Implement core area registration mechanism. Implement directly mapped zone corespoding to core areas.
Signed-off-by: Eugen Hristev <[email protected]> --- fs/pstore/platform.c | 67 ++++++++++++++++++++++++++++++++++++ fs/pstore/zone.c | 77 ++++++++++++++++++++++++++++++++++++++++++ include/linux/pstore.h | 16 +++++++++ 3 files changed, 160 insertions(+) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index e20e60b88727..32448d9dd316 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -68,6 +68,7 @@ static DECLARE_WORK(pstore_work, pstore_dowork); * the filesystem mount/unmount routines. */ static DEFINE_MUTEX(psinfo_lock); +static DEFINE_MUTEX(ps_dmr_lock); struct pstore_info *psinfo; static char *backend; @@ -99,6 +100,12 @@ MODULE_PARM_DESC(kmsg_bytes, "amount of kernel log to snapshot (in bytes)"); static void *compress_workspace; +static LIST_HEAD(rec_list); +struct rec_list_t { + struct pstore_record rec; + struct list_head list; +}; + /* * Compression is only used for dmesg output, which consists of low-entropy * ASCII text, and so we can assume worst-case 60%. @@ -271,6 +278,66 @@ void pstore_record_init(struct pstore_record *record, record->time = ns_to_timespec64(ktime_get_real_fast_ns()); } +int pstore_register_core_area(const char *handle, void *area, size_t size) +{ + struct rec_list_t *rec_element = kzalloc(sizeof (*rec_element), GFP_KERNEL); + struct pstore_record *record = &rec_element->rec; + int ret; + + if (!psinfo || !psinfo->register_dmr) { + pr_err("No pstore available ! Bailing out.\n"); + return -EAGAIN; + } + + pstore_record_init(record, psinfo); + record->type = PSTORE_TYPE_DMAPPED; + record->buf = area; + record->size = size; + + if (handle) { + record->priv = kmalloc(8, GFP_KERNEL); + strncpy(record->priv, handle, 8); + } + + mutex_lock(&ps_dmr_lock); + + ret = psinfo->register_dmr(record); + if (!ret) + list_add(&rec_element->list, &rec_list); + + mutex_unlock(&ps_dmr_lock); + return ret; +} +EXPORT_SYMBOL_GPL(pstore_register_core_area); + +int pstore_unregister_core_area(const char *handle, void *area, size_t size) +{ + struct rec_list_t *rec_element, *tmp; + int ret; + + if (!psinfo || !psinfo->unregister_dmr) + return -EAGAIN; + + mutex_lock(&ps_dmr_lock); + list_for_each_entry_safe(rec_element, tmp, &rec_list, list) { + struct pstore_record *record; + + record = &rec_element->rec; + + if (record->buf == area) { + ret = psinfo->unregister_dmr(record); + list_del(&rec_element->list); + mutex_unlock(&ps_dmr_lock); + return 0; + } + } + + mutex_unlock(&ps_dmr_lock); + return 0; + +} +EXPORT_SYMBOL_GPL(pstore_unregister_core_area); + /* * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the * end of the buffer. diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index affa4370208c..f9e2dc4252ea 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -35,6 +35,7 @@ struct psz_buffer { uint32_t sig; atomic_t datalen; atomic_t start; + void *data_ptr; uint8_t data[]; }; @@ -822,6 +823,38 @@ static int notrace psz_kmsg_write(struct psz_context *cxt, return 0; } +static int notrace psz_register_dmr_record(struct pstore_zone *zone, + struct pstore_record *record) +{ + struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; + int ret; + + if (!info->register_dmr) + return -ENOTSUPP; + + zone->buffer->data_ptr = record->buf; + atomic_set(&zone->buffer->datalen, record->size); + + ret = info->register_dmr(record->priv, record->id, record->buf, + record->size); + if (!ret) + atomic_set(&zone->dirty, true); + return ret; +} + +static int psz_unregister_dmr_zone(struct pstore_zone *zone) +{ + struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; + if (!info->unregister_dmr) + return -ENOTSUPP; + + info->unregister_dmr(zone->buffer->data_ptr, + atomic_read(&zone->buffer->datalen)); + + atomic_set(&zone->dirty, false); + return 0; +} + static int notrace psz_record_write(struct pstore_zone *zone, struct pstore_record *record) { @@ -906,6 +939,48 @@ static int notrace psz_pstore_write(struct pstore_record *record) } } +static int pstore_unregister_dmr(struct pstore_record *record) +{ + struct psz_context *cxt = record->psi->data; + int c = 0; + + if (!cxt->dmszs) + return -ENODEV; + + while (c < cxt->dmapped_max_cnt) { + if (!atomic_read(&cxt->dmszs[c]->dirty)) + continue; + + if (cxt->dmszs[c]->buffer->data_ptr == record->buf) + return psz_unregister_dmr_zone(cxt->dmszs[c]); + c++; + } + + return -ENOENT; +} + +static int pstore_register_dmr(struct pstore_record *record) +{ + struct psz_context *cxt = record->psi->data; + int c = 0; + + if (!cxt->dmszs) + return -ENODEV; + + while (c < cxt->dmapped_max_cnt) { + if (!atomic_read(&cxt->dmszs[c]->dirty)) + break; + c++; + } + + if (c == cxt->dmapped_max_cnt) + return -ENOSPC; + + record->id = c; + + return psz_register_dmr_record(cxt->dmszs[c], record); +} + static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) { struct pstore_zone *zone = NULL; @@ -1110,6 +1185,8 @@ static struct psz_context pstore_zone_cxt = { .read = psz_pstore_read, .write = psz_pstore_write, .erase = psz_pstore_erase, + .register_dmr = pstore_register_dmr, + .unregister_dmr = pstore_unregister_dmr, }, }; diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 8360d94c96b6..85f3f964b268 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -290,4 +290,20 @@ pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val) } #endif +#ifdef CONFIG_PSTORE +int pstore_register_core_area(const char *handle, void *area, size_t size); +int pstore_unregister_core_area(const char *handle, void *area, size_t size); +#else +static inline int pstore_register_core_area(const char *handle, void *area, + size_t size) +{ + return 0; +} +static inline int pstore_unregister_core_area(const char *handle, void *area, + size_t size) +{ + return 0; +} +#endif + #endif /*_LINUX_PSTORE_H*/ -- 2.43.0
