xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_vcbus.c (revision 1171c633fb097a19e1da87128604190bc6d27341)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2019 Kyle Evans <kevans@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*
34  * This file contains facilities for runtime determination of address space
35  * mappings for use in DMA/mailbox interactions.  This is only used for the
36  * arm64 SoC because the 32-bit SoC used the same mappings.
37  */
38 #if defined (__aarch64__)
39 #include "opt_soc.h"
40 #endif
41 
42 #include <sys/types.h>
43 #include <sys/systm.h>
44 
45 #include <dev/ofw/openfirm.h>
46 #include <dev/ofw/ofw_bus.h>
47 #include <dev/ofw/ofw_bus_subr.h>
48 
49 #include <machine/bus.h>
50 
51 #include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
52 
53 /*
54  * This structure describes mappings that need to take place when transforming
55  * ARM core addresses into vcbus addresses for use with the DMA/mailbox
56  * interfaces.  Currently, we only deal with peripheral/SDRAM address spaces
57  * here.
58  *
59  * The SDRAM address space is consistently mapped starting at 0 and extends to
60  * the size of the installed SDRAM.
61  *
62  * Peripherals are mapped further up at spots that vary per-SOC.
63  */
64 struct bcm283x_memory_mapping {
65 	vm_paddr_t	armc_start;
66 	vm_paddr_t	armc_size;
67 	vm_paddr_t	vcbus_start;
68 };
69 
70 #ifdef SOC_BCM2835
71 static struct bcm283x_memory_mapping bcm2835_memmap[] = {
72 	{
73 		/* SDRAM */
74 		.armc_start = 0x00000000,
75 		.armc_size = BCM2835_ARM_IO_BASE,
76 		.vcbus_start = BCM2835_VCBUS_SDRAM_BASE,
77 	},
78 	{
79 		/* Peripherals */
80 		.armc_start = BCM2835_ARM_IO_BASE,
81 		.armc_size  = BCM28XX_ARM_IO_SIZE,
82 		.vcbus_start = BCM2835_VCBUS_IO_BASE,
83 	},
84 	{ 0, 0, 0 },
85 };
86 #endif
87 
88 #ifdef SOC_BCM2836
89 static struct bcm283x_memory_mapping bcm2836_memmap[] = {
90 	{
91 		/* SDRAM */
92 		.armc_start = 0x00000000,
93 		.armc_size = BCM2836_ARM_IO_BASE,
94 		.vcbus_start = BCM2836_VCBUS_SDRAM_BASE,
95 	},
96 	{
97 		/* Peripherals */
98 		.armc_start = BCM2836_ARM_IO_BASE,
99 		.armc_size  = BCM28XX_ARM_IO_SIZE,
100 		.vcbus_start = BCM2836_VCBUS_IO_BASE,
101 	},
102 	{ 0, 0, 0 },
103 };
104 #endif
105 
106 #ifdef SOC_BRCM_BCM2837
107 static struct bcm283x_memory_mapping bcm2837_memmap[] = {
108 	{
109 		/* SDRAM */
110 		.armc_start = 0x00000000,
111 		.armc_size = BCM2837_ARM_IO_BASE,
112 		.vcbus_start = BCM2837_VCBUS_SDRAM_BASE,
113 	},
114 	{
115 		/* Peripherals */
116 		.armc_start = BCM2837_ARM_IO_BASE,
117 		.armc_size  = BCM28XX_ARM_IO_SIZE,
118 		.vcbus_start = BCM2837_VCBUS_IO_BASE,
119 	},
120 	{ 0, 0, 0 },
121 };
122 #endif
123 
124 #ifdef SOC_BRCM_BCM2838
125 
126 /*
127  * The BCM2838 supports up to 4GB of SDRAM, but unfortunately we can still only
128  * map the first 1GB into the "legacy master view" (vcbus) address space.  Thus,
129  * peripherals can still only access the lower end of SDRAM.  For this reason,
130  * we also capture the main-peripheral busdma restriction below.
131  */
132 static struct bcm283x_memory_mapping bcm2838_memmap[] = {
133 	{
134 		/* SDRAM */
135 		.armc_start = 0x00000000,
136 		.armc_size = 0x40000000,
137 		.vcbus_start = BCM2838_VCBUS_SDRAM_BASE,
138 	},
139 	{
140 		/* Main peripherals */
141 		.armc_start = BCM2838_ARM_IO_BASE,
142 		.armc_size = BCM28XX_ARM_IO_SIZE,
143 		.vcbus_start = BCM2838_VCBUS_IO_BASE,
144 	},
145 	{ 0, 0, 0 },
146 };
147 #endif
148 
149 static struct bcm283x_memory_soc_cfg {
150 	struct bcm283x_memory_mapping	*memmap;
151 	const char			*soc_compat;
152 	bus_addr_t			 busdma_lowaddr;
153 } bcm283x_memory_configs[] = {
154 #ifdef SOC_BCM2835
155 	/* Legacy */
156 	{
157 		.memmap = bcm2835_memmap,
158 		.soc_compat = "raspberrypi,model-b",
159 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
160 	},
161 	/* Modern */
162 	{
163 		.memmap = bcm2835_memmap,
164 		.soc_compat = "brcm,bcm2835",
165 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
166 	},
167 #endif
168 #ifdef SOC_BCM2836
169 	/* Legacy */
170 	{
171 		.memmap = bcm2836_memmap,
172 		.soc_compat = "brcm,bcm2709",
173 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
174 	},
175 	/* Modern */
176 	{
177 		.memmap = bcm2836_memmap,
178 		.soc_compat = "brcm,bcm2836",
179 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
180 	},
181 
182 #endif
183 #ifdef SOC_BRCM_BCM2837
184 	{
185 		.memmap = bcm2837_memmap,
186 		.soc_compat = "brcm,bcm2837",
187 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
188 	},
189 #endif
190 #ifdef SOC_BRCM_BCM2838
191 	{
192 		.memmap = bcm2838_memmap,
193 		.soc_compat = "brcm,bcm2711",
194 		.busdma_lowaddr = BCM2838_PERIPH_MAXADDR,
195 	},
196 	{
197 		.memmap = bcm2838_memmap,
198 		.soc_compat = "brcm,bcm2838",
199 		.busdma_lowaddr = BCM2838_PERIPH_MAXADDR,
200 	},
201 #endif
202 };
203 
204 static struct bcm283x_memory_soc_cfg *booted_soc_memcfg;
205 
206 static struct bcm283x_memory_soc_cfg *
207 bcm283x_get_current_memcfg(void)
208 {
209 	phandle_t root;
210 	int i;
211 
212 	/* We'll cache it once we decide, because it won't change per-boot. */
213 	if (booted_soc_memcfg != NULL)
214 		return (booted_soc_memcfg);
215 
216 	KASSERT(nitems(bcm283x_memory_configs) != 0,
217 	    ("No SOC memory configurations enabled!"));
218 
219 	root = OF_finddevice("/");
220 	for (i = 0; i < nitems(bcm283x_memory_configs); ++i) {
221 		booted_soc_memcfg = &bcm283x_memory_configs[i];
222 		if (bootverbose)
223 			printf("Checking root against %s\n",
224 			    booted_soc_memcfg->soc_compat);
225 		if (ofw_bus_node_is_compatible(root,
226 		    booted_soc_memcfg->soc_compat))
227 			return (booted_soc_memcfg);
228 	}
229 
230 	/*
231 	 * The kernel doesn't fit the board; we can't really make a reasonable
232 	 * guess, as these SOC are different enough that something will blow up
233 	 * later.
234 	 */
235 	panic("No suitable SOC memory configuration found.");
236 }
237 
238 #define	BCM283X_MEMMAP_ISTERM(ent)	\
239     ((ent)->armc_start == 0 && (ent)->armc_size == 0 && \
240     (ent)->vcbus_start == 0)
241 
242 vm_paddr_t
243 bcm283x_armc_to_vcbus(vm_paddr_t pa)
244 {
245 	struct bcm283x_memory_soc_cfg *cfg;
246 	struct bcm283x_memory_mapping *map, *ment;
247 
248 	/* Guaranteed not NULL if we haven't panicked yet. */
249 	cfg = bcm283x_get_current_memcfg();
250 	map = cfg->memmap;
251 	for (ment = map; !BCM283X_MEMMAP_ISTERM(ment); ++ment) {
252 		if (pa >= ment->armc_start &&
253 		    pa < ment->armc_start + ment->armc_size) {
254 			return (pa - ment->armc_start) + ment->vcbus_start;
255 		}
256 	}
257 
258 	/*
259 	 * Assume 1:1 mapping for anything else, but complain about it on
260 	 * verbose boots.
261 	 */
262 	if (bootverbose)
263 		printf("bcm283x_vcbus: No armc -> vcbus mapping found: %jx\n",
264 		    (uintmax_t)pa);
265 	return (pa);
266 }
267 
268 vm_paddr_t
269 bcm283x_vcbus_to_armc(vm_paddr_t vca)
270 {
271 	struct bcm283x_memory_soc_cfg *cfg;
272 	struct bcm283x_memory_mapping *map, *ment;
273 
274 	/* Guaranteed not NULL if we haven't panicked yet. */
275 	cfg = bcm283x_get_current_memcfg();
276 	map = cfg->memmap;
277 	for (ment = map; !BCM283X_MEMMAP_ISTERM(ment); ++ment) {
278 		if (vca >= ment->vcbus_start &&
279 		    vca < ment->vcbus_start + ment->armc_size) {
280 			return (vca - ment->vcbus_start) + ment->armc_start;
281 		}
282 	}
283 
284 	/*
285 	 * Assume 1:1 mapping for anything else, but complain about it on
286 	 * verbose boots.
287 	 */
288 	if (bootverbose)
289 		printf("bcm283x_vcbus: No vcbus -> armc mapping found: %jx\n",
290 		    (uintmax_t)vca);
291 	return (vca);
292 }
293 
294 bus_addr_t
295 bcm283x_dmabus_peripheral_lowaddr(void)
296 {
297 	struct bcm283x_memory_soc_cfg *cfg;
298 
299 	cfg = bcm283x_get_current_memcfg();
300 	return (cfg->busdma_lowaddr);
301 }
302