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authorJesper Dangaard Brouer <brouer@redhat.com>2018-04-17 16:46:22 +0200
committerDavid S. Miller <davem@davemloft.net>2018-04-17 10:50:29 -0400
commit57d0a1c1ac9e6a836bbab4698ba2a2e03f64bf1b (patch)
tree95b4f994d510df73d33388612778bfdcd433bb79 /net/core/xdp.c
parentff7d6b27f894f1469dc51ccb828b7363ccd9799f (diff)
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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 <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/xdp.c')
-rw-r--r--net/core/xdp.c60
1 files changed, 48 insertions, 12 deletions
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 8b2cb79b5de0..33e382afbd95 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -8,6 +8,7 @@
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/rhashtable.h>
+#include <net/page_pool.h>
#include <net/xdp.h>
@@ -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);