From 624676e788992e4da8de1fad93bfe51563a7f9a0 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Thu, 15 Aug 2019 15:13:55 +0300 Subject: [PATCH] xdp: xdp_umem: replace kmap on vmap for umem map For 64-bit there is no reason to use vmap/vunmap, so use page_address as it was initially. For 32 bits, in some apps, like in samples xdpsock_user.c when number of pgs in use is quite big, the kmap memory can be not enough, despite on this, kmap looks like is deprecated in such cases as it can block and should be used rather for dynamic mm. Signed-off-by: Ivan Khoronzhuk Acked-by: Jonathan Lemon Signed-off-by: Daniel Borkmann --- net/xdp/xdp_umem.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index cda6feb1edb0..2d65779282a1 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #include "xdp_umem.h" #include "xsk_queue.h" @@ -178,7 +178,30 @@ static void xdp_umem_unmap_pages(struct xdp_umem *umem) unsigned int i; for (i = 0; i < umem->npgs; i++) - kunmap(umem->pgs[i]); + if (PageHighMem(umem->pgs[i])) + vunmap(umem->pages[i].addr); +} + +static int xdp_umem_map_pages(struct xdp_umem *umem) +{ + unsigned int i; + void *addr; + + for (i = 0; i < umem->npgs; i++) { + if (PageHighMem(umem->pgs[i])) + addr = vmap(&umem->pgs[i], 1, VM_MAP, PAGE_KERNEL); + else + addr = page_address(umem->pgs[i]); + + if (!addr) { + xdp_umem_unmap_pages(umem); + return -ENOMEM; + } + + umem->pages[i].addr = addr; + } + + return 0; } static void xdp_umem_unpin_pages(struct xdp_umem *umem) @@ -320,7 +343,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) u32 chunk_size = mr->chunk_size, headroom = mr->headroom; unsigned int chunks, chunks_per_page; u64 addr = mr->addr, size = mr->len; - int size_chk, err, i; + int size_chk, err; if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) { /* Strictly speaking we could support this, if: @@ -386,10 +409,11 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) goto out_account; } - for (i = 0; i < umem->npgs; i++) - umem->pages[i].addr = kmap(umem->pgs[i]); + err = xdp_umem_map_pages(umem); + if (!err) + return 0; - return 0; + kfree(umem->pages); out_account: xdp_umem_unaccount_pages(umem); -- 2.30.2