Hi Christophe ，

On 2018/1/4 16:05, Christophe LEROY wrote:

Le 25/12/2017 à 02:34, Yisheng Xie a écrit :

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On 2017/12/24 17:05, christophe leroy wrote:

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Le 23/12/2017 à 14:48, Greg KH a écrit :

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On Sat, Dec 23, 2017 at 06:55:25PM +0800, Yisheng Xie wrote:

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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.

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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

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