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;
}
[...]
}
Thanks
Yisheng
>
> Christophe
>
>>
>> thanks,
>>
>> greg k-h
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