fs/pstore/ram_internal.h

   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);