blob: f1848cdd6d34855f9d32986d7e8d0c407823a625 [file] [log] [blame]
Thomas Gleixner9c92ab62019-05-29 07:17:56 -07001// SPDX-License-Identifier: GPL-2.0-only
Colin Crossc6725282012-03-07 17:34:32 -08002/*
3 * Copyright (C) 2012 Google, Inc.
Colin Crossc6725282012-03-07 17:34:32 -08004 */
5
Kees Cook9ee85b82018-10-26 01:14:01 -07006#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Fabian Frederickef748852014-06-06 14:37:31 -07007
Colin Cross404a6042012-03-07 17:34:34 -08008#include <linux/device.h>
9#include <linux/err.h>
Colin Crossc6725282012-03-07 17:34:32 -080010#include <linux/errno.h>
Colin Crossc6725282012-03-07 17:34:32 -080011#include <linux/init.h>
12#include <linux/io.h>
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -070013#include <linux/kernel.h>
Colin Cross404a6042012-03-07 17:34:34 -080014#include <linux/list.h>
15#include <linux/memblock.h>
Colin Cross9cc05ad2012-03-07 17:34:33 -080016#include <linux/rslib.h>
Colin Crossc6725282012-03-07 17:34:32 -080017#include <linux/slab.h>
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -070018#include <linux/uaccess.h>
Colin Cross404a6042012-03-07 17:34:34 -080019#include <linux/vmalloc.h>
Yuxiao Zhang104fd0b2023-06-27 13:25:41 -070020#include <linux/mm.h>
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -070021#include <asm/page.h>
Colin Crossc6725282012-03-07 17:34:32 -080022
Kees Cook8bd4da02022-10-11 13:01:10 -070023#include "ram_internal.h"
24
Kees Cookc208f7d2018-11-01 15:11:47 -070025/**
26 * struct persistent_ram_buffer - persistent circular RAM buffer
27 *
Matthew Wilcox (Oracle)af587402023-08-18 21:12:53 +010028 * @sig: Signature to indicate header (PERSISTENT_RAM_SIG xor PRZ-type value)
29 * @start: First valid byte in the buffer.
30 * @size: Number of valid bytes in the buffer.
31 * @data: The contents of the buffer.
Kees Cookc208f7d2018-11-01 15:11:47 -070032 */
Colin Crossc6725282012-03-07 17:34:32 -080033struct persistent_ram_buffer {
34 uint32_t sig;
Colin Cross808d0382012-03-07 17:34:35 -080035 atomic_t start;
36 atomic_t size;
Gustavo A. R. Silva8128d3a2020-03-09 15:23:27 -050037 uint8_t data[];
Colin Crossc6725282012-03-07 17:34:32 -080038};
39
40#define PERSISTENT_RAM_SIG (0x43474244) /* DBGC */
41
Colin Cross808d0382012-03-07 17:34:35 -080042static inline size_t buffer_size(struct persistent_ram_zone *prz)
43{
44 return atomic_read(&prz->buffer->size);
45}
46
47static inline size_t buffer_start(struct persistent_ram_zone *prz)
48{
49 return atomic_read(&prz->buffer->start);
50}
51
Rob Herring0405a5c2013-04-08 20:23:33 -050052/* increase and wrap the start pointer, returning the old value */
Sebastian Andrzej Siewiord5a9bf02016-09-08 13:48:06 +020053static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
Rob Herring0405a5c2013-04-08 20:23:33 -050054{
55 int old;
56 int new;
Joel Fernandes663deb42016-10-20 00:34:01 -070057 unsigned long flags = 0;
Rob Herring0405a5c2013-04-08 20:23:33 -050058
Joel Fernandes663deb42016-10-20 00:34:01 -070059 if (!(prz->flags & PRZ_FLAG_NO_LOCK))
60 raw_spin_lock_irqsave(&prz->buffer_lock, flags);
Rob Herring0405a5c2013-04-08 20:23:33 -050061
62 old = atomic_read(&prz->buffer->start);
63 new = old + a;
Liu ShuoX017321c2014-03-12 21:24:44 +080064 while (unlikely(new >= prz->buffer_size))
Rob Herring0405a5c2013-04-08 20:23:33 -050065 new -= prz->buffer_size;
66 atomic_set(&prz->buffer->start, new);
67
Joel Fernandes663deb42016-10-20 00:34:01 -070068 if (!(prz->flags & PRZ_FLAG_NO_LOCK))
69 raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
Rob Herring0405a5c2013-04-08 20:23:33 -050070
71 return old;
72}
73
74/* increase the size counter until it hits the max size */
Sebastian Andrzej Siewiord5a9bf02016-09-08 13:48:06 +020075static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
Rob Herring0405a5c2013-04-08 20:23:33 -050076{
77 size_t old;
78 size_t new;
Joel Fernandes663deb42016-10-20 00:34:01 -070079 unsigned long flags = 0;
Rob Herring0405a5c2013-04-08 20:23:33 -050080
Joel Fernandes663deb42016-10-20 00:34:01 -070081 if (!(prz->flags & PRZ_FLAG_NO_LOCK))
82 raw_spin_lock_irqsave(&prz->buffer_lock, flags);
Rob Herring0405a5c2013-04-08 20:23:33 -050083
84 old = atomic_read(&prz->buffer->size);
85 if (old == prz->buffer_size)
86 goto exit;
87
88 new = old + a;
89 if (new > prz->buffer_size)
90 new = prz->buffer_size;
91 atomic_set(&prz->buffer->size, new);
92
93exit:
Joel Fernandes663deb42016-10-20 00:34:01 -070094 if (!(prz->flags & PRZ_FLAG_NO_LOCK))
95 raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
Rob Herring0405a5c2013-04-08 20:23:33 -050096}
97
Colin Crossa15d0b32012-03-07 17:34:36 -080098static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
Colin Crossc6725282012-03-07 17:34:32 -080099 uint8_t *data, size_t len, uint8_t *ecc)
100{
101 int i;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800102
Colin Crossc6725282012-03-07 17:34:32 -0800103 /* Initialize the parity buffer */
Kees Cookf2531f12018-03-07 12:18:33 -0800104 memset(prz->ecc_info.par, 0,
105 prz->ecc_info.ecc_size * sizeof(prz->ecc_info.par[0]));
106 encode_rs8(prz->rs_decoder, data, len, prz->ecc_info.par, 0);
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700107 for (i = 0; i < prz->ecc_info.ecc_size; i++)
Kees Cookf2531f12018-03-07 12:18:33 -0800108 ecc[i] = prz->ecc_info.par[i];
Colin Crossc6725282012-03-07 17:34:32 -0800109}
110
111static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
112 void *data, size_t len, uint8_t *ecc)
113{
114 int i;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800115
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700116 for (i = 0; i < prz->ecc_info.ecc_size; i++)
Kees Cookf2531f12018-03-07 12:18:33 -0800117 prz->ecc_info.par[i] = ecc[i];
118 return decode_rs8(prz->rs_decoder, data, prz->ecc_info.par, len,
Colin Crossc6725282012-03-07 17:34:32 -0800119 NULL, 0, NULL, 0, NULL);
120}
Colin Cross9cc05ad2012-03-07 17:34:33 -0800121
Colin Crossa15d0b32012-03-07 17:34:36 -0800122static void notrace persistent_ram_update_ecc(struct persistent_ram_zone *prz,
Colin Cross808d0382012-03-07 17:34:35 -0800123 unsigned int start, unsigned int count)
Colin Cross9cc05ad2012-03-07 17:34:33 -0800124{
125 struct persistent_ram_buffer *buffer = prz->buffer;
126 uint8_t *buffer_end = buffer->data + prz->buffer_size;
127 uint8_t *block;
128 uint8_t *par;
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700129 int ecc_block_size = prz->ecc_info.block_size;
130 int ecc_size = prz->ecc_info.ecc_size;
131 int size = ecc_block_size;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800132
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700133 if (!ecc_size)
Colin Cross9cc05ad2012-03-07 17:34:33 -0800134 return;
135
Colin Cross808d0382012-03-07 17:34:35 -0800136 block = buffer->data + (start & ~(ecc_block_size - 1));
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700137 par = prz->par_buffer + (start / ecc_block_size) * ecc_size;
Colin Cross808d0382012-03-07 17:34:35 -0800138
Colin Cross9cc05ad2012-03-07 17:34:33 -0800139 do {
140 if (block + ecc_block_size > buffer_end)
141 size = buffer_end - block;
142 persistent_ram_encode_rs8(prz, block, size, par);
143 block += ecc_block_size;
144 par += ecc_size;
Colin Cross808d0382012-03-07 17:34:35 -0800145 } while (block < buffer->data + start + count);
Colin Cross9cc05ad2012-03-07 17:34:33 -0800146}
147
148static void persistent_ram_update_header_ecc(struct persistent_ram_zone *prz)
149{
150 struct persistent_ram_buffer *buffer = prz->buffer;
151
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700152 if (!prz->ecc_info.ecc_size)
Colin Cross9cc05ad2012-03-07 17:34:33 -0800153 return;
154
155 persistent_ram_encode_rs8(prz, (uint8_t *)buffer, sizeof(*buffer),
156 prz->par_header);
157}
158
159static void persistent_ram_ecc_old(struct persistent_ram_zone *prz)
160{
161 struct persistent_ram_buffer *buffer = prz->buffer;
162 uint8_t *block;
163 uint8_t *par;
164
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700165 if (!prz->ecc_info.ecc_size)
Colin Cross9cc05ad2012-03-07 17:34:33 -0800166 return;
167
168 block = buffer->data;
169 par = prz->par_buffer;
Colin Cross808d0382012-03-07 17:34:35 -0800170 while (block < buffer->data + buffer_size(prz)) {
Colin Cross9cc05ad2012-03-07 17:34:33 -0800171 int numerr;
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700172 int size = prz->ecc_info.block_size;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800173 if (block + size > buffer->data + prz->buffer_size)
174 size = buffer->data + prz->buffer_size - block;
175 numerr = persistent_ram_decode_rs8(prz, block, size, par);
176 if (numerr > 0) {
Fabian Frederickef748852014-06-06 14:37:31 -0700177 pr_devel("error in block %p, %d\n", block, numerr);
Colin Cross9cc05ad2012-03-07 17:34:33 -0800178 prz->corrected_bytes += numerr;
179 } else if (numerr < 0) {
Fabian Frederickef748852014-06-06 14:37:31 -0700180 pr_devel("uncorrectable error in block %p\n", block);
Colin Cross9cc05ad2012-03-07 17:34:33 -0800181 prz->bad_blocks++;
182 }
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700183 block += prz->ecc_info.block_size;
184 par += prz->ecc_info.ecc_size;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800185 }
186}
187
Anton Vorontsov5ca5d4e2012-07-09 17:03:19 -0700188static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700189 struct persistent_ram_ecc_info *ecc_info)
Colin Cross9cc05ad2012-03-07 17:34:33 -0800190{
191 int numerr;
192 struct persistent_ram_buffer *buffer = prz->buffer;
Sergey Shtylyov86222a82023-11-05 23:29:36 +0300193 size_t ecc_blocks;
Anton Vorontsov1e6a9e562012-06-18 19:15:53 -0700194 size_t ecc_total;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800195
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700196 if (!ecc_info || !ecc_info->ecc_size)
Colin Cross9cc05ad2012-03-07 17:34:33 -0800197 return 0;
198
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700199 prz->ecc_info.block_size = ecc_info->block_size ?: 128;
200 prz->ecc_info.ecc_size = ecc_info->ecc_size ?: 16;
201 prz->ecc_info.symsize = ecc_info->symsize ?: 8;
202 prz->ecc_info.poly = ecc_info->poly ?: 0x11d;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800203
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700204 ecc_blocks = DIV_ROUND_UP(prz->buffer_size - prz->ecc_info.ecc_size,
205 prz->ecc_info.block_size +
206 prz->ecc_info.ecc_size);
207 ecc_total = (ecc_blocks + 1) * prz->ecc_info.ecc_size;
Anton Vorontsov1e6a9e562012-06-18 19:15:53 -0700208 if (ecc_total >= prz->buffer_size) {
209 pr_err("%s: invalid ecc_size %u (total %zu, buffer size %zu)\n",
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700210 __func__, prz->ecc_info.ecc_size,
211 ecc_total, prz->buffer_size);
Colin Cross9cc05ad2012-03-07 17:34:33 -0800212 return -EINVAL;
213 }
214
Anton Vorontsov1e6a9e562012-06-18 19:15:53 -0700215 prz->buffer_size -= ecc_total;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800216 prz->par_buffer = buffer->data + prz->buffer_size;
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700217 prz->par_header = prz->par_buffer +
218 ecc_blocks * prz->ecc_info.ecc_size;
Colin Cross9cc05ad2012-03-07 17:34:33 -0800219
220 /*
221 * first consecutive root is 0
222 * primitive element to generate roots = 1
223 */
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700224 prz->rs_decoder = init_rs(prz->ecc_info.symsize, prz->ecc_info.poly,
225 0, 1, prz->ecc_info.ecc_size);
Colin Cross9cc05ad2012-03-07 17:34:33 -0800226 if (prz->rs_decoder == NULL) {
Fabian Frederickef748852014-06-06 14:37:31 -0700227 pr_info("init_rs failed\n");
Colin Cross9cc05ad2012-03-07 17:34:33 -0800228 return -EINVAL;
229 }
230
Kees Cookf2531f12018-03-07 12:18:33 -0800231 /* allocate workspace instead of using stack VLA */
232 prz->ecc_info.par = kmalloc_array(prz->ecc_info.ecc_size,
233 sizeof(*prz->ecc_info.par),
234 GFP_KERNEL);
235 if (!prz->ecc_info.par) {
236 pr_err("cannot allocate ECC parity workspace\n");
237 return -ENOMEM;
238 }
239
Colin Cross9cc05ad2012-03-07 17:34:33 -0800240 prz->corrected_bytes = 0;
241 prz->bad_blocks = 0;
242
243 numerr = persistent_ram_decode_rs8(prz, buffer, sizeof(*buffer),
244 prz->par_header);
245 if (numerr > 0) {
Fabian Frederickef748852014-06-06 14:37:31 -0700246 pr_info("error in header, %d\n", numerr);
Colin Cross9cc05ad2012-03-07 17:34:33 -0800247 prz->corrected_bytes += numerr;
248 } else if (numerr < 0) {
Dmitry Osipenko7db688e2021-03-02 12:58:50 +0300249 pr_info_ratelimited("uncorrectable error in header\n");
Colin Cross9cc05ad2012-03-07 17:34:33 -0800250 prz->bad_blocks++;
251 }
252
253 return 0;
254}
255
256ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
257 char *str, size_t len)
258{
259 ssize_t ret;
260
Arve Hjønnevågbd08ec32012-12-05 21:19:51 -0800261 if (!prz->ecc_info.ecc_size)
262 return 0;
263
Colin Cross9cc05ad2012-03-07 17:34:33 -0800264 if (prz->corrected_bytes || prz->bad_blocks)
265 ret = snprintf(str, len, ""
Vincent Whitchurch023bbde2022-03-01 15:49:32 +0100266 "\nECC: %d Corrected bytes, %d unrecoverable blocks\n",
Colin Cross9cc05ad2012-03-07 17:34:33 -0800267 prz->corrected_bytes, prz->bad_blocks);
268 else
Vincent Whitchurch023bbde2022-03-01 15:49:32 +0100269 ret = snprintf(str, len, "\nECC: No errors detected\n");
Colin Cross9cc05ad2012-03-07 17:34:33 -0800270
271 return ret;
272}
Colin Crossc6725282012-03-07 17:34:32 -0800273
Colin Crossa15d0b32012-03-07 17:34:36 -0800274static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
Colin Cross808d0382012-03-07 17:34:35 -0800275 const void *s, unsigned int start, unsigned int count)
Colin Crossc6725282012-03-07 17:34:32 -0800276{
277 struct persistent_ram_buffer *buffer = prz->buffer;
Furquan Shaikh7e756782016-02-15 09:19:48 +0100278 memcpy_toio(buffer->data + start, s, count);
Colin Cross808d0382012-03-07 17:34:35 -0800279 persistent_ram_update_ecc(prz, start, count);
Colin Crossc6725282012-03-07 17:34:32 -0800280}
281
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700282static int notrace persistent_ram_update_user(struct persistent_ram_zone *prz,
283 const void __user *s, unsigned int start, unsigned int count)
284{
285 struct persistent_ram_buffer *buffer = prz->buffer;
Al Viroff847782020-02-18 15:43:52 -0500286 int ret = unlikely(copy_from_user(buffer->data + start, s, count)) ?
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700287 -EFAULT : 0;
288 persistent_ram_update_ecc(prz, start, count);
289 return ret;
290}
291
Anton Vorontsov201e4ac2012-05-26 06:07:49 -0700292void persistent_ram_save_old(struct persistent_ram_zone *prz)
Colin Crossc6725282012-03-07 17:34:32 -0800293{
294 struct persistent_ram_buffer *buffer = prz->buffer;
Colin Cross808d0382012-03-07 17:34:35 -0800295 size_t size = buffer_size(prz);
296 size_t start = buffer_start(prz);
Colin Crossc6725282012-03-07 17:34:32 -0800297
Anton Vorontsov201e4ac2012-05-26 06:07:49 -0700298 if (!size)
299 return;
Colin Crossc6725282012-03-07 17:34:32 -0800300
Anton Vorontsov201e4ac2012-05-26 06:07:49 -0700301 if (!prz->old_log) {
302 persistent_ram_ecc_old(prz);
Yuxiao Zhang104fd0b2023-06-27 13:25:41 -0700303 prz->old_log = kvzalloc(size, GFP_KERNEL);
Anton Vorontsov201e4ac2012-05-26 06:07:49 -0700304 }
305 if (!prz->old_log) {
Fabian Frederickef748852014-06-06 14:37:31 -0700306 pr_err("failed to allocate buffer\n");
Colin Crossc6725282012-03-07 17:34:32 -0800307 return;
308 }
309
Colin Cross808d0382012-03-07 17:34:35 -0800310 prz->old_log_size = size;
Andrew Brestickerd771fdf2016-02-15 09:19:49 +0100311 memcpy_fromio(prz->old_log, &buffer->data[start], size - start);
312 memcpy_fromio(prz->old_log + size - start, &buffer->data[0], start);
Colin Crossc6725282012-03-07 17:34:32 -0800313}
314
Colin Crossa15d0b32012-03-07 17:34:36 -0800315int notrace persistent_ram_write(struct persistent_ram_zone *prz,
Colin Crossc6725282012-03-07 17:34:32 -0800316 const void *s, unsigned int count)
317{
318 int rem;
319 int c = count;
Colin Cross808d0382012-03-07 17:34:35 -0800320 size_t start;
Colin Crossc6725282012-03-07 17:34:32 -0800321
Colin Cross808d0382012-03-07 17:34:35 -0800322 if (unlikely(c > prz->buffer_size)) {
Colin Crossc6725282012-03-07 17:34:32 -0800323 s += c - prz->buffer_size;
324 c = prz->buffer_size;
325 }
Colin Cross808d0382012-03-07 17:34:35 -0800326
Anton Vorontsov484dd302012-05-11 17:17:17 -0700327 buffer_size_add(prz, c);
Colin Cross808d0382012-03-07 17:34:35 -0800328
329 start = buffer_start_add(prz, c);
330
331 rem = prz->buffer_size - start;
332 if (unlikely(rem < c)) {
333 persistent_ram_update(prz, s, start, rem);
Colin Crossc6725282012-03-07 17:34:32 -0800334 s += rem;
335 c -= rem;
Colin Cross808d0382012-03-07 17:34:35 -0800336 start = 0;
Colin Crossc6725282012-03-07 17:34:32 -0800337 }
Colin Cross808d0382012-03-07 17:34:35 -0800338 persistent_ram_update(prz, s, start, c);
Colin Crossc6725282012-03-07 17:34:32 -0800339
Colin Cross9cc05ad2012-03-07 17:34:33 -0800340 persistent_ram_update_header_ecc(prz);
Colin Crossc6725282012-03-07 17:34:32 -0800341
342 return count;
343}
344
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700345int notrace persistent_ram_write_user(struct persistent_ram_zone *prz,
346 const void __user *s, unsigned int count)
347{
348 int rem, ret = 0, c = count;
349 size_t start;
350
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700351 if (unlikely(c > prz->buffer_size)) {
352 s += c - prz->buffer_size;
353 c = prz->buffer_size;
354 }
355
356 buffer_size_add(prz, c);
357
358 start = buffer_start_add(prz, c);
359
360 rem = prz->buffer_size - start;
361 if (unlikely(rem < c)) {
362 ret = persistent_ram_update_user(prz, s, start, rem);
363 s += rem;
364 c -= rem;
365 start = 0;
366 }
367 if (likely(!ret))
368 ret = persistent_ram_update_user(prz, s, start, c);
369
370 persistent_ram_update_header_ecc(prz);
371
372 return unlikely(ret) ? ret : count;
373}
374
Colin Crossc6725282012-03-07 17:34:32 -0800375size_t persistent_ram_old_size(struct persistent_ram_zone *prz)
376{
377 return prz->old_log_size;
378}
379
380void *persistent_ram_old(struct persistent_ram_zone *prz)
381{
382 return prz->old_log;
383}
384
385void persistent_ram_free_old(struct persistent_ram_zone *prz)
386{
Yuxiao Zhang104fd0b2023-06-27 13:25:41 -0700387 kvfree(prz->old_log);
Colin Crossc6725282012-03-07 17:34:32 -0800388 prz->old_log = NULL;
389 prz->old_log_size = 0;
390}
391
Anton Vorontsovfce39792012-05-26 06:07:51 -0700392void persistent_ram_zap(struct persistent_ram_zone *prz)
393{
394 atomic_set(&prz->buffer->start, 0);
395 atomic_set(&prz->buffer->size, 0);
396 persistent_ram_update_header_ecc(prz);
397}
398
Mukesh Ojha9d843e82021-03-23 00:12:17 +0530399#define MEM_TYPE_WCOMBINE 0
400#define MEM_TYPE_NONCACHED 1
401#define MEM_TYPE_NORMAL 2
402
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700403static void *persistent_ram_vmap(phys_addr_t start, size_t size,
404 unsigned int memtype)
Colin Crossc6725282012-03-07 17:34:32 -0800405{
Colin Cross404a6042012-03-07 17:34:34 -0800406 struct page **pages;
407 phys_addr_t page_start;
408 unsigned int page_count;
409 pgprot_t prot;
410 unsigned int i;
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700411 void *vaddr;
Colin Crossc6725282012-03-07 17:34:32 -0800412
Colin Cross404a6042012-03-07 17:34:34 -0800413 page_start = start - offset_in_page(start);
414 page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
Colin Crossc6725282012-03-07 17:34:32 -0800415
Mukesh Ojha9d843e82021-03-23 00:12:17 +0530416 switch (memtype) {
417 case MEM_TYPE_NORMAL:
418 prot = PAGE_KERNEL;
419 break;
420 case MEM_TYPE_NONCACHED:
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700421 prot = pgprot_noncached(PAGE_KERNEL);
Mukesh Ojha9d843e82021-03-23 00:12:17 +0530422 break;
423 case MEM_TYPE_WCOMBINE:
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700424 prot = pgprot_writecombine(PAGE_KERNEL);
Mukesh Ojha9d843e82021-03-23 00:12:17 +0530425 break;
426 default:
427 pr_err("invalid mem_type=%d\n", memtype);
428 return NULL;
429 }
Colin Crossc6725282012-03-07 17:34:32 -0800430
Fabian Frederickb8f52d82014-08-08 14:22:35 -0700431 pages = kmalloc_array(page_count, sizeof(struct page *), GFP_KERNEL);
Colin Cross404a6042012-03-07 17:34:34 -0800432 if (!pages) {
Fabian Frederickef748852014-06-06 14:37:31 -0700433 pr_err("%s: Failed to allocate array for %u pages\n",
434 __func__, page_count);
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700435 return NULL;
Colin Crossc6725282012-03-07 17:34:32 -0800436 }
437
Colin Cross404a6042012-03-07 17:34:34 -0800438 for (i = 0; i < page_count; i++) {
439 phys_addr_t addr = page_start + i * PAGE_SIZE;
440 pages[i] = pfn_to_page(addr >> PAGE_SHIFT);
441 }
Stephen Boyde6b84272022-12-05 15:31:36 -0800442 /*
443 * VM_IOREMAP used here to bypass this region during vread()
444 * and kmap_atomic() (i.e. kcore) to avoid __va() failures.
445 */
446 vaddr = vmap(pages, page_count, VM_MAP | VM_IOREMAP, prot);
Colin Cross404a6042012-03-07 17:34:34 -0800447 kfree(pages);
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700448
Bin Yang831b6242018-09-12 03:36:34 +0000449 /*
450 * Since vmap() uses page granularity, we must add the offset
451 * into the page here, to get the byte granularity address
452 * into the mapping to represent the actual "start" location.
453 */
454 return vaddr + offset_in_page(start);
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700455}
456
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700457static void *persistent_ram_iomap(phys_addr_t start, size_t size,
Kees Cook1227daa2018-10-17 17:20:35 -0700458 unsigned int memtype, char *label)
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -0700459{
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700460 void *va;
461
Kees Cook1227daa2018-10-17 17:20:35 -0700462 if (!request_mem_region(start, size, label ?: "ramoops")) {
Kees Cook9ee85b82018-10-26 01:14:01 -0700463 pr_err("request mem region (%s 0x%llx@0x%llx) failed\n",
464 label ?: "ramoops",
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -0700465 (unsigned long long)size, (unsigned long long)start);
466 return NULL;
467 }
468
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700469 if (memtype)
470 va = ioremap(start, size);
471 else
472 va = ioremap_wc(start, size);
473
Bin Yang831b6242018-09-12 03:36:34 +0000474 /*
475 * Since request_mem_region() and ioremap() are byte-granularity
476 * there is no need handle anything special like we do when the
477 * vmap() case in persistent_ram_vmap() above.
478 */
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700479 return va;
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -0700480}
481
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700482static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700483 struct persistent_ram_zone *prz, int memtype)
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700484{
Anton Vorontsovd3b48762012-05-11 17:18:05 -0700485 prz->paddr = start;
486 prz->size = size;
487
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -0700488 if (pfn_valid(start >> PAGE_SHIFT))
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700489 prz->vaddr = persistent_ram_vmap(start, size, memtype);
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -0700490 else
Kees Cook1227daa2018-10-17 17:20:35 -0700491 prz->vaddr = persistent_ram_iomap(start, size, memtype,
492 prz->label);
Anton Vorontsov24c3d2f2012-05-11 17:17:54 -0700493
Colin Cross404a6042012-03-07 17:34:34 -0800494 if (!prz->vaddr) {
Anton Vorontsov2b1321e2012-05-11 17:17:43 -0700495 pr_err("%s: Failed to map 0x%llx pages at 0x%llx\n", __func__,
496 (unsigned long long)size, (unsigned long long)start);
Colin Cross404a6042012-03-07 17:34:34 -0800497 return -ENOMEM;
Colin Crossc6725282012-03-07 17:34:32 -0800498 }
499
Bin Yang831b6242018-09-12 03:36:34 +0000500 prz->buffer = prz->vaddr;
Colin Cross404a6042012-03-07 17:34:34 -0800501 prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
Colin Crossc6725282012-03-07 17:34:32 -0800502
503 return 0;
504}
505
Greg Kroah-Hartmanf568f6c2012-12-21 15:02:05 -0800506static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
Kees Cook76d56922017-02-09 15:43:44 -0800507 struct persistent_ram_ecc_info *ecc_info)
Colin Cross404a6042012-03-07 17:34:34 -0800508{
Anton Vorontsovbb4206f2012-05-11 17:17:25 -0700509 int ret;
Peng Wang7684bd32018-10-30 15:52:34 +0800510 bool zap = !!(prz->flags & PRZ_FLAG_ZAP_OLD);
Colin Cross404a6042012-03-07 17:34:34 -0800511
Arve Hjønnevågc31ad082012-05-22 16:33:23 -0700512 ret = persistent_ram_init_ecc(prz, ecc_info);
Kees Cook0eed84f2018-11-01 14:03:07 -0700513 if (ret) {
514 pr_warn("ECC failed %s\n", prz->label);
Anton Vorontsovbb4206f2012-05-11 17:17:25 -0700515 return ret;
Kees Cook0eed84f2018-11-01 14:03:07 -0700516 }
Colin Cross404a6042012-03-07 17:34:34 -0800517
Anton Vorontsovcbe7cbf2012-07-17 12:11:12 -0700518 sig ^= PERSISTENT_RAM_SIG;
519
520 if (prz->buffer->sig == sig) {
Enlin Mufe8c3622023-08-01 14:04:32 +0800521 if (buffer_size(prz) == 0 && buffer_start(prz) == 0) {
Joel Fernandes (Google)30696372018-11-03 16:38:18 -0700522 pr_debug("found existing empty buffer\n");
523 return 0;
524 }
525
Colin Cross808d0382012-03-07 17:34:35 -0800526 if (buffer_size(prz) > prz->buffer_size ||
Peng Wang7684bd32018-10-30 15:52:34 +0800527 buffer_start(prz) > buffer_size(prz)) {
Fabian Frederickef748852014-06-06 14:37:31 -0700528 pr_info("found existing invalid buffer, size %zu, start %zu\n",
529 buffer_size(prz), buffer_start(prz));
Peng Wang7684bd32018-10-30 15:52:34 +0800530 zap = true;
531 } else {
Fabian Frederickef748852014-06-06 14:37:31 -0700532 pr_debug("found existing buffer, size %zu, start %zu\n",
533 buffer_size(prz), buffer_start(prz));
Colin Cross404a6042012-03-07 17:34:34 -0800534 persistent_ram_save_old(prz);
535 }
536 } else {
Fabian Frederickef748852014-06-06 14:37:31 -0700537 pr_debug("no valid data in buffer (sig = 0x%08x)\n",
538 prz->buffer->sig);
Peng Wang7684bd32018-10-30 15:52:34 +0800539 prz->buffer->sig = sig;
540 zap = true;
Colin Cross404a6042012-03-07 17:34:34 -0800541 }
542
Peng Wang7684bd32018-10-30 15:52:34 +0800543 /* Reset missing, invalid, or single-use memory area. */
544 if (zap)
545 persistent_ram_zap(prz);
Colin Cross404a6042012-03-07 17:34:34 -0800546
Anton Vorontsovbb4206f2012-05-11 17:17:25 -0700547 return 0;
548}
549
Kees Cook06b4e092022-10-11 13:01:11 -0700550void persistent_ram_free(struct persistent_ram_zone **_prz)
Anton Vorontsovd3b48762012-05-11 17:18:05 -0700551{
Kees Cook06b4e092022-10-11 13:01:11 -0700552 struct persistent_ram_zone *prz;
553
554 if (!_prz)
555 return;
556
557 prz = *_prz;
Anton Vorontsovbeeb9432012-06-18 19:15:52 -0700558 if (!prz)
559 return;
560
561 if (prz->vaddr) {
562 if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
Bin Yang831b6242018-09-12 03:36:34 +0000563 /* We must vunmap() at page-granularity. */
564 vunmap(prz->vaddr - offset_in_page(prz->paddr));
Anton Vorontsovbeeb9432012-06-18 19:15:52 -0700565 } else {
566 iounmap(prz->vaddr);
567 release_mem_region(prz->paddr, prz->size);
568 }
569 prz->vaddr = NULL;
Anton Vorontsovd3b48762012-05-11 17:18:05 -0700570 }
Kees Cookf2531f12018-03-07 12:18:33 -0800571 if (prz->rs_decoder) {
572 free_rs(prz->rs_decoder);
573 prz->rs_decoder = NULL;
574 }
575 kfree(prz->ecc_info.par);
576 prz->ecc_info.par = NULL;
577
Anton Vorontsovd3b48762012-05-11 17:18:05 -0700578 persistent_ram_free_old(prz);
Kees Cook1227daa2018-10-17 17:20:35 -0700579 kfree(prz->label);
Anton Vorontsovd3b48762012-05-11 17:18:05 -0700580 kfree(prz);
Kees Cook06b4e092022-10-11 13:01:11 -0700581 *_prz = NULL;
Anton Vorontsovd3b48762012-05-11 17:18:05 -0700582}
583
Greg Kroah-Hartmanf568f6c2012-12-21 15:02:05 -0800584struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700585 u32 sig, struct persistent_ram_ecc_info *ecc_info,
Kees Cook1227daa2018-10-17 17:20:35 -0700586 unsigned int memtype, u32 flags, char *label)
Anton Vorontsov8cf5aff2012-05-11 17:17:34 -0700587{
588 struct persistent_ram_zone *prz;
589 int ret = -ENOMEM;
590
591 prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
592 if (!prz) {
Fabian Frederickef748852014-06-06 14:37:31 -0700593 pr_err("failed to allocate persistent ram zone\n");
Anton Vorontsov8cf5aff2012-05-11 17:17:34 -0700594 goto err;
595 }
596
Kees Cook76d56922017-02-09 15:43:44 -0800597 /* Initialize general buffer state. */
Kees Cooke9a330c2017-03-05 22:08:58 -0800598 raw_spin_lock_init(&prz->buffer_lock);
Kees Cook76d56922017-02-09 15:43:44 -0800599 prz->flags = flags;
Kees Cooke163fdb2020-01-08 10:06:54 -0800600 prz->label = kstrdup(label, GFP_KERNEL);
Jiasheng Jiangd97038d2023-06-14 17:37:33 +0800601 if (!prz->label)
602 goto err;
Kees Cook76d56922017-02-09 15:43:44 -0800603
Tony Lindgren027bc8b2014-09-16 13:50:01 -0700604 ret = persistent_ram_buffer_map(start, size, prz, memtype);
Anton Vorontsov8cf5aff2012-05-11 17:17:34 -0700605 if (ret)
606 goto err;
607
Kees Cook76d56922017-02-09 15:43:44 -0800608 ret = persistent_ram_post_init(prz, sig, ecc_info);
Anton Vorontsovbeeb9432012-06-18 19:15:52 -0700609 if (ret)
610 goto err;
Anton Vorontsov8cf5aff2012-05-11 17:17:34 -0700611
Kees Cookdc80b1e2018-11-01 14:14:47 -0700612 pr_debug("attached %s 0x%zx@0x%llx: %zu header, %zu data, %zu ecc (%d/%d)\n",
613 prz->label, prz->size, (unsigned long long)prz->paddr,
614 sizeof(*prz->buffer), prz->buffer_size,
615 prz->size - sizeof(*prz->buffer) - prz->buffer_size,
616 prz->ecc_info.ecc_size, prz->ecc_info.block_size);
617
Anton Vorontsov8cf5aff2012-05-11 17:17:34 -0700618 return prz;
619err:
Kees Cook06b4e092022-10-11 13:01:11 -0700620 persistent_ram_free(&prz);
Anton Vorontsov8cf5aff2012-05-11 17:17:34 -0700621 return ERR_PTR(ret);
622}