Instead of a ramoops-specific node, use a child node of /reserved-memory.
This requires that of_platform_device_create() be explicitly called
for the node, though, since "/reserved-memory" does not have its own
"compatible" property.
Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
+++ /dev/null
-Ramoops oops/panic logger
-=========================
-
-ramoops provides persistent RAM storage for oops and panics, so they can be
-recovered after a reboot. It is a backend to pstore, so this node is named
-"ramoops" after the backend, rather than "pstore" which is the subsystem.
-
-Parts of this storage may be set aside for other persistent log buffers, such
-as kernel log messages, or for optional ECC error-correction data. The total
-size of these optional buffers must fit in the reserved region.
-
-Any remaining space will be used for a circular buffer of oops and panic
-records. These records have a configurable size, with a size of 0 indicating
-that they should be disabled.
-
-At least one of "record-size", "console-size", "ftrace-size", or "pmsg-size"
-must be set non-zero, but are otherwise optional as listed below.
-
-
-Required properties:
-
-- compatible: must be "ramoops"
-
-- memory-region: phandle to a region of memory that is preserved between
- reboots
-
-
-Optional properties:
-
-- ecc-size: enables ECC support and specifies ECC buffer size in bytes
- (defaults to 0: no ECC)
-
-- record-size: maximum size in bytes of each dump done on oops/panic
- (defaults to 0: disabled)
-
-- console-size: size in bytes of log buffer reserved for kernel messages
- (defaults to 0: disabled)
-
-- ftrace-size: size in bytes of log buffer reserved for function tracing and
- profiling (defaults to 0: disabled)
-
-- pmsg-size: size in bytes of log buffer reserved for userspace messages
- (defaults to 0: disabled)
-
-- unbuffered: if present, use unbuffered mappings to map the reserved region
- (defaults to buffered mappings)
-
-- no-dump-oops: if present, only dump panics (defaults to panics and oops)
--- /dev/null
+Ramoops oops/panic logger
+=========================
+
+ramoops provides persistent RAM storage for oops and panics, so they can be
+recovered after a reboot. This is a child-node of "/reserved-memory", and
+is named "ramoops" after the backend, rather than "pstore" which is the
+subsystem.
+
+Parts of this storage may be set aside for other persistent log buffers, such
+as kernel log messages, or for optional ECC error-correction data. The total
+size of these optional buffers must fit in the reserved region.
+
+Any remaining space will be used for a circular buffer of oops and panic
+records. These records have a configurable size, with a size of 0 indicating
+that they should be disabled.
+
+At least one of "record-size", "console-size", "ftrace-size", or "pmsg-size"
+must be set non-zero, but are otherwise optional as listed below.
+
+
+Required properties:
+
+- compatible: must be "ramoops"
+
+- reg: region of memory that is preserved between reboots
+
+
+Optional properties:
+
+- ecc-size: enables ECC support and specifies ECC buffer size in bytes
+ (defaults to 0: no ECC)
+
+- record-size: maximum size in bytes of each dump done on oops/panic
+ (defaults to 0: disabled)
+
+- console-size: size in bytes of log buffer reserved for kernel messages
+ (defaults to 0: disabled)
+
+- ftrace-size: size in bytes of log buffer reserved for function tracing and
+ profiling (defaults to 0: disabled)
+
+- pmsg-size: size in bytes of log buffer reserved for userspace messages
+ (defaults to 0: disabled)
+
+- unbuffered: if present, use unbuffered mappings to map the reserved region
+ (defaults to buffered mappings)
+
+- no-dump-oops: if present, only dump panics (defaults to panics and oops)
2. Setting the parameters
-Setting the ramoops parameters can be done in 3 different manners:
- 1. Use the module parameters (which have the names of the variables described
- as before).
- For quick debugging, you can also reserve parts of memory during boot
- and then use the reserved memory for ramoops. For example, assuming a machine
- with > 128 MB of memory, the following kernel command line will tell the
- kernel to use only the first 128 MB of memory, and place ECC-protected ramoops
- region at 128 MB boundary:
+Setting the ramoops parameters can be done in several different manners:
+
+ A. Use the module parameters (which have the names of the variables described
+ as before). For quick debugging, you can also reserve parts of memory during
+ boot and then use the reserved memory for ramoops. For example, assuming a
+ machine with > 128 MB of memory, the following kernel command line will tell
+ the kernel to use only the first 128 MB of memory, and place ECC-protected
+ ramoops region at 128 MB boundary:
"mem=128M ramoops.mem_address=0x8000000 ramoops.ecc=1"
- 2. Use Device Tree bindings, as described in
- Documentation/device-tree/bindings/misc/ramoops.txt.
- 3. Use a platform device and set the platform data. The parameters can then
+
+ B. Use Device Tree bindings, as described in
+ Documentation/device-tree/bindings/reserved-memory/ramoops.txt.
+ For example:
+
+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ ranges;
+
+ ramoops@8f000000 {
+ compatible = "ramoops";
+ reg = <0 0x8f000000 0 0x100000>;
+ record-size = <0x4000>;
+ console-size = <0x4000>;
+ };
+ };
+
+ C. Use a platform device and set the platform data. The parameters can then
be set through that platform data. An example of doing that is:
#include <linux/pstore_ram.h>
static int __init of_platform_default_populate_init(void)
{
- if (of_have_populated_dt())
- of_platform_default_populate(NULL, NULL, NULL);
+ struct device_node *node;
+
+ if (!of_have_populated_dt())
+ return -ENODEV;
+
+ /*
+ * Handle ramoops explicitly, since it is inside /reserved-memory,
+ * which lacks a "compatible" property.
+ */
+ node = of_find_node_by_path("/reserved-memory");
+ if (node) {
+ node = of_find_compatible_node(node, NULL, "ramoops");
+ if (node)
+ of_platform_device_create(node, NULL, NULL);
+ }
+
+ /* Populate everything else. */
+ of_platform_default_populate(NULL, NULL, NULL);
return 0;
}
struct ramoops_platform_data *pdata)
{
struct device_node *of_node = pdev->dev.of_node;
- struct device_node *mem_region;
- struct resource res;
+ 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) {
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
dev_err(&pdev->dev,
- "failed to translate memory-region to resource: %d\n",
- ret);
- return ret;
+ "failed to locate DT /reserved-memory resource\n");
+ return -EINVAL;
}
- pdata->mem_size = resource_size(&res);
- pdata->mem_address = res.start;
+ 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");
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