summaryrefslogtreecommitdiff
path: root/arch/x86/lib/mrccache.c
blob: 2a8919885b7d96416815c0190bcf9688acb75f0a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
// SPDX-License-Identifier: GPL-2.0
/*
 * From coreboot src/southbridge/intel/bd82x6x/mrccache.c
 *
 * Copyright (C) 2014 Google Inc.
 * Copyright (C) 2015 Bin Meng <bmeng.cn@gmail.com>
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <net.h>
#include <spi.h>
#include <spi_flash.h>
#include <asm/mrccache.h>

DECLARE_GLOBAL_DATA_PTR;

static struct mrc_data_container *next_mrc_block(
	struct mrc_data_container *cache)
{
	/* MRC data blocks are aligned within the region */
	u32 mrc_size = sizeof(*cache) + cache->data_size;
	u8 *region_ptr = (u8 *)cache;

	if (mrc_size & (MRC_DATA_ALIGN - 1UL)) {
		mrc_size &= ~(MRC_DATA_ALIGN - 1UL);
		mrc_size += MRC_DATA_ALIGN;
	}

	region_ptr += mrc_size;

	return (struct mrc_data_container *)region_ptr;
}

static int is_mrc_cache(struct mrc_data_container *cache)
{
	return cache && (cache->signature == MRC_DATA_SIGNATURE);
}

struct mrc_data_container *mrccache_find_current(struct mrc_region *entry)
{
	struct mrc_data_container *cache, *next;
	ulong base_addr, end_addr;
	uint id;

	base_addr = entry->base + entry->offset;
	end_addr = base_addr + entry->length;
	cache = NULL;

	/* Search for the last filled entry in the region */
	for (id = 0, next = (struct mrc_data_container *)base_addr;
	     is_mrc_cache(next);
	     id++) {
		cache = next;
		next = next_mrc_block(next);
		if ((ulong)next >= end_addr)
			break;
	}

	if (id-- == 0) {
		debug("%s: No valid MRC cache found.\n", __func__);
		return NULL;
	}

	/* Verify checksum */
	if (cache->checksum != compute_ip_checksum(cache->data,
						   cache->data_size)) {
		printf("%s: MRC cache checksum mismatch\n", __func__);
		return NULL;
	}

	debug("%s: picked entry %u from cache block\n", __func__, id);

	return cache;
}

/**
 * find_next_mrc_cache() - get next cache entry
 *
 * @entry:	MRC cache flash area
 * @cache:	Entry to start from
 *
 * @return next cache entry if found, NULL if we got to the end
 */
static struct mrc_data_container *find_next_mrc_cache(struct mrc_region *entry,
		struct mrc_data_container *cache)
{
	ulong base_addr, end_addr;

	base_addr = entry->base + entry->offset;
	end_addr = base_addr + entry->length;

	cache = next_mrc_block(cache);
	if ((ulong)cache >= end_addr) {
		/* Crossed the boundary */
		cache = NULL;
		debug("%s: no available entries found\n", __func__);
	} else {
		debug("%s: picked next entry from cache block at %p\n",
		      __func__, cache);
	}

	return cache;
}

int mrccache_update(struct udevice *sf, struct mrc_region *entry,
		    struct mrc_data_container *cur)
{
	struct mrc_data_container *cache;
	ulong offset;
	ulong base_addr;
	int ret;

	if (!is_mrc_cache(cur))
		return -EINVAL;

	/* Find the last used block */
	base_addr = entry->base + entry->offset;
	debug("Updating MRC cache data\n");
	cache = mrccache_find_current(entry);
	if (cache && (cache->data_size == cur->data_size) &&
	    (!memcmp(cache, cur, cache->data_size + sizeof(*cur)))) {
		debug("MRC data in flash is up to date. No update\n");
		return -EEXIST;
	}

	/* Move to the next block, which will be the first unused block */
	if (cache)
		cache = find_next_mrc_cache(entry, cache);

	/*
	 * If we have got to the end, erase the entire mrc-cache area and start
	 * again at block 0.
	 */
	if (!cache) {
		debug("Erasing the MRC cache region of %x bytes at %x\n",
		      entry->length, entry->offset);

		ret = spi_flash_erase_dm(sf, entry->offset, entry->length);
		if (ret) {
			debug("Failed to erase flash region\n");
			return ret;
		}
		cache = (struct mrc_data_container *)base_addr;
	}

	/* Write the data out */
	offset = (ulong)cache - base_addr + entry->offset;
	debug("Write MRC cache update to flash at %lx\n", offset);
	ret = spi_flash_write_dm(sf, offset, cur->data_size + sizeof(*cur),
				 cur);
	if (ret) {
		debug("Failed to write to SPI flash\n");
		return ret;
	}

	return 0;
}

int mrccache_reserve(void)
{
	struct mrc_data_container *cache;
	u16 checksum;

	if (!gd->arch.mrc_output_len)
		return 0;

	/* adjust stack pointer to store pure cache data plus the header */
	gd->start_addr_sp -= (gd->arch.mrc_output_len + MRC_DATA_HEADER_SIZE);
	cache = (struct mrc_data_container *)gd->start_addr_sp;

	cache->signature = MRC_DATA_SIGNATURE;
	cache->data_size = gd->arch.mrc_output_len;
	checksum = compute_ip_checksum(gd->arch.mrc_output, cache->data_size);
	debug("Saving %d bytes for MRC output data, checksum %04x\n",
	      cache->data_size, checksum);
	cache->checksum = checksum;
	cache->reserved = 0;
	memcpy(cache->data, gd->arch.mrc_output, cache->data_size);

	/* gd->arch.mrc_output now points to the container */
	gd->arch.mrc_output = (char *)cache;

	gd->start_addr_sp &= ~0xf;

	return 0;
}

int mrccache_get_region(struct udevice **devp, struct mrc_region *entry)
{
	const void *blob = gd->fdt_blob;
	int node, mrc_node;
	u32 reg[2];
	int ret;

	/* Find the flash chip within the SPI controller node */
	node = fdtdec_next_compatible(blob, 0, COMPAT_GENERIC_SPI_FLASH);
	if (node < 0) {
		debug("%s: Cannot find SPI flash\n", __func__);
		return -ENOENT;
	}

	if (fdtdec_get_int_array(blob, node, "memory-map", reg, 2))
		return -EINVAL;
	entry->base = reg[0];

	/* Find the place where we put the MRC cache */
	mrc_node = fdt_subnode_offset(blob, node, "rw-mrc-cache");
	if (mrc_node < 0)
		return -EPERM;

	if (fdtdec_get_int_array(blob, mrc_node, "reg", reg, 2))
		return -EINVAL;
	entry->offset = reg[0];
	entry->length = reg[1];

	if (devp) {
		ret = uclass_get_device_by_of_offset(UCLASS_SPI_FLASH, node,
						     devp);
		debug("ret = %d\n", ret);
		if (ret)
			return ret;
	}

	return 0;
}

int mrccache_save(void)
{
	struct mrc_data_container *data;
	struct mrc_region entry;
	struct udevice *sf;
	int ret;

	if (!gd->arch.mrc_output_len)
		return 0;
	debug("Saving %d bytes of MRC output data to SPI flash\n",
	      gd->arch.mrc_output_len);

	ret = mrccache_get_region(&sf, &entry);
	if (ret)
		goto err_entry;
	data  = (struct mrc_data_container *)gd->arch.mrc_output;
	ret = mrccache_update(sf, &entry, data);
	if (!ret) {
		debug("Saved MRC data with checksum %04x\n", data->checksum);
	} else if (ret == -EEXIST) {
		debug("MRC data is the same as last time, skipping save\n");
		ret = 0;
	}

err_entry:
	if (ret)
		debug("%s: Failed: %d\n", __func__, ret);
	return ret;
}