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 <drm/drmP.h>
25 
26 #include "nouveau_drm.h"
27 #include "nouveau_reg.h"
28 #include "hw.h"
29 
30 /****************************************************************************\
31 *                                                                            *
32 * The video arbitration routines calculate some "magic" numbers.  Fixes      *
33 * the snow seen when accessing the framebuffer without it.                   *
34 * It just works (I hope).                                                    *
35 *                                                                            *
36 \****************************************************************************/
37 
38 struct nv_fifo_info {
39 	int lwm;
40 	int burst;
41 };
42 
43 struct nv_sim_state {
44 	int pclk_khz;
45 	int mclk_khz;
46 	int nvclk_khz;
47 	int bpp;
48 	int mem_page_miss;
49 	int mem_latency;
50 	int memory_type;
51 	int memory_width;
52 	int two_heads;
53 };
54 
55 static void
56 nv04_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
57 {
58 	int pagemiss, cas, width, bpp;
59 	int nvclks, mclks, pclks, crtpagemiss;
60 	int found, mclk_extra, mclk_loop, cbs, m1, p1;
61 	int mclk_freq, pclk_freq, nvclk_freq;
62 	int us_m, us_n, us_p, crtc_drain_rate;
63 	int cpm_us, us_crt, clwm;
64 
65 	pclk_freq = arb->pclk_khz;
66 	mclk_freq = arb->mclk_khz;
67 	nvclk_freq = arb->nvclk_khz;
68 	pagemiss = arb->mem_page_miss;
69 	cas = arb->mem_latency;
70 	width = arb->memory_width >> 6;
71 	bpp = arb->bpp;
72 	cbs = 128;
73 
74 	pclks = 2;
75 	nvclks = 10;
76 	mclks = 13 + cas;
77 	mclk_extra = 3;
78 	found = 0;
79 
80 	while (!found) {
81 		found = 1;
82 
83 		mclk_loop = mclks + mclk_extra;
84 		us_m = mclk_loop * 1000 * 1000 / mclk_freq;
85 		us_n = nvclks * 1000 * 1000 / nvclk_freq;
86 		us_p = nvclks * 1000 * 1000 / pclk_freq;
87 
88 		crtc_drain_rate = pclk_freq * bpp / 8;
89 		crtpagemiss = 2;
90 		crtpagemiss += 1;
91 		cpm_us = crtpagemiss * pagemiss * 1000 * 1000 / mclk_freq;
92 		us_crt = cpm_us + us_m + us_n + us_p;
93 		clwm = us_crt * crtc_drain_rate / (1000 * 1000);
94 		clwm++;
95 
96 		m1 = clwm + cbs - 512;
97 		p1 = m1 * pclk_freq / mclk_freq;
98 		p1 = p1 * bpp / 8;
99 		if ((p1 < m1 && m1 > 0) || clwm > 519) {
100 			found = !mclk_extra;
101 			mclk_extra--;
102 		}
103 		if (clwm < 384)
104 			clwm = 384;
105 
106 		fifo->lwm = clwm;
107 		fifo->burst = cbs;
108 	}
109 }
110 
111 static void
112 nv10_calc_arb(struct nv_fifo_info *fifo, struct nv_sim_state *arb)
113 {
114 	int fill_rate, drain_rate;
115 	int pclks, nvclks, mclks, xclks;
116 	int pclk_freq, nvclk_freq, mclk_freq;
117 	int fill_lat, extra_lat;
118 	int max_burst_o, max_burst_l;
119 	int fifo_len, min_lwm, max_lwm;
120 	const int burst_lat = 80; /* Maximum allowable latency due
121 				   * to the CRTC FIFO burst. (ns) */
122 
123 	pclk_freq = arb->pclk_khz;
124 	nvclk_freq = arb->nvclk_khz;
125 	mclk_freq = arb->mclk_khz;
126 
127 	fill_rate = mclk_freq * arb->memory_width / 8; /* kB/s */
128 	drain_rate = pclk_freq * arb->bpp / 8; /* kB/s */
129 
130 	fifo_len = arb->two_heads ? 1536 : 1024; /* B */
131 
132 	/* Fixed FIFO refill latency. */
133 
134 	pclks = 4;	/* lwm detect. */
135 
136 	nvclks = 3	/* lwm -> sync. */
137 		+ 2	/* fbi bus cycles (1 req + 1 busy) */
138 		+ 1	/* 2 edge sync.  may be very close to edge so
139 			 * just put one. */
140 		+ 1	/* fbi_d_rdv_n */
141 		+ 1	/* Fbi_d_rdata */
142 		+ 1;	/* crtfifo load */
143 
144 	mclks = 1	/* 2 edge sync.  may be very close to edge so
145 			 * just put one. */
146 		+ 1	/* arb_hp_req */
147 		+ 5	/* tiling pipeline */
148 		+ 2	/* latency fifo */
149 		+ 2	/* memory request to fbio block */
150 		+ 7;	/* data returned from fbio block */
151 
152 	/* Need to accumulate 256 bits for read */
153 	mclks += (arb->memory_type == 0 ? 2 : 1)
154 		* arb->memory_width / 32;
155 
156 	fill_lat = mclks * 1000 * 1000 / mclk_freq   /* minimum mclk latency */
157 		+ nvclks * 1000 * 1000 / nvclk_freq  /* nvclk latency */
158 		+ pclks * 1000 * 1000 / pclk_freq;   /* pclk latency */
159 
160 	/* Conditional FIFO refill latency. */
161 
162 	xclks = 2 * arb->mem_page_miss + mclks /* Extra latency due to
163 						* the overlay. */
164 		+ 2 * arb->mem_page_miss       /* Extra pagemiss latency. */
165 		+ (arb->bpp == 32 ? 8 : 4);    /* Margin of error. */
166 
167 	extra_lat = xclks * 1000 * 1000 / mclk_freq;
168 
169 	if (arb->two_heads)
170 		/* Account for another CRTC. */
171 		extra_lat += fill_lat + extra_lat + burst_lat;
172 
173 	/* FIFO burst */
174 
175 	/* Max burst not leading to overflows. */
176 	max_burst_o = (1 + fifo_len - extra_lat * drain_rate / (1000 * 1000))
177 		* (fill_rate / 1000) / ((fill_rate - drain_rate) / 1000);
178 	fifo->burst = min(max_burst_o, 1024);
179 
180 	/* Max burst value with an acceptable latency. */
181 	max_burst_l = burst_lat * fill_rate / (1000 * 1000);
182 	fifo->burst = min(max_burst_l, fifo->burst);
183 
184 	fifo->burst = rounddown_pow_of_two(fifo->burst);
185 
186 	/* FIFO low watermark */
187 
188 	min_lwm = (fill_lat + extra_lat) * drain_rate / (1000 * 1000) + 1;
189 	max_lwm = fifo_len - fifo->burst
190 		+ fill_lat * drain_rate / (1000 * 1000)
191 		+ fifo->burst * drain_rate / fill_rate;
192 
193 	fifo->lwm = min_lwm + 10 * (max_lwm - min_lwm) / 100; /* Empirical. */
194 }
195 
196 static void
197 nv04_update_arb(struct drm_device *dev, int VClk, int bpp,
198 		int *burst, int *lwm)
199 {
200 	struct nouveau_drm *drm = nouveau_drm(dev);
201 	struct nvif_device *device = &nouveau_drm(dev)->device;
202 	struct nv_fifo_info fifo_data;
203 	struct nv_sim_state sim_data;
204 	int MClk = nouveau_hw_get_clock(dev, PLL_MEMORY);
205 	int NVClk = nouveau_hw_get_clock(dev, PLL_CORE);
206 	uint32_t cfg1 = nvif_rd32(device, NV04_PFB_CFG1);
207 
208 	sim_data.pclk_khz = VClk;
209 	sim_data.mclk_khz = MClk;
210 	sim_data.nvclk_khz = NVClk;
211 	sim_data.bpp = bpp;
212 	sim_data.two_heads = nv_two_heads(dev);
213 	if ((dev->pdev->device & 0xffff) == 0x01a0 /*CHIPSET_NFORCE*/ ||
214 	    (dev->pdev->device & 0xffff) == 0x01f0 /*CHIPSET_NFORCE2*/) {
215 		uint32_t type;
216 
217 		pci_read_config_dword(pci_get_bus_and_slot(0, 1), 0x7c, &type);
218 
219 		sim_data.memory_type = (type >> 12) & 1;
220 		sim_data.memory_width = 64;
221 		sim_data.mem_latency = 3;
222 		sim_data.mem_page_miss = 10;
223 	} else {
224 		sim_data.memory_type = nvif_rd32(device, NV04_PFB_CFG0) & 0x1;
225 		sim_data.memory_width = (nvif_rd32(device, NV_PEXTDEV_BOOT_0) & 0x10) ? 128 : 64;
226 		sim_data.mem_latency = cfg1 & 0xf;
227 		sim_data.mem_page_miss = ((cfg1 >> 4) & 0xf) + ((cfg1 >> 31) & 0x1);
228 	}
229 
230 	if (drm->device.info.family == NV_DEVICE_INFO_V0_TNT)
231 		nv04_calc_arb(&fifo_data, &sim_data);
232 	else
233 		nv10_calc_arb(&fifo_data, &sim_data);
234 
235 	*burst = ilog2(fifo_data.burst >> 4);
236 	*lwm = fifo_data.lwm >> 3;
237 }
238 
239 static void
240 nv20_update_arb(int *burst, int *lwm)
241 {
242 	unsigned int fifo_size, burst_size, graphics_lwm;
243 
244 	fifo_size = 2048;
245 	burst_size = 512;
246 	graphics_lwm = fifo_size - burst_size;
247 
248 	*burst = ilog2(burst_size >> 5);
249 	*lwm = graphics_lwm >> 3;
250 }
251 
252 void
253 nouveau_calc_arb(struct drm_device *dev, int vclk, int bpp, int *burst, int *lwm)
254 {
255 	struct nouveau_drm *drm = nouveau_drm(dev);
256 
257 	if (drm->device.info.family < NV_DEVICE_INFO_V0_KELVIN)
258 		nv04_update_arb(dev, vclk, bpp, burst, lwm);
259 	else if ((dev->pdev->device & 0xfff0) == 0x0240 /*CHIPSET_C51*/ ||
260 		 (dev->pdev->device & 0xfff0) == 0x03d0 /*CHIPSET_C512*/) {
261 		*burst = 128;
262 		*lwm = 0x0480;
263 	} else
264 		nv20_update_arb(burst, lwm);
265 }
266