From: Greg Hackmann <ghackmann@xxxxxxxxxx> 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@xxxxxxxxxx> [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@xxxxxxxxxxxx> --- Documentation/devicetree/bindings/misc/ramoops.txt | 48 +++++++++++ Documentation/ramoops.txt | 6 +- fs/pstore/ram.c | 95 +++++++++++++++++++++- 3 files changed, 145 insertions(+), 4 deletions(-) create mode 100644 Documentation/devicetree/bindings/misc/ramoops.txt diff --git a/Documentation/devicetree/bindings/misc/ramoops.txt b/Documentation/devicetree/bindings/misc/ramoops.txt new file mode 100644 index 000000000000..cd02cec67d38 --- /dev/null +++ b/Documentation/devicetree/bindings/misc/ramoops.txt @@ -0,0 +1,48 @@ +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) diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt index 5d8675615e59..9264bcab4099 100644 --- a/Documentation/ramoops.txt +++ b/Documentation/ramoops.txt @@ -45,7 +45,7 @@ corrupt, but usually it is restorable. 2. Setting the parameters -Setting the ramoops parameters can be done in 2 different manners: +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 @@ -54,7 +54,9 @@ Setting the ramoops parameters can be done in 2 different manners: 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 a platform device and set the platform data. The parameters can then + 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 be set through that platform data. An example of doing that is: #include <linux/pstore_ram.h> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index d9668c2b43cb..47516a794011 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 @@ static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, 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 @@ static int ramoops_remove(struct platform_device *pdev) 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, }, }; -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html