On Tue, 7 Jun 2016 09:47:39 -0700 Stephen Boyd <stephen.b...@linaro.org> wrote:
> We use similar structured code to read and write the kmapped
> firmware pages. The only difference is read copies from the kmap
> region and write copies to it. Consolidate this into one function
> to reduce duplication.
>
> ...
>
> --- a/drivers/base/firmware_class.c
> +++ b/drivers/base/firmware_class.c
> @@ -691,6 +691,29 @@ out:
>
> static DEVICE_ATTR(loading, 0644, firmware_loading_show,
> firmware_loading_store);
>
> +static void firmware_rw(struct firmware_buf *buf, char *buffer,
> + loff_t offset, size_t count, bool read)
> +{
> + while (count) {
> + void *page_data;
> + int page_nr = offset >> PAGE_SHIFT;
> + int page_ofs = offset & (PAGE_SIZE-1);
> + int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
> +
> + page_data = kmap(buf->pages[page_nr]);
fwiw, we could switch the code to kmap_atomic() here. It is faster.
> + if (read)
> + memcpy(buffer, page_data + page_ofs, page_cnt);
> + else
> + memcpy(page_data + page_ofs, buffer, page_cnt);
> +
> + kunmap(buf->pages[page_nr]);
> + buffer += page_cnt;
> + offset += page_cnt;
> + count -= page_cnt;
> + }
> +}
