Commit 1751cc36 authored by Alex Maftei (amaftei)'s avatar Alex Maftei (amaftei) Committed by David S. Miller
Browse files

sfc: move common rx code



The moved code deals with managing rx buffers and queues.
A tiny bit of refactoring was required in other files to stitch the
code together.

Signed-off-by: default avatarAlexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5f999256
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+1 −1
Original line number Diff line number Diff line
# SPDX-License-Identifier: GPL-2.0
sfc-y			+= efx.o efx_common.o efx_channels.o nic.o \
			   farch.o siena.o ef10.o \
			   tx.o rx.o \
			   tx.o rx.o rx_common.o \
			   selftest.o ethtool.o ptp.o tx_tso.o \
			   mcdi.o mcdi_port.o \
			   mcdi_mon.o
+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@
 */

#include "net_driver.h"
#include "rx_common.h"
#include "ef10_regs.h"
#include "io.h"
#include "mcdi.h"
+0 −11
Original line number Diff line number Diff line
@@ -128,17 +128,6 @@ static int efx_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **xdpfs,
			ASSERT_RTNL();			\
	} while (0)

/**************************************************************************
 *
 * Channel handling
 *
 *************************************************************************/

void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
{
	mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
}

/**************************************************************************
 *
 * Port handling
+3 −0
Original line number Diff line number Diff line
@@ -37,6 +37,9 @@ static inline void efx_rx_flush_packet(struct efx_channel *channel)
		__efx_rx_packet(channel);
}

void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue);
struct page *efx_reuse_page(struct efx_rx_queue *rx_queue);

#define EFX_MAX_DMAQ_SIZE 4096UL
#define EFX_DEFAULT_DMAQ_SIZE 1024UL
#define EFX_MIN_DMAQ_SIZE 512UL
+3 −363
Original line number Diff line number Diff line
@@ -43,23 +43,10 @@
/* Size of buffer allocated for skb header area. */
#define EFX_SKB_HEADERS  128u

/* This is the percentage fill level below which new RX descriptors
 * will be added to the RX descriptor ring.
 */
static unsigned int rx_refill_threshold;

/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
				      EFX_RX_USR_BUF_SIZE)

/*
 * RX maximum head room required.
 *
 * This must be at least 1 to prevent overflow, plus one packet-worth
 * to allow pipelined receives.
 */
#define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)

static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
{
	return page_address(buf->page) + buf->page_offset;
@@ -86,22 +73,8 @@ static inline void efx_sync_rx_buffer(struct efx_nic *efx,
				DMA_FROM_DEVICE);
}

void efx_rx_config_page_split(struct efx_nic *efx)
{
	efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
				      XDP_PACKET_HEADROOM,
				      EFX_RX_BUF_ALIGNMENT);
	efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
		((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
		efx->rx_page_buf_step);
	efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
		efx->rx_bufs_per_page;
	efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
					       efx->rx_bufs_per_page);
}

/* Check the RX page recycle ring for a page that can be reused. */
static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
{
	struct efx_nic *efx = rx_queue->efx;
	struct page *page;
@@ -134,106 +107,6 @@ static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
	return NULL;
}

/**
 * efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 *
 * @rx_queue:		Efx RX queue
 *
 * This allocates a batch of pages, maps them for DMA, and populates
 * struct efx_rx_buffers for each one. Return a negative error code or
 * 0 on success. If a single page can be used for multiple buffers,
 * then the page will either be inserted fully, or not at all.
 */
int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
{
	struct efx_nic *efx = rx_queue->efx;
	struct efx_rx_buffer *rx_buf;
	struct page *page;
	unsigned int page_offset;
	struct efx_rx_page_state *state;
	dma_addr_t dma_addr;
	unsigned index, count;

	count = 0;
	do {
		page = efx_reuse_page(rx_queue);
		if (page == NULL) {
			page = alloc_pages(__GFP_COMP |
					   (atomic ? GFP_ATOMIC : GFP_KERNEL),
					   efx->rx_buffer_order);
			if (unlikely(page == NULL))
				return -ENOMEM;
			dma_addr =
				dma_map_page(&efx->pci_dev->dev, page, 0,
					     PAGE_SIZE << efx->rx_buffer_order,
					     DMA_FROM_DEVICE);
			if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
						       dma_addr))) {
				__free_pages(page, efx->rx_buffer_order);
				return -EIO;
			}
			state = page_address(page);
			state->dma_addr = dma_addr;
		} else {
			state = page_address(page);
			dma_addr = state->dma_addr;
		}

		dma_addr += sizeof(struct efx_rx_page_state);
		page_offset = sizeof(struct efx_rx_page_state);

		do {
			index = rx_queue->added_count & rx_queue->ptr_mask;
			rx_buf = efx_rx_buffer(rx_queue, index);
			rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
					   XDP_PACKET_HEADROOM;
			rx_buf->page = page;
			rx_buf->page_offset = page_offset + efx->rx_ip_align +
					      XDP_PACKET_HEADROOM;
			rx_buf->len = efx->rx_dma_len;
			rx_buf->flags = 0;
			++rx_queue->added_count;
			get_page(page);
			dma_addr += efx->rx_page_buf_step;
			page_offset += efx->rx_page_buf_step;
		} while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);

		rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
	} while (++count < efx->rx_pages_per_batch);

	return 0;
}

/* Unmap a DMA-mapped page.  This function is only called for the final RX
 * buffer in a page.
 */
void efx_unmap_rx_buffer(struct efx_nic *efx,
			 struct efx_rx_buffer *rx_buf)
{
	struct page *page = rx_buf->page;

	if (page) {
		struct efx_rx_page_state *state = page_address(page);
		dma_unmap_page(&efx->pci_dev->dev,
			       state->dma_addr,
			       PAGE_SIZE << efx->rx_buffer_order,
			       DMA_FROM_DEVICE);
	}
}

void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
			 struct efx_rx_buffer *rx_buf,
			 unsigned int num_bufs)
{
	do {
		if (rx_buf->page) {
			put_page(rx_buf->page);
			rx_buf->page = NULL;
		}
		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
	} while (--num_bufs);
}

/* Attempt to recycle the page if there is an RX recycle ring; the page can
 * only be added if this is the final RX buffer, to prevent pages being used in
 * the descriptor ring and appearing in the recycle ring simultaneously.
@@ -270,21 +143,6 @@ static void efx_recycle_rx_page(struct efx_channel *channel,
	put_page(rx_buf->page);
}

static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
			       struct efx_rx_buffer *rx_buf)
{
	/* Release the page reference we hold for the buffer. */
	if (rx_buf->page)
		put_page(rx_buf->page);

	/* If this is the last buffer in a page, unmap and free it. */
	if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
		efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
		efx_free_rx_buffers(rx_queue, rx_buf, 1);
	}
	rx_buf->page = NULL;
}

/* Recycle the pages that are used by buffers that have just been received. */
static void efx_recycle_rx_pages(struct efx_channel *channel,
				 struct efx_rx_buffer *rx_buf,
@@ -309,78 +167,6 @@ static void efx_discard_rx_packet(struct efx_channel *channel,
	efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
}

/**
 * efx_fast_push_rx_descriptors - push new RX descriptors quickly
 * @rx_queue:		RX descriptor queue
 *
 * This will aim to fill the RX descriptor queue up to
 * @rx_queue->@max_fill. If there is insufficient atomic
 * memory to do so, a slow fill will be scheduled.
 *
 * The caller must provide serialisation (none is used here). In practise,
 * this means this function must run from the NAPI handler, or be called
 * when NAPI is disabled.
 */
void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
{
	struct efx_nic *efx = rx_queue->efx;
	unsigned int fill_level, batch_size;
	int space, rc = 0;

	if (!rx_queue->refill_enabled)
		return;

	/* Calculate current fill level, and exit if we don't need to fill */
	fill_level = (rx_queue->added_count - rx_queue->removed_count);
	EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
	if (fill_level >= rx_queue->fast_fill_trigger)
		goto out;

	/* Record minimum fill level */
	if (unlikely(fill_level < rx_queue->min_fill)) {
		if (fill_level)
			rx_queue->min_fill = fill_level;
	}

	batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
	space = rx_queue->max_fill - fill_level;
	EFX_WARN_ON_ONCE_PARANOID(space < batch_size);

	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
		   "RX queue %d fast-filling descriptor ring from"
		   " level %d to level %d\n",
		   efx_rx_queue_index(rx_queue), fill_level,
		   rx_queue->max_fill);


	do {
		rc = efx_init_rx_buffers(rx_queue, atomic);
		if (unlikely(rc)) {
			/* Ensure that we don't leave the rx queue empty */
			efx_schedule_slow_fill(rx_queue);
			goto out;
		}
	} while ((space -= batch_size) >= batch_size);

	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
		   "RX queue %d fast-filled descriptor ring "
		   "to level %d\n", efx_rx_queue_index(rx_queue),
		   rx_queue->added_count - rx_queue->removed_count);

 out:
	if (rx_queue->notified_count != rx_queue->added_count)
		efx_nic_notify_rx_desc(rx_queue);
}

void efx_rx_slow_fill(struct timer_list *t)
{
	struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);

	/* Post an event to cause NAPI to run and refill the queue */
	efx_nic_generate_fill_event(rx_queue);
	++rx_queue->slow_fill_count;
}

static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
				     struct efx_rx_buffer *rx_buf,
				     int len)
@@ -797,41 +583,10 @@ out:
	channel->rx_pkt_n_frags = 0;
}

int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
{
	struct efx_nic *efx = rx_queue->efx;
	unsigned int entries;
	int rc;

	/* Create the smallest power-of-two aligned ring */
	entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
	EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
	rx_queue->ptr_mask = entries - 1;

	netif_dbg(efx, probe, efx->net_dev,
		  "creating RX queue %d size %#x mask %#x\n",
		  efx_rx_queue_index(rx_queue), efx->rxq_entries,
		  rx_queue->ptr_mask);

	/* Allocate RX buffers */
	rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
				   GFP_KERNEL);
	if (!rx_queue->buffer)
		return -ENOMEM;

	rc = efx_nic_probe_rx(rx_queue);
	if (rc) {
		kfree(rx_queue->buffer);
		rx_queue->buffer = NULL;
	}

	return rc;
}

static void efx_init_rx_recycle_ring(struct efx_nic *efx,
				     struct efx_rx_queue *rx_queue)
void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
{
	unsigned int bufs_in_recycle_ring, page_ring_size;
	struct efx_nic *efx = rx_queue->efx;

	/* Set the RX recycle ring size */
#ifdef CONFIG_PPC64
@@ -850,121 +605,6 @@ static void efx_init_rx_recycle_ring(struct efx_nic *efx,
	rx_queue->page_ptr_mask = page_ring_size - 1;
}

void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
{
	struct efx_nic *efx = rx_queue->efx;
	unsigned int max_fill, trigger, max_trigger;
	int rc = 0;

	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
		  "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));

	/* Initialise ptr fields */
	rx_queue->added_count = 0;
	rx_queue->notified_count = 0;
	rx_queue->removed_count = 0;
	rx_queue->min_fill = -1U;
	efx_init_rx_recycle_ring(efx, rx_queue);

	rx_queue->page_remove = 0;
	rx_queue->page_add = rx_queue->page_ptr_mask + 1;
	rx_queue->page_recycle_count = 0;
	rx_queue->page_recycle_failed = 0;
	rx_queue->page_recycle_full = 0;

	/* Initialise limit fields */
	max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
	max_trigger =
		max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
	if (rx_refill_threshold != 0) {
		trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
		if (trigger > max_trigger)
			trigger = max_trigger;
	} else {
		trigger = max_trigger;
	}

	rx_queue->max_fill = max_fill;
	rx_queue->fast_fill_trigger = trigger;
	rx_queue->refill_enabled = true;

	/* Initialise XDP queue information */
	rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
			      rx_queue->core_index);

	if (rc) {
		netif_err(efx, rx_err, efx->net_dev,
			  "Failure to initialise XDP queue information rc=%d\n",
			  rc);
		efx->xdp_rxq_info_failed = true;
	} else {
		rx_queue->xdp_rxq_info_valid = true;
	}

	/* Set up RX descriptor ring */
	efx_nic_init_rx(rx_queue);
}

void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
{
	int i;
	struct efx_nic *efx = rx_queue->efx;
	struct efx_rx_buffer *rx_buf;

	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
		  "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));

	del_timer_sync(&rx_queue->slow_fill);

	/* Release RX buffers from the current read ptr to the write ptr */
	if (rx_queue->buffer) {
		for (i = rx_queue->removed_count; i < rx_queue->added_count;
		     i++) {
			unsigned index = i & rx_queue->ptr_mask;
			rx_buf = efx_rx_buffer(rx_queue, index);
			efx_fini_rx_buffer(rx_queue, rx_buf);
		}
	}

	/* Unmap and release the pages in the recycle ring. Remove the ring. */
	for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
		struct page *page = rx_queue->page_ring[i];
		struct efx_rx_page_state *state;

		if (page == NULL)
			continue;

		state = page_address(page);
		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
			       PAGE_SIZE << efx->rx_buffer_order,
			       DMA_FROM_DEVICE);
		put_page(page);
	}
	kfree(rx_queue->page_ring);
	rx_queue->page_ring = NULL;

	if (rx_queue->xdp_rxq_info_valid)
		xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);

	rx_queue->xdp_rxq_info_valid = false;
}

void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
{
	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
		  "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));

	efx_nic_remove_rx(rx_queue);

	kfree(rx_queue->buffer);
	rx_queue->buffer = NULL;
}


module_param(rx_refill_threshold, uint, 0444);
MODULE_PARM_DESC(rx_refill_threshold,
		 "RX descriptor ring refill threshold (%)");

#ifdef CONFIG_RFS_ACCEL

static void efx_filter_rfs_work(struct work_struct *data)
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