This is now straightforward: just introduce a module parameter and pass the needed value to persistent_ram_new().
Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org Acked-by: Marco Stornelli marco.stornelli@gmail.com Acked-by: Kees Cook keescook@chromium.org --- Documentation/ramoops.txt | 6 ++++++ fs/pstore/ram.c | 15 ++++++++++++--- include/linux/pstore_ram.h | 1 + 3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt index 470d2c4..4ba7db2 100644 --- a/Documentation/ramoops.txt +++ b/Documentation/ramoops.txt @@ -30,6 +30,11 @@ variable while setting 0 in that variable dumps only the panics. The module uses a counter to record multiple dumps but the counter gets reset on restart (i.e. new dumps after the restart will overwrite old ones).
+Ramoops also supports software ECC protection of persistent memory regions. +This might be useful when a hardware reset was used to bring the machine back +to life (i.e. a watchdog triggered). In such cases, RAM may be somewhat +corrupt, but usually it is restorable. + 2. Setting the parameters
Setting the ramoops parameters can be done in 2 different manners: @@ -46,6 +51,7 @@ static struct ramoops_platform_data ramoops_data = { .mem_address = <...>, .record_size = <...>, .dump_oops = <...>, + .ecc = <...>, };
static struct platform_device ramoops_dev = { diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 62b13ed..9123cce 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -56,12 +56,18 @@ module_param(dump_oops, int, 0600); MODULE_PARM_DESC(dump_oops, "set to 1 to dump oopses, 0 to only dump panics (default 1)");
+static int ramoops_ecc; +module_param_named(ecc, ramoops_ecc, int, 0600); +MODULE_PARM_DESC(ramoops_ecc, + "set to 1 to enable ECC support"); + struct ramoops_context { struct persistent_ram_zone **przs; phys_addr_t phys_addr; unsigned long size; size_t record_size; int dump_oops; + bool ecc; unsigned int count; unsigned int max_count; unsigned int read_count; @@ -236,6 +242,7 @@ static int __init ramoops_probe(struct platform_device *pdev) cxt->phys_addr = pdata->mem_address; cxt->record_size = pdata->record_size; cxt->dump_oops = pdata->dump_oops; + cxt->ecc = pdata->ecc;
cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_count, GFP_KERNEL); if (!cxt->przs) { @@ -248,7 +255,7 @@ static int __init ramoops_probe(struct platform_device *pdev) size_t sz = cxt->record_size; phys_addr_t start = cxt->phys_addr + sz * i;
- cxt->przs[i] = persistent_ram_new(start, sz, 0); + cxt->przs[i] = persistent_ram_new(start, sz, cxt->ecc); if (IS_ERR(cxt->przs[i])) { err = PTR_ERR(cxt->przs[i]); dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", @@ -281,9 +288,10 @@ static int __init ramoops_probe(struct platform_device *pdev) record_size = pdata->record_size; dump_oops = pdata->dump_oops;
- pr_info("attached 0x%lx@0x%llx (%ux0x%zx)\n", + pr_info("attached 0x%lx@0x%llx (%ux0x%zx), ecc: %s\n", cxt->size, (unsigned long long)cxt->phys_addr, - cxt->max_count, cxt->record_size); + cxt->max_count, cxt->record_size, + ramoops_ecc ? "on" : "off");
return 0;
@@ -347,6 +355,7 @@ static int __init ramoops_init(void) dummy_data->mem_address = mem_address; dummy_data->record_size = record_size; dummy_data->dump_oops = dump_oops; + dummy_data->ecc = ramoops_ecc; dummy = platform_create_bundle(&ramoops_driver, ramoops_probe, NULL, 0, dummy_data, sizeof(struct ramoops_platform_data)); diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index ffe24a5..7ed7fd4 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -92,6 +92,7 @@ struct ramoops_platform_data { unsigned long mem_address; unsigned long record_size; int dump_oops; + bool ecc; };
#endif