include/linux/pstore_ram.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 #ifndef __LINUX_PSTORE_RAM_H__
   9 #define __LINUX_PSTORE_RAM_H__
  10
  11 #include <linux/compiler.h>
  12 #include <linux/device.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/list.h>
  16 #include <linux/pstore.h>
  17 #include <linux/types.h>
  18
  19 /*
  20  * Choose whether access to the RAM zone requires locking or not.  If a zone
  21  * can be written to from different CPUs like with ftrace for example, then
  22  * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required.
  23  */
  24 #define PRZ_FLAG_NO_LOCK        BIT(0)
  25 /*
  26  * If a PRZ should only have a single-boot lifetime, this marks it as
  27  * getting wiped after its contents get copied out after boot.
  28  */
  29 #define PRZ_FLAG_ZAP_OLD        BIT(1)
  30
  31 struct persistent_ram_buffer;
  32 struct rs_control;
  33
  34 struct persistent_ram_ecc_info {
  35         int block_size;
  36         int ecc_size;
  37         int symsize;
  38         int poly;
  39         uint16_t *par;
  40 };
  41
  42 /**
  43  * struct persistent_ram_zone - Details of a persistent RAM zone (PRZ)
  44  *                              used as a pstore backend
  45  *
  46  * @paddr:      physical address of the mapped RAM area
  47  * @size:       size of mapping
  48  * @label:      unique name of this PRZ
  49  * @type:       frontend type for this PRZ
  50  * @flags:      holds PRZ_FLAGS_* bits
  51  *
  52  * @buffer_lock:
  53  *      locks access to @buffer "size" bytes and "start" offset
  54  * @buffer:
  55  *      pointer to actual RAM area managed by this PRZ
  56  * @buffer_size:
  57  *      bytes in @buffer->data (not including any trailing ECC bytes)
  58  *
  59  * @par_buffer:
  60  *      pointer into @buffer->data containing ECC bytes for @buffer->data
  61  * @par_header:
  62  *      pointer into @buffer->data containing ECC bytes for @buffer header
  63  *      (i.e. all fields up to @data)
  64  * @rs_decoder:
  65  *      RSLIB instance for doing ECC calculations
  66  * @corrected_bytes:
  67  *      ECC corrected bytes accounting since boot
  68  * @bad_blocks:
  69  *      ECC uncorrectable bytes accounting since boot
  70  * @ecc_info:
  71  *      ECC configuration details
  72  *
  73  * @old_log:
  74  *      saved copy of @buffer->data prior to most recent wipe
  75  * @old_log_size:
  76  *      bytes contained in @old_log
  77  *
  78  */
  79 struct persistent_ram_zone {
  80         phys_addr_t paddr;
  81         size_t size;
  82         void *vaddr;
  83         char *label;
  84         enum pstore_type_id type;
  85         u32 flags;
  86
  87         raw_spinlock_t buffer_lock;
  88         struct persistent_ram_buffer *buffer;
  89         size_t buffer_size;
  90
  91         char *par_buffer;
  92         char *par_header;
  93         struct rs_control *rs_decoder;
  94         int corrected_bytes;
  95         int bad_blocks;
  96         struct persistent_ram_ecc_info ecc_info;
  97
  98         char *old_log;
  99         size_t old_log_size;
 100 };
 101
 102 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
 103                         u32 sig, struct persistent_ram_ecc_info *ecc_info,
 104                         unsigned int memtype, u32 flags, char *label);
 105 void persistent_ram_free(struct persistent_ram_zone *prz);
 106 void persistent_ram_zap(struct persistent_ram_zone *prz);
 107
 108 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
 109                          unsigned int count);
 110 int persistent_ram_write_user(struct persistent_ram_zone *prz,
 111                               const void __user *s, unsigned int count);
 112
 113 void persistent_ram_save_old(struct persistent_ram_zone *prz);
 114 size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
 115 void *persistent_ram_old(struct persistent_ram_zone *prz);
 116 void persistent_ram_free_old(struct persistent_ram_zone *prz);
 117 ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
 118         char *str, size_t len);
 119
 120 /*
 121  * Ramoops platform data
 122  * @mem_size    memory size for ramoops
 123  * @mem_address physical memory address to contain ramoops
 124  */
 125
 126 #define RAMOOPS_FLAG_FTRACE_PER_CPU     BIT(0)
 127
 128 struct ramoops_platform_data {
 129         unsigned long   mem_size;
 130         phys_addr_t     mem_address;
 131         unsigned int    mem_type;
 132         unsigned long   record_size;
 133         unsigned long   console_size;
 134         unsigned long   ftrace_size;
 135         unsigned long   pmsg_size;
 136         int             dump_oops;
 137         u32             flags;
 138         struct persistent_ram_ecc_info ecc_info;
 139 };
 140
 141 #endif