@@ -30,6 +30,7 @@ struct xdp_umem {
u8 flags;
int id;
bool zc;
+ struct list_head xsk_dma_list;
};
struct xsk_map {
@@ -28,10 +28,23 @@ struct xdp_buff_xsk {
struct list_head free_list_node;
};
+struct xsk_dma_map {
+ dma_addr_t *dma_pages;
+ struct device *dev;
+ struct net_device *netdev;
+ refcount_t users;
+ struct list_head list; /* Protected by the RTNL_LOCK */
+ u32 dma_pages_cnt;
+ bool dma_need_sync;
+};
+
struct xsk_buff_pool {
struct xsk_queue *fq;
struct xsk_queue *cq;
struct list_head free_list;
+ /* For performance reasons, each buff pool has its own array of dma_pages
+ * even when they are identical.
+ */
dma_addr_t *dma_pages;
struct xdp_buff_xsk *heads;
u64 chunk_mask;
@@ -198,6 +198,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
umem->user = NULL;
umem->flags = mr->flags;
+ INIT_LIST_HEAD(&umem->xsk_dma_list);
refcount_set(&umem->users, 1);
err = xdp_umem_account_pages(umem);
@@ -104,6 +104,25 @@ void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
}
EXPORT_SYMBOL(xp_set_rxq_info);
+static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
+{
+ struct netdev_bpf bpf;
+ int err;
+
+ ASSERT_RTNL();
+
+ if (pool->umem->zc) {
+ bpf.command = XDP_SETUP_XSK_POOL;
+ bpf.xsk.pool = NULL;
+ bpf.xsk.queue_id = pool->queue_id;
+
+ err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
+
+ if (err)
+ WARN(1, "Failed to disable zero-copy!\n");
+ }
+}
+
int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev,
u16 queue_id, u16 flags)
{
@@ -122,6 +141,8 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev,
if (xsk_get_pool_from_qid(netdev, queue_id))
return -EBUSY;
+ pool->netdev = netdev;
+ pool->queue_id = queue_id;
err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
if (err)
return err;
@@ -155,11 +176,15 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev,
if (err)
goto err_unreg_pool;
- pool->netdev = netdev;
- pool->queue_id = queue_id;
+ if (!pool->dma_pages) {
+ WARN(1, "Driver did not DMA map zero-copy buffers");
+ goto err_unreg_xsk;
+ }
pool->umem->zc = true;
return 0;
+err_unreg_xsk:
+ xp_disable_drv_zc(pool);
err_unreg_pool:
if (!force_zc)
err = 0; /* fallback to copy mode */
@@ -170,25 +195,10 @@ int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev,
void xp_clear_dev(struct xsk_buff_pool *pool)
{
- struct netdev_bpf bpf;
- int err;
-
- ASSERT_RTNL();
-
if (!pool->netdev)
return;
- if (pool->umem->zc) {
- bpf.command = XDP_SETUP_XSK_POOL;
- bpf.xsk.pool = NULL;
- bpf.xsk.queue_id = pool->queue_id;
-
- err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
-
- if (err)
- WARN(1, "Failed to disable zero-copy!\n");
- }
-
+ xp_disable_drv_zc(pool);
xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
dev_put(pool->netdev);
pool->netdev = NULL;
@@ -233,70 +243,159 @@ void xp_put_pool(struct xsk_buff_pool *pool)
}
}
-void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
+static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
+{
+ struct xsk_dma_map *dma_map;
+
+ list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
+ if (dma_map->netdev == pool->netdev)
+ return dma_map;
+ }
+
+ return NULL;
+}
+
+static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
+ u32 nr_pages, struct xdp_umem *umem)
+{
+ struct xsk_dma_map *dma_map;
+
+ dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
+ if (!dma_map)
+ return NULL;
+
+ dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
+ if (!dma_map) {
+ kfree(dma_map);
+ return NULL;
+ }
+
+ dma_map->netdev = netdev;
+ dma_map->dev = dev;
+ dma_map->dma_need_sync = false;
+ dma_map->dma_pages_cnt = nr_pages;
+ refcount_set(&dma_map->users, 0);
+ list_add(&dma_map->list, &umem->xsk_dma_list);
+ return dma_map;
+}
+
+static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
+{
+ list_del(&dma_map->list);
+ kvfree(dma_map->dma_pages);
+ kfree(dma_map);
+}
+
+static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
{
dma_addr_t *dma;
u32 i;
- if (pool->dma_pages_cnt == 0)
- return;
-
- for (i = 0; i < pool->dma_pages_cnt; i++) {
- dma = &pool->dma_pages[i];
+ for (i = 0; i < dma_map->dma_pages_cnt; i++) {
+ dma = &dma_map->dma_pages[i];
if (*dma) {
- dma_unmap_page_attrs(pool->dev, *dma, PAGE_SIZE,
+ dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
DMA_BIDIRECTIONAL, attrs);
*dma = 0;
}
}
+ xp_destroy_dma_map(dma_map);
+}
+
+void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
+{
+ struct xsk_dma_map *dma_map;
+
+ if (pool->dma_pages_cnt == 0)
+ return;
+
+ dma_map = xp_find_dma_map(pool);
+ if (!dma_map) {
+ WARN(1, "Could not find dma_map for device");
+ return;
+ }
+
+ if (!refcount_dec_and_test(&dma_map->users))
+ return;
+
+ __xp_dma_unmap(dma_map, attrs);
kvfree(pool->dma_pages);
pool->dma_pages_cnt = 0;
pool->dev = NULL;
}
EXPORT_SYMBOL(xp_dma_unmap);
-static void xp_check_dma_contiguity(struct xsk_buff_pool *pool)
+static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
{
u32 i;
- for (i = 0; i < pool->dma_pages_cnt - 1; i++) {
- if (pool->dma_pages[i] + PAGE_SIZE == pool->dma_pages[i + 1])
- pool->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
+ for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
+ if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
+ dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
else
- pool->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
+ dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
}
}
+static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
+{
+ pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
+ if (!pool->dma_pages)
+ return -ENOMEM;
+
+ pool->dev = dma_map->dev;
+ pool->dma_pages_cnt = dma_map->dma_pages_cnt;
+ pool->dma_need_sync = dma_map->dma_need_sync;
+ refcount_inc(&dma_map->users);
+ memcpy(pool->dma_pages, dma_map->dma_pages,
+ pool->dma_pages_cnt * sizeof(*pool->dma_pages));
+
+ return 0;
+}
+
int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
unsigned long attrs, struct page **pages, u32 nr_pages)
{
+ struct xsk_dma_map *dma_map;
dma_addr_t dma;
+ int err;
u32 i;
- pool->dma_pages = kvcalloc(nr_pages, sizeof(*pool->dma_pages),
- GFP_KERNEL);
- if (!pool->dma_pages)
- return -ENOMEM;
+ dma_map = xp_find_dma_map(pool);
+ if (dma_map) {
+ err = xp_init_dma_info(pool, dma_map);
+ if (err)
+ return err;
- pool->dev = dev;
- pool->dma_pages_cnt = nr_pages;
- pool->dma_need_sync = false;
+ return 0;
+ }
- for (i = 0; i < pool->dma_pages_cnt; i++) {
+ dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
+ if (!dma_map)
+ return -ENOMEM;
+
+ for (i = 0; i < dma_map->dma_pages_cnt; i++) {
dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
DMA_BIDIRECTIONAL, attrs);
if (dma_mapping_error(dev, dma)) {
- xp_dma_unmap(pool, attrs);
+ __xp_dma_unmap(dma_map, attrs);
return -ENOMEM;
}
if (dma_need_sync(dev, dma))
- pool->dma_need_sync = true;
- pool->dma_pages[i] = dma;
+ dma_map->dma_need_sync = true;
+ dma_map->dma_pages[i] = dma;
}
if (pool->unaligned)
- xp_check_dma_contiguity(pool);
+ xp_check_dma_contiguity(dma_map);
+
+ err = xp_init_dma_info(pool, dma_map);
+ if (err) {
+ __xp_dma_unmap(dma_map, attrs);
+ return err;
+ }
+
return 0;
}
EXPORT_SYMBOL(xp_dma_map);