Hi Greg,
On Thu, Jan 07, 2016 at 03:40:56PM -0800, Greg Hackmann wrote:
> 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 <ghackm...@google.com>
> Acked-by: Kees Cook <keesc...@chromium.org>
>
> ---
> Changes in V3:
> - documentation fixes
> - look for "no-ram-oops" property as documented
>
> Changes in V2:
> - make DT binding documentation more generic
>
> Documentation/devicetree/bindings/misc/ramoops.txt | 43 ++++++++
> Documentation/ramoops.txt | 6 +-
> fs/pstore/ram.c | 110
> ++++++++++++++++++++-
> 3 files changed, 155 insertions(+), 4 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/misc/ramoops.txt
>
[...]
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index 319c3a6..0f2912c 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 +460,112 @@ 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, 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, "no-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);
^^^ This is wrong. You don't set drvdata until later. This crashes
(e.g.) the Pixel 2, which uses platform data, not DT.
> 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.
> */
> @@ -561,6 +660,7 @@ 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);
You don't ever (properly) use drvdata, so this line is superfluous.
> return 0;
>
> fail_buf:
[...]
Brian
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