From 3f6e687dff395da43b056c18150a423bc7bf5d14 Mon Sep 17 00:00:00 2001 From: Kevin Hao Date: Thu, 4 Feb 2021 18:56:36 +0800 Subject: net: Introduce {netdev,napi}_alloc_frag_align() In the current implementation of {netdev,napi}_alloc_frag(), it doesn't have any align guarantee for the returned buffer address, But for some hardwares they do require the DMA buffer to be aligned correctly, so we would have to use some workarounds like below if the buffers allocated by the {netdev,napi}_alloc_frag() are used by these hardwares for DMA. buf = napi_alloc_frag(really_needed_size + align); buf = PTR_ALIGN(buf, align); These codes seems ugly and would waste a lot of memories if the buffers are used in a network driver for the TX/RX. We have added the align support for the page_frag functions, so add the corresponding {netdev,napi}_frag functions. Signed-off-by: Kevin Hao Reviewed-by: Alexander Duyck Signed-off-by: Jakub Kicinski --- net/core/skbuff.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) (limited to 'net/core') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3787093239f5..d380c7b5a12d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -374,29 +374,23 @@ struct napi_alloc_cache { static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache); -static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) +static void *__alloc_frag_align(unsigned int fragsz, gfp_t gfp_mask, + unsigned int align_mask) { struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); - return page_frag_alloc(&nc->page, fragsz, gfp_mask); + return page_frag_alloc_align(&nc->page, fragsz, gfp_mask, align_mask); } -void *napi_alloc_frag(unsigned int fragsz) +void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) { fragsz = SKB_DATA_ALIGN(fragsz); - return __napi_alloc_frag(fragsz, GFP_ATOMIC); + return __alloc_frag_align(fragsz, GFP_ATOMIC, align_mask); } -EXPORT_SYMBOL(napi_alloc_frag); +EXPORT_SYMBOL(__napi_alloc_frag_align); -/** - * netdev_alloc_frag - allocate a page fragment - * @fragsz: fragment size - * - * Allocates a frag from a page for receive buffer. - * Uses GFP_ATOMIC allocations. - */ -void *netdev_alloc_frag(unsigned int fragsz) +void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) { struct page_frag_cache *nc; void *data; @@ -404,15 +398,15 @@ void *netdev_alloc_frag(unsigned int fragsz) fragsz = SKB_DATA_ALIGN(fragsz); if (in_irq() || irqs_disabled()) { nc = this_cpu_ptr(&netdev_alloc_cache); - data = page_frag_alloc(nc, fragsz, GFP_ATOMIC); + data = page_frag_alloc_align(nc, fragsz, GFP_ATOMIC, align_mask); } else { local_bh_disable(); - data = __napi_alloc_frag(fragsz, GFP_ATOMIC); + data = __alloc_frag_align(fragsz, GFP_ATOMIC, align_mask); local_bh_enable(); } return data; } -EXPORT_SYMBOL(netdev_alloc_frag); +EXPORT_SYMBOL(__netdev_alloc_frag_align); /** * __netdev_alloc_skb - allocate an skbuff for rx on a specific device -- cgit v1.2.3