Directly mapped zones have a different semantic from usual pstore zones. Such zones use a pointer to data in their buffer struct, instead of keeping the buffer locally. The data pointer and size is then passed to the backend for further use. Having a different semantics, backends supporting only these do not offer read/write ops, and only new register_dmr and unregister_dmr ops. Ofcourse, a backend could support both classic zones and directly mapped. Directly mapped zones have the advantage of not being passed through in the event of a crashed, but rather at registration time.
Signed-off-by: Eugen Hristev <[email protected]> --- fs/pstore/platform.c | 1 + fs/pstore/smem.c | 6 ++--- fs/pstore/zone.c | 45 ++++++++++++++++++++++++++++--------- include/linux/pstore.h | 4 ++++ include/linux/pstore_zone.h | 3 +++ 5 files changed, 45 insertions(+), 14 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index f56b066ab80c..e20e60b88727 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -51,6 +51,7 @@ static const char * const pstore_type_names[] = { "powerpc-common", "pmsg", "powerpc-opal", + "directly-mapped", }; static int pstore_new_entry; diff --git a/fs/pstore/smem.c b/fs/pstore/smem.c index 9eedd7df5446..684ecc20cae5 100644 --- a/fs/pstore/smem.c +++ b/fs/pstore/smem.c @@ -36,15 +36,15 @@ static int __register_pstore_device(struct pstore_device_info *dev) pr_err("NULL device info\n"); return -EINVAL; } - if (!dev->zone.total_size) { + if (!dev->zone.total_size && !dev->zone.dmapped_cnt) { pr_err("zero sized device\n"); return -EINVAL; } - if (!dev->zone.read) { + if (!dev->zone.read && !dev->zone.dmapped_cnt) { pr_err("no read handler for device\n"); return -EINVAL; } - if (!dev->zone.write) { + if (!dev->zone.write && !dev->zone.dmapped_cnt) { pr_err("no write handler for device\n"); return -EINVAL; } diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index 5fa2fa2e7aa7..affa4370208c 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -113,6 +113,7 @@ struct psz_context { struct pstore_zone *ppsz; struct pstore_zone *cpsz; struct pstore_zone **fpszs; + struct pstore_zone **dmszs; unsigned int kmsg_max_cnt; unsigned int kmsg_read_cnt; unsigned int kmsg_write_cnt; @@ -120,6 +121,7 @@ struct psz_context { unsigned int console_read_cnt; unsigned int ftrace_max_cnt; unsigned int ftrace_read_cnt; + unsigned int dmapped_max_cnt; /* * These counters should be calculated during recovery. * It records the oops/panic times after crashes rather than boots. @@ -1148,6 +1150,8 @@ static void psz_free_all_zones(struct psz_context *cxt) psz_free_zone(&cxt->cpsz); if (cxt->fpszs) psz_free_zones(&cxt->fpszs, &cxt->ftrace_max_cnt); + if (cxt->dmszs) + psz_free_zones(&cxt->dmszs, &cxt->dmapped_max_cnt); } static struct pstore_zone *psz_init_zone(enum pstore_type_id type, @@ -1160,9 +1164,9 @@ static struct pstore_zone *psz_init_zone(enum pstore_type_id type, if (!size) return NULL; - if (*off + size > info->total_size) { - pr_err("no room for %s (0x%zx@0x%llx over 0x%lx)\n", - name, size, *off, info->total_size); + if (*off + size > info->total_size && type != PSTORE_TYPE_DMAPPED) { + pr_err("no room for %s type %d (0x%zx@0x%llx over 0x%lx)\n", + name, type, size, *off, info->total_size); return ERR_PTR(-ENOMEM); } @@ -1170,7 +1174,8 @@ static struct pstore_zone *psz_init_zone(enum pstore_type_id type, if (!zone) return ERR_PTR(-ENOMEM); - zone->buffer = kmalloc(size, GFP_KERNEL); + zone->buffer = kmalloc(type == PSTORE_TYPE_DMAPPED ? + sizeof(struct psz_buffer) : size, GFP_KERNEL); if (!zone->buffer) { kfree(zone); return ERR_PTR(-ENOMEM); @@ -1179,7 +1184,10 @@ static struct pstore_zone *psz_init_zone(enum pstore_type_id type, zone->off = *off; zone->name = name; zone->type = type; - zone->buffer_size = size - sizeof(struct psz_buffer); + if (zone->type == PSTORE_TYPE_DMAPPED) + zone->buffer_size = 0; + else + zone->buffer_size = size - sizeof(struct psz_buffer); zone->buffer->sig = type ^ PSZ_SIG; zone->oldbuf = NULL; atomic_set(&zone->dirty, 0); @@ -1188,8 +1196,9 @@ static struct pstore_zone *psz_init_zone(enum pstore_type_id type, *off += size; - pr_debug("pszone %s: off 0x%llx, %zu header, %zu data\n", zone->name, - zone->off, sizeof(*zone->buffer), zone->buffer_size); + pr_debug("pszone %s: off 0x%llx, %zu header, %zu data %s\n", zone->name, + zone->off, sizeof(*zone->buffer), zone->buffer_size, + zone->type == PSTORE_TYPE_DMAPPED ? " dmapped " : ""); return zone; } @@ -1206,7 +1215,7 @@ static struct pstore_zone **psz_init_zones(enum pstore_type_id type, if (!total_size || !record_size) return NULL; - if (*off + total_size > info->total_size) { + if (*off + total_size > info->total_size && type != PSTORE_TYPE_DMAPPED) { pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n", name, total_size, *off, info->total_size); return ERR_PTR(-ENOMEM); @@ -1245,6 +1254,15 @@ static int psz_alloc_zones(struct psz_context *cxt) int err; size_t off_size = 0; + cxt->dmszs = psz_init_zones(PSTORE_TYPE_DMAPPED, &off, + info->dmapped_cnt, + 1, &cxt->dmapped_max_cnt); + if (IS_ERR(cxt->dmszs)) { + err = PTR_ERR(cxt->dmszs); + cxt->dmszs = NULL; + goto free_out; + } + off_size += info->pmsg_size; cxt->ppsz = psz_init_zone(PSTORE_TYPE_PMSG, &off, info->pmsg_size); if (IS_ERR(cxt->ppsz)) { @@ -1302,7 +1320,7 @@ int register_pstore_zone(struct pstore_zone_info *info) int err = -EINVAL; struct psz_context *cxt = &pstore_zone_cxt; - if (info->total_size < 4096) { + if (info->total_size < 4096 && !info->dmapped_cnt) { pr_warn("total_size must be >= 4096\n"); return -EINVAL; } @@ -1312,7 +1330,7 @@ int register_pstore_zone(struct pstore_zone_info *info) } if (!info->kmsg_size && !info->pmsg_size && !info->console_size && - !info->ftrace_size) { + !info->ftrace_size && !info->dmapped_cnt) { pr_warn("at least one record size must be non-zero\n"); return -EINVAL; } @@ -1345,7 +1363,7 @@ int register_pstore_zone(struct pstore_zone_info *info) * if no @read, pstore may mount failed. * if no @write, pstore do not support to remove record file. */ - if (!info->read || !info->write) { + if (!info->dmapped_cnt && (!info->read || !info->write)) { pr_err("no valid general read/write interface\n"); return -EINVAL; } @@ -1365,6 +1383,7 @@ int register_pstore_zone(struct pstore_zone_info *info) pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size); pr_debug("\tconsole size : %ld Bytes\n", info->console_size); pr_debug("\tftrace size : %ld Bytes\n", info->ftrace_size); + pr_debug("\tdmapped areas : %ld\n", info->dmapped_cnt); err = psz_alloc_zones(cxt); if (err) { @@ -1406,6 +1425,10 @@ int register_pstore_zone(struct pstore_zone_info *info) cxt->pstore.flags |= PSTORE_FLAGS_FTRACE; pr_cont(" ftrace"); } + if (info->dmapped_cnt) { + cxt->pstore.flags |= PSTORE_FLAGS_DMAPPED; + pr_cont(" dmapped"); + } pr_cont("\n"); err = pstore_register(&cxt->pstore); diff --git a/include/linux/pstore.h b/include/linux/pstore.h index fed601053c51..8360d94c96b6 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -39,6 +39,7 @@ enum pstore_type_id { PSTORE_TYPE_PMSG = 7, PSTORE_TYPE_PPC_OPAL = 8, + PSTORE_TYPE_DMAPPED = 9, /* End of the list */ PSTORE_TYPE_MAX }; @@ -199,6 +200,8 @@ struct pstore_info { int (*write_user)(struct pstore_record *record, const char __user *buf); int (*erase)(struct pstore_record *record); + int (*register_dmr)(struct pstore_record *record); + int (*unregister_dmr)(struct pstore_record *record); }; /* Supported frontends */ @@ -206,6 +209,7 @@ struct pstore_info { #define PSTORE_FLAGS_CONSOLE BIT(1) #define PSTORE_FLAGS_FTRACE BIT(2) #define PSTORE_FLAGS_PMSG BIT(3) +#define PSTORE_FLAGS_DMAPPED BIT(4) extern int pstore_register(struct pstore_info *); extern void pstore_unregister(struct pstore_info *); diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 284364234162..a74d0cc75577 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -48,10 +48,13 @@ struct pstore_zone_info { unsigned long pmsg_size; unsigned long console_size; unsigned long ftrace_size; + unsigned long dmapped_cnt; pstore_zone_read_op read; pstore_zone_write_op write; pstore_zone_erase_op erase; pstore_zone_write_op panic_write; + int (*register_dmr)(char *, int, void *, size_t); + int (*unregister_dmr)(void *, size_t); }; /** -- 2.43.0
