Commit bb837a37 authored by Gerhard Engleder's avatar Gerhard Engleder Committed by David S. Miller
Browse files

tsnep: Use page pool for RX 



Use page pool for RX buffer handling. Makes RX path more efficient and
is required prework for future XDP support.

Signed-off-by: default avatarGerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 308ce142

drivers/net/ethernet/engleder/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ config TSNEP 
	depends on HAS_IOMEM && HAS_DMA

	depends on PTP_1588_CLOCK_OPTIONAL

	select PHYLIB

	select PAGE_POOL

	help

	  Support for the Engleder TSN endpoint Ethernet MAC IP Core.

drivers/net/ethernet/engleder/tsnep.h

+3 −2
Original line number Diff line number Diff line
@@ -96,9 +96,9 @@ struct tsnep_rx_entry { 


	u32 properties;



	struct sk_buff *skb;

	struct page *page;

	size_t len;

	DEFINE_DMA_UNMAP_ADDR(dma);

	dma_addr_t dma;

};



struct tsnep_rx {
@@ -113,6 +113,7 @@ struct tsnep_rx { 
	int read;

	u32 owner_counter;

	int increment_owner_counter;

	struct page_pool *page_pool;



	u32 packets;

	u32 bytes;

drivers/net/ethernet/engleder/tsnep_main.c

+96 −66
Original line number Diff line number Diff line
@@ -27,10 +27,10 @@ 
#include <linux/phy.h>

#include <linux/iopoll.h>



#define RX_SKB_LENGTH (round_up(TSNEP_RX_INLINE_METADATA_SIZE + ETH_HLEN + \

				TSNEP_MAX_FRAME_SIZE + ETH_FCS_LEN, 4))

#define RX_SKB_RESERVE ((16 - TSNEP_RX_INLINE_METADATA_SIZE) + NET_IP_ALIGN)

#define RX_SKB_ALLOC_LENGTH (RX_SKB_RESERVE + RX_SKB_LENGTH)

#define TSNEP_SKB_PAD (NET_SKB_PAD + NET_IP_ALIGN)

#define TSNEP_HEADROOM ALIGN(TSNEP_SKB_PAD, 4)

#define TSNEP_MAX_RX_BUF_SIZE (PAGE_SIZE - TSNEP_HEADROOM - \

			       SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))



#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT

#define DMA_ADDR_HIGH(dma_addr) ((u32)(((dma_addr) >> 32) & 0xFFFFFFFF))
@@ -587,14 +587,15 @@ static void tsnep_rx_ring_cleanup(struct tsnep_rx *rx) 


	for (i = 0; i < TSNEP_RING_SIZE; i++) {

		entry = &rx->entry[i];

		if (dma_unmap_addr(entry, dma))

			dma_unmap_single(dmadev, dma_unmap_addr(entry, dma),

					 dma_unmap_len(entry, len),

					 DMA_FROM_DEVICE);

		if (entry->skb)

			dev_kfree_skb(entry->skb);

		if (entry->page)

			page_pool_put_full_page(rx->page_pool, entry->page,

						false);

		entry->page = NULL;

	}



	if (rx->page_pool)

		page_pool_destroy(rx->page_pool);



	memset(rx->entry, 0, sizeof(rx->entry));



	for (i = 0; i < TSNEP_RING_PAGE_COUNT; i++) {
@@ -607,31 +608,19 @@ static void tsnep_rx_ring_cleanup(struct tsnep_rx *rx) 
	}

}



static int tsnep_rx_alloc_and_map_skb(struct tsnep_rx *rx,

static int tsnep_rx_alloc_buffer(struct tsnep_rx *rx,

				 struct tsnep_rx_entry *entry)

{

	struct device *dmadev = rx->adapter->dmadev;

	struct sk_buff *skb;

	dma_addr_t dma;

	struct page *page;



	skb = __netdev_alloc_skb(rx->adapter->netdev, RX_SKB_ALLOC_LENGTH,

				 GFP_ATOMIC | GFP_DMA);

	if (!skb)

	page = page_pool_dev_alloc_pages(rx->page_pool);

	if (unlikely(!page))

		return -ENOMEM;



	skb_reserve(skb, RX_SKB_RESERVE);



	dma = dma_map_single(dmadev, skb->data, RX_SKB_LENGTH,

			     DMA_FROM_DEVICE);

	if (dma_mapping_error(dmadev, dma)) {

		dev_kfree_skb(skb);

		return -ENOMEM;

	}



	entry->skb = skb;

	entry->len = RX_SKB_LENGTH;

	dma_unmap_addr_set(entry, dma, dma);

	entry->desc->rx = __cpu_to_le64(dma);

	entry->page = page;

	entry->len = TSNEP_MAX_RX_BUF_SIZE;

	entry->dma = page_pool_get_dma_addr(entry->page);

	entry->desc->rx = __cpu_to_le64(entry->dma + TSNEP_SKB_PAD);



	return 0;

}
@@ -640,6 +629,7 @@ static int tsnep_rx_ring_init(struct tsnep_rx *rx) 
{

	struct device *dmadev = rx->adapter->dmadev;

	struct tsnep_rx_entry *entry;

	struct page_pool_params pp_params = { 0 };

	struct tsnep_rx_entry *next_entry;

	int i, j;

	int retval;
@@ -661,12 +651,28 @@ static int tsnep_rx_ring_init(struct tsnep_rx *rx) 
			entry->desc_dma = rx->page_dma[i] + TSNEP_DESC_SIZE * j;

		}

	}



	pp_params.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV;

	pp_params.order = 0;

	pp_params.pool_size = TSNEP_RING_SIZE;

	pp_params.nid = dev_to_node(dmadev);

	pp_params.dev = dmadev;

	pp_params.dma_dir = DMA_FROM_DEVICE;

	pp_params.max_len = TSNEP_MAX_RX_BUF_SIZE;

	pp_params.offset = TSNEP_SKB_PAD;

	rx->page_pool = page_pool_create(&pp_params);

	if (IS_ERR(rx->page_pool)) {

		retval = PTR_ERR(rx->page_pool);

		rx->page_pool = NULL;

		goto failed;

	}



	for (i = 0; i < TSNEP_RING_SIZE; i++) {

		entry = &rx->entry[i];

		next_entry = &rx->entry[(i + 1) % TSNEP_RING_SIZE];

		entry->desc->next = __cpu_to_le64(next_entry->desc_dma);



		retval = tsnep_rx_alloc_and_map_skb(rx, entry);

		retval = tsnep_rx_alloc_buffer(rx, entry);

		if (retval)

			goto failed;

	}
@@ -682,7 +688,7 @@ static void tsnep_rx_activate(struct tsnep_rx *rx, int index) 
{

	struct tsnep_rx_entry *entry = &rx->entry[index];



	/* RX_SKB_LENGTH is a multiple of 4 */

	/* TSNEP_MAX_RX_BUF_SIZE is a multiple of 4 */

	entry->properties = entry->len & TSNEP_DESC_LENGTH_MASK;

	entry->properties |= TSNEP_DESC_INTERRUPT_FLAG;

	if (index == rx->increment_owner_counter) {
@@ -705,19 +711,52 @@ static void tsnep_rx_activate(struct tsnep_rx *rx, int index) 
	entry->desc->properties = __cpu_to_le32(entry->properties);

}



static struct sk_buff *tsnep_build_skb(struct tsnep_rx *rx, struct page *page,

				       int length)

{

	struct sk_buff *skb;



	skb = napi_build_skb(page_address(page), PAGE_SIZE);

	if (unlikely(!skb))

		return NULL;



	/* update pointers within the skb to store the data */

	skb_reserve(skb, TSNEP_SKB_PAD + TSNEP_RX_INLINE_METADATA_SIZE);

	__skb_put(skb, length - TSNEP_RX_INLINE_METADATA_SIZE - ETH_FCS_LEN);



	if (rx->adapter->hwtstamp_config.rx_filter == HWTSTAMP_FILTER_ALL) {

		struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);

		struct tsnep_rx_inline *rx_inline =

			(struct tsnep_rx_inline *)(page_address(page) +

						   TSNEP_SKB_PAD);



		skb_shinfo(skb)->tx_flags |=

			SKBTX_HW_TSTAMP_NETDEV;

		memset(hwtstamps, 0, sizeof(*hwtstamps));

		hwtstamps->netdev_data = rx_inline;

	}



	skb_record_rx_queue(skb, rx->queue_index);

	skb->protocol = eth_type_trans(skb, rx->adapter->netdev);



	return skb;

}



static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi,

			 int budget)

{

	struct device *dmadev = rx->adapter->dmadev;

	int done = 0;

	enum dma_data_direction dma_dir;

	struct tsnep_rx_entry *entry;

	struct page *page;

	struct sk_buff *skb;

	size_t len;

	dma_addr_t dma;

	int length;

	bool enable = false;

	int retval;



	dma_dir = page_pool_get_dma_dir(rx->page_pool);



	while (likely(done < budget)) {

		entry = &rx->entry[rx->read];

		if ((__le32_to_cpu(entry->desc_wb->properties) &
@@ -730,43 +769,34 @@ static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi, 
		 */

		dma_rmb();



		skb = entry->skb;

		len = dma_unmap_len(entry, len);

		dma = dma_unmap_addr(entry, dma);

		prefetch(page_address(entry->page) + TSNEP_SKB_PAD);

		length = __le32_to_cpu(entry->desc_wb->properties) &

			 TSNEP_DESC_LENGTH_MASK;

		dma_sync_single_range_for_cpu(dmadev, entry->dma, TSNEP_SKB_PAD,

					      length, dma_dir);

		page = entry->page;



		/* forward skb only if allocation is successful, otherwise

		 * skb is reused and frame dropped

		 * page is reused and frame dropped

		 */

		retval = tsnep_rx_alloc_and_map_skb(rx, entry);

		retval = tsnep_rx_alloc_buffer(rx, entry);

		if (!retval) {

			dma_unmap_single(dmadev, dma, len, DMA_FROM_DEVICE);



			length = __le32_to_cpu(entry->desc_wb->properties) &

				 TSNEP_DESC_LENGTH_MASK;

			skb_put(skb, length - ETH_FCS_LEN);

			if (rx->adapter->hwtstamp_config.rx_filter ==

			    HWTSTAMP_FILTER_ALL) {

				struct skb_shared_hwtstamps *hwtstamps =

					skb_hwtstamps(skb);

				struct tsnep_rx_inline *rx_inline =

					(struct tsnep_rx_inline *)skb->data;



				skb_shinfo(skb)->tx_flags |=

					SKBTX_HW_TSTAMP_NETDEV;

				memset(hwtstamps, 0, sizeof(*hwtstamps));

				hwtstamps->netdev_data = rx_inline;

			}

			skb_pull(skb, TSNEP_RX_INLINE_METADATA_SIZE);

			skb_record_rx_queue(skb, rx->queue_index);

			skb->protocol = eth_type_trans(skb,

						       rx->adapter->netdev);

			skb = tsnep_build_skb(rx, page, length);

			if (skb) {

				page_pool_release_page(rx->page_pool, page);



				rx->packets++;

			rx->bytes += length - TSNEP_RX_INLINE_METADATA_SIZE;

				rx->bytes += length -

					     TSNEP_RX_INLINE_METADATA_SIZE;

				if (skb->pkt_type == PACKET_MULTICAST)

					rx->multicast++;



				napi_gro_receive(napi, skb);

			} else {

				page_pool_recycle_direct(rx->page_pool, page);



				rx->dropped++;

			}

			done++;

		} else {

			rx->dropped++;