Re: [PATCH 1/4] mm/highmem: Lift memcpy_[to|from]_page to core

From: Chaitanya Kulkarni
Date: Sat Feb 06 2021 - 20:48:03 EST


On 2/5/21 18:35, ira.weiny@xxxxxxxxx wrote:
> +static inline void memmove_page(struct page *dst_page, size_t dst_off,
> + struct page *src_page, size_t src_off,
> + size_t len)
> +{
> + char *dst = kmap_local_page(dst_page);
> + char *src = kmap_local_page(src_page);
> +
> + BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE);
> + memmove(dst + dst_off, src + src_off, len);
> + kunmap_local(src);
> + kunmap_local(dst);
> +}
> +
> +static inline void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
How about following ?
static inline void memcpy_from_page(char *to, struct page *page, size_t
offset,
size_t len)
> +{
> + char *from = kmap_local_page(page);
> +
> + BUG_ON(offset + len > PAGE_SIZE);
> + memcpy(to, from + offset, len);
> + kunmap_local(from);
> +}
> +
> +static inline void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len)
How about following ?
static inline void memcpy_to_page(struct page *page, size_t offset,
const char *from, size_t len)
> +{
> + char *to = kmap_local_page(page);
> +
> + BUG_ON(offset + len > PAGE_SIZE);
> + memcpy(to + offset, from, len);
> + kunmap_local(to);
> +}
> +
> +static inline void memset_page(struct page *page, size_t offset, int val, size_t len)
How about following ?
static inline void memset_page(struct page *page, size_t offset, int val,
size_t len)
> +{
> + char *addr = kmap_local_page(page);
> +
> + BUG_ON(offset + len > PAGE_SIZE);
> + memset(addr + offset, val, len);
> + kunmap_local(addr);
> +}
> +