1 files changed, 40 insertions, 13 deletions

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 8613e5b35c22..39d1373128e9 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -51,6 +51,10 @@ static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
 
+static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
+module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
+MODULE_PARM_DESC(pmsg_size, "size of user space message log");
+
 static ulong mem_address;
 module_param(mem_address, ulong, 0400);
 MODULE_PARM_DESC(mem_address,
@@ -82,12 +86,14 @@ struct ramoops_context {
         struct persistent_ram_zone **przs;
         struct persistent_ram_zone *cprz;
         struct persistent_ram_zone *fprz;
+        struct persistent_ram_zone *mprz;
         phys_addr_t phys_addr;
         unsigned long size;
         unsigned int memtype;
         size_t record_size;
         size_t console_size;
         size_t ftrace_size;
+        size_t pmsg_size;
         int dump_oops;
         struct persistent_ram_ecc_info ecc_info;
         unsigned int max_dump_cnt;
@@ -96,6 +102,7 @@ struct ramoops_context {
         unsigned int dump_read_cnt;
         unsigned int console_read_cnt;
         unsigned int ftrace_read_cnt;
+        unsigned int pmsg_read_cnt;
         struct pstore_info pstore;
 };
 
@@ -109,6 +116,7 @@ static int ramoops_pstore_open(struct pstore_info *psi)
         cxt->dump_read_cnt = 0;
         cxt->console_read_cnt = 0;
         cxt->ftrace_read_cnt = 0;
+        cxt->pmsg_read_cnt = 0;
         return 0;
 }
 
@@ -164,6 +172,12 @@ static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
         return header_length;
 }
 
+static bool prz_ok(struct persistent_ram_zone *prz)
+{
+        return !!prz && !!(persistent_ram_old_size(prz) +
+                           persistent_ram_ecc_string(prz, NULL, 0));
+}
+
 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
                                    int *count, struct timespec *time,
                                    char **buf, bool *compressed,
@@ -178,13 +192,16 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
                                    cxt->max_dump_cnt, id, type,
                                    PSTORE_TYPE_DMESG, 1);
-        if (!prz)
+        if (!prz_ok(prz))
                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
-        if (!prz)
+        if (!prz_ok(prz))
                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
-        if (!prz)
+        if (!prz_ok(prz))
+                prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
+                                           1, id, type, PSTORE_TYPE_PMSG, 0);
+        if (!prz_ok(prz))
                 return 0;
 
         if (!persistent_ram_old(prz))
@@ -252,6 +269,11 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
                         return -ENOMEM;
                 persistent_ram_write(cxt->fprz, buf, size);
                 return 0;
+        } else if (type == PSTORE_TYPE_PMSG) {
+                if (!cxt->mprz)
+                        return -ENOMEM;
+                persistent_ram_write(cxt->mprz, buf, size);
+                return 0;
         }
 
         if (type != PSTORE_TYPE_DMESG)
@@ -309,6 +331,9 @@ static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
         case PSTORE_TYPE_FTRACE:
                 prz = cxt->fprz;
                 break;
+        case PSTORE_TYPE_PMSG:
+                prz = cxt->mprz;
+                break;
         default:
                 return -EINVAL;
         }
@@ -435,7 +460,7 @@ static int ramoops_probe(struct platform_device *pdev)
                 goto fail_out;
 
         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
-                        !pdata->ftrace_size)) {
+                        !pdata->ftrace_size && !pdata->pmsg_size)) {
                 pr_err("The memory size and the record/console size must be "
                         "non-zero\n");
                 goto fail_out;
@@ -447,6 +472,8 @@ static int ramoops_probe(struct platform_device *pdev)
                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
+        if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
+                pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 
         cxt->size = pdata->mem_size;
         cxt->phys_addr = pdata->mem_address;
@@ -454,12 +481,14 @@ static int ramoops_probe(struct platform_device *pdev)
         cxt->record_size = pdata->record_size;
         cxt->console_size = pdata->console_size;
         cxt->ftrace_size = pdata->ftrace_size;
+        cxt->pmsg_size = pdata->pmsg_size;
         cxt->dump_oops = pdata->dump_oops;
         cxt->ecc_info = pdata->ecc_info;
 
         paddr = cxt->phys_addr;
 
-        dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
+        dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
+                        - cxt->pmsg_size;
         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
         if (err)
                 goto fail_out;
@@ -474,13 +503,9 @@ static int ramoops_probe(struct platform_device *pdev)
         if (err)
                 goto fail_init_fprz;
 
-        if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
-                pr_err("memory size too small, minimum is %zu\n",
-                        cxt->console_size + cxt->record_size +
-                        cxt->ftrace_size);
-                err = -EINVAL;
-                goto fail_cnt;
-        }
+        err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
+        if (err)
+                goto fail_init_mprz;
 
         cxt->pstore.data = cxt;
         /*
@@ -525,7 +550,8 @@ fail_buf:
         kfree(cxt->pstore.buf);
 fail_clear:
         cxt->pstore.bufsize = 0;
-fail_cnt:
+        kfree(cxt->mprz);
+fail_init_mprz:
         kfree(cxt->fprz);
 fail_init_fprz:
         kfree(cxt->cprz);
@@ -583,6 +609,7 @@ static void ramoops_register_dummy(void)
         dummy_data->record_size = record_size;
         dummy_data->console_size = ramoops_console_size;
         dummy_data->ftrace_size = ramoops_ftrace_size;
+        dummy_data->pmsg_size = ramoops_pmsg_size;
         dummy_data->dump_oops = dump_oops;
         /*
          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC