On Sun, Aug 18, 2019 at 2:10 AM Christoph Hellwig <hch@xxxxxx> wrote:
>
> Factor out the guts of devm_request_free_mem_region so that we can
> implement both a device managed and a manually release version as
> tiny wrappers around it.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> ---
> include/linux/ioport.h | 2 ++
> kernel/resource.c | 45 +++++++++++++++++++++++++++++-------------
> 2 files changed, 33 insertions(+), 14 deletions(-)
>
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index 5b6a7121c9f0..7bddddfc76d6 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -297,6 +297,8 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2)
>
> struct resource *devm_request_free_mem_region(struct device *dev,
> struct resource *base, unsigned long size);
> +struct resource *request_free_mem_region(struct resource *base,
> + unsigned long size, const char *name);
>
> #endif /* __ASSEMBLY__ */
> #endif /* _LINUX_IOPORT_H */
> diff --git a/kernel/resource.c b/kernel/resource.c
> index 7ea4306503c5..74877e9d90ca 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -1644,19 +1644,8 @@ void resource_list_free(struct list_head *head)
> EXPORT_SYMBOL(resource_list_free);
>
> #ifdef CONFIG_DEVICE_PRIVATE
> -/**
> - * devm_request_free_mem_region - find free region for device private memory
> - *
> - * @dev: device struct to bind the resource to
> - * @size: size in bytes of the device memory to add
> - * @base: resource tree to look in
> - *
> - * This function tries to find an empty range of physical address big enough to
> - * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
> - * memory, which in turn allocates struct pages.
> - */
> -struct resource *devm_request_free_mem_region(struct device *dev,
> - struct resource *base, unsigned long size)
> +static struct resource *__request_free_mem_region(struct device *dev,
> + struct resource *base, unsigned long size, const char *name)
> {
> resource_size_t end, addr;
> struct resource *res;
> @@ -1670,7 +1659,10 @@ struct resource *devm_request_free_mem_region(struct device *dev,
> REGION_DISJOINT)
> continue;
>
> - res = devm_request_mem_region(dev, addr, size, dev_name(dev));
> + if (dev)
> + res = devm_request_mem_region(dev, addr, size, name);
> + else
> + res = request_mem_region(addr, size, name);
> if (!res)
> return ERR_PTR(-ENOMEM);
> res->desc = IORES_DESC_DEVICE_PRIVATE_MEMORY;
> @@ -1679,7 +1671,32 @@ struct resource *devm_request_free_mem_region(struct device *dev,
>
> return ERR_PTR(-ERANGE);
> }
> +
> +/**
> + * devm_request_free_mem_region - find free region for device private memory
> + *
> + * @dev: device struct to bind the resource to
> + * @size: size in bytes of the device memory to add
> + * @base: resource tree to look in
> + *
> + * This function tries to find an empty range of physical address big enough to
> + * contain the new resource, so that it can later be hotplugged as ZONE_DEVICE
> + * memory, which in turn allocates struct pages.
> + */
> +struct resource *devm_request_free_mem_region(struct device *dev,
> + struct resource *base, unsigned long size)
> +{
Previously we would loudly crash if someone passed NULL to
devm_request_free_mem_region(), but now it will silently work and the
result will leak. Perhaps this wants a:
if (!dev)
return NULL;
...to head off those mistakes?
No major heartburn if you keep it as is, you can add:
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
