Hi Christophe ，
On 2018/1/4 16:05, Christophe LEROY wrote:
Le 25/12/2017 à 02:34, Yisheng Xie a écrit :
On 2017/12/24 17:05, christophe leroy wrote:
Le 23/12/2017 à 14:48, Greg KH a écrit :
On Sat, Dec 23, 2017 at 06:55:25PM +0800, Yisheng Xie wrote:
Hi all,
When I tried to use devm_ioremap function and review related code, I found devm_ioremap and devm_ioremap_nocache is almost the same with each other, except one use ioremap while the other use ioremap_nocache.
For all arches? Really? Look at MIPS, and x86, they have different functions.
While ioremap's default function is ioremap_nocache, so devm_ioremap_nocache also have the same function with devm_ioremap, which can just be killed to reduce the size of devres.o(from 20304 bytes to 18992 bytes in my compile environment).
I have posted two versions, which use macro instead of function for devm_ioremap_nocache[1] or devm_ioremap[2]. And Greg suggest me to kill devm_ioremap_nocache for no need to keep a macro around for the duplicate thing. So here comes v3 and please help to review.
I don't think this can be done, what am I missing? These functions are not identical, sorry for missing that before.
devm_ioremap() and devm_ioremap_nocache() are quite similar, both use devm_ioremap_release() for the release, why not just defining:
static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset, resource_size_t size, bool nocache) { [...] if (nocache) addr = ioremap_nocache(offset, size); else addr = ioremap(offset, size); [...] }
then in include/linux/io.h
static inline void __iomem *devm_ioremap(struct device *dev, resource_size_t offset, resource_size_t size) {return __devm_ioremap(dev, offset, size, false);}
static inline void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, resource_size_t size); {return __devm_ioremap(dev, offset, size, true);}
Yeah, this seems good to me, right now we have devm_ioremap, devm_ioremap_wc, devm_ioremap_nocache May be we can use an enum like: typedef enum { DEVM_IOREMAP = 0, DEVM_IOREMAP_NOCACHE, DEVM_IOREMAP_WC, } devm_ioremap_type;
static inline void __iomem *devm_ioremap(struct device *dev, resource_size_t offset, resource_size_t size) {return __devm_ioremap(dev, offset, size, DEVM_IOREMAP);}
static inline void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, resource_size_t size); {return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_NOCACHE);}
static inline void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, resource_size_t size); {return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_WC);}
static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset, resource_size_t size, devm_ioremap_type type) { void __iomem **ptr, *addr = NULL; [...] switch (type){ case DEVM_IOREMAP: addr = ioremap(offset, size); break; case DEVM_IOREMAP_NOCACHE: addr = ioremap_nocache(offset, size); break; case DEVM_IOREMAP_WC: addr = ioremap_wc(offset, size); break; } [...] }
That looks good to me, will you submit a v4 ?
Sorry for late response. And I will submit the v4 as your suggestion.
Thanks Yisheng
Christophe