Hi Christoph, On Fri, Jul 5, 2024 at 10:15 AM Christoph Hellwig <hch@xxxxxx> wrote:
Get callers out of poking into bvec internals a bit more. Not a huge win right now, but with the proposed new DMA mapping API we might end up with a lot more of this otherwise. Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Thanks for your patch!
arch/m68k/emu/nfblock.c | 2 +-
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
--- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -255,8 +255,7 @@ static bool bvec_split_segs(const struct queue_limits *lim, unsigned seg_size = 0; while (len && *nsegs < max_segs) { - seg_size = get_max_segment_size(lim, page_to_phys(bv->bv_page) + - bv->bv_offset + total_len); + seg_size = get_max_segment_size(lim, bvec_phys(bv) + total_len); seg_size = min(seg_size, len); (*nsegs)++; @@ -492,8 +491,7 @@ static unsigned blk_bvec_map_sg(struct request_queue *q, while (nbytes > 0) { unsigned offset = bvec->bv_offset + total; unsigned len = min(get_max_segment_size(&q->limits, - page_to_phys(bvec->bv_page) + offset), - nbytes); + bvec_phys(bvec) + total), nbytes); struct page *page = bvec->bv_page; /*
If you would have introduce bvec_phys() first, you could fold the above two hunks into [PATCH 1/2].
--- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -280,4 +280,19 @@ static inline void *bvec_virt(struct bio_vec *bvec) return page_address(bvec->bv_page) + bvec->bv_offset; } +/** + * bvec_phys - return the physical address for a bvec + * @bvec: bvec to return the physical address for + */ +static inline phys_addr_t bvec_phys(const struct bio_vec *bvec) +{ + /* + * Note this open codes page_to_phys because page_to_phys is defined in + * <asm/io.h>, which we don't want to pull in here. If it ever moves to
Which suggests this is arch-specific, and may not always be defined the same? I checked a few (but not all) that seem to differ from the above at first sight, but end up doing the same... I think it would be good to make sure they are identical, and if they are, move them to a common place first, to any subtle breakages.
+ * a sensible place we should start using it. + */ + return ((phys_addr_t)page_to_pfn(bvec->bv_page) << PAGE_SHIFT) + + bvec->bv_offset; +} + #endif /* __LINUX_BVEC_H */
Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds