From: Jesper Dangaard Brouer Date: Tue, 17 Apr 2018 14:46:22 +0000 (+0200) Subject: xdp: allow page_pool as an allocator type in xdp_return_frame X-Git-Tag: v4.19~872^2~450^2~4 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=57d0a1c1ac9e6a836bbab4698ba2a2e03f64bf1b;p=platform%2Fkernel%2Flinux-rpi.git xdp: allow page_pool as an allocator type in xdp_return_frame New allocator type MEM_TYPE_PAGE_POOL for page_pool usage. The registered allocator page_pool pointer is not available directly from xdp_rxq_info, but it could be (if needed). For now, the driver should keep separate track of the page_pool pointer, which it should use for RX-ring page allocation. As suggested by Saeed, to maintain a symmetric API it is the drivers responsibility to allocate/create and free/destroy the page_pool. Thus, after the driver have called xdp_rxq_info_unreg(), it is drivers responsibility to free the page_pool, but with a RCU free call. This is done easily via the page_pool helper page_pool_destroy() (which avoids touching any driver code during the RCU callback, which could happen after the driver have been unloaded). V8: address issues found by kbuild test robot - Address sparse should be static warnings - Allow xdp.o to be compiled without page_pool.o V9: Remove inline from .c file, compiler knows best Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- diff --git a/include/net/page_pool.h b/include/net/page_pool.h index 1fe77db..c790871 100644 --- a/include/net/page_pool.h +++ b/include/net/page_pool.h @@ -117,7 +117,12 @@ void __page_pool_put_page(struct page_pool *pool, static inline void page_pool_put_page(struct page_pool *pool, struct page *page) { + /* When page_pool isn't compiled-in, net/core/xdp.c doesn't + * allow registering MEM_TYPE_PAGE_POOL, but shield linker. + */ +#ifdef CONFIG_PAGE_POOL __page_pool_put_page(pool, page, false); +#endif } /* Very limited use-cases allow recycle direct */ static inline void page_pool_recycle_direct(struct page_pool *pool, @@ -126,4 +131,13 @@ static inline void page_pool_recycle_direct(struct page_pool *pool, __page_pool_put_page(pool, page, true); } +static inline bool is_page_pool_compiled_in(void) +{ +#ifdef CONFIG_PAGE_POOL + return true; +#else + return false; +#endif +} + #endif /* _NET_PAGE_POOL_H */ diff --git a/include/net/xdp.h b/include/net/xdp.h index 5f67c62..d0ee437 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -36,6 +36,7 @@ enum xdp_mem_type { MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */ MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */ + MEM_TYPE_PAGE_POOL, MEM_TYPE_MAX, }; @@ -44,6 +45,8 @@ struct xdp_mem_info { u32 id; }; +struct page_pool; + struct xdp_rxq_info { struct net_device *dev; u32 queue_index; diff --git a/net/core/xdp.c b/net/core/xdp.c index 8b2cb79..33e382a 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -8,6 +8,7 @@ #include #include #include +#include #include @@ -27,7 +28,10 @@ static struct rhashtable *mem_id_ht; struct xdp_mem_allocator { struct xdp_mem_info mem; - void *allocator; + union { + void *allocator; + struct page_pool *page_pool; + }; struct rhash_head node; struct rcu_head rcu; }; @@ -74,7 +78,9 @@ static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu) /* Allow this ID to be reused */ ida_simple_remove(&mem_id_pool, xa->mem.id); - /* TODO: Depending on allocator type/pointer free resources */ + /* Notice, driver is expected to free the *allocator, + * e.g. page_pool, and MUST also use RCU free. + */ /* Poison memory */ xa->mem.id = 0xFFFF; @@ -225,6 +231,17 @@ again: return id; } +static bool __is_supported_mem_type(enum xdp_mem_type type) +{ + if (type == MEM_TYPE_PAGE_POOL) + return is_page_pool_compiled_in(); + + if (type >= MEM_TYPE_MAX) + return false; + + return true; +} + int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, enum xdp_mem_type type, void *allocator) { @@ -238,13 +255,16 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, return -EFAULT; } - if (type >= MEM_TYPE_MAX) - return -EINVAL; + if (!__is_supported_mem_type(type)) + return -EOPNOTSUPP; xdp_rxq->mem.type = type; - if (!allocator) + if (!allocator) { + if (type == MEM_TYPE_PAGE_POOL) + return -EINVAL; /* Setup time check page_pool req */ return 0; + } /* Delay init of rhashtable to save memory if feature isn't used */ if (!mem_id_init) { @@ -290,15 +310,31 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model); void xdp_return_frame(void *data, struct xdp_mem_info *mem) { - if (mem->type == MEM_TYPE_PAGE_SHARED) { + struct xdp_mem_allocator *xa; + struct page *page; + + switch (mem->type) { + case MEM_TYPE_PAGE_POOL: + rcu_read_lock(); + /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */ + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + page = virt_to_head_page(data); + if (xa) + page_pool_put_page(xa->page_pool, page); + else + put_page(page); + rcu_read_unlock(); + break; + case MEM_TYPE_PAGE_SHARED: page_frag_free(data); - return; - } - - if (mem->type == MEM_TYPE_PAGE_ORDER0) { - struct page *page = virt_to_page(data); /* Assumes order0 page*/ - + break; + case MEM_TYPE_PAGE_ORDER0: + page = virt_to_page(data); /* Assumes order0 page*/ put_page(page); + break; + default: + /* Not possible, checked in xdp_rxq_info_reg_mem_model() */ + break; } } EXPORT_SYMBOL_GPL(xdp_return_frame);