On Fri, Mar 1, 2024 at 11:28 PM Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Feb 22, 2024 at 03:06:17PM +1300, Barry Song wrote: > > > > - scatterwalk_map_and_copy(scratch->src, req->src, 0, req->slen, 0); > > + if (sg_nents(req->src) == 1 && !PageHighMem(sg_page(req->src))) { > > + src = page_to_virt(sg_page(req->src)) + req->src->offset; > > Incidentally this made me look at other uses of PageHighMem in > the kernel. > > The one in copy_page_from_iter_atomic looks buggy because it assumes > that the kmap never maps a page if PageHighMem is false, which is not > the case for CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP. You are right. This needs to be fixed. > > > @@ -152,8 +165,12 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir) > > ret = -ENOSPC; > > goto out; > > } > > - scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen, > > - 1); > > + if (dst == scratch->dst) { > > + scatterwalk_map_and_copy(scratch->dst, req->dst, 0, > > + req->dlen, 1); > > + } else { > > + flush_dcache_page(sg_page(req->dst)); > > I think this is still wrong for the > PAGE_SIZE case. The existing > code flushes each page sequentially but the new code only flushes the > first page. right, can it be fixed like the below? diff --git a/crypto/scompress.c b/crypto/scompress.c index 185d2359f28b..d85f0318f273 100644 --- a/crypto/scompress.c +++ b/crypto/scompress.c @@ -169,7 +169,11 @@ static int scomp_acomp_comp_decomp(struct acomp_req *req, int dir) scatterwalk_map_and_copy(scratch->dst, req->dst, 0, req->dlen, 1); } else { - flush_dcache_page(sg_page(req->dst)); + int nr_pages = DIV_ROUND_UP(req->dst->offset + req->dlen, PAGE_SIZE); + int i; + + for (i = 0; i < nr_pages; i++) + flush_dcache_page(sg_page(req->dst) + i); } } out: > > Thanks, > -- > Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt > Thanks Barry