On 10/02/2025 12:33, Meghana Malladi wrote: > From: Roger Quadros <rogerq@xxxxxxxxxx> > > This is to prepare for native XDP support. > > The page pool API is more faster in allocating pages than > __alloc_skb(). Drawback is that it works at PAGE_SIZE granularity > so we are not efficient in memory usage. > i.e. we are using PAGE_SIZE (4KB) memory for 1.5KB max packet size. > > Signed-off-by: Roger Quadros <rogerq@xxxxxxxxxx> > Signed-off-by: MD Danish Anwar <danishanwar@xxxxxx> > Signed-off-by: Meghana Malladi <m-malladi@xxxxxx> > --- > v1: https://lore.kernel.org/all/20250122124951.3072410-1-m-malladi@xxxxxx/ > > Changes since v1 (v2-v1): > - Recycle pages wherever necessary using skb_mark_for_recycle() > - Use napi_build_skb() instead of build_skb() > - Update with correct frag_size argument in napi_build_skb() > - Use napi_gro_receive() instead of netif_receive_skb() > - Use PP_FLAG_DMA_SYNC_DEV to enable DMA sync with device > - Use page_pool_dma_sync_for_cpu() to sync Rx page pool for CPU > > All the above changes have been suggested by Ido Schimmel <idosch@xxxxxxxxxx> > > drivers/net/ethernet/ti/Kconfig | 1 + > drivers/net/ethernet/ti/icssg/icssg_common.c | 174 ++++++++++++------ > drivers/net/ethernet/ti/icssg/icssg_prueth.h | 14 +- > .../net/ethernet/ti/icssg/icssg_prueth_sr1.c | 21 ++- > 4 files changed, 140 insertions(+), 70 deletions(-) > > diff --git a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig > index 0d5a862cd78a..b461281d31b6 100644 > --- a/drivers/net/ethernet/ti/Kconfig > +++ b/drivers/net/ethernet/ti/Kconfig > @@ -204,6 +204,7 @@ config TI_ICSSG_PRUETH_SR1 > select PHYLIB > select TI_ICSS_IEP > select TI_K3_CPPI_DESC_POOL > + select PAGE_POOL > depends on PRU_REMOTEPROC > depends on NET_SWITCHDEV > depends on ARCH_K3 && OF && TI_K3_UDMA_GLUE_LAYER > diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c > index 74f0f200a89d..c3c1e2bf461e 100644 > --- a/drivers/net/ethernet/ti/icssg/icssg_common.c > +++ b/drivers/net/ethernet/ti/icssg/icssg_common.c > @@ -45,6 +45,11 @@ void prueth_cleanup_rx_chns(struct prueth_emac *emac, > struct prueth_rx_chn *rx_chn, > int max_rflows) > { > + if (rx_chn->pg_pool) { > + page_pool_destroy(rx_chn->pg_pool); > + rx_chn->pg_pool = NULL; > + } > + > if (rx_chn->desc_pool) > k3_cppi_desc_pool_destroy(rx_chn->desc_pool); > > @@ -461,17 +466,17 @@ int prueth_init_rx_chns(struct prueth_emac *emac, > } > EXPORT_SYMBOL_GPL(prueth_init_rx_chns); > > -int prueth_dma_rx_push(struct prueth_emac *emac, > - struct sk_buff *skb, > - struct prueth_rx_chn *rx_chn) > +int prueth_dma_rx_push_mapped(struct prueth_emac *emac, > + struct prueth_rx_chn *rx_chn, > + struct page *page, u32 buf_len) > { > struct net_device *ndev = emac->ndev; > struct cppi5_host_desc_t *desc_rx; > - u32 pkt_len = skb_tailroom(skb); > dma_addr_t desc_dma; > dma_addr_t buf_dma; > void **swdata; > > + buf_dma = page_pool_get_dma_addr(page) + PRUETH_HEADROOM; > desc_rx = k3_cppi_desc_pool_alloc(rx_chn->desc_pool); > if (!desc_rx) { > netdev_err(ndev, "rx push: failed to allocate descriptor\n"); > @@ -479,25 +484,18 @@ int prueth_dma_rx_push(struct prueth_emac *emac, > } > desc_dma = k3_cppi_desc_pool_virt2dma(rx_chn->desc_pool, desc_rx); > > - buf_dma = dma_map_single(rx_chn->dma_dev, skb->data, pkt_len, DMA_FROM_DEVICE); > - if (unlikely(dma_mapping_error(rx_chn->dma_dev, buf_dma))) { > - k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx); > - netdev_err(ndev, "rx push: failed to map rx pkt buffer\n"); > - return -EINVAL; > - } > - > cppi5_hdesc_init(desc_rx, CPPI5_INFO0_HDESC_EPIB_PRESENT, > PRUETH_NAV_PS_DATA_SIZE); > k3_udma_glue_rx_dma_to_cppi5_addr(rx_chn->rx_chn, &buf_dma); > - cppi5_hdesc_attach_buf(desc_rx, buf_dma, skb_tailroom(skb), buf_dma, skb_tailroom(skb)); > + cppi5_hdesc_attach_buf(desc_rx, buf_dma, buf_len, buf_dma, buf_len); > > swdata = cppi5_hdesc_get_swdata(desc_rx); > - *swdata = skb; > + *swdata = page; > > - return k3_udma_glue_push_rx_chn(rx_chn->rx_chn, 0, > + return k3_udma_glue_push_rx_chn(rx_chn->rx_chn, PRUETH_RX_FLOW_DATA, > desc_rx, desc_dma); > } > -EXPORT_SYMBOL_GPL(prueth_dma_rx_push); > +EXPORT_SYMBOL_GPL(prueth_dma_rx_push_mapped); > > u64 icssg_ts_to_ns(u32 hi_sw, u32 hi, u32 lo, u32 cycle_time_ns) > { > @@ -541,12 +539,16 @@ static int emac_rx_packet(struct prueth_emac *emac, u32 flow_id) > u32 buf_dma_len, pkt_len, port_id = 0; > struct net_device *ndev = emac->ndev; > struct cppi5_host_desc_t *desc_rx; > - struct sk_buff *skb, *new_skb; > dma_addr_t desc_dma, buf_dma; > + struct page *page, *new_page; > + struct page_pool *pool; > + struct sk_buff *skb; > void **swdata; > u32 *psdata; > + void *pa; > int ret; > > + pool = rx_chn->pg_pool; > ret = k3_udma_glue_pop_rx_chn(rx_chn->rx_chn, flow_id, &desc_dma); > if (ret) { > if (ret != -ENODATA) > @@ -558,15 +560,10 @@ static int emac_rx_packet(struct prueth_emac *emac, u32 flow_id) > return 0; > > desc_rx = k3_cppi_desc_pool_dma2virt(rx_chn->desc_pool, desc_dma); > - > swdata = cppi5_hdesc_get_swdata(desc_rx); > - skb = *swdata; > - > - psdata = cppi5_hdesc_get_psdata(desc_rx); > - /* RX HW timestamp */ > - if (emac->rx_ts_enabled) > - emac_rx_timestamp(emac, skb, psdata); > + page = *swdata; > Unnecessary blank line. > + page_pool_dma_sync_for_cpu(pool, page, 0, PAGE_SIZE); > cppi5_hdesc_get_obuf(desc_rx, &buf_dma, &buf_dma_len); > k3_udma_glue_rx_cppi5_to_dma_addr(rx_chn->rx_chn, &buf_dma); > pkt_len = cppi5_hdesc_get_pktlen(desc_rx); > @@ -574,32 +571,51 @@ static int emac_rx_packet(struct prueth_emac *emac, u32 flow_id) > pkt_len -= 4; > cppi5_desc_get_tags_ids(&desc_rx->hdr, &port_id, NULL); > > - dma_unmap_single(rx_chn->dma_dev, buf_dma, buf_dma_len, DMA_FROM_DEVICE); > k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx); > > - skb->dev = ndev; > - new_skb = netdev_alloc_skb_ip_align(ndev, PRUETH_MAX_PKT_SIZE); > /* if allocation fails we drop the packet but push the > - * descriptor back to the ring with old skb to prevent a stall > + * descriptor back to the ring with old page to prevent a stall > */ > - if (!new_skb) { > + new_page = page_pool_dev_alloc_pages(pool); > + if (unlikely(!new_page)) { > + new_page = page; > ndev->stats.rx_dropped++; > - new_skb = skb; > - } else { > - /* send the filled skb up the n/w stack */ > - skb_put(skb, pkt_len); > - if (emac->prueth->is_switch_mode) > - skb->offload_fwd_mark = emac->offload_fwd_mark; > - skb->protocol = eth_type_trans(skb, ndev); > - napi_gro_receive(&emac->napi_rx, skb); > - ndev->stats.rx_bytes += pkt_len; > - ndev->stats.rx_packets++; > + goto requeue; > + } > + > + /* prepare skb and send to n/w stack */ > + pa = page_address(page); > + skb = napi_build_skb(pa, PAGE_SIZE); > + if (!skb) { > + ndev->stats.rx_dropped++; > + page_pool_recycle_direct(pool, page); > + goto requeue; > } > > + skb_reserve(skb, PRUETH_HEADROOM); > + skb_put(skb, pkt_len); > + skb->dev = ndev; > + > + psdata = cppi5_hdesc_get_psdata(desc_rx); > + /* RX HW timestamp */ > + if (emac->rx_ts_enabled) > + emac_rx_timestamp(emac, skb, psdata); > + > + if (emac->prueth->is_switch_mode) > + skb->offload_fwd_mark = emac->offload_fwd_mark; > + skb->protocol = eth_type_trans(skb, ndev); > + > + skb_mark_for_recycle(skb); > + napi_gro_receive(&emac->napi_rx, skb); > + ndev->stats.rx_bytes += pkt_len; > + ndev->stats.rx_packets++; > + > +requeue: > /* queue another RX DMA */ > - ret = prueth_dma_rx_push(emac, new_skb, &emac->rx_chns); > + ret = prueth_dma_rx_push_mapped(emac, &emac->rx_chns, new_page, > + PRUETH_MAX_PKT_SIZE); > if (WARN_ON(ret < 0)) { > - dev_kfree_skb_any(new_skb); > + page_pool_recycle_direct(pool, new_page); > ndev->stats.rx_errors++; > ndev->stats.rx_dropped++; > } > @@ -611,22 +627,17 @@ static void prueth_rx_cleanup(void *data, dma_addr_t desc_dma) > { > struct prueth_rx_chn *rx_chn = data; > struct cppi5_host_desc_t *desc_rx; > - struct sk_buff *skb; > - dma_addr_t buf_dma; > - u32 buf_dma_len; > + struct page_pool *pool; > + struct page *page; > void **swdata; > > + pool = rx_chn->pg_pool; > + here too. > desc_rx = k3_cppi_desc_pool_dma2virt(rx_chn->desc_pool, desc_dma); > swdata = cppi5_hdesc_get_swdata(desc_rx); > - skb = *swdata; > - cppi5_hdesc_get_obuf(desc_rx, &buf_dma, &buf_dma_len); > - k3_udma_glue_rx_cppi5_to_dma_addr(rx_chn->rx_chn, &buf_dma); > - > - dma_unmap_single(rx_chn->dma_dev, buf_dma, buf_dma_len, > - DMA_FROM_DEVICE); > + page = *swdata; > + page_pool_recycle_direct(pool, page); > k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx); > - > - dev_kfree_skb_any(skb); > } > > static int prueth_tx_ts_cookie_get(struct prueth_emac *emac) > @@ -907,29 +918,71 @@ int icssg_napi_rx_poll(struct napi_struct *napi_rx, int budget) > } > EXPORT_SYMBOL_GPL(icssg_napi_rx_poll); > > +static struct page_pool *prueth_create_page_pool(struct prueth_emac *emac, > + struct device *dma_dev, > + int size) > +{ > + struct page_pool_params pp_params = { 0 }; > + struct page_pool *pool; > + > + pp_params.order = 0; > + pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV; > + pp_params.pool_size = size; > + pp_params.nid = dev_to_node(emac->prueth->dev); > + pp_params.dma_dir = DMA_BIDIRECTIONAL; > + pp_params.dev = dma_dev; > + pp_params.napi = &emac->napi_rx; > + pp_params.max_len = PAGE_SIZE; > + > + pool = page_pool_create(&pp_params); > + if (IS_ERR(pool)) > + netdev_err(emac->ndev, "cannot create rx page pool\n"); > + > + return pool; > +} > + > int prueth_prepare_rx_chan(struct prueth_emac *emac, > struct prueth_rx_chn *chn, > int buf_size) > { > - struct sk_buff *skb; > + struct page_pool *pool; > + struct page *page; > int i, ret; > > + pool = prueth_create_page_pool(emac, chn->dma_dev, chn->descs_num); > + if (IS_ERR(pool)) > + return PTR_ERR(pool); > + > + chn->pg_pool = pool; > + > for (i = 0; i < chn->descs_num; i++) { > - skb = __netdev_alloc_skb_ip_align(NULL, buf_size, GFP_KERNEL); > - if (!skb) > - return -ENOMEM; > + /* NOTE: we're not using memory efficiently here. > + * 1 full page (4KB?) used here instead of > + * PRUETH_MAX_PKT_SIZE (~1.5KB?) > + */ > + page = page_pool_dev_alloc_pages(pool); Did you evaluate Ido's suggestion to use page_pool_alloc_frag()? > + if (!page) { > + netdev_err(emac->ndev, "couldn't allocate rx page\n"); > + ret = -ENOMEM; > + goto recycle_alloc_pg; > + } > > - ret = prueth_dma_rx_push(emac, skb, chn); > + ret = prueth_dma_rx_push_mapped(emac, chn, page, buf_size); > if (ret < 0) { > netdev_err(emac->ndev, > - "cannot submit skb for rx chan %s ret %d\n", > + "cannot submit page for rx chan %s ret %d\n", > chn->name, ret); > - kfree_skb(skb); > - return ret; > + page_pool_recycle_direct(pool, page); > + goto recycle_alloc_pg; > } > } > > return 0; > + > +recycle_alloc_pg: > + prueth_reset_rx_chan(&emac->rx_chns, PRUETH_MAX_RX_FLOWS, false); > + > + return ret; > } > EXPORT_SYMBOL_GPL(prueth_prepare_rx_chan); > > @@ -958,6 +1011,9 @@ void prueth_reset_rx_chan(struct prueth_rx_chn *chn, > prueth_rx_cleanup, !!i); > if (disable) > k3_udma_glue_disable_rx_chn(chn->rx_chn); > + > + page_pool_destroy(chn->pg_pool); > + chn->pg_pool = NULL; > } > EXPORT_SYMBOL_GPL(prueth_reset_rx_chan); > > diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h > index 329b46e9ee53..c7b906de18af 100644 > --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h > +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h > @@ -33,6 +33,8 @@ > #include <linux/dma/k3-udma-glue.h> > > #include <net/devlink.h> > +#include <net/xdp.h> > +#include <net/page_pool/helpers.h> > > #include "icssg_config.h" > #include "icss_iep.h" > @@ -131,6 +133,7 @@ struct prueth_rx_chn { > u32 descs_num; > unsigned int irq[ICSSG_MAX_RFLOWS]; /* separate irq per flow */ > char name[32]; > + struct page_pool *pg_pool; > }; > > /* There are 4 Tx DMA channels, but the highest priority is CH3 (thread 3) > @@ -210,6 +213,10 @@ struct prueth_emac { > struct netdev_hw_addr_list vlan_mcast_list[MAX_VLAN_ID]; > }; > > +/* The buf includes headroom compatible with both skb and xdpf */ > +#define PRUETH_HEADROOM_NA (max(XDP_PACKET_HEADROOM, NET_SKB_PAD) + NET_IP_ALIGN) > +#define PRUETH_HEADROOM ALIGN(PRUETH_HEADROOM_NA, sizeof(long)) > + > /** > * struct prueth_pdata - PRUeth platform data > * @fdqring_mode: Free desc queue mode > @@ -410,9 +417,10 @@ int prueth_init_rx_chns(struct prueth_emac *emac, > struct prueth_rx_chn *rx_chn, > char *name, u32 max_rflows, > u32 max_desc_num); > -int prueth_dma_rx_push(struct prueth_emac *emac, > - struct sk_buff *skb, > - struct prueth_rx_chn *rx_chn); > +int prueth_dma_rx_push_mapped(struct prueth_emac *emac, > + struct prueth_rx_chn *rx_chn, > + struct page *page, u32 buf_len); > +unsigned int prueth_rxbuf_total_len(unsigned int len); > void emac_rx_timestamp(struct prueth_emac *emac, > struct sk_buff *skb, u32 *psdata); > enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev); > diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c b/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c > index 64a19ff39562..aeeb8a50376b 100644 > --- a/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c > +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth_sr1.c > @@ -274,10 +274,12 @@ static struct sk_buff *prueth_process_rx_mgm(struct prueth_emac *emac, > struct prueth_rx_chn *rx_chn = &emac->rx_mgm_chn; > struct net_device *ndev = emac->ndev; > struct cppi5_host_desc_t *desc_rx; > - struct sk_buff *skb, *new_skb; > + struct page *page, *new_page; > dma_addr_t desc_dma, buf_dma; > u32 buf_dma_len, pkt_len; > + struct sk_buff *skb; Can we get rid of SKB entirely from the management channel code? The packet received on this channel is never passed to user space so I don't see why SKB is required. > void **swdata; > + void *pa; > int ret; > > ret = k3_udma_glue_pop_rx_chn(rx_chn->rx_chn, flow_id, &desc_dma); > @@ -299,32 +301,35 @@ static struct sk_buff *prueth_process_rx_mgm(struct prueth_emac *emac, > } > > swdata = cppi5_hdesc_get_swdata(desc_rx); > - skb = *swdata; > + page = *swdata; > cppi5_hdesc_get_obuf(desc_rx, &buf_dma, &buf_dma_len); > pkt_len = cppi5_hdesc_get_pktlen(desc_rx); > > dma_unmap_single(rx_chn->dma_dev, buf_dma, buf_dma_len, DMA_FROM_DEVICE); > k3_cppi_desc_pool_free(rx_chn->desc_pool, desc_rx); > > - new_skb = netdev_alloc_skb_ip_align(ndev, PRUETH_MAX_PKT_SIZE); > + new_page = page_pool_dev_alloc_pages(rx_chn->pg_pool); > /* if allocation fails we drop the packet but push the > * descriptor back to the ring with old skb to prevent a stall > */ > - if (!new_skb) { > + if (!new_page) { > netdev_err(ndev, > - "skb alloc failed, dropped mgm pkt from flow %d\n", > + "page alloc failed, dropped mgm pkt from flow %d\n", > flow_id); > - new_skb = skb; > + new_page = page; > skb = NULL; /* return NULL */ > } else { > /* return the filled skb */ > + pa = page_address(page); > + skb = napi_build_skb(pa, PAGE_SIZE); > skb_put(skb, pkt_len); > } > > /* queue another DMA */ > - ret = prueth_dma_rx_push(emac, new_skb, &emac->rx_mgm_chn); > + ret = prueth_dma_rx_push_mapped(emac, &emac->rx_chns, new_page, > + PRUETH_MAX_PKT_SIZE); > if (WARN_ON(ret < 0)) > - dev_kfree_skb_any(new_skb); > + page_pool_recycle_direct(rx_chn->pg_pool, new_page); > > return skb; > } -- cheers, -roger
