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
36struct nv_fifo_info {
37	int lwm;
38	int burst;
39};
40
41struct 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
53static void
54nv04_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
107static void
108nv10_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
192static void
193nv04_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	struct pci_dev *pdev = to_pci_dev(dev->dev);
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 ((pdev->device & 0xffff) == 0x01a0 /*CHIPSET_NFORCE*/ ||
211	    (pdev->device & 0xffff) == 0x01f0 /*CHIPSET_NFORCE2*/) {
212		uint32_t type;
213		int domain = pci_domain_nr(pdev->bus);
214
215		pci_read_config_dword(pci_get_domain_bus_and_slot(domain, 0, 1),
216				      0x7c, &type);
217
218		sim_data.memory_type = (type >> 12) & 1;
219		sim_data.memory_width = 64;
220		sim_data.mem_latency = 3;
221		sim_data.mem_page_miss = 10;
222	} else {
223		sim_data.memory_type = nvif_rd32(device, NV04_PFB_CFG0) & 0x1;
224		sim_data.memory_width = (nvif_rd32(device, NV_PEXTDEV_BOOT_0) & 0x10) ? 128 : 64;
225		sim_data.mem_latency = cfg1 & 0xf;
226		sim_data.mem_page_miss = ((cfg1 >> 4) & 0xf) + ((cfg1 >> 31) & 0x1);
227	}
228
229	if (drm->client.device.info.family == NV_DEVICE_INFO_V0_TNT)
230		nv04_calc_arb(&fifo_data, &sim_data);
231	else
232		nv10_calc_arb(&fifo_data, &sim_data);
233
234	*burst = ilog2(fifo_data.burst >> 4);
235	*lwm = fifo_data.lwm >> 3;
236}
237
238static void
239nv20_update_arb(int *burst, int *lwm)
240{
241	unsigned int fifo_size, burst_size, graphics_lwm;
242
243	fifo_size = 2048;
244	burst_size = 512;
245	graphics_lwm = fifo_size - burst_size;
246
247	*burst = ilog2(burst_size >> 5);
248	*lwm = graphics_lwm >> 3;
249}
250
251void
252nouveau_calc_arb(struct drm_device *dev, int vclk, int bpp, int *burst, int *lwm)
253{
254	struct nouveau_drm *drm = nouveau_drm(dev);
255	struct pci_dev *pdev = to_pci_dev(dev->dev);
256
257	if (drm->client.device.info.family < NV_DEVICE_INFO_V0_KELVIN)
258		nv04_update_arb(dev, vclk, bpp, burst, lwm);
259	else if ((pdev->device & 0xfff0) == 0x0240 /*CHIPSET_C51*/ ||
260		 (pdev->device & 0xfff0) == 0x03d0 /*CHIPSET_C512*/) {
261		*burst = 128;
262		*lwm = 0x0480;
263	} else
264		nv20_update_arb(burst, lwm);
265}
266