2012-06-05 20:23:23

by Bryan Freed

[permalink] [raw]
Subject: [PATCH v2] pstore/ram: Add ramoops support for the Flattened Device Tree.

When called with a non-zero of_node, fill out a new ramoops_platform_data
with data from the specified Flattened Device Tree node.
Update ramoops documentation with the new FDT interface.

Signed-off-by: Bryan Freed <[email protected]>
---
Documentation/ramoops.txt | 19 +++++++++++++++-
fs/pstore/ram.c | 50 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt
index 4ba7db2..9ed3ab7 100644
--- a/Documentation/ramoops.txt
+++ b/Documentation/ramoops.txt
@@ -3,7 +3,7 @@ Ramoops oops/panic logger

Sergiu Iordache <[email protected]>

-Updated: 17 November 2011
+Updated: 5 June 2012

0. Introduction

@@ -37,7 +37,7 @@ 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).
2. Use a platform device and set the platform data. The parameters can then
@@ -70,6 +70,21 @@ if (ret) {
return ret;
}

+ 3. Use the Flattened Device Tree to set the platform data. For example:
+ arch/arm/boot/dts/$BOARD.dts:
+ ramoops {
+ compatible = "ramoops";
+ reg = <0x41f00000 0x00100000>;
+ record-size = <0x00020000>;
+ dump-oops = <1>;
+ ecc = <0>;
+ };
+ The "reg = <0x41f00000 0x00100000>" line specifies a mem_size of 1MB at
+ mem_address 0x41f00000.
+ The "record-size = <0x00020000>" line specifies a record size of 128KB.
+ The "dump-oops = <1>" line tells us to dump oopses as well as panics.
+ The "ecc = <0>" line tells us to turn off ECC protection.
+
3. Dump format

The data dump begins with a header, currently defined as "====" followed by a
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 9123cce..1b44be3 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -32,6 +32,7 @@
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pstore_ram.h>
+#include <linux/of_address.h>

#define RAMOOPS_KERNMSG_HDR "===="
#define MIN_MEM_SIZE 4096UL
@@ -199,10 +200,44 @@ static struct ramoops_context oops_cxt = {
},
};

+static int __init of_ramoops_platform_data(struct device_node *node,
+ struct ramoops_platform_data *pdata)
+{
+ const __be32 *addrp;
+ const __be32 *prop;
+ u64 size;
+
+ addrp = of_get_address(node, 0, &size, NULL);
+ if (addrp == NULL)
+ return -EINVAL;
+ pdata->mem_address = of_translate_address(node, addrp);
+ pdata->mem_size = size;
+
+ prop = of_get_property(node, "record-size", NULL);
+ if (!prop)
+ return -EINVAL;
+ pdata->record_size = be32_to_cpup(prop);
+
+ prop = of_get_property(node, "dump-oops", NULL);
+ if (!prop)
+ pdata->dump_oops = 0;
+ else
+ pdata->dump_oops = be32_to_cpup(prop);
+
+ prop = of_get_property(node, "ecc", NULL);
+ if (!prop)
+ pdata->ecc = 0;
+ else
+ pdata->ecc = be32_to_cpup(prop);
+
+ return 0;
+}
+
static int __init ramoops_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ramoops_platform_data *pdata = pdev->dev.platform_data;
+ struct ramoops_platform_data of_pdata;
struct ramoops_context *cxt = &oops_cxt;
int err = -EINVAL;
int i;
@@ -213,6 +248,14 @@ static int __init ramoops_probe(struct platform_device *pdev)
if (cxt->max_count)
goto fail_out;

+ if (pdev->dev.of_node) {
+ if (of_ramoops_platform_data(pdev->dev.of_node, &of_pdata)) {
+ pr_err("Invalid ramoops device tree data\n");
+ goto fail_out;
+ }
+ pdata = &of_pdata;
+ }
+
if (!pdata->mem_size || !pdata->record_size) {
pr_err("The memory size and the record size must be "
"non-zero\n");
@@ -329,11 +372,18 @@ static int __exit ramoops_remove(struct platform_device *pdev)
return -EBUSY;
}

+static const struct of_device_id ramoops_of_match[] = {
+ { .compatible = "ramoops", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ramoops_of_match);
+
static struct platform_driver ramoops_driver = {
.remove = __exit_p(ramoops_remove),
.driver = {
.name = "ramoops",
.owner = THIS_MODULE,
+ .of_match_table = ramoops_of_match,
},
};

--
1.7.7.3


2012-06-05 21:10:41

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH v2] pstore/ram: Add ramoops support for the Flattened Device Tree.

On Tue, Jun 5, 2012 at 1:23 PM, Bryan Freed <[email protected]> wrote:
> When called with a non-zero of_node, fill out a new ramoops_platform_data
> with data from the specified Flattened Device Tree node.
> Update ramoops documentation with the new FDT interface.
>
> Signed-off-by: Bryan Freed <[email protected]>

Acked-by: Kees Cook <[email protected]>

Looks good, thanks!

-Kees

--
Kees Cook
Chrome OS Security