Jul 05 2009

i2c: Use resource_size 

Author: Julia Lawall <julia@diku.dk>

Use the function resource_size, which reduces the chance of introducing
off-by-one errors in calculating the resource size.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@@
struct resource *res;
@@

- (res->end - res->start) + 1
+ resource_size(res)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Ben Dooks 

---
 drivers/i2c/busses/i2c-davinci.c   | 6 +++---
 drivers/i2c/busses/i2c-omap.c      | 6 +++---
 drivers/i2c/busses/i2c-sh_mobile.c | 2 +-
 drivers/i2c/busses/i2c-simtec.c    | 2 +-
 4 files changed, 8 insertions(+), 8 deletions(-)
 
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 1f3d89c..c89687a 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -515,7 +515,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
+	ioarea = request_mem_region(mem->start, resource_size(mem),
 				    pdev->name);
 	if (!ioarea) {
 		dev_err(&pdev->dev, "I2C region already claimed\n");
@@ -578,7 +578,7 @@ err_free_mem:
 	put_device(&pdev->dev);
 	kfree(dev);
 err_release_region:
-	release_mem_region(mem->start, (mem->end - mem->start) + 1);
+	release_mem_region(mem->start, resource_size(mem));
 
 	return r;
 }
@@ -601,7 +601,7 @@ static int davinci_i2c_remove(struct platform_device *pdev)
 	kfree(dev);
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(mem->start, (mem->end - mem->start) + 1);
+	release_mem_region(mem->start, resource_size(mem));
 	return 0;
 }
 
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index ad8d201..fdd8327 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -806,7 +806,7 @@ omap_i2c_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
+	ioarea = request_mem_region(mem->start, resource_size(mem),
 			pdev->name);
 	if (!ioarea) {
 		dev_err(&pdev->dev, "I2C region already claimed\n");
@@ -905,7 +905,7 @@ err_free_mem:
 	platform_set_drvdata(pdev, NULL);
 	kfree(dev);
 err_release_region:
-	release_mem_region(mem->start, (mem->end - mem->start) + 1);
+	release_mem_region(mem->start, resource_size(mem));
 
 	return r;
 }
@@ -925,7 +925,7 @@ omap_i2c_remove(struct platform_device *pdev)
 	iounmap(dev->base);
 	kfree(dev);
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(mem->start, (mem->end - mem->start) + 1);
+	release_mem_region(mem->start, resource_size(mem));
 	return 0;
 }
 
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 1c01083..4f3d99c 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -563,7 +563,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 		goto err_irq;
 	}
 
-	size = (res->end - res->start) + 1;
+	size = resource_size(res);
 
 	pd->reg = ioremap(res->start, size);
 	if (pd->reg == NULL) {
diff --git a/drivers/i2c/busses/i2c-simtec.c b/drivers/i2c/busses/i2c-simtec.c
index 042fda2..6407f47 100644
--- a/drivers/i2c/busses/i2c-simtec.c
+++ b/drivers/i2c/busses/i2c-simtec.c
@@ -92,7 +92,7 @@ static int simtec_i2c_probe(struct platform_device *dev)
 		goto err;
 	}
 
-	size = (res->end-res->start)+1;
+	size = resource_size(res);
 
 	pd->ioarea = request_mem_region(res->start, size, dev->name);
 	if (pd->ioarea == NULL) {

qlambert