1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com> 4 * Copyright (C) 2011 Kees Cook <keescook@chromium.org> 5 * Copyright (C) 2011 Google, Inc. 6 */ 7 8 #include <linux/pstore_ram.h> 9 10 /* 11 * Choose whether access to the RAM zone requires locking or not. If a zone 12 * can be written to from different CPUs like with ftrace for example, then 13 * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required. 14 */ 15 #define PRZ_FLAG_NO_LOCK BIT(0) 16 /* 17 * If a PRZ should only have a single-boot lifetime, this marks it as 18 * getting wiped after its contents get copied out after boot. 19 */ 20 #define PRZ_FLAG_ZAP_OLD BIT(1) 21 22 /** 23 * struct persistent_ram_zone - Details of a persistent RAM zone (PRZ) 24 * used as a pstore backend 25 * 26 * @paddr: physical address of the mapped RAM area 27 * @size: size of mapping 28 * @label: unique name of this PRZ 29 * @type: frontend type for this PRZ 30 * @flags: holds PRZ_FLAGS_* bits 31 * 32 * @buffer_lock: 33 * locks access to @buffer "size" bytes and "start" offset 34 * @buffer: 35 * pointer to actual RAM area managed by this PRZ 36 * @buffer_size: 37 * bytes in @buffer->data (not including any trailing ECC bytes) 38 * 39 * @par_buffer: 40 * pointer into @buffer->data containing ECC bytes for @buffer->data 41 * @par_header: 42 * pointer into @buffer->data containing ECC bytes for @buffer header 43 * (i.e. all fields up to @data) 44 * @rs_decoder: 45 * RSLIB instance for doing ECC calculations 46 * @corrected_bytes: 47 * ECC corrected bytes accounting since boot 48 * @bad_blocks: 49 * ECC uncorrectable bytes accounting since boot 50 * @ecc_info: 51 * ECC configuration details 52 * 53 * @old_log: 54 * saved copy of @buffer->data prior to most recent wipe 55 * @old_log_size: 56 * bytes contained in @old_log 57 * 58 */ 59 struct persistent_ram_zone { 60 phys_addr_t paddr; 61 size_t size; 62 void *vaddr; 63 char *label; 64 enum pstore_type_id type; 65 u32 flags; 66 67 raw_spinlock_t buffer_lock; 68 struct persistent_ram_buffer *buffer; 69 size_t buffer_size; 70 71 char *par_buffer; 72 char *par_header; 73 struct rs_control *rs_decoder; 74 int corrected_bytes; 75 int bad_blocks; 76 struct persistent_ram_ecc_info ecc_info; 77 78 char *old_log; 79 size_t old_log_size; 80 }; 81 82 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size, 83 u32 sig, struct persistent_ram_ecc_info *ecc_info, 84 unsigned int memtype, u32 flags, char *label); 85 void persistent_ram_free(struct persistent_ram_zone **_prz); 86 void persistent_ram_zap(struct persistent_ram_zone *prz); 87 88 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s, 89 unsigned int count); 90 int persistent_ram_write_user(struct persistent_ram_zone *prz, 91 const void __user *s, unsigned int count); 92 93 void persistent_ram_save_old(struct persistent_ram_zone *prz); 94 size_t persistent_ram_old_size(struct persistent_ram_zone *prz); 95 void *persistent_ram_old(struct persistent_ram_zone *prz); 96 void persistent_ram_free_old(struct persistent_ram_zone *prz); 97 ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz, 98 char *str, size_t len); 99