Re: [PATCH v6] devres: combine function devm_ioremap*

From: Yisheng Xie
Date: Mon Feb 12 2018 - 06:08:00 EST


Hi Greg, Christophe,

Any comment about this version? And sorry to disturb :)

Thanks
Yisheng

On 2018/1/29 19:48, Yisheng Xie wrote:
> 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);
>
>