreq;
283 	int minP = pll_lim->max_p ? pll_lim->min_p : 0;
284 	int maxP = pll_lim->max_p ? pll_lim->max_p : pll_lim->max_usable_log2p;
285 	int crystal = pll_lim->refclk;
286 	int M, N, thisP, P;
287 	int clkP, calcclk;
288 	int delta, bestdelta = INT_MAX;
289 	int bestclk = 0;
290 
291 	/* this division verified for nv20, nv18, nv28 (Haiku), and nv34 */
292 	/* possibly correlated with introduction of 27MHz crystal */
293 	if (dev_priv->card_type < NV_50) {
294 		if (cv < 0x17 || cv == 0x1a || cv == 0x20) {
295 			if (clk > 250000)
296 				maxM = 6;
297 			if (clk > 340000)
298 				maxM = 2;
299 		} else if (cv < 0x40) {
300 			if (clk > 150000)
301 				maxM = 6;
302 			if (clk > 200000)
303 				maxM = 4;
304 			if (clk > 340000)
305 				maxM = 2;
306 		}
307 	}
308 
309 	P = pll_lim->max_p ? maxP : (1 << maxP);
310 	if ((clk * P) < minvco) {
311 		minvco = clk * maxP;
312 		maxvco = minvco * 2;
313 	}
314 
315 	if (clk + clk/200 > maxvco)	/* +0.5% */
316 		maxvco = clk + clk/200;
317 
318 	/* NV34 goes maxlog2P->0, NV20 goes 0->maxlog2P */
319 	for (thisP = minP; thisP <= maxP; thisP++) {
320 		P = pll_lim->max_p ? thisP : (1 << thisP);
321 		clkP = clk * P;
322 
323 		if (clkP < minvco)
324 			continue;
325 		if (clkP > maxvco)
326 			return bestclk;
327 
328 		for (M = minM; M <= maxM; M++) {
329 			if (crystal/M < minU)
330 				return bestclk;
331 			if (crystal/M > maxU)
332 				continue;
333 
334 			/* add crystal/2 to round better */
335 			N = (clkP * M + crystal/2) / crystal;
336 
337 			if (N < minN)
338 				continue;
339 			if (N > maxN)
340 				break;
341 
342 			/* more rounding additions */
343 			calcclk = ((N * crystal + P/2) / P + M/2) / M;
344 			delta = abs(calcclk - clk);
345 			/* we do an exhaustive search rather than terminating
346 			 * on an optimality condition...
347 			 */
348 			if (delta < bestdelta) {
349 				bestdelta = delta;
350 				bestclk = calcclk;
351 				bestpv->N1 = N;
352 				bestpv->M1 = M;
353 				bestpv->log2P = thisP;
354 				if (delta == 0)	/* except this one */
355 					return bestclk;
356 			}
357 		}
358 	}
359 
360 	return bestclk;
361 }
362 
363 static int
getMNP_double(struct drm_device * dev,struct pll_lims * pll_lim,int clk,struct nouveau_pll_vals * bestpv)364 getMNP_double(struct drm_device *dev, struct pll_lims *pll_lim, int clk,
365 	      struct nouveau_pll_vals *bestpv)
366 {
367 	/* Find M, N and P for a two stage PLL
368 	 *
369 	 * Note that some bioses (NV30+) have lookup tables of precomputed MNP
370 	 * values, but we're too lazy to use those atm
371 	 *
372 	 * "clk" parameter in kHz
373 	 * returns calculated clock
374 	 */
375 	struct drm_nouveau_private *dev_priv = dev->dev_private;
376 	int chip_version = dev_priv->vbios.chip_version;
377 	int minvco1 = pll_lim->vco1.minfreq, maxvco1 = pll_lim->vco1.maxfreq;
378 	int minvco2 = pll_lim->vco2.minfreq, maxvco2 = pll_lim->vco2.maxfreq;
379 	int minU1 = pll_lim->vco1.min_inputfreq, minU2 = pll_lim->vco2.min_inputfreq;
380 	int maxU1 = pll_lim->vco1.max_inputfreq, maxU2 = pll_lim->vco2.max_inputfreq;
381 	int minM1 = pll_lim->vco1.min_m, maxM1 = pll_lim->vco1.max_m;
382 	int minN1 = pll_lim->vco1.min_n, maxN1 = pll_lim->vco1.max_n;
383 	int minM2 = pll_lim->vco2.min_m, maxM2 = pll_lim->vco2.max_m;
384 	int minN2 = pll_lim->vco2.min_n, maxN2 = pll_lim->vco2.max_n;
385 	int maxlog2P = pll_lim->max_usable_log2p;
386 	int crystal = pll_lim->refclk;
387 	bool fixedgain2 = (minM2 == maxM2 && minN2 == maxN2);
388 	int M1, N1, M2, N2, log2P;
389 	int clkP, calcclk1, calcclk2, calcclkout;
390 	int delta, bestdelta = INT_MAX;
391 	int bestclk = 0;
392 
393 	int vco2 = (maxvco2 - maxvco2/200) / 2;
394 	for (log2P = 0; clk && log2P < maxlog2P && clk <= (vco2 >> log2P); log2P++)
395 		;
396 	clkP = clk << log2P;
397 
398 	if (maxvco2 < clk + clk/200)	/* +0.5% */
399 		maxvco2 = clk + clk/200;
400 
401 	for (M1 = minM1; M1 <= maxM1; M1++) {
402 		if (crystal/M1 < minU1)
403 			return bestclk;
404 		if (crystal/M1 > maxU1)
405 			continue;
406 
407 		for (N1 = minN1; N1 <= maxN1; N1++) {
408 			calcclk1 = crystal * N1 / M1;
409 			if (calcclk1 < minvco1)
410 				continue;
411 			if (calcclk1 > maxvco1)
412 				break;
413 
414 			for (M2 = minM2; M2 <= maxM2; M2++) {
415 				if (calcclk1/M2 < minU2)
416 					break;
417 				if (calcclk1/M2 > maxU2)
418 					continue;
419 
420 				/* add calcclk1/2 to round better */
421 				N2 = (clkP * M2 + calcclk1/2) / calcclk1;
422 				if (N2 < minN2)
423 					continue;
424 				if (N2 > maxN2)
425 					break;
426 
427 				if (!fixedgain2) {
428 					if (chip_version < 0x60)
429 						if (N2/M2 < 4 || N2/M2 > 10)
430 							continue;
431 
432 					calcclk2 = calcclk1 * N2 / M2;
433 					if (calcclk2 < minvco2)
434 						break;
435 					if (calcclk2 > maxvco2)
436 						continue;
437 				} else
438 					calcclk2 = calcclk1;
439 
440 				calcclkout = calcclk2 >> log2P;
441 				delta = abs(calcclkout - clk);
442 				/* we do an exhaustive search rather than terminating
443 				 * on an optimality condition...
444 				 */
445 				if (delta < bestdelta) {
446 					bestdelta = delta;
447 					bestclk = calcclkout;
448 					bestpv->N1 = N1;
449 					bestpv->M1 = M1;
450 					bestpv->N2 = N2;
451 					bestpv->M2 = M2;
452 					bestpv->log2P = log2P;
453 					if (delta == 0)	/* except this one */
454 						return bestclk;
455 				}
456 			}
457 		}
458 	}
459 
460 	return bestclk;
461 }
462 
463 int
nouveau_calc_pll_mnp(struct drm_device * dev,struct pll_lims * pll_lim,int clk,struct nouveau_pll_vals * pv)464 nouveau_calc_pll_mnp(struct drm_device *dev, struct pll_lims *pll_lim, int clk,
465 		     struct nouveau_pll_vals *pv)
466 {
467 	int outclk;
468 
469 	if (!pll_lim->vco2.maxfreq)
470 		outclk = getMNP_single(dev, pll_lim, clk, pv);
471 	else
472 		outclk = getMNP_double(dev, pll_lim, clk, pv);
473 
474 	if (!outclk)
475 		NV_ERROR(dev, "Could not find a compatible set of PLL values\n");
476 
477 	return outclk;
478 }
479