On Fri, Jul 05, 2024 at 10:50:31AM +0200, Geert Uytterhoeven wrote:
+ 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].
Not sure what the advantage of that is, though?
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.
It fundamentally is a wrapper around page_to_pfn that converts from the PFN to the full physical address. There a bunch of weird incosnsitencies and it should really move to common code, but I don't want this series to depend on that. The only interesting part is that for architectures with physical addresses larger than unsigned long we need to cast to a 64-bit type, although all the architectures that actually do that in the page_to_phys helper itself do that incorrectly by casting to a dma_addr_t instdead of a phys_addr_t. Fortunately we've stopped supporting a dma_addr_t smaller than phys_addr_t a long time ago, and even back then that only affected sparc (IIRC).
