[PATCH v6] devres: combine function devm_ioremap*

From: Yisheng Xie
Date: Mon Jan 29 2018 - 06:57:22 EST


When I tried to use devm_ioremap function and review related
code, I found devm_ioremap_* almost have the similar realize
with each other, which can be combined.

In the former version, I have tried to kill ioremap_cache to
reduce the size of devres, which can not work for ioremap is
not the same as ioremap_nocache in some ARCHs likes ia64.
Therefore, as the suggestion of Christophe, I introduce a help
function __devm_ioremap, let devm_ioremap* inline and call
__devm_ioremap with different devm_ioremap_type.

After apply the patch, the size of devres.o can be reduce from
8216 Bytes to 8052 Bytes in my compile environment.

Suggested-by: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Suggested-by: Christophe LEROY <christophe.leroy@xxxxxx>
Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
v2:
- use MARCO for ioremap
v3:
- kill dev_ioremap_nocache
v4:
- combine function devm_ioremap* - per Christophe
v5:
- fix code style. - per Christophe
v6:
- just put the cleanup in the devres.c - per Greg

lib/devres.c | 78 +++++++++++++++++++++++++++++-------------------------------
1 file changed, 38 insertions(+), 40 deletions(-)

diff --git a/lib/devres.c b/lib/devres.c
index 5f2aedd..5bec112 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -5,6 +5,12 @@
#include <linux/gfp.h>
#include <linux/export.h>

+enum devm_ioremap_type {
+ DEVM_IOREMAP = 0,
+ DEVM_IOREMAP_NC,
+ DEVM_IOREMAP_WC,
+};
+
void devm_ioremap_release(struct device *dev, void *res)
{
iounmap(*(void __iomem **)res);
@@ -15,24 +21,28 @@ static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
return *(void **)res == match_data;
}

-/**
- * devm_ioremap - Managed ioremap()
- * @dev: Generic device to remap IO address for
- * @offset: Resource address to map
- * @size: Size of map
- *
- * Managed ioremap(). Map is automatically unmapped on driver detach.
- */
-void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
- resource_size_t size)
+static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset,
+ resource_size_t size,
+ enum devm_ioremap_type type)
{
- void __iomem **ptr, *addr;
+ void __iomem **ptr, *addr = NULL;

ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;

- addr = ioremap(offset, size);
+ switch (type) {
+ case DEVM_IOREMAP:
+ addr = ioremap(offset, size);
+ break;
+ case DEVM_IOREMAP_NC:
+ addr = ioremap_nocache(offset, size);
+ break;
+ case DEVM_IOREMAP_WC:
+ addr = ioremap_wc(offset, size);
+ break;
+ }
+
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
@@ -41,6 +51,20 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,

return addr;
}
+
+/**
+ * devm_ioremap - Managed ioremap()
+ * @dev: Generic device to remap IO address for
+ * @offset: Resource address to map
+ * @size: Size of map
+ *
+ * Managed ioremap(). Map is automatically unmapped on driver detach.
+ */
+void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
+ resource_size_t size)
+{
+ return __devm_ioremap(dev, offset, size, DEVM_IOREMAP);
+}
EXPORT_SYMBOL(devm_ioremap);

/**
@@ -55,20 +79,7 @@ void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
resource_size_t size)
{
- void __iomem **ptr, *addr;
-
- ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
- return NULL;
-
- addr = ioremap_nocache(offset, size);
- if (addr) {
- *ptr = addr;
- devres_add(dev, ptr);
- } else
- devres_free(ptr);
-
- return addr;
+ return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_NC);
}
EXPORT_SYMBOL(devm_ioremap_nocache);

@@ -83,20 +94,7 @@ void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
resource_size_t size)
{
- void __iomem **ptr, *addr;
-
- ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
- if (!ptr)
- return NULL;
-
- addr = ioremap_wc(offset, size);
- if (addr) {
- *ptr = addr;
- devres_add(dev, ptr);
- } else
- devres_free(ptr);
-
- return addr;
+ return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_WC);
}
EXPORT_SYMBOL(devm_ioremap_wc);

--
1.8.3.1