Re: [PATCH net-next 2/4] mvpp2: use page_pool allocator
From: ilias . apalodimas
Date: Thu Jul 02 2020 - 03:31:12 EST
Hi Matteo,
Thanks for working on this!
On Tue, Jun 30, 2020 at 08:09:28PM +0200, Matteo Croce wrote:
> From: Matteo Croce <mcroce@xxxxxxxxxxxxx>
>
> Use the page_pool API for memory management. This is a prerequisite for
> native XDP support.
>
> Tested-by: Sven Auhagen <sven.auhagen@xxxxxxxxxxxx>
> Signed-off-by: Matteo Croce <mcroce@xxxxxxxxxxxxx>
> ---
> drivers/net/ethernet/marvell/Kconfig | 1 +
> drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 8 +
> .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 155 +++++++++++++++---
> 3 files changed, 139 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/Kconfig b/drivers/net/ethernet/marvell/Kconfig
> index cd8ddd1ef6f2..ef4f35ba077d 100644
> --- a/drivers/net/ethernet/marvell/Kconfig
> +++ b/drivers/net/ethernet/marvell/Kconfig
> @@ -87,6 +87,7 @@ config MVPP2
> depends on ARCH_MVEBU || COMPILE_TEST
> select MVMDIO
> select PHYLINK
> + select PAGE_POOL
> help
> This driver supports the network interface units in the
> Marvell ARMADA 375, 7K and 8K SoCs.
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
> index 543a310ec102..4c16c9e9c1e5 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
> @@ -15,6 +15,7 @@
> #include <linux/phy.h>
> #include <linux/phylink.h>
> #include <net/flow_offload.h>
> +#include <net/page_pool.h>
>
> /* Fifo Registers */
> #define MVPP2_RX_DATA_FIFO_SIZE_REG(port) (0x00 + 4 * (port))
> @@ -820,6 +821,9 @@ struct mvpp2 {
>
> /* RSS Indirection tables */
> struct mvpp2_rss_table *rss_tables[MVPP22_N_RSS_TABLES];
> +
> + /* page_pool allocator */
> + struct page_pool *page_pool[MVPP2_PORT_MAX_RXQ];
> };
>
> struct mvpp2_pcpu_stats {
> @@ -1161,6 +1165,10 @@ struct mvpp2_rx_queue {
>
> /* Port's logic RXQ number to which physical RXQ is mapped */
> int logic_rxq;
> +
> + /* XDP memory accounting */
> + struct xdp_rxq_info xdp_rxq_short;
> + struct xdp_rxq_info xdp_rxq_long;
> };
>
> struct mvpp2_bm_pool {
> diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> index 027de7291f92..9e2e8fb0a0b8 100644
> --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
> @@ -95,6 +95,22 @@ static inline u32 mvpp2_cpu_to_thread(struct mvpp2 *priv, int cpu)
> return cpu % priv->nthreads;
> }
>
> +static struct page_pool *
> +mvpp2_create_page_pool(struct device *dev, int num, int len)
> +{
> + struct page_pool_params pp_params = {
> + /* internal DMA mapping in page_pool */
> + .flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
> + .pool_size = num,
> + .nid = NUMA_NO_NODE,
> + .dev = dev,
> + .dma_dir = DMA_FROM_DEVICE,
> + .max_len = len,
> + };
> +
> + return page_pool_create(&pp_params);
> +}
> +
> /* These accessors should be used to access:
> *
> * - per-thread registers, where each thread has its own copy of the
> @@ -327,17 +343,26 @@ static inline int mvpp2_txq_phys(int port, int txq)
> return (MVPP2_MAX_TCONT + port) * MVPP2_MAX_TXQ + txq;
> }
>
> -static void *mvpp2_frag_alloc(const struct mvpp2_bm_pool *pool)
> +/* Returns a struct page if page_pool is set, otherwise a buffer */
> +static void *mvpp2_frag_alloc(const struct mvpp2_bm_pool *pool,
> + struct page_pool *page_pool)
> {
> + if (page_pool)
> + return page_pool_alloc_pages(page_pool,
> + GFP_ATOMIC | __GFP_NOWARN);
page_pool_dev_alloc_pages() can set these flags for you, instead of explicitly
calling them
> +
> if (likely(pool->frag_size <= PAGE_SIZE))
> return netdev_alloc_frag(pool->frag_size);
> - else
> - return kmalloc(pool->frag_size, GFP_ATOMIC);
> +
> + return kmalloc(pool->frag_size, GFP_ATOMIC);
> }
>
> -static void mvpp2_frag_free(const struct mvpp2_bm_pool *pool, void *data)
> +static void mvpp2_frag_free(const struct mvpp2_bm_pool *pool,
> + struct page_pool *page_pool, void *data)
> {
> - if (likely(pool->frag_size <= PAGE_SIZE))
> + if (page_pool)
> + page_pool_put_full_page(page_pool, virt_to_head_page(data), false);
> + else if (likely(pool->frag_size <= PAGE_SIZE))
> skb_free_frag(data);
> else
> kfree(data);
> @@ -442,6 +467,7 @@ static void mvpp2_bm_bufs_get_addrs(struct device *dev, struct mvpp2 *priv,
> static void mvpp2_bm_bufs_free(struct device *dev, struct mvpp2 *priv,
> struct mvpp2_bm_pool *bm_pool, int buf_num)
> {
> + struct page_pool *pp = NULL;
> int i;
>
> if (buf_num > bm_pool->buf_num) {
> @@ -450,6 +476,9 @@ static void mvpp2_bm_bufs_free(struct device *dev, struct mvpp2 *priv,
> buf_num = bm_pool->buf_num;
> }
>
> + if (priv->percpu_pools)
> + pp = priv->page_pool[bm_pool->id];
> +
> for (i = 0; i < buf_num; i++) {
> dma_addr_t buf_dma_addr;
> phys_addr_t buf_phys_addr;
> @@ -458,14 +487,15 @@ static void mvpp2_bm_bufs_free(struct device *dev, struct mvpp2 *priv,
> mvpp2_bm_bufs_get_addrs(dev, priv, bm_pool,
> &buf_dma_addr, &buf_phys_addr);
>
> - dma_unmap_single(dev, buf_dma_addr,
> - bm_pool->buf_size, DMA_FROM_DEVICE);
> + if (!pp)
> + dma_unmap_single(dev, buf_dma_addr,
> + bm_pool->buf_size, DMA_FROM_DEVICE);
>
> data = (void *)phys_to_virt(buf_phys_addr);
> if (!data)
> break;
>
> - mvpp2_frag_free(bm_pool, data);
> + mvpp2_frag_free(bm_pool, pp, data);
> }
>
> /* Update BM driver with number of buffers removed from pool */
> @@ -496,6 +526,9 @@ static int mvpp2_bm_pool_destroy(struct device *dev, struct mvpp2 *priv,
> int buf_num;
> u32 val;
>
> + if (priv->percpu_pools)
> + page_pool_destroy(priv->page_pool[bm_pool->id]);
> +
> buf_num = mvpp2_check_hw_buf_num(priv, bm_pool);
> mvpp2_bm_bufs_free(dev, priv, bm_pool, buf_num);
>
> @@ -548,8 +581,20 @@ static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
> {
> int i, err, poolnum = MVPP2_BM_POOLS_NUM;
>
> - if (priv->percpu_pools)
> + if (priv->percpu_pools) {
> poolnum = mvpp2_get_nrxqs(priv) * 2;
> + for (i = 0; i < poolnum; i++) {
> + /* the pool in use */
> + int pn = i / (poolnum / 2);
> +
> + priv->page_pool[i] =
> + mvpp2_create_page_pool(dev,
> + mvpp2_pools[pn].buf_num,
> + mvpp2_pools[pn].pkt_size);
> + if (IS_ERR(priv->page_pool[i]))
> + return PTR_ERR(priv->page_pool[i]);
> + }
> + }
>
> dev_info(dev, "using %d %s buffers\n", poolnum,
> priv->percpu_pools ? "per-cpu" : "shared");
> @@ -632,23 +677,31 @@ static void mvpp2_rxq_short_pool_set(struct mvpp2_port *port,
>
> static void *mvpp2_buf_alloc(struct mvpp2_port *port,
> struct mvpp2_bm_pool *bm_pool,
> + struct page_pool *page_pool,
> dma_addr_t *buf_dma_addr,
> phys_addr_t *buf_phys_addr,
> gfp_t gfp_mask)
> {
> dma_addr_t dma_addr;
> + struct page *page;
> void *data;
>
> - data = mvpp2_frag_alloc(bm_pool);
> + data = mvpp2_frag_alloc(bm_pool, page_pool);
> if (!data)
> return NULL;
>
> - dma_addr = dma_map_single(port->dev->dev.parent, data,
> - MVPP2_RX_BUF_SIZE(bm_pool->pkt_size),
> - DMA_FROM_DEVICE);
> - if (unlikely(dma_mapping_error(port->dev->dev.parent, dma_addr))) {
> - mvpp2_frag_free(bm_pool, data);
> - return NULL;
> + if (page_pool) {
> + page = (struct page *)data;
> + dma_addr = page_pool_get_dma_addr(page);
> + data = page_to_virt(page);
> + } else {
> + dma_addr = dma_map_single(port->dev->dev.parent, data,
> + MVPP2_RX_BUF_SIZE(bm_pool->pkt_size),
> + DMA_FROM_DEVICE);
> + if (unlikely(dma_mapping_error(port->dev->dev.parent, dma_addr))) {
> + mvpp2_frag_free(bm_pool, NULL, data);
> + return NULL;
> + }
> }
> *buf_dma_addr = dma_addr;
> *buf_phys_addr = virt_to_phys(data);
> @@ -706,6 +759,7 @@ static int mvpp2_bm_bufs_add(struct mvpp2_port *port,
> int i, buf_size, total_size;
> dma_addr_t dma_addr;
> phys_addr_t phys_addr;
> + struct page_pool *pp = NULL;
> void *buf;
>
> if (port->priv->percpu_pools &&
> @@ -726,8 +780,10 @@ static int mvpp2_bm_bufs_add(struct mvpp2_port *port,
> return 0;
> }
>
> + if (port->priv->percpu_pools)
> + pp = port->priv->page_pool[bm_pool->id];
> for (i = 0; i < buf_num; i++) {
> - buf = mvpp2_buf_alloc(port, bm_pool, &dma_addr,
> + buf = mvpp2_buf_alloc(port, bm_pool, pp, &dma_addr,
> &phys_addr, GFP_KERNEL);
> if (!buf)
> break;
> @@ -2374,10 +2430,11 @@ static int mvpp2_aggr_txq_init(struct platform_device *pdev,
> /* Create a specified Rx queue */
> static int mvpp2_rxq_init(struct mvpp2_port *port,
> struct mvpp2_rx_queue *rxq)
> -
> {
> + struct mvpp2 *priv = port->priv;
> unsigned int thread;
> u32 rxq_dma;
> + int err;
>
> rxq->size = port->rx_ring_size;
>
> @@ -2415,7 +2472,41 @@ static int mvpp2_rxq_init(struct mvpp2_port *port,
> /* Add number of descriptors ready for receiving packets */
> mvpp2_rxq_status_update(port, rxq->id, 0, rxq->size);
>
> + if (priv->percpu_pools) {
> + err = xdp_rxq_info_reg(&rxq->xdp_rxq_short, port->dev, rxq->id);
> + if (err < 0)
> + goto err_free_dma;
> +
> + err = xdp_rxq_info_reg(&rxq->xdp_rxq_long, port->dev, rxq->id);
> + if (err < 0)
> + goto err_unregister_rxq_short;
> +
> + /* Every RXQ has a pool for short and another for long packets */
> + err = xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq_short,
> + MEM_TYPE_PAGE_POOL,
> + priv->page_pool[rxq->logic_rxq]);
> + if (err < 0)
> + goto err_unregister_rxq_short;
> +
> + err = xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq_long,
> + MEM_TYPE_PAGE_POOL,
> + priv->page_pool[rxq->logic_rxq +
> + port->nrxqs]);
> + if (err < 0)
> + goto err_unregister_rxq_long;
Since mvpp2_rxq_init() will return an error shouldn't we unregister the short
memory pool as well?
> + }
> +
> return 0;
> +
> +err_unregister_rxq_long:
> + xdp_rxq_info_unreg(&rxq->xdp_rxq_long);
> +err_unregister_rxq_short:
> + xdp_rxq_info_unreg(&rxq->xdp_rxq_short);
> +err_free_dma:
> + dma_free_coherent(port->dev->dev.parent,
> + rxq->size * MVPP2_DESC_ALIGNED_SIZE,
> + rxq->descs, rxq->descs_dma);
> + return err;
> }
>
> /* Push packets received by the RXQ to BM pool */
> @@ -2449,6 +2540,12 @@ static void mvpp2_rxq_deinit(struct mvpp2_port *port,
> {
> unsigned int thread;
>
> + if (xdp_rxq_info_is_reg(&rxq->xdp_rxq_short))
> + xdp_rxq_info_unreg(&rxq->xdp_rxq_short);
> +
> + if (xdp_rxq_info_is_reg(&rxq->xdp_rxq_long))
> + xdp_rxq_info_unreg(&rxq->xdp_rxq_long);
> +
> mvpp2_rxq_drop_pkts(port, rxq);
>
> if (rxq->descs)
> @@ -2890,14 +2987,15 @@ static void mvpp2_rx_csum(struct mvpp2_port *port, u32 status,
>
> /* Allocate a new skb and add it to BM pool */
> static int mvpp2_rx_refill(struct mvpp2_port *port,
> - struct mvpp2_bm_pool *bm_pool, int pool)
> + struct mvpp2_bm_pool *bm_pool,
> + struct page_pool *page_pool, int pool)
> {
> dma_addr_t dma_addr;
> phys_addr_t phys_addr;
> void *buf;
>
> - buf = mvpp2_buf_alloc(port, bm_pool, &dma_addr, &phys_addr,
> - GFP_ATOMIC);
> + buf = mvpp2_buf_alloc(port, bm_pool, page_pool,
> + &dma_addr, &phys_addr, GFP_ATOMIC);
> if (!buf)
> return -ENOMEM;
>
> @@ -2956,6 +3054,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
> while (rx_done < rx_todo) {
> struct mvpp2_rx_desc *rx_desc = mvpp2_rxq_next_desc_get(rxq);
> struct mvpp2_bm_pool *bm_pool;
> + struct page_pool *pp = NULL;
> struct sk_buff *skb;
> unsigned int frag_size;
> dma_addr_t dma_addr;
> @@ -2989,6 +3088,9 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
> DMA_FROM_DEVICE);
> prefetch(data);
>
> + if (port->priv->percpu_pools)
> + pp = port->priv->page_pool[pool];
> +
> if (bm_pool->frag_size > PAGE_SIZE)
> frag_size = 0;
> else
> @@ -3000,15 +3102,18 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
> goto err_drop_frame;
> }
>
> - err = mvpp2_rx_refill(port, bm_pool, pool);
> + err = mvpp2_rx_refill(port, bm_pool, pp, pool);
> if (err) {
> netdev_err(port->dev, "failed to refill BM pools\n");
> goto err_drop_frame;
> }
>
> - dma_unmap_single_attrs(dev->dev.parent, dma_addr,
> - bm_pool->buf_size, DMA_FROM_DEVICE,
> - DMA_ATTR_SKIP_CPU_SYNC);
> + if (pp)
> + page_pool_release_page(pp, virt_to_page(data));
> + else
> + dma_unmap_single_attrs(dev->dev.parent, dma_addr,
> + bm_pool->buf_size, DMA_FROM_DEVICE,
> + DMA_ATTR_SKIP_CPU_SYNC);
>
> rcvd_pkts++;
> rcvd_bytes += rx_bytes;
> --
> 2.26.2
>