xref: /openbmc/hiomapd/lpc.c (revision 8cef63e3)
1 // SPDX-License-Identifier: Apache-2.0
2 // Copyright (C) 2018 IBM Corp.
3 
4 #define _GNU_SOURCE
5 #include <assert.h>
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <getopt.h>
9 #include <limits.h>
10 #include <poll.h>
11 #include <stdbool.h>
12 #include <stdint.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <syslog.h>
17 #include <signal.h>
18 #include <sys/ioctl.h>
19 #include <sys/mman.h>
20 #include <sys/stat.h>
21 #include <sys/timerfd.h>
22 #include <sys/types.h>
23 #include <time.h>
24 #include <unistd.h>
25 #include <inttypes.h>
26 
27 #include "mboxd.h"
28 #include "common.h"
29 #include "lpc.h"
30 #include "backend.h"
31 #include <linux/aspeed-lpc-ctrl.h>
32 
33 #define LPC_CTRL_PATH		"/dev/aspeed-lpc-ctrl"
34 
35 int __lpc_dev_init(struct mbox_context *context, const char *path)
36 {
37 	struct aspeed_lpc_ctrl_mapping map = {
38 		.window_type = ASPEED_LPC_CTRL_WINDOW_MEMORY,
39 		.window_id = 0, /* There's only one */
40 		.flags = 0,
41 		.addr = 0,
42 		.offset = 0,
43 		.size = 0
44 	};
45 	int fd;
46 
47 	/* Open LPC Device */
48 	MSG_DBG("Opening %s\n", path);
49 	fd = open(path, O_RDWR | O_SYNC);
50 	if (fd < 0) {
51 		MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n",
52 			path, strerror(errno));
53 		return -errno;
54 	}
55 
56 	context->fds[LPC_CTRL_FD].fd = fd;
57 
58 	/* Find Size of Reserved Memory Region */
59 	MSG_DBG("Getting buffer size...\n");
60 	if (ioctl(fd, ASPEED_LPC_CTRL_IOCTL_GET_SIZE, &map) < 0) {
61 		MSG_ERR("Couldn't get lpc control buffer size: %s\n",
62 			strerror(errno));
63 		return -errno;
64 	}
65 
66 	context->mem_size = map.size;
67 	/* Map at the top of the 28-bit LPC firmware address space-0 */
68 	context->lpc_base = 0x0FFFFFFF & -context->mem_size;
69 
70 	/* mmap the Reserved Memory Region */
71 	MSG_DBG("Mapping in 0x%.8x bytes of %s\n", context->mem_size, path);
72 	context->mem = mmap(NULL, context->mem_size, PROT_READ | PROT_WRITE,
73 				MAP_SHARED, fd, 0);
74 	if (context->mem == MAP_FAILED) {
75 		MSG_ERR("Failed to map %s: %s\n", path, strerror(errno));
76 		return -errno;
77 	}
78 
79 	return 0;
80 }
81 
82 int lpc_dev_init(struct mbox_context *context)
83 {
84 	return __lpc_dev_init(context, LPC_CTRL_PATH);
85 }
86 
87 void lpc_dev_free(struct mbox_context *context)
88 {
89 	if (context->mem) {
90 		munmap(context->mem, context->mem_size);
91 	}
92 	close(context->fds[LPC_CTRL_FD].fd);
93 }
94 
95 /*
96  * lpc_map_flash() - Point the lpc bus mapping to the actual flash device
97  * @context:	The mbox context pointer
98  *
99  * Return:	0 on success otherwise negative error code
100  */
101 int lpc_map_flash(struct mbox_context *context)
102 {
103 	struct aspeed_lpc_ctrl_mapping map = {
104 		.window_type = ASPEED_LPC_CTRL_WINDOW_FLASH,
105 		.window_id = 0, /* Theres only one */
106 		.flags = 0,
107 		/*
108 		 * The mask is because the top nibble is the host LPC FW space,
109 		 * we want space 0.
110 		 */
111 		.addr = 0x0FFFFFFF & -context->backend.flash_size,
112 		.offset = 0,
113 		.size = context->backend.flash_size
114 	};
115 
116 	if (context->state & MAPS_FLASH) {
117 		return 0; /* LPC Bus already points to flash */
118 	}
119 	/* Don't let the host access flash while we're suspended */
120 	if (context->state & STATE_SUSPENDED) {
121 		MSG_ERR("Can't point lpc mapping to flash while suspended\n");
122 		return -EBUSY;
123 	}
124 
125 	MSG_INFO("Pointing HOST LPC bus at the flash\n");
126 	MSG_INFO("Assuming %dMB of flash: HOST LPC 0x%08x\n",
127 		context->backend.flash_size >> 20, map.addr);
128 
129 	if (ioctl(context->fds[LPC_CTRL_FD].fd, ASPEED_LPC_CTRL_IOCTL_MAP, &map)
130 			== -1) {
131 		MSG_ERR("Failed to point the LPC BUS at the actual flash: %s\n",
132 			strerror(errno));
133 		return -errno;
134 	}
135 
136 	context->state = ACTIVE_MAPS_FLASH;
137 	/*
138 	 * Since the host now has access to the flash it can change it out from
139 	 * under us
140 	 */
141 	return backend_set_bytemap(&context->backend, 0,
142 				   context->backend.flash_size, FLASH_DIRTY);
143 }
144 
145 /*
146  * lpc_map_memory() - Point the lpc bus mapping to the reserved memory region
147  * @context:	The mbox context pointer
148  *
149  * Return:	0 on success otherwise negative error code
150  */
151 int lpc_map_memory(struct mbox_context *context)
152 {
153 	struct aspeed_lpc_ctrl_mapping map = {
154 		.window_type = ASPEED_LPC_CTRL_WINDOW_MEMORY,
155 		.window_id = 0, /* There's only one */
156 		.flags = 0,
157 		.addr = context->lpc_base,
158 		.offset = 0,
159 		.size = context->mem_size
160 	};
161 
162 	if (context->state & MAPS_MEM) {
163 		return 0; /* LPC Bus already points to reserved memory area */
164 	}
165 
166 	MSG_INFO("Pointing HOST LPC bus at memory region %p of size 0x%.8x\n",
167 			context->mem, context->mem_size);
168 	MSG_INFO("LPC address 0x%.8x\n", map.addr);
169 
170 	if (ioctl(context->fds[LPC_CTRL_FD].fd, ASPEED_LPC_CTRL_IOCTL_MAP,
171 		  &map)) {
172 		MSG_ERR("Failed to point the LPC BUS to memory: %s\n",
173 			strerror(errno));
174 		return -errno;
175 	}
176 
177 	/* LPC now maps memory (keep suspended state) */
178 	context->state = MAPS_MEM | (context->state & STATE_SUSPENDED);
179 
180 	return 0;
181 }
182