xref: /freebsd/sys/arm/broadcom/bcm2835/bcm2835_vcbus.c (revision 8bcb0991864975618c09697b1aca10683346d9f0)
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 
39 #include <sys/types.h>
40 #include <sys/systm.h>
41 
42 #include <dev/ofw/openfirm.h>
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 
46 #include <machine/bus.h>
47 
48 #include <arm/broadcom/bcm2835/bcm2835_vcbus.h>
49 
50 /*
51  * This structure describes mappings that need to take place when transforming
52  * ARM core addresses into vcbus addresses for use with the DMA/mailbox
53  * interfaces.  Currently, we only deal with peripheral/SDRAM address spaces
54  * here.
55  *
56  * The SDRAM address space is consistently mapped starting at 0 and extends to
57  * the size of the installed SDRAM.
58  *
59  * Peripherals are mapped further up at spots that vary per-SOC.
60  */
61 struct bcm283x_memory_mapping {
62 	vm_paddr_t	armc_start;
63 	vm_paddr_t	armc_size;
64 	vm_paddr_t	vcbus_start;
65 };
66 
67 static struct bcm283x_memory_mapping bcm2835_memmap[] = {
68 	{
69 		/* SDRAM */
70 		.armc_start = 0x00000000,
71 		.armc_size = BCM2835_ARM_IO_BASE,
72 		.vcbus_start = BCM2835_VCBUS_SDRAM_BASE,
73 	},
74 	{
75 		/* Peripherals */
76 		.armc_start = BCM2835_ARM_IO_BASE,
77 		.armc_size  = BCM28XX_ARM_IO_SIZE,
78 		.vcbus_start = BCM2835_VCBUS_IO_BASE,
79 	},
80 	{ 0, 0, 0 },
81 };
82 
83 static struct bcm283x_memory_mapping bcm2836_memmap[] = {
84 	{
85 		/* SDRAM */
86 		.armc_start = 0x00000000,
87 		.armc_size = BCM2836_ARM_IO_BASE,
88 		.vcbus_start = BCM2836_VCBUS_SDRAM_BASE,
89 	},
90 	{
91 		/* Peripherals */
92 		.armc_start = BCM2836_ARM_IO_BASE,
93 		.armc_size  = BCM28XX_ARM_IO_SIZE,
94 		.vcbus_start = BCM2836_VCBUS_IO_BASE,
95 	},
96 	{ 0, 0, 0 },
97 };
98 
99 static struct bcm283x_memory_mapping bcm2837_memmap[] = {
100 	{
101 		/* SDRAM */
102 		.armc_start = 0x00000000,
103 		.armc_size = BCM2837_ARM_IO_BASE,
104 		.vcbus_start = BCM2837_VCBUS_SDRAM_BASE,
105 	},
106 	{
107 		/* Peripherals */
108 		.armc_start = BCM2837_ARM_IO_BASE,
109 		.armc_size  = BCM28XX_ARM_IO_SIZE,
110 		.vcbus_start = BCM2837_VCBUS_IO_BASE,
111 	},
112 	{ 0, 0, 0 },
113 };
114 
115 /*
116  * The BCM2838 supports up to 4GB of SDRAM, but unfortunately we can still only
117  * map the first 1GB into the "legacy master view" (vcbus) address space.  Thus,
118  * peripherals can still only access the lower end of SDRAM.  For this reason,
119  * we also capture the main-peripheral busdma restriction below.
120  */
121 static struct bcm283x_memory_mapping bcm2838_memmap[] = {
122 	{
123 		/* SDRAM */
124 		.armc_start = 0x00000000,
125 		.armc_size = 0x40000000,
126 		.vcbus_start = BCM2838_VCBUS_SDRAM_BASE,
127 	},
128 	{
129 		/* Main peripherals */
130 		.armc_start = BCM2838_ARM_IO_BASE,
131 		.armc_size = BCM28XX_ARM_IO_SIZE,
132 		.vcbus_start = BCM2838_VCBUS_IO_BASE,
133 	},
134 	{ 0, 0, 0 },
135 };
136 
137 static struct bcm283x_memory_soc_cfg {
138 	struct bcm283x_memory_mapping	*memmap;
139 	const char			*soc_compat;
140 	bus_addr_t			 busdma_lowaddr;
141 } bcm283x_memory_configs[] = {
142 	/* Legacy */
143 	{
144 		.memmap = bcm2835_memmap,
145 		.soc_compat = "raspberrypi,model-b",
146 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
147 	},
148 	/* Modern */
149 	{
150 		.memmap = bcm2835_memmap,
151 		.soc_compat = "brcm,bcm2835",
152 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
153 	},
154 	/* Legacy */
155 	{
156 		.memmap = bcm2836_memmap,
157 		.soc_compat = "brcm,bcm2709",
158 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
159 	},
160 	/* Modern */
161 	{
162 		.memmap = bcm2836_memmap,
163 		.soc_compat = "brcm,bcm2836",
164 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
165 	},
166 	{
167 		.memmap = bcm2837_memmap,
168 		.soc_compat = "brcm,bcm2837",
169 		.busdma_lowaddr = BUS_SPACE_MAXADDR_32BIT,
170 	},
171 	{
172 		.memmap = bcm2838_memmap,
173 		.soc_compat = "brcm,bcm2711",
174 		.busdma_lowaddr = BCM2838_PERIPH_MAXADDR,
175 	},
176 	{
177 		.memmap = bcm2838_memmap,
178 		.soc_compat = "brcm,bcm2838",
179 		.busdma_lowaddr = BCM2838_PERIPH_MAXADDR,
180 	},
181 };
182 
183 static struct bcm283x_memory_soc_cfg *booted_soc_memcfg;
184 
185 static struct bcm283x_memory_soc_cfg *
186 bcm283x_get_current_memcfg(void)
187 {
188 	phandle_t root;
189 	int i;
190 
191 	/* We'll cache it once we decide, because it won't change per-boot. */
192 	if (booted_soc_memcfg != NULL)
193 		return (booted_soc_memcfg);
194 
195 	KASSERT(nitems(bcm283x_memory_configs) != 0,
196 	    ("No SOC memory configurations enabled!"));
197 
198 	root = OF_finddevice("/");
199 	for (i = 0; i < nitems(bcm283x_memory_configs); ++i) {
200 		booted_soc_memcfg = &bcm283x_memory_configs[i];
201 		if (bootverbose)
202 			printf("Checking root against %s\n",
203 			    booted_soc_memcfg->soc_compat);
204 		if (ofw_bus_node_is_compatible(root,
205 		    booted_soc_memcfg->soc_compat))
206 			return (booted_soc_memcfg);
207 	}
208 
209 	/*
210 	 * The kernel doesn't fit the board; we can't really make a reasonable
211 	 * guess, as these SOC are different enough that something will blow up
212 	 * later.
213 	 */
214 	panic("No suitable SOC memory configuration found.");
215 }
216 
217 #define	BCM283X_MEMMAP_ISTERM(ent)	\
218     ((ent)->armc_start == 0 && (ent)->armc_size == 0 && \
219     (ent)->vcbus_start == 0)
220 
221 vm_paddr_t
222 bcm283x_armc_to_vcbus(vm_paddr_t pa)
223 {
224 	struct bcm283x_memory_soc_cfg *cfg;
225 	struct bcm283x_memory_mapping *map, *ment;
226 
227 	/* Guaranteed not NULL if we haven't panicked yet. */
228 	cfg = bcm283x_get_current_memcfg();
229 	map = cfg->memmap;
230 	for (ment = map; !BCM283X_MEMMAP_ISTERM(ment); ++ment) {
231 		if (pa >= ment->armc_start &&
232 		    pa < ment->armc_start + ment->armc_size) {
233 			return (pa - ment->armc_start) + ment->vcbus_start;
234 		}
235 	}
236 
237 	/*
238 	 * Assume 1:1 mapping for anything else, but complain about it on
239 	 * verbose boots.
240 	 */
241 	if (bootverbose)
242 		printf("bcm283x_vcbus: No armc -> vcbus mapping found: %jx\n",
243 		    (uintmax_t)pa);
244 	return (pa);
245 }
246 
247 vm_paddr_t
248 bcm283x_vcbus_to_armc(vm_paddr_t vca)
249 {
250 	struct bcm283x_memory_soc_cfg *cfg;
251 	struct bcm283x_memory_mapping *map, *ment;
252 
253 	/* Guaranteed not NULL if we haven't panicked yet. */
254 	cfg = bcm283x_get_current_memcfg();
255 	map = cfg->memmap;
256 	for (ment = map; !BCM283X_MEMMAP_ISTERM(ment); ++ment) {
257 		if (vca >= ment->vcbus_start &&
258 		    vca < ment->vcbus_start + ment->armc_size) {
259 			return (vca - ment->vcbus_start) + ment->armc_start;
260 		}
261 	}
262 
263 	/*
264 	 * Assume 1:1 mapping for anything else, but complain about it on
265 	 * verbose boots.
266 	 */
267 	if (bootverbose)
268 		printf("bcm283x_vcbus: No vcbus -> armc mapping found: %jx\n",
269 		    (uintmax_t)vca);
270 	return (vca);
271 }
272 
273 bus_addr_t
274 bcm283x_dmabus_peripheral_lowaddr(void)
275 {
276 	struct bcm283x_memory_soc_cfg *cfg;
277 
278 	cfg = bcm283x_get_current_memcfg();
279 	return (cfg->busdma_lowaddr);
280 }
281