pstore/ram: Add ECC support

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Anton Vorontsov 2012-05-17 00:15:34 -07:00 committed by Greg Kroah-Hartman
parent 896fc1f0c4
commit 39eb7e9791
3 changed files with 19 additions and 3 deletions

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@ -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 = {

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@ -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));

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@ -92,6 +92,7 @@ struct ramoops_platform_data {
unsigned long mem_address;
unsigned long record_size;
int dump_oops;
bool ecc;
};
#endif