xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_vcbus.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 /*
32  * This file contains facilities for runtime determination of address space
33  * mappings for use in DMA/mailbox interactions.  This is only used for the
34  * arm64 SoC because the 32-bit SoC used the same mappings.
35  */
36 
37 #include <sys/types.h>
38 #include <sys/systm.h>
39 
40 #include <dev/ofw/openfirm.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 
44 #include <machine/bus.h>
45 
46 #include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
47 
48 /*
49  * This structure describes mappings that need to take place when transforming
50  * ARM core addresses into vcbus addresses for use with the DMA/mailbox
51  * interfaces.  Currently, we only deal with peripheral/SDRAM address spaces
52  * here.
53  *
54  * The SDRAM address space is consistently mapped starting at 0 and extends to
55  * the size of the installed SDRAM.
56  *
57  * Peripherals are mapped further up at spots that vary per-SOC.
58  */
59 struct bcm283x_memory_mapping {
60 	vm_paddr_t	armc_start;
61 	vm_paddr_t	armc_size;
62 	vm_paddr_t	vcbus_start;
63 };
64 
65 static struct bcm283x_memory_mapping bcm2835_memmap[] = {
66 	{
67 		/* SDRAM */
68 		.armc_start = 0x00000000,
69 		.armc_size = BCM2835_ARM_IO_BASE,
70 		.vcbus_start = BCM2835_VCBUS_SDRAM_BASE,
71 	},
72 	{
73 		/* Peripherals */
74 		.armc_start = BCM2835_ARM_IO_BASE,
75 		.armc_size  = BCM28XX_ARM_IO_SIZE,
76 		.vcbus_start = BCM2835_VCBUS_IO_BASE,
77 	},
78 	{ 0, 0, 0 },
79 };
80 
81 static struct bcm283x_memory_mapping bcm2836_memmap[] = {
82 	{
83 		/* SDRAM */
84 		.armc_start = 0x00000000,
85 		.armc_size = BCM2836_ARM_IO_BASE,
86 		.vcbus_start = BCM2836_VCBUS_SDRAM_BASE,
87 	},
88 	{
89 		/* Peripherals */
90 		.armc_start = BCM2836_ARM_IO_BASE,
91 		.armc_size  = BCM28XX_ARM_IO_SIZE,
92 		.vcbus_start = BCM2836_VCBUS_IO_BASE,
93 	},
94 	{ 0, 0, 0 },
95 };
96 
97 static struct bcm283x_memory_mapping bcm2837_memmap[] = {
98 	{
99 		/* SDRAM */
100 		.armc_start = 0x00000000,
101 		.armc_size = BCM2837_ARM_IO_BASE,
102 		.vcbus_start = BCM2837_VCBUS_SDRAM_BASE,
103 	},
104 	{
105 		/* Peripherals */
106 		.armc_start = BCM2837_ARM_IO_BASE,
107 		.armc_size  = BCM28XX_ARM_IO_SIZE,
108 		.vcbus_start = BCM2837_VCBUS_IO_BASE,
109 	},
110 	{ 0, 0, 0 },
111 };
112 
113 /*
114  * The BCM2838 supports up to 4GB of SDRAM, but unfortunately we can still only
115  * map the first 1GB into the "legacy master view" (vcbus) address space.  Thus,
116  * peripherals can still only access the lower end of SDRAM.  For this reason,
117  * we also capture the main-peripheral busdma restriction below.
118  */
119 static struct bcm283x_memory_mapping bcm2838_memmap[] = {
120 	{
121 		/* SDRAM */
122 		.armc_start = 0x00000000,
123 		.armc_size = 0x40000000,
124 		.vcbus_start = BCM2838_VCBUS_SDRAM_BASE,
125 	},
126 	{
127 		/* Main peripherals */
128 		.armc_start = BCM2838_ARM_IO_BASE,
129 		.armc_size = BCM28XX_ARM_IO_SIZE,
130 		.vcbus_start = BCM2838_VCBUS_IO_BASE,
131 	},
132 	{ 0, 0, 0 },
133 };
134 
135 static struct bcm283x_memory_soc_cfg {
136 	struct bcm283x_memory_mapping	*memmap;
137 	const char			*soc_compat;
138 	bus_addr_t			 busdma_lowaddr;
139 } bcm283x_memory_configs[] = {
140 	/* Legacy */
141 	{
142 		.memmap = bcm2835_memmap,
143 		.soc_compat = "raspberrypi,model-b",
144 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
145 	},
146 	/* Modern */
147 	{
148 		.memmap = bcm2835_memmap,
149 		.soc_compat = "brcm,bcm2835",
150 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
151 	},
152 	/* Legacy */
153 	{
154 		.memmap = bcm2836_memmap,
155 		.soc_compat = "brcm,bcm2709",
156 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
157 	},
158 	/* Modern */
159 	{
160 		.memmap = bcm2836_memmap,
161 		.soc_compat = "brcm,bcm2836",
162 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
163 	},
164 	{
165 		.memmap = bcm2837_memmap,
166 		.soc_compat = "brcm,bcm2837",
167 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
168 	},
169 	{
170 		.memmap = bcm2838_memmap,
171 		.soc_compat = "brcm,bcm2711",
172 		.busdma_lowaddr = BCM2838_PERIPH_MAXADDR,
173 	},
174 	{
175 		.memmap = bcm2838_memmap,
176 		.soc_compat = "brcm,bcm2838",
177 		.busdma_lowaddr = BCM2838_PERIPH_MAXADDR,
178 	},
179 };
180 
181 static struct bcm283x_memory_soc_cfg *booted_soc_memcfg;
182 
183 static struct bcm283x_memory_soc_cfg *
184 bcm283x_get_current_memcfg(void)
185 {
186 	phandle_t root;
187 	int i;
188 
189 	/* We'll cache it once we decide, because it won't change per-boot. */
190 	if (booted_soc_memcfg != NULL)
191 		return (booted_soc_memcfg);
192 
193 	KASSERT(nitems(bcm283x_memory_configs) != 0,
194 	    ("No SOC memory configurations enabled!"));
195 
196 	root = OF_finddevice("/");
197 	for (i = 0; i < nitems(bcm283x_memory_configs); ++i) {
198 		booted_soc_memcfg = &bcm283x_memory_configs[i];
199 		if (bootverbose)
200 			printf("Checking root against %s\n",
201 			    booted_soc_memcfg->soc_compat);
202 		if (ofw_bus_node_is_compatible(root,
203 		    booted_soc_memcfg->soc_compat))
204 			return (booted_soc_memcfg);
205 	}
206 
207 	/*
208 	 * The kernel doesn't fit the board; we can't really make a reasonable
209 	 * guess, as these SOC are different enough that something will blow up
210 	 * later.
211 	 */
212 	panic("No suitable SOC memory configuration found.");
213 }
214 
215 #define	BCM283X_MEMMAP_ISTERM(ent)	\
216     ((ent)->armc_start == 0 && (ent)->armc_size == 0 && \
217     (ent)->vcbus_start == 0)
218 
219 vm_paddr_t
220 bcm283x_armc_to_vcbus(vm_paddr_t pa)
221 {
222 	struct bcm283x_memory_soc_cfg *cfg;
223 	struct bcm283x_memory_mapping *map, *ment;
224 
225 	/* Guaranteed not NULL if we haven't panicked yet. */
226 	cfg = bcm283x_get_current_memcfg();
227 	map = cfg->memmap;
228 	for (ment = map; !BCM283X_MEMMAP_ISTERM(ment); ++ment) {
229 		if (pa >= ment->armc_start &&
230 		    pa < ment->armc_start + ment->armc_size) {
231 			return (pa - ment->armc_start) + ment->vcbus_start;
232 		}
233 	}
234 
235 	/*
236 	 * Assume 1:1 mapping for anything else, but complain about it on
237 	 * verbose boots.
238 	 */
239 	if (bootverbose)
240 		printf("bcm283x_vcbus: No armc -> vcbus mapping found: %jx\n",
241 		    (uintmax_t)pa);
242 	return (pa);
243 }
244 
245 vm_paddr_t
246 bcm283x_vcbus_to_armc(vm_paddr_t vca)
247 {
248 	struct bcm283x_memory_soc_cfg *cfg;
249 	struct bcm283x_memory_mapping *map, *ment;
250 
251 	/* Guaranteed not NULL if we haven't panicked yet. */
252 	cfg = bcm283x_get_current_memcfg();
253 	map = cfg->memmap;
254 	for (ment = map; !BCM283X_MEMMAP_ISTERM(ment); ++ment) {
255 		if (vca >= ment->vcbus_start &&
256 		    vca < ment->vcbus_start + ment->armc_size) {
257 			return (vca - ment->vcbus_start) + ment->armc_start;
258 		}
259 	}
260 
261 	/*
262 	 * Assume 1:1 mapping for anything else, but complain about it on
263 	 * verbose boots.
264 	 */
265 	if (bootverbose)
266 		printf("bcm283x_vcbus: No vcbus -> armc mapping found: %jx\n",
267 		    (uintmax_t)vca);
268 	return (vca);
269 }
270 
271 bus_addr_t
272 bcm283x_dmabus_peripheral_lowaddr(void)
273 {
274 	struct bcm283x_memory_soc_cfg *cfg;
275 
276 	cfg = bcm283x_get_current_memcfg();
277 	return (cfg->busdma_lowaddr);
278 }
279