| Message ID | 20241204172204.4180482-7-dw@davidwei.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | io_uring zero copy rx | expand |
On Wed, 4 Dec 2024 09:21:45 -0800 David Wei wrote: > From: Pavel Begunkov <asml.silence@gmail.com> > > Add a helper that takes an array of pages and initialises passed in > memory provider's area with them, where each net_iov takes one page. > It's also responsible for setting up dma mappings. > > We keep it in page_pool.c not to leak netmem details to outside > providers like io_uring, which don't have access to netmem_priv.h > and other private helpers. User space will likely give us hugepages. Feels a bit wasteful to map and manage them 4k at a time. But okay, we can optimize this later. > diff --git a/include/net/page_pool/memory_provider.h b/include/net/page_pool/memory_provider.h > new file mode 100644 > index 000000000000..83d7eec0058d > --- /dev/null > +++ b/include/net/page_pool/memory_provider.h > @@ -0,0 +1,10 @@ nit: missing SPDX > +#ifndef _NET_PAGE_POOL_MEMORY_PROVIDER_H > +#define _NET_PAGE_POOL_MEMORY_PROVIDER_H > + > +int page_pool_mp_init_paged_area(struct page_pool *pool, > + struct net_iov_area *area, > + struct page **pages); > +void page_pool_mp_release_area(struct page_pool *pool, > + struct net_iov_area *area); > + > +#endif > +static void page_pool_release_page_dma(struct page_pool *pool, > + netmem_ref netmem) > +{ > + __page_pool_release_page_dma(pool, netmem); I'm guessing this is to save text? Because __page_pool_release_page_dma() is always_inline? Maybe add a comment? > +} > + > +int page_pool_mp_init_paged_area(struct page_pool *pool, > + struct net_iov_area *area, > + struct page **pages) > +{ > + struct net_iov *niov; > + netmem_ref netmem; > + int i, ret = 0; > + > + if (!pool->dma_map) > + return -EOPNOTSUPP; > + > + for (i = 0; i < area->num_niovs; i++) { > + niov = &area->niovs[i]; > + netmem = net_iov_to_netmem(niov); > + > + page_pool_set_pp_info(pool, netmem); Maybe move setting pp down, after we successfully mapped. Technically it's not a bug to leave it set on netmem, but it would be on a page struct. > + if (!page_pool_dma_map_page(pool, netmem, pages[i])) { > + ret = -EINVAL; > + goto err_unmap_dma; > + } > + } > + return 0; > + > +err_unmap_dma: > + while (i--) { > + netmem = net_iov_to_netmem(&area->niovs[i]); > + page_pool_release_page_dma(pool, netmem); > + } > + return ret; > +} > + > +void page_pool_mp_release_area(struct page_pool *pool, > + struct net_iov_area *area) > +{ > + int i; > + > + if (!pool->dma_map) > + return; > + > + for (i = 0; i < area->num_niovs; i++) { > + struct net_iov *niov = &area->niovs[i]; > + > + page_pool_release_page_dma(pool, net_iov_to_netmem(niov)); > + } > +}
On 12/10/24 03:29, Jakub Kicinski wrote: > On Wed, 4 Dec 2024 09:21:45 -0800 David Wei wrote: >> From: Pavel Begunkov <asml.silence@gmail.com> >> >> Add a helper that takes an array of pages and initialises passed in >> memory provider's area with them, where each net_iov takes one page. >> It's also responsible for setting up dma mappings. >> >> We keep it in page_pool.c not to leak netmem details to outside >> providers like io_uring, which don't have access to netmem_priv.h >> and other private helpers. > > User space will likely give us hugepages. Feels a bit wasteful to map > and manage them 4k at a time. But okay, we can optimize this later. I killed the api and moved bits of it out of net/. If multiple pools are expected, dma mapping and pp assigning need to happen at different points in time, and having such api doesn't make sense.
diff --git a/include/net/page_pool/memory_provider.h b/include/net/page_pool/memory_provider.h new file mode 100644 index 000000000000..83d7eec0058d --- /dev/null +++ b/include/net/page_pool/memory_provider.h @@ -0,0 +1,10 @@ +#ifndef _NET_PAGE_POOL_MEMORY_PROVIDER_H +#define _NET_PAGE_POOL_MEMORY_PROVIDER_H + +int page_pool_mp_init_paged_area(struct page_pool *pool, + struct net_iov_area *area, + struct page **pages); +void page_pool_mp_release_area(struct page_pool *pool, + struct net_iov_area *area); + +#endif diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 13f1a4a63760..d17e536ba8b8 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -13,6 +13,7 @@ #include <net/netdev_rx_queue.h> #include <net/page_pool/helpers.h> +#include <net/page_pool/memory_provider.h> #include <net/xdp.h> #include <linux/dma-direction.h> @@ -459,7 +460,8 @@ page_pool_dma_sync_for_device(const struct page_pool *pool, __page_pool_dma_sync_for_device(pool, netmem, dma_sync_size); } -static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem) +static bool page_pool_dma_map_page(struct page_pool *pool, netmem_ref netmem, + struct page *page) { dma_addr_t dma; @@ -468,7 +470,7 @@ static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem) * into page private data (i.e 32bit cpu with 64bit DMA caps) * This mapping is kept for lifetime of page, until leaving pool. */ - dma = dma_map_page_attrs(pool->p.dev, netmem_to_page(netmem), 0, + dma = dma_map_page_attrs(pool->p.dev, page, 0, (PAGE_SIZE << pool->p.order), pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING); @@ -490,6 +492,11 @@ static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem) return false; } +static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem) +{ + return page_pool_dma_map_page(pool, netmem, netmem_to_page(netmem)); +} + static struct page *__page_pool_alloc_page_order(struct page_pool *pool, gfp_t gfp) { @@ -1154,3 +1161,55 @@ void page_pool_update_nid(struct page_pool *pool, int new_nid) } } EXPORT_SYMBOL(page_pool_update_nid); + +static void page_pool_release_page_dma(struct page_pool *pool, + netmem_ref netmem) +{ + __page_pool_release_page_dma(pool, netmem); +} + +int page_pool_mp_init_paged_area(struct page_pool *pool, + struct net_iov_area *area, + struct page **pages) +{ + struct net_iov *niov; + netmem_ref netmem; + int i, ret = 0; + + if (!pool->dma_map) + return -EOPNOTSUPP; + + for (i = 0; i < area->num_niovs; i++) { + niov = &area->niovs[i]; + netmem = net_iov_to_netmem(niov); + + page_pool_set_pp_info(pool, netmem); + if (!page_pool_dma_map_page(pool, netmem, pages[i])) { + ret = -EINVAL; + goto err_unmap_dma; + } + } + return 0; + +err_unmap_dma: + while (i--) { + netmem = net_iov_to_netmem(&area->niovs[i]); + page_pool_release_page_dma(pool, netmem); + } + return ret; +} + +void page_pool_mp_release_area(struct page_pool *pool, + struct net_iov_area *area) +{ + int i; + + if (!pool->dma_map) + return; + + for (i = 0; i < area->num_niovs; i++) { + struct net_iov *niov = &area->niovs[i]; + + page_pool_release_page_dma(pool, net_iov_to_netmem(niov)); + } +}