From: Greg Hackmann ghackmann@google.com

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.

Cc: Rob Herring rob.herring@linaro.org Cc: Arnd Bergmann arnd.bergmann@linaro.org Cc: Haojian Zhuang haojian.zhuang@linaro.org Cc: Guodong Xu guodong.xu@linaro.org Cc: Vishal Bhoj vishal.bhoj@linaro.org Signed-off-by: Greg Hackmann ghackmann@google.com [jstultz: Backported to 4.1] Signed-off-by: John Stultz john.stultz@linaro.org --- Documentation/ramoops.txt | 6 ++- fs/pstore/ram.c | 114 ++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 114 insertions(+), 6 deletions(-)

diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt index 5d86756..9264bca 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 257dec9..6a89024 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 @@ -450,15 +452,112 @@ void notrace ramoops_console_write_buf(const char *buf, size_t size) persistent_ram_write(cxt->cprz, buf, size); }

+static int ramoops_parse_dt_size(struct platform_device *pdev, + const char *propname, unsigned long *val) +{ + u64 val64; + int ret; + + ret = of_property_read_u64(pdev->dev.of_node, propname, &val64); + if (ret == -EINVAL) { + *val = 0; + return 0; + } else if (ret != 0) { + dev_err(&pdev->dev, "failed to parse property %s: %d\n", + propname, ret); + return ret; + } + + if (val64 > ULONG_MAX) { + dev_err(&pdev->dev, "invalid %s %llu\n", propname, val64); + return -EOVERFLOW; + } + + *val = val64; + 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 ecc_size; + 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, "dump-oops"); + + ret = ramoops_parse_dt_size(pdev, "record-size", &pdata->record_size); + if (ret < 0) + return ret; + + ret = ramoops_parse_dt_size(pdev, "console-size", &pdata->console_size); + if (ret < 0) + return ret; + + ret = ramoops_parse_dt_size(pdev, "ftrace-size", &pdata->ftrace_size); + if (ret < 0) + return ret; + + ret = ramoops_parse_dt_size(pdev, "pmsg-size", &pdata->pmsg_size); + if (ret < 0) + return ret; + + ret = of_property_read_u32(of_node, "ecc-size", &ecc_size); + if (ret == 0) { + if (ecc_size > INT_MAX) { + dev_err(&pdev->dev, "invalid ecc-size %u\n", ecc_size); + return -EOVERFLOW; + } + pdata->ecc_info.ecc_size = ecc_size; + } else if (ret != -EINVAL) { + return ret; + } + + 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 = platform_get_drvdata(pdev); struct ramoops_context *cxt = &oops_cxt; size_t dump_mem_sz; phys_addr_t paddr; int err = -EINVAL;

+ if (dev->of_node && !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. */ @@ -553,6 +652,7 @@ static int ramoops_probe(struct platform_device *pdev) cxt->size, (unsigned long long)cxt->phys_addr, cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);

+ platform_set_drvdata(pdev, pdata); return 0;

fail_buf: @@ -591,11 +691,17 @@ static int __exit ramoops_remove(struct platform_device *pdev) return -EBUSY; }

+static const struct of_device_id dt_match[] = { + { .compatible = "ramoops" }, + {} +}; + static struct platform_driver ramoops_driver = { - .probe = ramoops_probe, + .probe = ramoops_probe, .remove = __exit_p(ramoops_remove), - .driver = { - .name = "ramoops", + .driver = { + .name = "ramoops", + .of_match_table = dt_match, }, };