ramoops: make record_size a module parameter

The size of the dump is currently set using the RECORD_SIZE macro which
is set to a page size.  This patch makes the record size a module
parameter and allows it to be set through platform data as well to allow
larger dumps if needed.

Signed-off-by: Sergiu Iordache <sergiu@chromium.org>
Acked-by: Marco Stornelli <marco.stornelli@gmail.com>
Cc: "Ahmed S. Darwish" <darwish.07@gmail.com>
Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 10 deletions

diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c
index 5349d94e17da..bd9b94b518f3 100644
--- a/drivers/char/ramoops.c
+++ b/drivers/char/ramoops.c
@@ -32,8 +32,12 @@
 #include <linux/ramoops.h>
 
 #define RAMOOPS_KERNMSG_HDR "===="
+#define MIN_MEM_SIZE 4096UL
 
-#define RECORD_SIZE 4096UL
+static ulong record_size = MIN_MEM_SIZE;
+module_param(record_size, ulong, 0400);
+MODULE_PARM_DESC(record_size,
+                "size of each dump done on oops/panic");
 
 static ulong mem_address;
 module_param(mem_address, ulong, 0400);
@@ -55,6 +59,7 @@ static struct ramoops_context {
         void *virt_addr;
         phys_addr_t phys_addr;
         unsigned long size;
+        unsigned long record_size;
         int dump_oops;
         int count;
         int max_count;
@@ -84,10 +89,10 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper,
         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
                 return;
 
-        buf = cxt->virt_addr + (cxt->count * RECORD_SIZE);
+        buf = cxt->virt_addr + (cxt->count * cxt->record_size);
         buf_orig = buf;
 
-        memset(buf, '\0', RECORD_SIZE);
+        memset(buf, '\0', cxt->record_size);
         res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
         buf += res;
         do_gettimeofday(&timestamp);
@@ -95,8 +100,8 @@ static void ramoops_do_dump(struct kmsg_dumper *dumper,
         buf += res;
 
         hdr_size = buf - buf_orig;
-        l2_cpy = min(l2, RECORD_SIZE - hdr_size);
-        l1_cpy = min(l1, RECORD_SIZE - hdr_size - l2_cpy);
+        l2_cpy = min(l2, cxt->record_size - hdr_size);
+        l1_cpy = min(l1, cxt->record_size - hdr_size - l2_cpy);
 
         s2_start = l2 - l2_cpy;
         s1_start = l1 - l1_cpy;
@@ -113,22 +118,33 @@ static int __init ramoops_probe(struct platform_device *pdev)
         struct ramoops_context *cxt = &oops_cxt;
         int err = -EINVAL;
 
-        if (!pdata->mem_size) {
-                pr_err("invalid size specification\n");
+        if (!pdata->mem_size || !pdata->record_size) {
+                pr_err("The memory size and the record size must be "
+                        "non-zero\n");
                 goto fail3;
         }
 
         rounddown_pow_of_two(pdata->mem_size);
+        rounddown_pow_of_two(pdata->record_size);
 
-        if (pdata->mem_size < RECORD_SIZE) {
-                pr_err("size too small\n");
+        /* Check for the minimum memory size */
+        if (pdata->mem_size < MIN_MEM_SIZE &&
+                        pdata->record_size < MIN_MEM_SIZE) {
+                pr_err("memory size too small, minium is %lu\n", MIN_MEM_SIZE);
                 goto fail3;
         }
 
-        cxt->max_count = pdata->mem_size / RECORD_SIZE;
+        if (pdata->mem_size < pdata->record_size) {
+                pr_err("The memory size must be larger than the "
+                        "records size\n");
+                goto fail3;
+        }
+
+        cxt->max_count = pdata->mem_size / pdata->record_size;
         cxt->count = 0;
         cxt->size = pdata->mem_size;
         cxt->phys_addr = pdata->mem_address;
+        cxt->record_size = pdata->record_size;
         cxt->dump_oops = pdata->dump_oops;
 
         if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
@@ -196,6 +212,7 @@ static int __init ramoops_init(void)
                         return -ENOMEM;
                 dummy_data->mem_size = mem_size;
                 dummy_data->mem_address = mem_address;
+                dummy_data->record_size = record_size;
                 dummy_data->dump_oops = dump_oops;
                 dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
                         NULL, 0, dummy_data,