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 "nouveau_drv.h"
25 #include "nouveau_reg.h"
26 #include "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
54 nv04_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
55 {
56 	int pagemiss, cas, bpp;
57 	int nvclks, mclks, 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 	bpp = arb->bpp;
69 	cbs = 128;
70 
71 	nvclks = 10;
72 	mclks = 13 + cas;
73 	mclk_extra = 3;
74 	found = 0;
75 
76 	while (!found) {
77 		found = 1;
78 
79 		mclk_loop = mclks + mclk_extra;
80 		us_m = mclk_loop * 1000 * 1000 / mclk_freq;
81 		us_n = nvclks * 1000 * 1000 / nvclk_freq;
82 		us_p = nvclks * 1000 * 1000 / pclk_freq;
83 
84 		crtc_drain_rate = pclk_freq * bpp / 8;
85 		crtpagemiss = 2;
86 		crtpagemiss += 1;
87 		cpm_us = crtpagemiss * pagemiss * 1000 * 1000 / mclk_freq;
88 		us_crt = cpm_us + us_m + us_n + us_p;
89 		clwm = us_crt * crtc_drain_rate / (1000 * 1000);
90 		clwm++;
91 
92 		m1 = clwm + cbs - 512;
93 		p1 = m1 * pclk_freq / mclk_freq;
94 		p1 = p1 * bpp / 8;
95 		if ((p1 < m1 && m1 > 0) || clwm > 519) {
96 			found = !mclk_extra;
97 			mclk_extra--;
98 		}
99 		if (clwm < 384)
100 			clwm = 384;
101 
102 		fifo->lwm = clwm;
103 		fifo->burst = cbs;
104 	}
105 }
106 
107 static void
108 nv10_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
109 {
110 	int fill_rate, drain_rate;
111 	int pclks, nvclks, mclks, xclks;
112 	int pclk_freq, nvclk_freq, mclk_freq;
113 	int fill_lat, extra_lat;
114 	int max_burst_o, max_burst_l;
115 	int fifo_len, min_lwm, max_lwm;
116 	const int burst_lat = 80; /* Maximum allowable latency due
117 				   * to the CRTC FIFO burst. (ns) */
118 
119 	pclk_freq = arb->pclk_khz;
120 	nvclk_freq = arb->nvclk_khz;
121 	mclk_freq = arb->mclk_khz;
122 
123 	fill_rate = mclk_freq * arb->memory_width / 8; /* kB/s */
124 	drain_rate = pclk_freq * arb->bpp / 8; /* kB/s */
125 
126 	fifo_len = arb->two_heads ? 1536 : 1024; /* B */
127 
128 	/* Fixed FIFO refill latency. */
129 
130 	pclks = 4;	/* lwm detect. */
131 
132 	nvclks = 3	/* lwm -> sync. */
133 		+ 2	/* fbi bus cycles (1 req + 1 busy) */
134 		+ 1	/* 2 edge sync.  may be very close to edge so
135 			 * just put one. */
136 		+ 1	/* fbi_d_rdv_n */
137 		+ 1	/* Fbi_d_rdata */
138 		+ 1;	/* crtfifo load */
139 
140 	mclks = 1	/* 2 edge sync.  may be very close to edge so
141 			 * just put one. */
142 		+ 1	/* arb_hp_req */
143 		+ 5	/* tiling pipeline */
144 		+ 2	/* latency fifo */
145 		+ 2	/* memory request to fbio block */
146 		+ 7;	/* data returned from fbio block */
147 
148 	/* Need to accumulate 256 bits for read */
149 	mclks += (arb->memory_type == 0 ? 2 : 1)
150 		* arb->memory_width / 32;
151 
152 	fill_lat = mclks * 1000 * 1000 / mclk_freq   /* minimum mclk latency */
153 		+ nvclks * 1000 * 1000 / nvclk_freq  /* nvclk latency */
154 		+ pclks * 1000 * 1000 / pclk_freq;   /* pclk latency */
155 
156 	/* Conditional FIFO refill latency. */
157 
158 	xclks = 2 * arb->mem_page_miss + mclks /* Extra latency due to
159 						* the overlay. */
160 		+ 2 * arb->mem_page_miss       /* Extra pagemiss latency. */
161 		+ (arb->bpp == 32 ? 8 : 4);    /* Margin of error. */
162 
163 	extra_lat = xclks * 1000 * 1000 / mclk_freq;
164 
165 	if (arb->two_heads)
166 		/* Account for another CRTC. */
167 		extra_lat += fill_lat + extra_lat + burst_lat;
168 
169 	/* FIFO burst */
170 
171 	/* Max burst not leading to overflows. */
172 	max_burst_o = (1 + fifo_len - extra_lat * drain_rate / (1000 * 1000))
173 		* (fill_rate / 1000) / ((fill_rate - drain_rate) / 1000);
174 	fifo->burst = min(max_burst_o, 1024);
175 
176 	/* Max burst value with an acceptable latency. */
177 	max_burst_l = burst_lat * fill_rate / (1000 * 1000);
178 	fifo->burst = min(max_burst_l, fifo->burst);
179 
180 	fifo->burst = rounddown_pow_of_two(fifo->burst);
181 
182 	/* FIFO low watermark */
183 
184 	min_lwm = (fill_lat + extra_lat) * drain_rate / (1000 * 1000) + 1;
185 	max_lwm = fifo_len - fifo->burst
186 		+ fill_lat * drain_rate / (1000 * 1000)
187 		+ fifo->burst * drain_rate / fill_rate;
188 
189 	fifo->lwm = min_lwm + 10 * (max_lwm - min_lwm) / 100; /* Empirical. */
190 }
191 
192 static void
193 nv04_update_arb(struct drm_device *dev, int VClk, int bpp,
194 		int *burst, int *lwm)
195 {
196 	struct nouveau_drm *drm = nouveau_drm(dev);
197 	struct nvif_object *device = &nouveau_drm(dev)->client.device.object;
198 	struct nv_fifo_info fifo_data;
199 	struct nv_sim_state sim_data;
200 	int MClk = nouveau_hw_get_clock(dev, PLL_MEMORY);
201 	int NVClk = nouveau_hw_get_clock(dev, PLL_CORE);
202 	uint32_t cfg1 = nvif_rd32(device, NV04_PFB_CFG1);
203 
204 	sim_data.pclk_khz = VClk;
205 	sim_data.mclk_khz = MClk;
206 	sim_data.nvclk_khz = NVClk;
207 	sim_data.bpp = bpp;
208 	sim_data.two_heads = nv_two_heads(dev);
209 	if ((dev->pdev->device & 0xffff) == 0x01a0 /*CHIPSET_NFORCE*/ ||
210 	    (dev->pdev->device & 0xffff) == 0x01f0 /*CHIPSET_NFORCE2*/) {
211 		uint32_t type;
212 		int domain = pci_domain_nr(dev->pdev->bus);
213 
214 		pci_read_config_dword(pci_get_domain_bus_and_slot(domain, 0, 1),
215 				      0x7c, &type);
216 
217 		sim_data.memory_type = (type >> 12) & 1;
218 		sim_data.memory_width = 64;
219 		sim_data.mem_latency = 3;
220 		sim_data.mem_page_miss = 10;
221 	} else {
222 		sim_data.memory_type = nvif_rd32(device, NV04_PFB_CFG0) & 0x1;
223 		sim_data.memory_width = (nvif_rd32(device, NV_PEXTDEV_BOOT_0) & 0x10) ? 128 : 64;
224 		sim_data.mem_latency = cfg1 & 0xf;
225 		sim_data.mem_page_miss = ((cfg1 >> 4) & 0xf) + ((cfg1 >> 31) & 0x1);
226 	}
227 
228 	if (drm->client.device.info.family == NV_DEVICE_INFO_V0_TNT)
229 		nv04_calc_arb(&fifo_data, &sim_data);
230 	else
231 		nv10_calc_arb(&fifo_data, &sim_data);
232 
233 	*burst = ilog2(fifo_data.burst >> 4);
234 	*lwm = fifo_data.lwm >> 3;
235 }
236 
237 static void
238 nv20_update_arb(int *burst, int *lwm)
239 {
240 	unsigned int fifo_size, burst_size, graphics_lwm;
241 
242 	fifo_size = 2048;
243 	burst_size = 512;
244 	graphics_lwm = fifo_size - burst_size;
245 
246 	*burst = ilog2(burst_size >> 5);
247 	*lwm = graphics_lwm >> 3;
248 }
249 
250 void
251 nouveau_calc_arb(struct drm_device *dev, int vclk, int bpp, int *burst, int *lwm)
252 {
253 	struct nouveau_drm *drm = nouveau_drm(dev);
254 
255 	if (drm->client.device.info.family < NV_DEVICE_INFO_V0_KELVIN)
256 		nv04_update_arb(dev, vclk, bpp, burst, lwm);
257 	else if ((dev->pdev->device & 0xfff0) == 0x0240 /*CHIPSET_C51*/ ||
258 		 (dev->pdev->device & 0xfff0) == 0x03d0 /*CHIPSET_C512*/) {
259 		*burst = 128;
260 		*lwm = 0x0480;
261 	} else
262 		nv20_update_arb(burst, lwm);
263 }
264