pstore/ram: add Device Tree bindings
ramoops is one of the remaining places where ARM vendors still rely on
board-specific shims. Device Tree lets us replace those shims with
generic code.
These bindings mirror the ramoops module parameters, with two small
differences:
(1) dump_oops becomes an optional "no-dump-oops" property, since ramoops
sets dump_oops=1 by default.
(2) mem_type=1 becomes the more self-explanatory "unbuffered" property.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
[fixed platform_get_drvdata() crash, thanks to Brian Norris]
[switched from u64 to u32 to simplify code, various whitespace fixes]
[use dev_of_node() to gain code-elimination for CONFIG_OF=n]
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index d9668c2..47516a7 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -34,6 +34,8 @@
#include <linux/slab.h>
#include <linux/compiler.h>
#include <linux/pstore_ram.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
#define RAMOOPS_KERNMSG_HDR "===="
#define MIN_MEM_SIZE 4096UL
@@ -458,15 +460,98 @@
return 0;
}
+static int ramoops_parse_dt_size(struct platform_device *pdev,
+ const char *propname, u32 *value)
+{
+ u32 val32 = 0;
+ int ret;
+
+ ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(&pdev->dev, "failed to parse property %s: %d\n",
+ propname, ret);
+ return ret;
+ }
+
+ if (val32 > INT_MAX) {
+ dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
+ return -EOVERFLOW;
+ }
+
+ *value = val32;
+ return 0;
+}
+
+static int ramoops_parse_dt(struct platform_device *pdev,
+ struct ramoops_platform_data *pdata)
+{
+ struct device_node *of_node = pdev->dev.of_node;
+ struct device_node *mem_region;
+ struct resource res;
+ u32 value;
+ int ret;
+
+ dev_dbg(&pdev->dev, "using Device Tree\n");
+
+ mem_region = of_parse_phandle(of_node, "memory-region", 0);
+ if (!mem_region) {
+ dev_err(&pdev->dev, "no memory-region phandle\n");
+ return -ENODEV;
+ }
+
+ ret = of_address_to_resource(mem_region, 0, &res);
+ of_node_put(mem_region);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "failed to translate memory-region to resource: %d\n",
+ ret);
+ return ret;
+ }
+
+ pdata->mem_size = resource_size(&res);
+ pdata->mem_address = res.start;
+ pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
+ pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
+
+#define parse_size(name, field) { \
+ ret = ramoops_parse_dt_size(pdev, name, &value); \
+ if (ret < 0) \
+ return ret; \
+ field = value; \
+ }
+
+ parse_size("record-size", pdata->record_size);
+ parse_size("console-size", pdata->console_size);
+ parse_size("ftrace-size", pdata->ftrace_size);
+ parse_size("pmsg-size", pdata->pmsg_size);
+ parse_size("ecc-size", pdata->ecc_info.ecc_size);
+
+#undef parse_size
+
+ return 0;
+}
+
static int ramoops_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- struct ramoops_platform_data *pdata = pdev->dev.platform_data;
+ struct ramoops_platform_data *pdata = dev->platform_data;
struct ramoops_context *cxt = &oops_cxt;
size_t dump_mem_sz;
phys_addr_t paddr;
int err = -EINVAL;
+ if (dev_of_node(dev) && !pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ err = -ENOMEM;
+ goto fail_out;
+ }
+
+ err = ramoops_parse_dt(pdev, pdata);
+ if (err < 0)
+ goto fail_out;
+ }
+
/* Only a single ramoops area allowed at a time, so fail extra
* probes.
*/
@@ -596,11 +681,17 @@
return 0;
}
+static const struct of_device_id dt_match[] = {
+ { .compatible = "ramoops" },
+ {}
+};
+
static struct platform_driver ramoops_driver = {
.probe = ramoops_probe,
.remove = ramoops_remove,
.driver = {
- .name = "ramoops",
+ .name = "ramoops",
+ .of_match_table = dt_match,
},
};