This patchset adds frag page support in page pool and enable skb's page frag recycling based on page pool in hns3 drvier.

V2: 1. resend based on the latest net-next.

V1: 1. avoid atomic_long_read() in case of freeing or draining page frag, and drop RFC tag.

RFC v6: 1. Disable frag page support in system 32-bit arch and 64-bit DMA.

RFC v5: 1. Rename dma_addr[0] to pp_frag_count and adjust codes according to the rename.

RFC v4: 1. Use the dma_addr[1] to store bias. 2. Default to a pagecnt_bias of PAGE_SIZE - 1. 3. other minor comment suggested by Alexander.

RFC v3: 1. Implement the semantic of "page recycling only wait for the page pool user instead of all user of a page" 2. Support the frag allocation of different sizes 3. Merge patch 4 & 5 to one patch as it does not make sense to use page_pool_dev_alloc_pages() API directly with elevated refcnt. 4. other minor comment suggested by Alexander.

RFC v2: 1. Split patch 1 to more reviewable one. 2. Repurpose the lower 12 bits of the dma address to store the pagecnt_bias as suggested by Alexander. 3. support recycling to pool->alloc for elevated refcnt case too.

Yunsheng Lin (4): page_pool: keep pp info as long as page pool owns the page page_pool: add interface to manipulate frag count in page pool page_pool: add frag page recycling support in page pool net: hns3: support skb's frag page recycling based on page pool

drivers/net/ethernet/hisilicon/Kconfig | 1 + drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 79 +++++++++++++++-- drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 3 + drivers/net/ethernet/marvell/mvneta.c | 6 +- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +- drivers/net/ethernet/ti/cpsw.c | 2 +- drivers/net/ethernet/ti/cpsw_new.c | 2 +- include/linux/mm_types.h | 18 ++-- include/linux/skbuff.h | 4 +- include/net/page_pool.h | 68 +++++++++++--- net/core/page_pool.c | 112 +++++++++++++++++++++++- 11 files changed, 258 insertions(+), 39 deletions(-)