// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2018, Intel Corporation. */
/* The driver transmit and receive code */
#include <linux/prefetch.h>
#include <linux/mm.h>
#include "ice.h"
#include "ice_dcb_lib.h"
#define ICE_RX_HDR_SIZE 256
/**
* ice_unmap_and_free_tx_buf - Release a Tx buffer
* @ring: the ring that owns the buffer
* @tx_buf: the buffer to free
*/
static void
ice_unmap_and_free_tx_buf(struct ice_ring *ring, struct ice_tx_buf *tx_buf)
{
if (tx_buf->skb) {
dev_kfree_skb_any(tx_buf->skb);
if (dma_unmap_len(tx_buf, len))
dma_unmap_single(ring->dev,
dma_unmap_addr(tx_buf, dma),
dma_unmap_len(tx_buf, len),
DMA_TO_DEVICE);
} else if (dma_unmap_len(tx_buf, len)) {
dma_unmap_page(ring->dev,
dma_unmap_addr(tx_buf, dma),
dma_unmap_len(tx_buf, len),
DMA_TO_DEVICE);
}
tx_buf->next_to_watch = NULL;
tx_buf->skb = NULL;
dma_unmap_len_set(tx_buf, len, 0);
/* tx_buf must be completely set up in the transmit path */
}
static struct netdev_queue *txring_txq(const struct ice_ring *ring)
{
return netdev_get_tx_queue(ring->netdev, ring->q_index);
}
/**
* ice_clean_tx_ring - Free any empty Tx buffers
* @tx_ring: ring to be cleaned
*/
void ice_clean_tx_ring(struct ice_ring *tx_ring)
{
u16 i;
/* ring already cleared, nothing to do */
if (!tx_ring->tx_buf)
return;
/* Free all the Tx ring sk_buffs */
for (i = 0; i < tx_ring->count; i++)
ice_unmap_and_free_tx_buf(tx_ring, &tx_ring->tx_buf[i]);
memset(tx_ring->tx_buf, 0, sizeof(*tx_ring->tx_buf) * tx_ring->count);
/* Zero out the descriptor ring */
memset(tx_ring->desc, 0, tx_ring->size);
tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0;
if (!tx_ring->netdev)
return;
/* cleanup Tx queue statistics */
netdev_tx_reset_queue(txring_txq(tx_ring));
}
/**
* ice_free_tx_ring - Free Tx resources per queue
* @tx_ring: Tx descriptor ring for a specific queue
*
* Free all transmit software resources
*/
void ice_free_tx_ring(struct ice_ring *tx_ring)
{
ice_clean_tx_ring(tx_ring);
devm_kfree(tx_ring->dev, tx_ring->tx_buf);
tx_ring->tx_buf = NULL;
if (tx_ring->desc) {
dmam_free_coherent(tx_ring->dev, tx_ring->size,
tx_ring->desc, tx_ring->dma);
tx_ring->desc = NULL;
}
}
/**
* ice_clean_tx_irq - Reclaim resources after transmit completes
* @vsi: the VSI we care about
* @tx_ring: Tx ring to clean
* @napi_budget: Used to determine if we are in netpoll
*
* Returns true if there's any budget left (e.g. the clean is finished)
*/
static bool
ice_clean_tx_irq(struct ice_vsi *vsi, struct ice_ring *tx_ring, int napi_budget)
{
unsigned int total_bytes = 0, total_pkts = 0;
unsigned int budget = vsi->work_lmt;
s16 i = tx_ring->next_to_clean;
struct ice_tx_desc *tx_desc;
struct ice_tx_buf *tx_buf;
tx_buf = &tx_ring->tx_buf[i];
tx_desc = ICE_TX_DESC(tx_ring, i);
i -= tx_ring->count;
do {
struct ice_tx_desc *eop_desc = tx_buf->next_to_watch;
/* if next_to_watch is not set then there is no work pending */
if (!eop_desc)
break;
smp_rmb(); /* prevent any other reads prior to eop_desc */
/* if the descriptor isn't done, no work yet to do */
if (!(eop_desc->cmd_type_offset_bsz &
cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE)))
break;
/* clear next_to_watch to prevent false hangs */
tx_buf->next_to_watch = NULL;
/* update the statistics for this packet */
total_bytes += tx_buf->bytecount;
total_pkts += tx_buf->gso_segs;
/* free the skb */
napi_consume_skb(tx_buf->skb, napi_budget);
/* unmap skb header data */
dma_unmap_single(tx_ring->dev,
dma_unmap_addr(tx_buf, dma),
dma_unmap_len(tx_buf, len),
DMA_TO_DEVICE);
/* clear tx_buf data */
tx_buf->skb = NULL;
dma_unmap_len_set(tx_buf, len, 0);
/* unmap remaining buffers */
while (tx_desc != eop_desc) {
tx_buf++;
tx_desc++;
i++;
if (unlikely(!i)) {
i -= tx_ring->count;
tx_buf = tx_ring->tx_buf;
tx_desc = ICE_TX_DESC(tx_ring, 0);
}
/* unmap any remaining paged data */
if (dma_unmap_len(tx_buf, len)) {
dma_unmap_page(tx_ring->dev,
dma_unmap_addr(tx_buf, dma),
dma_unmap_len(tx_buf, len),
DMA_TO_DEVICE);
dma_unmap_len_set(tx_buf, len, 0);
}
}
/* move us one more past the eop_desc for start of next pkt */
tx_buf++;
tx_desc++;
i++;
if (unlikely(!i)) {
i -= tx_ring->count;
tx_buf = tx_ring->tx_buf;
tx_desc = ICE_TX_DESC(tx_ring, 0);
}
prefetch(tx_desc);
/* update budget accounting */
budget--;
} while (likely(budget));
i += tx_ring->count;
tx_ring->next_to_clean = i;
u64_stats_update_begin(&tx_ring->syncp);
tx_ring->stats.bytes += total_bytes;
tx_ring->stats.pkts += total_pkts;
u64_stats_update_end(&tx_ring->syncp);
tx_ring->q_vector->tx.total_bytes += total_bytes;
tx_ring->q_vector->tx.total_pkts += total_pkts;
netdev_tx_completed_queue(txring_txq(tx_ring), total_pkts,
total_bytes);
#define TX_WAKE_THRESHOLD ((s16)(DESC_NEEDED * 2))
if (unlikely(total_pkts && netif_carrier_ok(tx_ring->netdev) &&
(ICE_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) {
/* Make sure that anybody stopping the queue after this
* sees the new next_to_clean.
*/
smp_mb();
if (__netif_subqueue_stopped(tx_ring->netdev,
tx_ring->q_index) &&
!test_bit(__ICE_DOWN, vsi->state)) {
netif_wake_subqueue(tx_ring->netdev,
tx_ring->q_index);
++tx_ring->tx_stats.restart_q;
}
}
return !!budget;
}
/**
* ice_setup_tx_ring - Allocate the Tx descriptors
* @tx_ring: the Tx ring to set up
*
* Return 0 on success, negative on error
*/
int ice_setup_tx_ring(struct ice_ring *tx_ring)
{
struct device *dev = tx_ring->dev;
if (!dev)
return -ENOMEM;
/* warn if we are about to overwrite the pointer */
WARN_ON(tx_ring->tx_buf);
tx_ring->tx_buf =
devm_kzalloc(dev, sizeof(*tx_ring->tx_buf) * tx_ring->count,
GFP_KERNEL);
if (!tx_ring->tx_buf)
return -ENOMEM;
/* round up to nearest page */
tx_ring->size = ALIGN(tx_ring->count * sizeof(struct ice_tx_desc),
PAGE_SIZE);
tx_ring->desc = dmam_alloc_coherent(dev, tx_ring->size, &tx_ring->dma,
GFP_KERNEL);
if (!tx_ring->desc) {
dev_err(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n",
tx_ring->size);
goto err;
}
tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0;
tx_ring->tx_stats.prev_pkt = -1;
return 0;
err:
devm_kfree(dev, tx_ring->tx_buf);
tx_ring->tx_buf = NULL;
return -ENOMEM;
}
/**
* ice_clean_rx_ring - Free Rx buffers
* @rx_ring: ring to be cleaned
*/
void ice_clean_rx_ring(struct ice_ring *rx_ring)
{
struct device *dev = rx_ring->dev;
u16 i;
/* ring already cleared, nothing to do */
if (!rx_ring->rx_buf)
return;
/* Free all the Rx ring sk_buffs */
for (i = 0; i < rx_ring->count; i++) {
struct ice_rx_buf *rx_buf = &rx_ring->rx_buf[i];
if (rx_buf->skb) {
dev_kfree_skb(rx_buf->skb);
rx_buf->skb = NULL;
}
if (!rx_buf->page)
continue;
/* Invalidate cache lines that may have been written to by
* device so that we avoid corrupting memory.
*/
dma_sync_single_range_for_cpu(dev, rx_buf->dma,
rx_buf->page_offset,
ICE_RXBUF_2048, DMA_FROM_DEVICE);
/* free resources associated with mapping */
dma_unmap_page_attrs(dev, rx_buf->dma, PAGE_SIZE,
DMA_FROM_DEVICE, ICE_RX_DMA_ATTR);
__page_frag_cache_drain(rx_buf->page, rx_buf->pagecnt_bias);
rx_buf->page = NULL;
rx_buf->page_offset = 0;
}
memset(rx_ring->rx_buf, 0, sizeof(*rx_ring->rx_buf) * rx_ring->count);
/* Zero out the descriptor ring */
memset(rx_ring->desc, 0, rx_ring->size);
rx_ring->next_to_alloc = 0;
rx_ring->next_to_clean = 0;
rx_ring->next_to_use = 0;
}
/**
* ice_free_rx_ring - Free Rx resources
* @rx_ring: ring to clean the resources from
*
* Free all receive software resources
*/
void ice_free_rx_ring(struct ice_ring *rx_ring)
{
ice_clean_rx_ring(rx_ring);
devm_kfree(rx_ring->dev, rx_ring->rx_buf);
rx_ring->rx_buf = NULL;
if (rx_ring->desc) {
dmam_free_coherent(rx_ring->dev, rx_ring->size,
rx_ring->desc, rx_ring->dma);
rx_ring->desc = NULL;
}
}
/**
* ice_setup_rx_ring - Allocate the Rx descriptors
* @rx_ring: the Rx ring to set up
*
* Return 0 on success, negative on error
*/
int ice_setup_rx_ring(struct ice_ring *rx_ring)
{
struct device *dev = rx_ring->dev;
if (!dev)
return -ENOMEM;
/* warn if we are about to overwrite the pointer */
WARN_ON(rx_ring->rx_buf);
rx_ring->rx_buf =
devm_kzalloc(dev, sizeof(*rx_ring->rx_buf) * rx_ring->count,
GFP_KERNEL);
if (!rx_ring->rx_buf)
return -ENOMEM;
/* round up to nearest page */
rx_ring->size = ALIGN(rx_ring->count * sizeof(union ice_32byte_rx_desc),
PAGE_SIZE);
rx_ring->desc = dmam_alloc_coherent(dev, rx_ring->size, &rx_ring->dma,
GFP_KERNEL);
if (!rx_ring->desc) {
dev_err(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n",
rx_ring->size);
goto err;
}
rx_ring->next_to_use = 0;
rx_ring->next_to_clean = 0;
return 0;
err:
devm_kfree(dev, rx_ring->rx_buf);
rx_ring->rx_buf = NULL;
return -ENOMEM;
}
/**
* ice_release_rx_desc - Store the new tail and head values
* @rx_ring: ring to bump
* @val: new head index
*/
static void ice_release_rx_desc(struct ice_ring *rx_ring, u32 val)
{
rx_ring->next_to_use = val;
/* update next to alloc since we have filled the ring */
rx_ring->next_to_alloc = val;
/* Force memory writes to complete before letting h/w
* know there are new descriptors to fetch. (Only
* applicable for weak-ordered memory model archs,
* such as IA-64).
*/
wmb();
writel(val, rx_ring->tail);
}
/**
* ice_alloc_mapped_page - recycle or make a new page
* @rx_ring: ring to use
* @bi: rx_buf struct to modify
*
* Returns true if the page was successfully allocated or
* reused.
*/
static bool
ice_alloc_mapped_page(struct ice_ring *rx_ring, struct ice_rx_buf *bi)
{
struct page *page = bi->page;
dma_addr_t dma;
/* since we are recycling buffers we should seldom need to alloc */
if (likely(page)) {
rx_ring->rx_stats.page_reuse_count++;
return true;
}
/* alloc new page for storage */
page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!page)) {
rx_ring->rx_stats.alloc_page_failed++;
return false;
}
/* map page for use */
dma = dma_map_page_attrs(rx_ring->dev, page, 0, PAGE_SIZE,
DMA_FROM_DEVICE, ICE_RX_DMA_ATTR);
/* if mapping failed free memory back to system since
* there isn't much point in holding memory we can't use
*/
if (dma_mapping_error(rx_ring->dev, dma)) {
__free_pages(page, 0);
rx_ring->rx_stats.alloc_page_failed++;
return false;
}
bi->dma = dma;
bi->page = page;
bi->page_offset = 0;
page_ref_add(page, USHRT_MAX - 1);
bi->pagecnt_bias = USHRT_MAX;
return true;
}
/**
* ice_alloc_rx_bufs - Replace used receive buffers
* @rx_ring: ring to place buffers on
* @cleaned_count: number of buffers to replace
*
* Returns false if all allocations were successful, true if any fail
*/
bool ice_alloc_rx_bufs(struct ice_ring *rx_ring, u16 cleaned_count)
{
union ice_32b_rx_flex_desc *rx_desc;
u16 ntu = rx_ring->next_to_use;
struct ice_rx_buf *bi;
/* do nothing if no valid netdev defined */
if (!rx_ring->netdev || !cleaned_count)
return false;
/* get the Rx descriptor and buffer based on next_to_use */
rx_desc = ICE_RX_DESC(rx_ring, ntu);
bi = &rx_ring->rx_buf[ntu];
do {
if (!ice_alloc_mapped_page(rx_ring, bi))
goto no_bufs;
/* sync the buffer for use by the device */
dma_sync_single_range_for_device(rx_ring->dev, bi->dma,
bi->page_offset,
ICE_RXBUF_2048,
DMA_FROM_DEVICE);
/* Refresh the desc even if buffer_addrs didn't change
* because each write-back erases this info.
*/
rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);
rx_desc++;
bi++;
ntu++;
if (unlikely(ntu == rx_ring->count)) {
rx_desc = ICE_RX_DESC(rx_ring, 0);
bi = rx_ring->rx_buf;
ntu = 0;
}
/* clear the status bits for the next_to_use descriptor */
rx_desc->wb.status_error0 = 0;
cleaned_count--;
} while (cleaned_count);
if (rx_ring->next_to_use != ntu)
ice_release_rx_desc(rx_ring, ntu);
return false;
no_bufs:
if (rx_ring->next_to_use != ntu)
ice_release_rx_desc(rx_ring, ntu);
/* make sure to come back via polling to try again after
* allocation failure
*/
return true;
}
/**
* ice_page_is_reserved - check if reuse is possible
* @page: page struct to check
*/
static bool ice_page_is_reserved(struct page *page)
{
return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
}
/**
* ice_rx_buf_adjust_pg_offset - Prepare Rx buffer for reuse
* @rx_buf: Rx buffer to adjust
* @size: Size of adjustment
*
* Update the offset within page so that Rx buf will be ready to be reused.
* For systems with PAGE_SIZE < 8192 this function will flip the page offset
* so the second half of page assigned to Rx buffer will be used, otherwise
* the offset is moved by the @size bytes
*/
static void
ice_rx_buf_adjust_pg_offset(struct ice_rx_buf *rx_buf, unsigned int size)
{
#if (PAGE_SIZE < 8192)
/* flip page offset to other buffer */
rx_buf->page_offset ^= size;
#else
/* move offset up to the next cache line */
rx_buf->page_offset += size;
#endif
}
/**
* ice_can_reuse_rx_page - Determine if page can be reused for another Rx
* @rx_buf: buffer containing the page
*
* If page is reusable, we have a green light for calling ice_reuse_rx_page,
* which will assign the current buffer to the buffer that next_to_alloc is
* pointing to; otherwise, the DMA mapping needs to be destroyed and
* page freed
*/
static bool ice_can_reuse_rx_page(struct ice_rx_buf *rx_buf)
{
#if (PAGE_SIZE >= 8192)
unsigned int last_offset = PAGE_SIZE - ICE_RXBUF_2048;
#endif
unsigned int pagecnt_bias = rx_buf->pagecnt_bias;
struct page *page = rx_buf->page;
/* avoid re-using remote pages */
if (unlikely(ice_page_is_reserved(page)))
return false;
#if (PAGE_SIZE < 8192)
/* if we are only owner of page we can reuse it */
if (unlikely((page_count(page) - pagecnt_bias) > 1))
return false;
#else
if (rx_buf->page_offset > last_offset)
return false;
#endif /* PAGE_SIZE < 8192) */
/* If we have drained the page fragment pool we need to update
* the pagecnt_bias and page count so that we fully restock the
* number of references the driver holds.
*/
if (unlikely(pagecnt_bias == 1)) {
page_ref_add(page, USHRT_MAX - 1);
rx_buf->pagecnt_bias = USHRT_MAX;
}
return true;
}
/**
* ice_add_rx_frag - Add contents of Rx buffer to sk_buff as a frag
* @rx_buf: buffer containing page to add
* @skb: sk_buff to place the data into
* @size: packet length from rx_desc
*
* This function will add the data contained in rx_buf->page to the skb.
* It will just attach the page as a frag to the skb.
* The function will then update the page offset.
*/
static void
ice_add_rx_frag(struct ice_rx_buf *rx_buf, struct sk_buff *skb,
unsigned int size)
{
#if (PAGE_SIZE >= 8192)
unsigned int truesize = SKB_DATA_ALIGN(size);
#else
unsigned int truesize = ICE_RXBUF_2048;
#endif
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buf->page,
rx_buf->page_offset, size, truesize);
/* page is being used so we must update the page offset */
ice_rx_buf_adjust_pg_offset(rx_buf, truesize);
}
/**
* ice_reuse_rx_page - page flip buffer and store it back on the ring
* @rx_ring: Rx descriptor ring to store buffers on
* @old_buf: donor buffer to have page reused
*
* Synchronizes page for reuse by the adapter
*/
static void
ice_reuse_rx_page(struct ice_ring *rx_ring, struct ice_rx_buf *old_buf)
{
u16 nta = rx_ring->next_to_alloc;
struct ice_rx_buf *new_buf;
new_buf = &rx_ring->rx_buf[nta];
/* update, and store next to alloc */
nta++;
rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
/* Transfer page from old buffer to new buffer.
* Move each member individually to avoid possible store
* forwarding stalls and unnecessary copy of skb.
*/
new_buf->dma = old_buf->dma;
new_buf->page = old_buf->page;
new_buf->page_offset = old_buf->page_offset;
new_buf->pagecnt_bias = old_buf->pagecnt_bias;
}
/**
* ice_get_rx_buf - Fetch Rx buffer and synchronize data for use
* @rx_ring: Rx descriptor ring to transact packets on
* @skb: skb to be used
* @size: size of buffer to add to skb
*
* This function will pull an Rx buffer from the ring and synchronize it
* for use by the CPU.
*/
static struct ice_rx_buf *
ice_get_rx_buf(struct ice_ring *rx_ring, struct sk_buff **skb,
const unsigned int size)
{
struct ice_rx_buf *rx_buf;
rx_buf = &rx_ring->rx_buf[rx_ring->next_to_clean];
prefetchw(rx_buf->page);
*skb = rx_buf->skb;
/* we are reusing so sync this buffer for CPU use */
dma_sync_single_range_for_cpu(rx_ring->dev, rx_buf->dma,
rx_buf->page_offset, size,
DMA_FROM_DEVICE);
/* We have pulled a buffer for use, so decrement pagecnt_bias */
rx_buf->pagecnt_bias--;
return rx_buf;
}
/**
* ice_construct_skb - Allocate skb and populate it
* @rx_ring: Rx descriptor ring to transact packets on
* @rx_buf: Rx buffer to pull data from
* @size: the length of the packet
*
* This function allocates an skb. It then populates it with the page
* data from the current receive descriptor, taking care to set up the
* skb correctly.
*/
static struct sk_buff *
ice_construct_skb(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,
unsigned int size)
{
void *va = page_address(rx_buf->page) + rx_buf->page_offset;
unsigned int headlen;
struct sk_buff *skb;
/* prefetch first cache line of first page */
prefetch(va);
#if L1_CACHE_BYTES < 128
prefetch((u8 *)va + L1_CACHE_BYTES);
#endif /* L1_CACHE_BYTES */
/* allocate a skb to store the frags */
skb = __napi_alloc_skb(&rx_ring->q_vector->napi, ICE_RX_HDR_SIZE,
GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!skb))
return NULL;
skb_record_rx_queue(skb, rx_ring->q_index);
/* Determine available headroom for copy */
headlen = size;
if (headlen > ICE_RX_HDR_SIZE)
headlen = eth_get_headlen(skb->dev, va, ICE_RX_HDR_SIZE);
/* align pull length to size of long to optimize memcpy performance */
memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long)));
/* if we exhaust the linear part then add what is left as a frag */
size -= headlen;
if (size) {
#if (PAGE_SIZE >= 8192)
unsigned int truesize = SKB_DATA_ALIGN(size);
#else
unsigned int truesize = ICE_RXBUF_2048;
#endif
skb_add_rx_frag(skb, 0, rx_buf->page,
rx_buf->page_offset + headlen, size, truesize);
/* buffer is used by skb, update page_offset */
ice_rx_buf_adjust_pg_offset(rx_buf, truesize);
} else {
/* buffer is unused, reset bias back to rx_buf; data was copied
* onto skb's linear part so there's no need for adjusting
* page offset and we can reuse this buffer as-is
*/
rx_buf->pagecnt_bias++;
}
return skb;
}
/**
* ice_put_rx_buf - Clean up used buffer and either recycle or free
* @rx_ring: Rx descriptor ring to transact packets on
* @rx_buf: Rx buffer to pull data from
*
* This function will clean up the contents of the rx_buf. It will
* either recycle the buffer or unmap it and free the associated resources.
*/
static void ice_put_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf)
{
/* hand second half of page back to the ring */
if (ice_can_reuse_rx_page(rx_buf)) {
ice_reuse_rx_page(rx_ring, rx_buf);
rx_ring->rx_stats.page_reuse_count++;
} else {
/* we are not reusing the buffer so unmap it */
dma_unmap_page_attrs(rx_ring->dev, rx_buf->dma, PAGE_SIZE,
DMA_FROM_DEVICE, ICE_RX_DMA_ATTR);
__page_frag_cache_drain(rx_buf->page, rx_buf->pagecnt_bias);
}
/* clear contents of buffer_info */
rx_buf->page = NULL;
rx_buf->skb = NULL;
}
/**
* ice_cleanup_headers - Correct empty headers
* @skb: pointer to current skb being fixed
*
* Also address the case where we are pulling data in on pages only
* and as such no data is present in the skb header.
*
* In addition if skb is not at least 60 bytes we need to pad it so that
* it is large enough to qualify as a valid Ethernet frame.
*
* Returns true if an error was encountered and skb was freed.
*/
static bool ice_cleanup_headers(struct sk_buff *skb)
{
/* if eth_skb_pad returns an error the skb was freed */
if (eth_skb_pad(skb))
return true;
return false;
}
/**
* ice_test_staterr - tests bits in Rx descriptor status and error fields
* @rx_desc: pointer to receive descriptor (in le64 format)
* @stat_err_bits: value to mask
*
* This function does some fast chicanery in order to return the
* value of the mask which is really only used for boolean tests.
* The status_error_len doesn't need to be shifted because it begins
* at offset zero.
*/
static bool
ice_test_staterr(union ice_32b_rx_flex_desc *rx_desc, const u16 stat_err_bits)
{
return !!(rx_desc->wb.status_error0 &
cpu_to_le16(stat_err_bits));
}
/**
* ice_is_non_eop - process handling of non-EOP buffers
* @rx_ring: Rx ring being processed
* @rx_desc: Rx descriptor for current buffer
* @skb: Current socket buffer containing buffer in progress
*
* This function updates next to clean. If the buffer is an EOP buffer
* this function exits returning false, otherwise it will place the
* sk_buff in the next buffer to be chained and return true indicating
* that this is in fact a non-EOP buffer.
*/
static bool
ice_is_non_eop(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
struct sk_buff *skb)
{
u32 ntc = rx_ring->next_to_clean + 1;
/* fetch, update, and store next to clean */
ntc = (ntc < rx_ring->count) ? ntc : 0;
rx_ring->next_to_clean = ntc;
prefetch(ICE_RX_DESC(rx_ring, ntc));
/* if we are the last buffer then there is nothing else to do */
#define ICE_RXD_EOF BIT(ICE_RX_FLEX_DESC_STATUS0_EOF_S)
if (likely(ice_test_staterr(rx_desc, ICE_RXD_EOF)))
return false;
/* place skb in next buffer to be received */
rx_ring->rx_buf[ntc].skb = skb;
rx_ring->rx_stats.non_eop_descs++;
return true;
}
/**
* ice_ptype_to_htype - get a hash type
* @ptype: the ptype value from the descriptor
*
* Returns a hash type to be used by skb_set_hash
*/
static enum pkt_hash_types ice_ptype_to_htype(u8 __always_unused ptype)
{
return PKT_HASH_TYPE_NONE;
}
/**
* ice_rx_hash - set the hash value in the skb
* @rx_ring: descriptor ring
* @rx_desc: specific descriptor
* @skb: pointer to current skb
* @rx_ptype: the ptype value from the descriptor
*/
static void
ice_rx_hash(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
struct sk_buff *skb, u8 rx_ptype)
{
struct ice_32b_rx_flex_desc_nic *nic_mdid;
u32 hash;
if (!(rx_ring->netdev->features & NETIF_F_RXHASH))
return;
if (rx_desc->wb.rxdid != ICE_RXDID_FLEX_NIC)
return;
nic_mdid = (struct ice_32b_rx_flex_desc_nic *)rx_desc;
hash = le32_to_cpu(nic_mdid->rss_hash);
skb_set_hash(skb, hash, ice_ptype_to_htype(rx_ptype));
}
/**
* ice_rx_csum - Indicate in skb if checksum is good
* @vsi: the VSI we care about
* @skb: skb currently being received and modified
* @rx_desc: the receive descriptor
* @ptype: the packet type decoded by hardware
*
* skb->protocol must be set before this function is called
*/
static void
ice_rx_csum(struct ice_vsi *vsi, struct sk_buff *skb,
union ice_32b_rx_flex_desc *rx_desc, u8 ptype)
{
struct ice_rx_ptype_decoded decoded;
u32 rx_error, rx_status;
bool ipv4, ipv6;
rx_status = le16_to_cpu(rx_desc->wb.status_error0);
rx_error = rx_status;
decoded = ice_decode_rx_desc_ptype(ptype);
/* Start with CHECKSUM_NONE and by default csum_level = 0 */
skb->ip_summed = CHECKSUM_NONE;
skb_checksum_none_assert(skb);
/* check if Rx checksum is enabled */
if (!(vsi->netdev->features & NETIF_F_RXCSUM))
return;
/* check if HW has decoded the packet and checksum */
if (!(rx_status & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S)))
return;
if (!(decoded.known && decoded.outer_ip))
return;
ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
(decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
(decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
if (ipv4 && (rx_error & (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S))))
goto checksum_fail;
else if (ipv6 && (rx_status &
(BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))))
goto checksum_fail;
/* check for L4 errors and handle packets that were not able to be
* checksummed due to arrival speed
*/
if (rx_error & BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S))
goto checksum_fail;
/* Only report checksum unnecessary for TCP, UDP, or SCTP */
switch (decoded.inner_prot) {
case ICE_RX_PTYPE_INNER_PROT_TCP:
case ICE_RX_PTYPE_INNER_PROT_UDP:
case ICE_RX_PTYPE_INNER_PROT_SCTP:
skb->ip_summed = CHECKSUM_UNNECESSARY;
default:
break;
}
return;
checksum_fail:
vsi->back->hw_csum_rx_error++;
}
/**
* ice_process_skb_fields - Populate skb header fields from Rx descriptor
* @rx_ring: Rx descriptor ring packet is being transacted on
* @rx_desc: pointer to the EOP Rx descriptor
* @skb: pointer to current skb being populated
* @ptype: the packet type decoded by hardware
*
* This function checks the ring, descriptor, and packet information in
* order to populate the hash, checksum, VLAN, protocol, and
* other fields within the skb.
*/
static void
ice_process_skb_fields(struct ice_ring *rx_ring,
union ice_32b_rx_flex_desc *rx_desc,
struct sk_buff *skb, u8 ptype)
{
ice_rx_hash(rx_ring, rx_desc, skb, ptype);
/* modifies the skb - consumes the enet header */
skb->protocol = eth_type_trans(skb, rx_ring->netdev);
ice_rx_csum(rx_ring->vsi, skb, rx_desc, ptype);
}
/**
* ice_receive_skb - Send a completed packet up the stack
* @rx_ring: Rx ring in play
* @skb: packet to send up
* @vlan_tag: VLAN tag for packet
*
* This function sends the completed packet (via. skb) up the stack using
* gro receive functions (with/without VLAN tag)
*/
static void
ice_receive_skb(struct ice_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag)
{
if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
(vlan_tag & VLAN_VID_MASK))
__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
napi_gro_receive(&rx_ring->q_vector->napi, skb);
}
/**
* ice_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf
* @rx_ring: Rx descriptor ring to transact packets on
* @budget: Total limit on number of packets to process
*
* This function provides a "bounce buffer" approach to Rx interrupt
* processing. The advantage to this is that on systems that have
* expensive overhead for IOMMU access this provides a means of avoiding
* it by maintaining the mapping of the page to the system.
*
* Returns amount of work completed
*/
static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
{
unsigned int total_rx_bytes = 0, total_rx_pkts = 0;
u16 cleaned_count = ICE_DESC_UNUSED(rx_ring);
bool failure = false;
/* start the loop to process Rx packets bounded by 'budget' */
while (likely(total_rx_pkts < (unsigned int)budget)) {
union ice_32b_rx_flex_desc *rx_desc;
struct ice_rx_buf *rx_buf;
struct sk_buff *skb;
unsigned int size;
u16 stat_err_bits;
u16 vlan_tag = 0;
u8 rx_ptype;
/* return some buffers to hardware, one at a time is too slow */
if (cleaned_count >= ICE_RX_BUF_WRITE) {
failure = failure ||
ice_alloc_rx_bufs(rx_ring, cleaned_count);
cleaned_count = 0;
}
/* get the Rx desc from Rx ring based on 'next_to_clean' */
rx_desc = ICE_RX_DESC(rx_ring, rx_ring->next_to_clean);
/* status_error_len will always be zero for unused descriptors
* because it's cleared in cleanup, and overlaps with hdr_addr
* which is always zero because packet split isn't used, if the
* hardware wrote DD then it will be non-zero
*/
stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_DD_S);
if (!ice_test_staterr(rx_desc, stat_err_bits))
break;
/* This memory barrier is needed to keep us from reading
* any other fields out of the rx_desc until we know the
* DD bit is set.
*/
dma_rmb();
size = le16_to_cpu(rx_desc->wb.pkt_len) &
ICE_RX_FLX_DESC_PKT_LEN_M;
rx_buf = ice_get_rx_buf(rx_ring, &skb, size);
/* allocate (if needed) and populate skb */
if (skb)
ice_add_rx_frag(rx_buf, skb, size);
else
skb = ice_construct_skb(rx_ring, rx_buf, size);
/* exit if we failed to retrieve a buffer */
if (!skb) {
rx_ring->rx_stats.alloc_buf_failed++;
rx_buf->pagecnt_bias++;
break;
}
ice_put_rx_buf(rx_ring, rx_buf);
cleaned_count++;
/* skip if it is NOP desc */
if (ice_is_non_eop(rx_ring, rx_desc, skb))
continue;
stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_RXE_S);
if (unlikely(ice_test_staterr(rx_desc, stat_err_bits))) {
dev_kfree_skb_any(skb);
continue;
}
rx_ptype = le16_to_cpu(rx_desc->wb.ptype_flex_flags0) &
ICE_RX_FLEX_DESC_PTYPE_M;
stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_L2TAG1P_S);
if (ice_test_staterr(rx_desc, stat_err_bits))
vlan_tag = le16_to_cpu(rx_desc->wb.l2tag1);
/* correct empty headers and pad skb if needed (to make valid
* ethernet frame
*/
if (ice_cleanup_headers(skb)) {
skb = NULL;
continue;
}
/* probably a little skewed due to removing CRC */
total_rx_bytes += skb->len;
/* populate checksum, VLAN, and protocol */
ice_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype);
/* send completed skb up the stack */
ice_receive_skb(rx_ring, skb, vlan_tag);
/* update budget accounting */
total_rx_pkts++;
}
/* update queue and vector specific stats */
u64_stats_update_begin(&rx_ring->syncp);
rx_ring->stats.pkts += total_rx_pkts;
rx_ring->stats.bytes += total_rx_bytes;
u64_stats_update_end(&rx_ring->syncp);
rx_ring->q_vector->rx.total_pkts += total_rx_pkts;
rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
/* guarantee a trip back through this routine if there was a failure */
return failure ? budget : (int)total_rx_pkts;
}
/**
* ice_adjust_itr_by_size_and_speed - Adjust ITR based on current traffic
* @port_info: port_info structure containing the current link speed
* @avg_pkt_size: average size of Tx or Rx packets based on clean routine
* @itr: ITR value to update
*
* Calculate how big of an increment should be applied to the ITR value passed
* in based on wmem_default, SKB overhead, Ethernet overhead, and the current
* link speed.
*
* The following is a calculation derived from:
* wmem_default / (size + overhead) = desired_pkts_per_int
* rate / bits_per_byte / (size + Ethernet overhead) = pkt_rate
* (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value
*
* Assuming wmem_default is 212992 and overhead is 640 bytes per
* packet, (256 skb, 64 headroom, 320 shared info), we can reduce the
* formula down to:
*
* wmem_default * bits_per_byte * usecs_per_sec pkt_size + 24
* ITR = -------------------------------------------- * --------------
* rate pkt_size + 640
*/
static unsigned int
ice_adjust_itr_by_size_and_speed(struct ice_port_info *port_info,
unsigned int avg_pkt_size,
unsigned int itr)
{
switch (port_info->phy.link_info.link_speed) {
case ICE_AQ_LINK_SPEED_100GB:
itr += DIV_ROUND_UP(17 * (avg_pkt_size + 24),
avg_pkt_size + 640);
break;
case ICE_AQ_LINK_SPEED_50GB:
itr += DIV_ROUND_UP(34 * (avg_pkt_size + 24),
avg_pkt_size + 640);
break;
case ICE_AQ_LINK_SPEED_40GB:
itr += DIV_ROUND_UP(43 * (avg_pkt_size + 24),
avg_pkt_size + 640);
break;
case ICE_AQ_LINK_SPEED_25GB:
itr += DIV_ROUND_UP(68 * (avg_pkt_size + 24),
avg_pkt_size + 640);
break;
case ICE_AQ_LINK_SPEED_20GB:
itr += DIV_ROUND_UP(85 * (avg_pkt_size + 24),
avg_pkt_size + 640);
break;
case ICE_AQ_LINK_SPEED_10GB:
/* fall through */
default:
itr += DIV_ROUND_UP(170 * (avg_pkt_size + 24),
avg_pkt_size + 640);
break;
}
if ((itr & ICE_ITR_MASK) > ICE_ITR_ADAPTIVE_MAX_USECS) {
itr &= ICE_ITR_ADAPTIVE_LATENCY;
itr += ICE_ITR_ADAPTIVE_MAX_USECS;
}
return itr;
}
/**
* ice_update_itr - update the adaptive ITR value based on statistics
* @q_vector: structure containing interrupt and ring information
* @rc: structure containing ring performance data
*
* Stores a new ITR value based on packets and byte
* counts during the last interrupt. The advantage of per interrupt
* computation is faster updates and more accurate ITR for the current
* traffic pattern. Constants in this function were computed
* based on theoretical maximum wire speed and thresholds were set based
* on testing data as well as attempting to minimize response time
* while increasing bulk throughput.
*/
static void
ice_update_itr(struct ice_q_vector *q_vector, struct ice_ring_container *rc)
{
unsigned long next_update = jiffies;
unsigned int packets, bytes, itr;
bool container_is_rx;
if (!rc->ring || !ITR_IS_DYNAMIC(rc->itr_setting))
return;
/* If itr_countdown is set it means we programmed an ITR within
* the last 4 interrupt cycles. This has a side effect of us
* potentially firing an early interrupt. In order to work around
* this we need to throw out any data received for a few
* interrupts following the update.
*/
if (q_vector->itr_countdown) {
itr = rc->target_itr;
goto clear_counts;
}
container_is_rx = (&q_vector->rx == rc);
/* For Rx we want to push the delay up and default to low latency.
* for Tx we want to pull the delay down and default to high latency.
*/
itr = container_is_rx ?
ICE_ITR_ADAPTIVE_MIN_USECS | ICE_ITR_ADAPTIVE_LATENCY :
ICE_ITR_ADAPTIVE_MAX_USECS | ICE_ITR_ADAPTIVE_LATENCY;
/* If we didn't update within up to 1 - 2 jiffies we can assume
* that either packets are coming in so slow there hasn't been
* any work, or that there is so much work that NAPI is dealing
* with interrupt moderation and we don't need to do anything.
*/
if (time_after(next_update, rc->next_update))
goto clear_counts;
packets = rc->total_pkts;
bytes = rc->total_bytes;
if (container_is_rx) {
/* If Rx there are 1 to 4 packets and bytes are less than
* 9000 assume insufficient data to use bulk rate limiting
* approach unless Tx is already in bulk rate limiting. We
* are likely latency driven.
*/
if (packets && packets < 4 && bytes < 9000 &&
(q_vector->tx.target_itr & ICE_ITR_ADAPTIVE_LATENCY)) {
itr = ICE_ITR_ADAPTIVE_LATENCY;
goto adjust_by_size_and_speed;
}
} else if (packets < 4) {
/* If we have Tx and Rx ITR maxed and Tx ITR is running in
* bulk mode and we are receiving 4 or fewer packets just
* reset the ITR_ADAPTIVE_LATENCY bit for latency mode so
* that the Rx can relax.
*/
if (rc->target_itr == ICE_ITR_ADAPTIVE_MAX_USECS &&
(q_vector->rx.target_itr & ICE_ITR_MASK) ==
ICE_ITR_ADAPTIVE_MAX_USECS)
goto clear_counts;
} else if (packets > 32) {
/* If we have processed over 32 packets in a single interrupt
* for Tx assume we need to switch over to "bulk" mode.
*/
rc->target_itr &= ~ICE_ITR_ADAPTIVE_LATENCY;
}
/* We have no packets to actually measure against. This means
* either one of the other queues on this vector is active or
* we are a Tx queue doing TSO with too high of an interrupt rate.
*
* Between 4 and 56 we can assume that our current interrupt delay
* is only slightly too low. As such we should increase it by a small
* fixed amount.
*/
if (packets < 56) {
itr = rc->target_itr + ICE_ITR_ADAPTIVE_MIN_INC;
if ((itr & ICE_ITR_MASK) > ICE_ITR_ADAPTIVE_MAX_USECS) {
itr &= ICE_ITR_ADAPTIVE_LATENCY;
itr += ICE_ITR_ADAPTIVE_MAX_USECS;
}
goto clear_counts;
}
if (packets <= 256) {
itr = min(q_vector->tx.current_itr, q_vector->rx.current_itr);
itr &= ICE_ITR_MASK;
/* Between 56 and 112 is our "goldilocks" zone where we are
* working out "just right". Just report that our current
* ITR is good for us.
*/
if (packets <= 112)
goto clear_counts;
/* If packet count is 128 or greater we are likely looking
* at a slight overrun of the delay we want. Try halving
* our delay to see if that will cut the number of packets
* in half per interrupt.
*/
itr >>= 1;
itr &= ICE_ITR_MASK;
if (itr < ICE_ITR_ADAPTIVE_MIN_USECS)
itr = ICE_ITR_ADAPTIVE_MIN_USECS;
goto clear_counts;
}
/* The paths below assume we are dealing with a bulk ITR since
* number of packets is greater than 256. We are just going to have
* to compute a value and try to bring the count under control,
* though for smaller packet sizes there isn't much we can do as
* NAPI polling will likely be kicking in sooner rather than later.
*/
itr = ICE_ITR_ADAPTIVE_BULK;
adjust_by_size_and_speed:
/* based on checks above packets cannot be 0 so division is safe */
itr = ice_adjust_itr_by_size_and_speed(q_vector->vsi->port_info,
bytes / packets, itr);
clear_counts:
/* write back value */
rc->target_itr = itr;
/* next update should occur within next jiffy */
rc->next_update = next_update + 1;
rc->total_bytes = 0;
rc->total_pkts = 0;
}
/**
* ice_buildreg_itr - build value for writing to the GLINT_DYN_CTL register
* @itr_idx: interrupt throttling index
* @itr: interrupt throttling value in usecs
*/
static u32 ice_buildreg_itr(u16 itr_idx, u16 itr)
{
/* The ITR value is reported in microseconds, and the register value is
* recorded in 2 microsecond units. For this reason we only need to
* shift by the GLINT_DYN_CTL_INTERVAL_S - ICE_ITR_GRAN_S to apply this
* granularity as a shift instead of division. The mask makes sure the
* ITR value is never odd so we don't accidentally write into the field
* prior to the ITR field.
*/
itr &= ICE_ITR_MASK;
return GLINT_DYN_CTL_INTENA_M | GLINT_DYN_CTL_CLEARPBA_M |
(itr_idx << GLINT_DYN_CTL_ITR_INDX_S) |
(itr << (GLINT_DYN_CTL_INTERVAL_S - ICE_ITR_GRAN_S));
}
/* The act of updating the ITR will cause it to immediately trigger. In order
* to prevent this from throwing off adaptive update statistics we defer the
* update so that it can only happen so often. So after either Tx or Rx are
* updated we make the adaptive scheme wait until either the ITR completely
* expires via the next_update expiration or we have been through at least
* 3 interrupts.
*/
#define ITR_COUNTDOWN_START 3
/**
* ice_update_ena_itr - Update ITR and re-enable MSIX interrupt
* @vsi: the VSI associated with the q_vector
* @q_vector: q_vector for which ITR is being updated and interrupt enabled
*/
static void
ice_update_ena_itr(struct ice_vsi *vsi, struct ice_q_vector *q_vector)
{
struct ice_ring_container *tx = &q_vector->tx;
struct ice_ring_container *rx = &q_vector->rx;
u32 itr_val;
/* This will do nothing if dynamic updates are not enabled */
ice_update_itr(q_vector, tx);
ice_update_itr(q_vector, rx);
/* This block of logic allows us to get away with only updating
* one ITR value with each interrupt. The idea is to perform a
* pseudo-lazy update with the following criteria.
*
* 1. Rx is given higher priority than Tx if both are in same state
* 2. If we must reduce an ITR that is given highest priority.
* 3. We then give priority to increasing ITR based on amount.
*/
if (rx->target_itr < rx->current_itr) {
/* Rx ITR needs to be reduced, this is highest priority */
itr_val = ice_buildreg_itr(rx->itr_idx, rx->target_itr);
rx->current_itr = rx->target_itr;
q_vector->itr_countdown = ITR_COUNTDOWN_START;
} else if ((tx->target_itr < tx->current_itr) ||
((rx->target_itr - rx->current_itr) <
(tx->target_itr - tx->current_itr))) {
/* Tx ITR needs to be reduced, this is second priority
* Tx ITR needs to be increased more than Rx, fourth priority
*/
itr_val = ice_buildreg_itr(tx->itr_idx, tx->target_itr);
tx->current_itr = tx->target_itr;
q_vector->itr_countdown = ITR_COUNTDOWN_START;
} else if (rx->current_itr != rx->target_itr) {
/* Rx ITR needs to be increased, third priority */
itr_val = ice_buildreg_itr(rx->itr_idx, rx->target_itr);
rx->current_itr = rx->target_itr;
q_vector->itr_countdown = ITR_COUNTDOWN_START;
} else {
/* Still have to re-enable the interrupts */
itr_val = ice_buildreg_itr(ICE_ITR_NONE, 0);
if (q_vector->itr_countdown)
q_vector->itr_countdown--;
}
if (!test_bit(__ICE_DOWN, vsi->state))
wr32(&vsi->back->hw,
GLINT_DYN_CTL(q_vector->reg_idx),
itr_val);
}
/**
* ice_napi_poll - NAPI polling Rx/Tx cleanup routine
* @napi: napi struct with our devices info in it
* @budget: amount of work driver is allowed to do this pass, in packets
*
* This function will clean all queues associated with a q_vector.
*
* Returns the amount of work done
*/
int ice_napi_poll(struct napi_struct *napi, int budget)
{
struct ice_q_vector *q_vector =
container_of(napi, struct ice_q_vector, napi);
struct ice_vsi *vsi = q_vector->vsi;
struct ice_pf *pf = vsi->back;
bool clean_complete = true;
int budget_per_ring = 0;
struct ice_ring *ring;
int work_done = 0;
/* Since the actual Tx work is minimal, we can give the Tx a larger
* budget and be more aggressive about cleaning up the Tx descriptors.
*/
ice_for_each_ring(ring, q_vector->tx)
if (!ice_clean_tx_irq(vsi, ring, budget))
clean_complete = false;
/* Handle case where we are called by netpoll with a budget of 0 */
if (budget <= 0)
return budget;
/* We attempt to distribute budget to each Rx queue fairly, but don't
* allow the budget to go below 1 because that would exit polling early.
*/
if (q_vector->num_ring_rx)
budget_per_ring = max(budget / q_vector->num_ring_rx, 1);
ice_for_each_ring(ring, q_vector->rx) {
int cleaned;
cleaned = ice_clean_rx_irq(ring, budget_per_ring);
work_done += cleaned;
/* if we clean as many as budgeted, we must not be done */
if (cleaned >= budget_per_ring)
clean_complete = false;
}
/* If work not completed, return budget and polling will return */
if (!clean_complete)
return budget;
/* Exit the polling mode, but don't re-enable interrupts if stack might
* poll us due to busy-polling
*/
if (likely(napi_complete_done(napi, work_done)))
if (test_bit(ICE_FLAG_MSIX_ENA, pf->flags))
ice_update_ena_itr(vsi, q_vector);
return min_t(int, work_done, budget - 1);
}
/* helper function for building cmd/type/offset */
static __le64
build_ctob(u64 td_cmd, u64 td_offset, unsigned int size, u64 td_tag)
{
return cpu_to_le64(ICE_TX_DESC_DTYPE_DATA |
(td_cmd << ICE_TXD_QW1_CMD_S) |
(td_offset << ICE_TXD_QW1_OFFSET_S) |
((u64)size << ICE_TXD_QW1_TX_BUF_SZ_S) |
(td_tag << ICE_TXD_QW1_L2TAG1_S));
}
/**
* __ice_maybe_stop_tx - 2nd level check for Tx stop conditions
* @tx_ring: the ring to be checked
* @size: the size buffer we want to assure is available
*
* Returns -EBUSY if a stop is needed, else 0
*/
static int __ice_maybe_stop_tx(struct ice_ring *tx_ring, unsigned int size)
{
netif_stop_subqueue(tx_ring->netdev, tx_ring->q_index);
/* Memory barrier before checking head and tail */
smp_mb();
/* Check again in a case another CPU has just made room available. */
if (likely(ICE_DESC_UNUSED(tx_ring) < size))
return -EBUSY;
/* A reprieve! - use start_subqueue because it doesn't call schedule */
netif_start_subqueue(tx_ring->netdev, tx_ring->q_index);
++tx_ring->tx_stats.restart_q;
return 0;
}
/**
* ice_maybe_stop_tx - 1st level check for Tx stop conditions
* @tx_ring: the ring to be checked
* @size: the size buffer we want to assure is available
*
* Returns 0 if stop is not needed
*/
static int ice_maybe_stop_tx(struct ice_ring *tx_ring, unsigned int size)
{
if (likely(ICE_DESC_UNUSED(tx_ring) >= size))
return 0;
return __ice_maybe_stop_tx(tx_ring, size);
}
/**
* ice_tx_map - Build the Tx descriptor
* @tx_ring: ring to send buffer on
* @first: first buffer info buffer to use
* @off: pointer to struct that holds offload parameters
*
* This function loops over the skb data pointed to by *first
* and gets a physical address for each memory location and programs
* it and the length into the transmit descriptor.
*/
static void
ice_tx_map(struct ice_ring *tx_ring, struct ice_tx_buf *first,
struct ice_tx_offload_params *off)
{
u64 td_offset, td_tag, td_cmd;
u16 i = tx_ring->next_to_use;
struct skb_frag_struct *frag;
unsigned int data_len, size;
struct ice_tx_desc *tx_desc;
struct ice_tx_buf *tx_buf;
struct sk_buff *skb;
dma_addr_t dma;
td_tag = off->td_l2tag1;
td_cmd = off->td_cmd;
td_offset = off->td_offset;
skb = first->skb;
data_len = skb->data_len;
size = skb_headlen(skb);
tx_desc = ICE_TX_DESC(tx_ring, i);
if (first->tx_flags & ICE_TX_FLAGS_HW_VLAN) {
td_cmd |= (u64)ICE_TX_DESC_CMD_IL2TAG1;
td_tag = (first->tx_flags & ICE_TX_FLAGS_VLAN_M) >>
ICE_TX_FLAGS_VLAN_S;
}
dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
tx_buf = first;
for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
unsigned int max_data = ICE_MAX_DATA_PER_TXD_ALIGNED;
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
/* record length, and DMA address */
dma_unmap_len_set(tx_buf, len, size);
dma_unmap_addr_set(tx_buf, dma, dma);
/* align size to end of page */
max_data += -dma & (ICE_MAX_READ_REQ_SIZE - 1);
tx_desc->buf_addr = cpu_to_le64(dma);
/* account for data chunks larger than the hardware
* can handle
*/
while (unlikely(size > ICE_MAX_DATA_PER_TXD)) {
tx_desc->cmd_type_offset_bsz =
build_ctob(td_cmd, td_offset, max_data, td_tag);
tx_desc++;
i++;
if (i == tx_ring->count) {
tx_desc = ICE_TX_DESC(tx_ring, 0);
i = 0;
}
dma += max_data;
size -= max_data;
max_data = ICE_MAX_DATA_PER_TXD_ALIGNED;
tx_desc->buf_addr = cpu_to_le64(dma);
}
if (likely(!data_len))
break;
tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset,
size, td_tag);
tx_desc++;
i++;
if (i == tx_ring->count) {
tx_desc = ICE_TX_DESC(tx_ring, 0);
i = 0;
}
size = skb_frag_size(frag);
data_len -= size;
dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
DMA_TO_DEVICE);
tx_buf = &tx_ring->tx_buf[i];
}
/* record bytecount for BQL */
netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);
/* record SW timestamp if HW timestamp is not available */
skb_tx_timestamp(first->skb);
i++;
if (i == tx_ring->count)
i = 0;
/* write last descriptor with RS and EOP bits */
td_cmd |= (u64)(ICE_TX_DESC_CMD_EOP | ICE_TX_DESC_CMD_RS);
tx_desc->cmd_type_offset_bsz =
build_ctob(td_cmd, td_offset, size, td_tag);
/* Force memory writes to complete before letting h/w know there
* are new descriptors to fetch.
*
* We also use this memory barrier to make certain all of the
* status bits have been updated before next_to_watch is written.
*/
wmb();
/* set next_to_watch value indicating a packet is present */
first->next_to_watch = tx_desc;
tx_ring->next_to_use = i;
ice_maybe_stop_tx(tx_ring, DESC_NEEDED);
/* notify HW of packet */
if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) {
writel(i, tx_ring->tail);
}
return;
dma_error:
/* clear DMA mappings for failed tx_buf map */
for (;;) {
tx_buf = &tx_ring->tx_buf[i];
ice_unmap_and_free_tx_buf(tx_ring, tx_buf);
if (tx_buf == first)
break;
if (i == 0)
i = tx_ring->count;
i--;
}
tx_ring->next_to_use = i;
}
/**
* ice_tx_csum - Enable Tx checksum offloads
* @first: pointer to the first descriptor
* @off: pointer to struct that holds offload parameters
*
* Returns 0 or error (negative) if checksum offload can't happen, 1 otherwise.
*/
static
int ice_tx_csum(struct ice_tx_buf *first, struct ice_tx_offload_params *off)
{
u32 l4_len = 0, l3_len = 0, l2_len = 0;
struct sk_buff *skb = first->skb;
union {
struct iphdr *v4;
struct ipv6hdr *v6;
unsigned char *hdr;
} ip;
union {
struct tcphdr *tcp;
unsigned char *hdr;
} l4;
__be16 frag_off, protocol;
unsigned char *exthdr;
u32 offset, cmd = 0;
u8 l4_proto = 0;
if (skb->ip_summed != CHECKSUM_PARTIAL)
return 0;
ip.hdr = skb_network_header(skb);
l4.hdr = skb_transport_header(skb);
/* compute outer L2 header size */
l2_len = ip.hdr - skb->data;
offset = (l2_len / 2) << ICE_TX_DESC_LEN_MACLEN_S;
if (skb->encapsulation)
return -1;
/* Enable IP checksum offloads */
protocol = vlan_get_protocol(skb);
if (protocol == htons(ETH_P_IP)) {
l4_proto = ip.v4->protocol;
/* the stack computes the IP header already, the only time we
* need the hardware to recompute it is in the case of TSO.
*/
if (first->tx_flags & ICE_TX_FLAGS_TSO)
cmd |= ICE_TX_DESC_CMD_IIPT_IPV4_CSUM;
else
cmd |= ICE_TX_DESC_CMD_IIPT_IPV4;
} else if (protocol == htons(ETH_P_IPV6)) {
cmd |= ICE_TX_DESC_CMD_IIPT_IPV6;
exthdr = ip.hdr + sizeof(*ip.v6);
l4_proto = ip.v6->nexthdr;
if (l4.hdr != exthdr)
ipv6_skip_exthdr(skb, exthdr - skb->data, &l4_proto,
&frag_off);
} else {
return -1;
}
/* compute inner L3 header size */
l3_len = l4.hdr - ip.hdr;
offset |= (l3_len / 4) << ICE_TX_DESC_LEN_IPLEN_S;
/* Enable L4 checksum offloads */
switch (l4_proto) {
case IPPROTO_TCP:
/* enable checksum offloads */
cmd |= ICE_TX_DESC_CMD_L4T_EOFT_TCP;
l4_len = l4.tcp->doff;
offset |= l4_len << ICE_TX_DESC_LEN_L4_LEN_S;
break;
case IPPROTO_UDP:
/* enable UDP checksum offload */
cmd |= ICE_TX_DESC_CMD_L4T_EOFT_UDP;
l4_len = (sizeof(struct udphdr) >> 2);
offset |= l4_len << ICE_TX_DESC_LEN_L4_LEN_S;
break;
case IPPROTO_SCTP:
/* enable SCTP checksum offload */
cmd |= ICE_TX_DESC_CMD_L4T_EOFT_SCTP;
l4_len = sizeof(struct sctphdr) >> 2;
offset |= l4_len << ICE_TX_DESC_LEN_L4_LEN_S;
break;
default:
if (first->tx_flags & ICE_TX_FLAGS_TSO)
return -1;
skb_checksum_help(skb);
return 0;
}
off->td_cmd |= cmd;
off->td_offset |= offset;
return 1;
}
/**
* ice_tx_prepare_vlan_flags - prepare generic Tx VLAN tagging flags for HW
* @tx_ring: ring to send buffer on
* @first: pointer to struct ice_tx_buf
*
* Checks the skb and set up correspondingly several generic transmit flags
* related to VLAN tagging for the HW, such as VLAN, DCB, etc.
*
* Returns error code indicate the frame should be dropped upon error and the
* otherwise returns 0 to indicate the flags has been set properly.
*/
static int
ice_tx_prepare_vlan_flags(struct ice_ring *tx_ring, struct ice_tx_buf *first)
{
struct sk_buff *skb = first->skb;
__be16 protocol = skb->protocol;
if (protocol == htons(ETH_P_8021Q) &&
!(tx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_TX)) {
/* when HW VLAN acceleration is turned off by the user the
* stack sets the protocol to 8021q so that the driver
* can take any steps required to support the SW only
* VLAN handling. In our case the driver doesn't need
* to take any further steps so just set the protocol
* to the encapsulated ethertype.
*/
skb->protocol = vlan_get_protocol(skb);
return 0;
}
/* if we have a HW VLAN tag being added, default to the HW one */
if (skb_vlan_tag_present(skb)) {
first->tx_flags |= skb_vlan_tag_get(skb) << ICE_TX_FLAGS_VLAN_S;
first->tx_flags |= ICE_TX_FLAGS_HW_VLAN;
} else if (protocol == htons(ETH_P_8021Q)) {
struct vlan_hdr *vhdr, _vhdr;
/* for SW VLAN, check the next protocol and store the tag */
vhdr = (struct vlan_hdr *)skb_header_pointer(skb, ETH_HLEN,
sizeof(_vhdr),
&_vhdr);
if (!vhdr)
return -EINVAL;
first->tx_flags |= ntohs(vhdr->h_vlan_TCI) <<
ICE_TX_FLAGS_VLAN_S;
first->tx_flags |= ICE_TX_FLAGS_SW_VLAN;
}
return ice_tx_prepare_vlan_flags_dcb(tx_ring, first);
}
/**
* ice_tso - computes mss and TSO length to prepare for TSO
* @first: pointer to struct ice_tx_buf
* @off: pointer to struct that holds offload parameters
*
* Returns 0 or error (negative) if TSO can't happen, 1 otherwise.
*/
static
int ice_tso(struct ice_tx_buf *first, struct ice_tx_offload_params *off)
{
struct sk_buff *skb = first->skb;
union {
struct iphdr *v4;
struct ipv6hdr *v6;
unsigned char *hdr;
} ip;
union {
struct tcphdr *tcp;
unsigned char *hdr;
} l4;
u64 cd_mss, cd_tso_len;
u32 paylen, l4_start;
int err;
if (skb->ip_summed != CHECKSUM_PARTIAL)
return 0;
if (!skb_is_gso(skb))
return 0;
err = skb_cow_head(skb, 0);
if (err < 0)
return err;
/* cppcheck-suppress unreadVariable */
ip.hdr = skb_network_header(skb);
l4.hdr = skb_transport_header(skb);
/* initialize outer IP header fields */
if (ip.v4->version == 4) {
ip.v4->tot_len = 0;
ip.v4->check = 0;
} else {
ip.v6->payload_len = 0;
}
/* determine offset of transport header */
l4_start = l4.hdr - skb->data;
/* remove payload length from checksum */
paylen = skb->len - l4_start;
csum_replace_by_diff(&l4.tcp->check, (__force __wsum)htonl(paylen));
/* compute length of segmentation header */
off->header_len = (l4.tcp->doff * 4) + l4_start;
/* update gso_segs and bytecount */
first->gso_segs = skb_shinfo(skb)->gso_segs;
first->bytecount += (first->gso_segs - 1) * off->header_len;
cd_tso_len = skb->len - off->header_len;
cd_mss = skb_shinfo(skb)->gso_size;
/* record cdesc_qw1 with TSO parameters */
off->cd_qw1 |= (u64)(ICE_TX_DESC_DTYPE_CTX |
(ICE_TX_CTX_DESC_TSO << ICE_TXD_CTX_QW1_CMD_S) |
(cd_tso_len << ICE_TXD_CTX_QW1_TSO_LEN_S) |
(cd_mss << ICE_TXD_CTX_QW1_MSS_S));
first->tx_flags |= ICE_TX_FLAGS_TSO;
return 1;
}
/**
* ice_txd_use_count - estimate the number of descriptors needed for Tx
* @size: transmit request size in bytes
*
* Due to hardware alignment restrictions (4K alignment), we need to
* assume that we can have no more than 12K of data per descriptor, even
* though each descriptor can take up to 16K - 1 bytes of aligned memory.
* Thus, we need to divide by 12K. But division is slow! Instead,
* we decompose the operation into shifts and one relatively cheap
* multiply operation.
*
* To divide by 12K, we first divide by 4K, then divide by 3:
* To divide by 4K, shift right by 12 bits
* To divide by 3, multiply by 85, then divide by 256
* (Divide by 256 is done by shifting right by 8 bits)
* Finally, we add one to round up. Because 256 isn't an exact multiple of
* 3, we'll underestimate near each multiple of 12K. This is actually more
* accurate as we have 4K - 1 of wiggle room that we can fit into the last
* segment. For our purposes this is accurate out to 1M which is orders of
* magnitude greater than our largest possible GSO size.
*
* This would then be implemented as:
* return (((size >> 12) * 85) >> 8) + ICE_DESCS_FOR_SKB_DATA_PTR;
*
* Since multiplication and division are commutative, we can reorder
* operations into:
* return ((size * 85) >> 20) + ICE_DESCS_FOR_SKB_DATA_PTR;
*/
static unsigned int ice_txd_use_count(unsigned int size)
{
return ((size * 85) >> 20) + ICE_DESCS_FOR_SKB_DATA_PTR;
}
/**
* ice_xmit_desc_count - calculate number of Tx descriptors needed
* @skb: send buffer
*
* Returns number of data descriptors needed for this skb.
*/
static unsigned int ice_xmit_desc_count(struct sk_buff *skb)
{
const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
unsigned int nr_frags = skb_shinfo(skb)->nr_frags;
unsigned int count = 0, size = skb_headlen(skb);
for (;;) {
count += ice_txd_use_count(size);
if (!nr_frags--)
break;
size = skb_frag_size(frag++);
}
return count;
}
/**
* __ice_chk_linearize - Check if there are more than 8 buffers per packet
* @skb: send buffer
*
* Note: This HW can't DMA more than 8 buffers to build a packet on the wire
* and so we need to figure out the cases where we need to linearize the skb.
*
* For TSO we need to count the TSO header and segment payload separately.
* As such we need to check cases where we have 7 fragments or more as we
* can potentially require 9 DMA transactions, 1 for the TSO header, 1 for
* the segment payload in the first descriptor, and another 7 for the
* fragments.
*/
static bool __ice_chk_linearize(struct sk_buff *skb)
{
const struct skb_frag_struct *frag, *stale;
int nr_frags, sum;
/* no need to check if number of frags is less than 7 */
nr_frags = skb_shinfo(skb)->nr_frags;
if (nr_frags < (ICE_MAX_BUF_TXD - 1))
return false;
/* We need to walk through the list and validate that each group
* of 6 fragments totals at least gso_size.
*/
nr_frags -= ICE_MAX_BUF_TXD - 2;
frag = &skb_shinfo(skb)->frags[0];
/* Initialize size to the negative value of gso_size minus 1. We
* use this as the worst case scenerio in which the frag ahead
* of us only provides one byte which is why we are limited to 6
* descriptors for a single transmit as the header and previous
* fragment are already consuming 2 descriptors.
*/
sum = 1 - skb_shinfo(skb)->gso_size;
/* Add size of frags 0 through 4 to create our initial sum */
sum += skb_frag_size(frag++);
sum += skb_frag_size(frag++);
sum += skb_frag_size(frag++);
sum += skb_frag_size(frag++);
sum += skb_frag_size(frag++);
/* Walk through fragments adding latest fragment, testing it, and
* then removing stale fragments from the sum.
*/
stale = &skb_shinfo(skb)->frags[0];
for (;;) {
sum += skb_frag_size(frag++);
/* if sum is negative we failed to make sufficient progress */
if (sum < 0)
return true;
if (!nr_frags--)
break;
sum -= skb_frag_size(stale++);
}
return false;
}
/**
* ice_chk_linearize - Check if there are more than 8 fragments per packet
* @skb: send buffer
* @count: number of buffers used
*
* Note: Our HW can't scatter-gather more than 8 fragments to build
* a packet on the wire and so we need to figure out the cases where we
* need to linearize the skb.
*/
static bool ice_chk_linearize(struct sk_buff *skb, unsigned int count)
{
/* Both TSO and single send will work if count is less than 8 */
if (likely(count < ICE_MAX_BUF_TXD))
return false;
if (skb_is_gso(skb))
return __ice_chk_linearize(skb);
/* we can support up to 8 data buffers for a single send */
return count != ICE_MAX_BUF_TXD;
}
/**
* ice_xmit_frame_ring - Sends buffer on Tx ring
* @skb: send buffer
* @tx_ring: ring to send buffer on
*
* Returns NETDEV_TX_OK if sent, else an error code
*/
static netdev_tx_t
ice_xmit_frame_ring(struct sk_buff *skb, struct ice_ring *tx_ring)
{
struct ice_tx_offload_params offload = { 0 };
struct ice_tx_buf *first;
unsigned int count;
int tso, csum;
count = ice_xmit_desc_count(skb);
if (ice_chk_linearize(skb, count)) {
if (__skb_linearize(skb))
goto out_drop;
count = ice_txd_use_count(skb->len);
tx_ring->tx_stats.tx_linearize++;
}
/* need: 1 descriptor per page * PAGE_SIZE/ICE_MAX_DATA_PER_TXD,
* + 1 desc for skb_head_len/ICE_MAX_DATA_PER_TXD,
* + 4 desc gap to avoid the cache line where head is,
* + 1 desc for context descriptor,
* otherwise try next time
*/
if (ice_maybe_stop_tx(tx_ring, count + ICE_DESCS_PER_CACHE_LINE +
ICE_DESCS_FOR_CTX_DESC)) {
tx_ring->tx_stats.tx_busy++;
return NETDEV_TX_BUSY;
}
offload.tx_ring = tx_ring;
/* record the location of the first descriptor for this packet */
first = &tx_ring->tx_buf[tx_ring->next_to_use];
first->skb = skb;
first->bytecount = max_t(unsigned int, skb->len, ETH_ZLEN);
first->gso_segs = 1;
first->tx_flags = 0;
/* prepare the VLAN tagging flags for Tx */
if (ice_tx_prepare_vlan_flags(tx_ring, first))
goto out_drop;
/* set up TSO offload */
tso = ice_tso(first, &offload);
if (tso < 0)
goto out_drop;
/* always set up Tx checksum offload */
csum = ice_tx_csum(first, &offload);
if (csum < 0)
goto out_drop;
if (tso || offload.cd_tunnel_params) {
struct ice_tx_ctx_desc *cdesc;
int i = tx_ring->next_to_use;
/* grab the next descriptor */
cdesc = ICE_TX_CTX_DESC(tx_ring, i);
i++;
tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
/* setup context descriptor */
cdesc->tunneling_params = cpu_to_le32(offload.cd_tunnel_params);
cdesc->l2tag2 = cpu_to_le16(offload.cd_l2tag2);
cdesc->rsvd = cpu_to_le16(0);
cdesc->qw1 = cpu_to_le64(offload.cd_qw1);
}
ice_tx_map(tx_ring, first, &offload);
return NETDEV_TX_OK;
out_drop:
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/**
* ice_start_xmit - Selects the correct VSI and Tx queue to send buffer
* @skb: send buffer
* @netdev: network interface device structure
*
* Returns NETDEV_TX_OK if sent, else an error code
*/
netdev_tx_t ice_start_xmit(struct sk_buff *skb, struct net_device *netdev)
{
struct ice_netdev_priv *np = netdev_priv(netdev);
struct ice_vsi *vsi = np->vsi;
struct ice_ring *tx_ring;
tx_ring = vsi->tx_rings[skb->queue_mapping];
/* hardware can't handle really short frames, hardware padding works
* beyond this point
*/
if (skb_put_padto(skb, ICE_MIN_TX_LEN))
return NETDEV_TX_OK;
return ice_xmit_frame_ring(skb, tx_ring);
}
