[RFC PATCH 03/11] misc: SRAM: Add option to map SRAM to allow code execution

From: Russ Dill
Date: Tue Sep 17 2013 - 08:47:00 EST


This is necessary for platforms that use SRAM to execute suspend/resume stubs.

Signed-off-by: Russ Dill <Russ.Dill@xxxxxx>
---
Documentation/devicetree/bindings/misc/sram.txt | 4 ++++
drivers/misc/sram.c | 13 ++++++++++++-
include/linux/platform_data/sram.h | 8 ++++++++
3 files changed, 24 insertions(+), 1 deletion(-)
create mode 100644 include/linux/platform_data/sram.h

diff --git a/Documentation/devicetree/bindings/misc/sram.txt b/Documentation/devicetree/bindings/misc/sram.txt
index 4d0a00e..4fa9af3 100644
--- a/Documentation/devicetree/bindings/misc/sram.txt
+++ b/Documentation/devicetree/bindings/misc/sram.txt
@@ -8,6 +8,10 @@ Required properties:

- reg : SRAM iomem address range

+Optional properties:
+
+- map-exec: Map range to allow code execution
+
Example:

sram: sram@5c000000 {
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index d87cc91..baa5008 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -28,6 +28,7 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/genalloc.h>
+#include <linux/platform_data/sram.h>

#define SRAM_GRANULARITY 32

@@ -38,14 +39,24 @@ struct sram_dev {

static int sram_probe(struct platform_device *pdev)
{
+ struct sram_platform_data *pdata = pdev->dev.platform_data;
void __iomem *virt_base;
struct sram_dev *sram;
struct resource *res;
unsigned long size;
+ bool map_exec = false;
int ret;

+ if (of_get_property(pdev->dev.of_node, "map-exec", NULL))
+ map_exec = true;
+ if (pdata && pdata->map_exec)
+ map_exec |= true;
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- virt_base = devm_ioremap_resource(&pdev->dev, res);
+ if (map_exec)
+ virt_base = devm_ioremap_exec_resource(&pdev->dev, res);
+ else
+ virt_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(virt_base))
return PTR_ERR(virt_base);

diff --git a/include/linux/platform_data/sram.h b/include/linux/platform_data/sram.h
new file mode 100644
index 0000000..8f5c4ba
--- /dev/null
+++ b/include/linux/platform_data/sram.h
@@ -0,0 +1,8 @@
+#ifndef _LINUX_SRAM_H
+#define _LINUX_SRAM_H
+
+struct sram_platform_data {
+ bool map_exec;
+};
+
+#endif
--
1.8.3.2

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