xref: /linux/fs/pstore/ram_internal.h (revision 06b4e09aab6c1ae6b3991a729d2fcb31e358e7f3)
18bd4da0fSKees Cook /* SPDX-License-Identifier: GPL-2.0-only */
28bd4da0fSKees Cook /*
38bd4da0fSKees Cook  * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
48bd4da0fSKees Cook  * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
58bd4da0fSKees Cook  * Copyright (C) 2011 Google, Inc.
68bd4da0fSKees Cook  */
78bd4da0fSKees Cook 
88bd4da0fSKees Cook #include <linux/pstore_ram.h>
98bd4da0fSKees Cook 
108bd4da0fSKees Cook /*
118bd4da0fSKees Cook  * Choose whether access to the RAM zone requires locking or not.  If a zone
128bd4da0fSKees Cook  * can be written to from different CPUs like with ftrace for example, then
138bd4da0fSKees Cook  * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required.
148bd4da0fSKees Cook  */
158bd4da0fSKees Cook #define PRZ_FLAG_NO_LOCK	BIT(0)
168bd4da0fSKees Cook /*
178bd4da0fSKees Cook  * If a PRZ should only have a single-boot lifetime, this marks it as
188bd4da0fSKees Cook  * getting wiped after its contents get copied out after boot.
198bd4da0fSKees Cook  */
208bd4da0fSKees Cook #define PRZ_FLAG_ZAP_OLD	BIT(1)
218bd4da0fSKees Cook 
228bd4da0fSKees Cook /**
238bd4da0fSKees Cook  * struct persistent_ram_zone - Details of a persistent RAM zone (PRZ)
248bd4da0fSKees Cook  *                              used as a pstore backend
258bd4da0fSKees Cook  *
268bd4da0fSKees Cook  * @paddr:	physical address of the mapped RAM area
278bd4da0fSKees Cook  * @size:	size of mapping
288bd4da0fSKees Cook  * @label:	unique name of this PRZ
298bd4da0fSKees Cook  * @type:	frontend type for this PRZ
308bd4da0fSKees Cook  * @flags:	holds PRZ_FLAGS_* bits
318bd4da0fSKees Cook  *
328bd4da0fSKees Cook  * @buffer_lock:
338bd4da0fSKees Cook  *	locks access to @buffer "size" bytes and "start" offset
348bd4da0fSKees Cook  * @buffer:
358bd4da0fSKees Cook  *	pointer to actual RAM area managed by this PRZ
368bd4da0fSKees Cook  * @buffer_size:
378bd4da0fSKees Cook  *	bytes in @buffer->data (not including any trailing ECC bytes)
388bd4da0fSKees Cook  *
398bd4da0fSKees Cook  * @par_buffer:
408bd4da0fSKees Cook  *	pointer into @buffer->data containing ECC bytes for @buffer->data
418bd4da0fSKees Cook  * @par_header:
428bd4da0fSKees Cook  *	pointer into @buffer->data containing ECC bytes for @buffer header
438bd4da0fSKees Cook  *	(i.e. all fields up to @data)
448bd4da0fSKees Cook  * @rs_decoder:
458bd4da0fSKees Cook  *	RSLIB instance for doing ECC calculations
468bd4da0fSKees Cook  * @corrected_bytes:
478bd4da0fSKees Cook  *	ECC corrected bytes accounting since boot
488bd4da0fSKees Cook  * @bad_blocks:
498bd4da0fSKees Cook  *	ECC uncorrectable bytes accounting since boot
508bd4da0fSKees Cook  * @ecc_info:
518bd4da0fSKees Cook  *	ECC configuration details
528bd4da0fSKees Cook  *
538bd4da0fSKees Cook  * @old_log:
548bd4da0fSKees Cook  *	saved copy of @buffer->data prior to most recent wipe
558bd4da0fSKees Cook  * @old_log_size:
568bd4da0fSKees Cook  *	bytes contained in @old_log
578bd4da0fSKees Cook  *
588bd4da0fSKees Cook  */
598bd4da0fSKees Cook struct persistent_ram_zone {
608bd4da0fSKees Cook 	phys_addr_t paddr;
618bd4da0fSKees Cook 	size_t size;
628bd4da0fSKees Cook 	void *vaddr;
638bd4da0fSKees Cook 	char *label;
648bd4da0fSKees Cook 	enum pstore_type_id type;
658bd4da0fSKees Cook 	u32 flags;
668bd4da0fSKees Cook 
678bd4da0fSKees Cook 	raw_spinlock_t buffer_lock;
688bd4da0fSKees Cook 	struct persistent_ram_buffer *buffer;
698bd4da0fSKees Cook 	size_t buffer_size;
708bd4da0fSKees Cook 
718bd4da0fSKees Cook 	char *par_buffer;
728bd4da0fSKees Cook 	char *par_header;
738bd4da0fSKees Cook 	struct rs_control *rs_decoder;
748bd4da0fSKees Cook 	int corrected_bytes;
758bd4da0fSKees Cook 	int bad_blocks;
768bd4da0fSKees Cook 	struct persistent_ram_ecc_info ecc_info;
778bd4da0fSKees Cook 
788bd4da0fSKees Cook 	char *old_log;
798bd4da0fSKees Cook 	size_t old_log_size;
808bd4da0fSKees Cook };
818bd4da0fSKees Cook 
828bd4da0fSKees Cook struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
838bd4da0fSKees Cook 			u32 sig, struct persistent_ram_ecc_info *ecc_info,
848bd4da0fSKees Cook 			unsigned int memtype, u32 flags, char *label);
85*06b4e09aSKees Cook void persistent_ram_free(struct persistent_ram_zone **_prz);
868bd4da0fSKees Cook void persistent_ram_zap(struct persistent_ram_zone *prz);
878bd4da0fSKees Cook 
888bd4da0fSKees Cook int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
898bd4da0fSKees Cook 			 unsigned int count);
908bd4da0fSKees Cook int persistent_ram_write_user(struct persistent_ram_zone *prz,
918bd4da0fSKees Cook 			      const void __user *s, unsigned int count);
928bd4da0fSKees Cook 
938bd4da0fSKees Cook void persistent_ram_save_old(struct persistent_ram_zone *prz);
948bd4da0fSKees Cook size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
958bd4da0fSKees Cook void *persistent_ram_old(struct persistent_ram_zone *prz);
968bd4da0fSKees Cook void persistent_ram_free_old(struct persistent_ram_zone *prz);
978bd4da0fSKees Cook ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
988bd4da0fSKees Cook 	char *str, size_t len);
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