/* Intel Ethernet Switch Host Interface Driver
* Copyright(c) 2013 - 2014 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* The full GNU General Public License is included in this distribution in
* the file called "COPYING".
*
* Contact Information:
* e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*/
#include <linux/types.h>
#include <linux/module.h>
#include <net/ipv6.h>
#include <net/ip.h>
#include <net/tcp.h>
#include <linux/if_macvlan.h>
#include <linux/prefetch.h>
#include "fm10k.h"
#define DRV_VERSION "0.12.2-k"
const char fm10k_driver_version[] = DRV_VERSION;
char fm10k_driver_name[] = "fm10k";
static const char fm10k_driver_string[] =
"Intel(R) Ethernet Switch Host Interface Driver";
static const char fm10k_copyright[] =
"Copyright (c) 2013 Intel Corporation.";
MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
MODULE_DESCRIPTION("Intel(R) Ethernet Switch Host Interface Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
/**
* fm10k_init_module - Driver Registration Routine
*
* fm10k_init_module is the first routine called when the driver is
* loaded. All it does is register with the PCI subsystem.
**/
static int __init fm10k_init_module(void)
{
pr_info("%s - version %s\n", fm10k_driver_string, fm10k_driver_version);
pr_info("%s\n", fm10k_copyright);
return fm10k_register_pci_driver();
}
module_init(fm10k_init_module);
/**
* fm10k_exit_module - Driver Exit Cleanup Routine
*
* fm10k_exit_module is called just before the driver is removed
* from memory.
**/
static void __exit fm10k_exit_module(void)
{
fm10k_unregister_pci_driver();
}
module_exit(fm10k_exit_module);
static bool fm10k_alloc_mapped_page(struct fm10k_ring *rx_ring,
struct fm10k_rx_buffer *bi)
{
struct page *page = bi->page;
dma_addr_t dma;
/* Only page will be NULL if buffer was consumed */
if (likely(page))
return true;
/* alloc new page for storage */
page = alloc_page(GFP_ATOMIC | __GFP_COLD);
if (unlikely(!page)) {
rx_ring->rx_stats.alloc_failed++;
return false;
}
/* map page for use */
dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
/* 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_page(page);
bi->page = NULL;
rx_ring->rx_stats.alloc_failed++;
return false;
}
bi->dma = dma;
bi->page = page;
bi->page_offset = 0;
return true;
}
/**
* fm10k_alloc_rx_buffers - Replace used receive buffers
* @rx_ring: ring to place buffers on
* @cleaned_count: number of buffers to replace
**/
void fm10k_alloc_rx_buffers(struct fm10k_ring *rx_ring, u16 cleaned_count)
{
union fm10k_rx_desc *rx_desc;
struct fm10k_rx_buffer *bi;
u16 i = rx_ring->next_to_use;
/* nothing to do */
if (!cleaned_count)
return;
rx_desc = FM10K_RX_DESC(rx_ring, i);
bi = &rx_ring->rx_buffer[i];
i -= rx_ring->count;
do {
if (!fm10k_alloc_mapped_page(rx_ring, bi))
break;
/* Refresh the desc even if buffer_addrs didn't change
* because each write-back erases this info.
*/
rx_desc->q.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);
rx_desc++;
bi++;
i++;
if (unlikely(!i)) {
rx_desc = FM10K_RX_DESC(rx_ring, 0);
bi = rx_ring->rx_buffer;
i -= rx_ring->count;
}
/* clear the hdr_addr for the next_to_use descriptor */
rx_desc->q.hdr_addr = 0;
cleaned_count--;
} while (cleaned_count);
i += rx_ring->count;
if (rx_ring->next_to_use != i) {
/* record the next descriptor to use */
rx_ring->next_to_use = i;
/* update next to alloc since we have filled the ring */
rx_ring->next_to_alloc = i;
/* 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();
/* notify hardware of new descriptors */
writel(i, rx_ring->tail);
}
}
/**
* fm10k_reuse_rx_page - page flip buffer and store it back on the ring
* @rx_ring: rx descriptor ring to store buffers on
* @old_buff: donor buffer to have page reused
*
* Synchronizes page for reuse by the interface
**/
static void fm10k_reuse_rx_page(struct fm10k_ring *rx_ring,
struct fm10k_rx_buffer *old_buff)
{
struct fm10k_rx_buffer *new_buff;
u16 nta = rx_ring->next_to_alloc;
new_buff = &rx_ring->rx_buffer[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 */
memcpy(new_buff, old_buff, sizeof(struct fm10k_rx_buffer));
/* sync the buffer for use by the device */
dma_sync_single_range_for_device(rx_ring->dev, old_buff->dma,
old_buff->page_offset,
FM10K_RX_BUFSZ,
DMA_FROM_DEVICE);
}
static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer,
struct page *page,
unsigned int truesize)
{
/* avoid re-using remote pages */
if (unlikely(page_to_nid(page) != numa_mem_id()))
return false;
#if (PAGE_SIZE < 8192)
/* if we are only owner of page we can reuse it */
if (unlikely(page_count(page) != 1))
return false;
/* flip page offset to other buffer */
rx_buffer->page_offset ^= FM10K_RX_BUFSZ;
/* since we are the only owner of the page and we need to
* increment it, just set the value to 2 in order to avoid
* an unnecessary locked operation
*/
atomic_set(&page->_count, 2);
#else
/* move offset up to the next cache line */
rx_buffer->page_offset += truesize;
if (rx_buffer->page_offset > (PAGE_SIZE - FM10K_RX_BUFSZ))
return false;
/* bump ref count on page before it is given to the stack */
get_page(page);
#endif
return true;
}
/**
* fm10k_add_rx_frag - Add contents of Rx buffer to sk_buff
* @rx_ring: rx descriptor ring to transact packets on
* @rx_buffer: buffer containing page to add
* @rx_desc: descriptor containing length of buffer written by hardware
* @skb: sk_buff to place the data into
*
* This function will add the data contained in rx_buffer->page to the skb.
* This is done either through a direct copy if the data in the buffer is
* less than the skb header size, otherwise it will just attach the page as
* a frag to the skb.
*
* The function will then update the page offset if necessary and return
* true if the buffer can be reused by the interface.
**/
static bool fm10k_add_rx_frag(struct fm10k_ring *rx_ring,
struct fm10k_rx_buffer *rx_buffer,
union fm10k_rx_desc *rx_desc,
struct sk_buff *skb)
{
struct page *page = rx_buffer->page;
unsigned int size = le16_to_cpu(rx_desc->w.length);
#if (PAGE_SIZE < 8192)
unsigned int truesize = FM10K_RX_BUFSZ;
#else
unsigned int truesize = ALIGN(size, L1_CACHE_BYTES);
#endif
if ((size <= FM10K_RX_HDR_LEN) && !skb_is_nonlinear(skb)) {
unsigned char *va = page_address(page) + rx_buffer->page_offset;
memcpy(__skb_put(skb, size), va, ALIGN(size, sizeof(long)));
/* we can reuse buffer as-is, just make sure it is local */
if (likely(page_to_nid(page) == numa_mem_id()))
return true;
/* this page cannot be reused so discard it */
put_page(page);
return false;
}
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
rx_buffer->page_offset, size, truesize);
return fm10k_can_reuse_rx_page(rx_buffer, page, truesize);
}
static struct sk_buff *fm10k_fetch_rx_buffer(struct fm10k_ring *rx_ring,
union fm10k_rx_desc *rx_desc,
struct sk_buff *skb)
{
struct fm10k_rx_buffer *rx_buffer;
struct page *page;
rx_buffer = &rx_ring->rx_buffer[rx_ring->next_to_clean];
page = rx_buffer->page;
prefetchw(page);
if (likely(!skb)) {
void *page_addr = page_address(page) +
rx_buffer->page_offset;
/* prefetch first cache line of first page */
prefetch(page_addr);
#if L1_CACHE_BYTES < 128
prefetch(page_addr + L1_CACHE_BYTES);
#endif
/* allocate a skb to store the frags */
skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
FM10K_RX_HDR_LEN);
if (unlikely(!skb)) {
rx_ring->rx_stats.alloc_failed++;
return NULL;
}
/* we will be copying header into skb->data in
* pskb_may_pull so it is in our interest to prefetch
* it now to avoid a possible cache miss
*/
prefetchw(skb->data);
}
/* we are reusing so sync this buffer for CPU use */
dma_sync_single_range_for_cpu(rx_ring->dev,
rx_buffer->dma,
rx_buffer->page_offset,
FM10K_RX_BUFSZ,
DMA_FROM_DEVICE);
/* pull page into skb */
if (fm10k_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {
/* hand second half of page back to the ring */
fm10k_reuse_rx_page(rx_ring, rx_buffer);
} else {
/* we are not reusing the buffer so unmap it */
dma_unmap_page(rx_ring->dev, rx_buffer->dma,
PAGE_SIZE, DMA_FROM_DEVICE);
}
/* clear contents of rx_buffer */
rx_buffer->page = NULL;
return skb;
}
/**
* fm10k_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
*
* This function checks the ring, descriptor, and packet information in
* order to populate the hash, checksum, VLAN, timestamp, protocol, and
* other fields within the skb.
**/
static unsigned int fm10k_process_skb_fields(struct fm10k_ring *rx_ring,
union fm10k_rx_desc *rx_desc,
struct sk_buff *skb)
{
unsigned int len = skb->len;
FM10K_CB(skb)->fi.w.vlan = rx_desc->w.vlan;
skb_record_rx_queue(skb, rx_ring->queue_index);
FM10K_CB(skb)->fi.d.glort = rx_desc->d.glort;
if (rx_desc->w.vlan) {
u16 vid = le16_to_cpu(rx_desc->w.vlan);
if (vid != rx_ring->vid)
__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vid);
}
skb->protocol = eth_type_trans(skb, rx_ring->netdev);
return len;
}
/**
* fm10k_is_non_eop - process handling of non-EOP buffers
* @rx_ring: Rx ring being processed
* @rx_desc: Rx descriptor for current buffer
*
* 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 fm10k_is_non_eop(struct fm10k_ring *rx_ring,
union fm10k_rx_desc *rx_desc)
{
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(FM10K_RX_DESC(rx_ring, ntc));
if (likely(fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_EOP)))
return false;
return true;
}
/**
* fm10k_pull_tail - fm10k specific version of skb_pull_tail
* @rx_ring: rx descriptor ring packet is being transacted on
* @rx_desc: pointer to the EOP Rx descriptor
* @skb: pointer to current skb being adjusted
*
* This function is an fm10k specific version of __pskb_pull_tail. The
* main difference between this version and the original function is that
* this function can make several assumptions about the state of things
* that allow for significant optimizations versus the standard function.
* As a result we can do things like drop a frag and maintain an accurate
* truesize for the skb.
*/
static void fm10k_pull_tail(struct fm10k_ring *rx_ring,
union fm10k_rx_desc *rx_desc,
struct sk_buff *skb)
{
struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
unsigned char *va;
unsigned int pull_len;
/* it is valid to use page_address instead of kmap since we are
* working with pages allocated out of the lomem pool per
* alloc_page(GFP_ATOMIC)
*/
va = skb_frag_address(frag);
/* we need the header to contain the greater of either ETH_HLEN or
* 60 bytes if the skb->len is less than 60 for skb_pad.
*/
pull_len = eth_get_headlen(va, FM10K_RX_HDR_LEN);
/* align pull length to size of long to optimize memcpy performance */
skb_copy_to_linear_data(skb, va, ALIGN(pull_len, sizeof(long)));
/* update all of the pointers */
skb_frag_size_sub(frag, pull_len);
frag->page_offset += pull_len;
skb->data_len -= pull_len;
skb->tail += pull_len;
}
/**
* fm10k_cleanup_headers - Correct corrupted or empty headers
* @rx_ring: rx descriptor ring packet is being transacted on
* @rx_desc: pointer to the EOP Rx descriptor
* @skb: pointer to current skb being fixed
*
* 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 fm10k_cleanup_headers(struct fm10k_ring *rx_ring,
union fm10k_rx_desc *rx_desc,
struct sk_buff *skb)
{
if (unlikely((fm10k_test_staterr(rx_desc,
FM10K_RXD_STATUS_RXE)))) {
dev_kfree_skb_any(skb);
rx_ring->rx_stats.errors++;
return true;
}
/* place header in linear portion of buffer */
if (skb_is_nonlinear(skb))
fm10k_pull_tail(rx_ring, rx_desc, skb);
/* if skb_pad returns an error the skb was freed */
if (unlikely(skb->len < 60)) {
int pad_len = 60 - skb->len;
if (skb_pad(skb, pad_len))
return true;
__skb_put(skb, pad_len);
}
return false;
}
/**
* fm10k_receive_skb - helper function to handle rx indications
* @q_vector: structure containing interrupt and ring information
* @skb: packet to send up
**/
static void fm10k_receive_skb(struct fm10k_q_vector *q_vector,
struct sk_buff *skb)
{
napi_gro_receive(&q_vector->napi, skb);
}
static bool fm10k_clean_rx_irq(struct fm10k_q_vector *q_vector,
struct fm10k_ring *rx_ring,
int budget)
{
struct sk_buff *skb = rx_ring->skb;
unsigned int total_bytes = 0, total_packets = 0;
u16 cleaned_count = fm10k_desc_unused(rx_ring);
do {
union fm10k_rx_desc *rx_desc;
/* return some buffers to hardware, one at a time is too slow */
if (cleaned_count >= FM10K_RX_BUFFER_WRITE) {
fm10k_alloc_rx_buffers(rx_ring, cleaned_count);
cleaned_count = 0;
}
rx_desc = FM10K_RX_DESC(rx_ring, rx_ring->next_to_clean);
if (!fm10k_test_staterr(rx_desc, FM10K_RXD_STATUS_DD))
break;
/* This memory barrier is needed to keep us from reading
* any other fields out of the rx_desc until we know the
* RXD_STATUS_DD bit is set
*/
rmb();
/* retrieve a buffer from the ring */
skb = fm10k_fetch_rx_buffer(rx_ring, rx_desc, skb);
/* exit if we failed to retrieve a buffer */
if (!skb)
break;
cleaned_count++;
/* fetch next buffer in frame if non-eop */
if (fm10k_is_non_eop(rx_ring, rx_desc))
continue;
/* verify the packet layout is correct */
if (fm10k_cleanup_headers(rx_ring, rx_desc, skb)) {
skb = NULL;
continue;
}
/* populate checksum, timestamp, VLAN, and protocol */
total_bytes += fm10k_process_skb_fields(rx_ring, rx_desc, skb);
fm10k_receive_skb(q_vector, skb);
/* reset skb pointer */
skb = NULL;
/* update budget accounting */
total_packets++;
} while (likely(total_packets < budget));
/* place incomplete frames back on ring for completion */
rx_ring->skb = skb;
u64_stats_update_begin(&rx_ring->syncp);
rx_ring->stats.packets += total_packets;
rx_ring->stats.bytes += total_bytes;
u64_stats_update_end(&rx_ring->syncp);
q_vector->rx.total_packets += total_packets;
q_vector->rx.total_bytes += total_bytes;
return total_packets < budget;
}
static bool fm10k_tx_desc_push(struct fm10k_ring *tx_ring,
struct fm10k_tx_desc *tx_desc, u16 i,
dma_addr_t dma, unsigned int size, u8 desc_flags)
{
/* set RS and INT for last frame in a cache line */
if ((++i & (FM10K_TXD_WB_FIFO_SIZE - 1)) == 0)
desc_flags |= FM10K_TXD_FLAG_RS | FM10K_TXD_FLAG_INT;
/* record values to descriptor */
tx_desc->buffer_addr = cpu_to_le64(dma);
tx_desc->flags = desc_flags;
tx_desc->buflen = cpu_to_le16(size);
/* return true if we just wrapped the ring */
return i == tx_ring->count;
}
static void fm10k_tx_map(struct fm10k_ring *tx_ring,
struct fm10k_tx_buffer *first)
{
struct sk_buff *skb = first->skb;
struct fm10k_tx_buffer *tx_buffer;
struct fm10k_tx_desc *tx_desc;
struct skb_frag_struct *frag;
unsigned char *data;
dma_addr_t dma;
unsigned int data_len, size;
u16 i = tx_ring->next_to_use;
u8 flags = 0;
tx_desc = FM10K_TX_DESC(tx_ring, i);
/* add HW VLAN tag */
if (vlan_tx_tag_present(skb))
tx_desc->vlan = cpu_to_le16(vlan_tx_tag_get(skb));
else
tx_desc->vlan = 0;
size = skb_headlen(skb);
data = skb->data;
dma = dma_map_single(tx_ring->dev, data, size, DMA_TO_DEVICE);
data_len = skb->data_len;
tx_buffer = first;
for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
/* record length, and DMA address */
dma_unmap_len_set(tx_buffer, len, size);
dma_unmap_addr_set(tx_buffer, dma, dma);
while (unlikely(size > FM10K_MAX_DATA_PER_TXD)) {
if (fm10k_tx_desc_push(tx_ring, tx_desc++, i++, dma,
FM10K_MAX_DATA_PER_TXD, flags)) {
tx_desc = FM10K_TX_DESC(tx_ring, 0);
i = 0;
}
dma += FM10K_MAX_DATA_PER_TXD;
size -= FM10K_MAX_DATA_PER_TXD;
}
if (likely(!data_len))
break;
if (fm10k_tx_desc_push(tx_ring, tx_desc++, i++,
dma, size, flags)) {
tx_desc = FM10K_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_buffer = &tx_ring->tx_buffer[i];
}
/* write last descriptor with LAST bit set */
flags |= FM10K_TXD_FLAG_LAST;
if (fm10k_tx_desc_push(tx_ring, tx_desc, i++, dma, size, flags))
i = 0;
/* 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);
/* 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).
*
* We also need 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;
/* notify HW of packet */
writel(i, tx_ring->tail);
/* we need this if more than one processor can write to our tail
* at a time, it synchronizes IO on IA64/Altix systems
*/
mmiowb();
return;
dma_error:
dev_err(tx_ring->dev, "TX DMA map failed\n");
/* clear dma mappings for failed tx_buffer map */
for (;;) {
tx_buffer = &tx_ring->tx_buffer[i];
fm10k_unmap_and_free_tx_resource(tx_ring, tx_buffer);
if (tx_buffer == first)
break;
if (i == 0)
i = tx_ring->count;
i--;
}
tx_ring->next_to_use = i;
}
static int __fm10k_maybe_stop_tx(struct fm10k_ring *tx_ring, u16 size)
{
netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
smp_mb();
/* We need to check again in a case another CPU has just
* made room available. */
if (likely(fm10k_desc_unused(tx_ring) < size))
return -EBUSY;
/* A reprieve! - use start_queue because it doesn't call schedule */
netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
++tx_ring->tx_stats.restart_queue;
return 0;
}
static inline int fm10k_maybe_stop_tx(struct fm10k_ring *tx_ring, u16 size)
{
if (likely(fm10k_desc_unused(tx_ring) >= size))
return 0;
return __fm10k_maybe_stop_tx(tx_ring, size);
}
netdev_tx_t fm10k_xmit_frame_ring(struct sk_buff *skb,
struct fm10k_ring *tx_ring)
{
struct fm10k_tx_buffer *first;
u32 tx_flags = 0;
#if PAGE_SIZE > FM10K_MAX_DATA_PER_TXD
unsigned short f;
#endif
u16 count = TXD_USE_COUNT(skb_headlen(skb));
/* need: 1 descriptor per page * PAGE_SIZE/FM10K_MAX_DATA_PER_TXD,
* + 1 desc for skb_headlen/FM10K_MAX_DATA_PER_TXD,
* + 2 desc gap to keep tail from touching head
* otherwise try next time
*/
#if PAGE_SIZE > FM10K_MAX_DATA_PER_TXD
for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size);
#else
count += skb_shinfo(skb)->nr_frags;
#endif
if (fm10k_maybe_stop_tx(tx_ring, count + 3)) {
tx_ring->tx_stats.tx_busy++;
return NETDEV_TX_BUSY;
}
/* record the location of the first descriptor for this packet */
first = &tx_ring->tx_buffer[tx_ring->next_to_use];
first->skb = skb;
first->bytecount = max_t(unsigned int, skb->len, ETH_ZLEN);
first->gso_segs = 1;
/* record initial flags and protocol */
first->tx_flags = tx_flags;
fm10k_tx_map(tx_ring, first);
fm10k_maybe_stop_tx(tx_ring, DESC_NEEDED);
return NETDEV_TX_OK;
}
static u64 fm10k_get_tx_completed(struct fm10k_ring *ring)
{
return ring->stats.packets;
}
static u64 fm10k_get_tx_pending(struct fm10k_ring *ring)
{
/* use SW head and tail until we have real hardware */
u32 head = ring->next_to_clean;
u32 tail = ring->next_to_use;
return ((head <= tail) ? tail : tail + ring->count) - head;
}
bool fm10k_check_tx_hang(struct fm10k_ring *tx_ring)
{
u32 tx_done = fm10k_get_tx_completed(tx_ring);
u32 tx_done_old = tx_ring->tx_stats.tx_done_old;
u32 tx_pending = fm10k_get_tx_pending(tx_ring);
clear_check_for_tx_hang(tx_ring);
/* Check for a hung queue, but be thorough. This verifies
* that a transmit has been completed since the previous
* check AND there is at least one packet pending. By
* requiring this to fail twice we avoid races with
* clearing the ARMED bit and conditions where we
* run the check_tx_hang logic with a transmit completion
* pending but without time to complete it yet.
*/
if (!tx_pending || (tx_done_old != tx_done)) {
/* update completed stats and continue */
tx_ring->tx_stats.tx_done_old = tx_done;
/* reset the countdown */
clear_bit(__FM10K_HANG_CHECK_ARMED, &tx_ring->state);
return false;
}
/* make sure it is true for two checks in a row */
return test_and_set_bit(__FM10K_HANG_CHECK_ARMED, &tx_ring->state);
}
/**
* fm10k_tx_timeout_reset - initiate reset due to Tx timeout
* @interface: driver private struct
**/
void fm10k_tx_timeout_reset(struct fm10k_intfc *interface)
{
/* Do the reset outside of interrupt context */
if (!test_bit(__FM10K_DOWN, &interface->state)) {
netdev_err(interface->netdev, "Reset interface\n");
interface->tx_timeout_count++;
interface->flags |= FM10K_FLAG_RESET_REQUESTED;
fm10k_service_event_schedule(interface);
}
}
/**
* fm10k_clean_tx_irq - Reclaim resources after transmit completes
* @q_vector: structure containing interrupt and ring information
* @tx_ring: tx ring to clean
**/
static bool fm10k_clean_tx_irq(struct fm10k_q_vector *q_vector,
struct fm10k_ring *tx_ring)
{
struct fm10k_intfc *interface = q_vector->interface;
struct fm10k_tx_buffer *tx_buffer;
struct fm10k_tx_desc *tx_desc;
unsigned int total_bytes = 0, total_packets = 0;
unsigned int budget = q_vector->tx.work_limit;
unsigned int i = tx_ring->next_to_clean;
if (test_bit(__FM10K_DOWN, &interface->state))
return true;
tx_buffer = &tx_ring->tx_buffer[i];
tx_desc = FM10K_TX_DESC(tx_ring, i);
i -= tx_ring->count;
do {
struct fm10k_tx_desc *eop_desc = tx_buffer->next_to_watch;
/* if next_to_watch is not set then there is no work pending */
if (!eop_desc)
break;
/* prevent any other reads prior to eop_desc */
read_barrier_depends();
/* if DD is not set pending work has not been completed */
if (!(eop_desc->flags & FM10K_TXD_FLAG_DONE))
break;
/* clear next_to_watch to prevent false hangs */
tx_buffer->next_to_watch = NULL;
/* update the statistics for this packet */
total_bytes += tx_buffer->bytecount;
total_packets += tx_buffer->gso_segs;
/* free the skb */
dev_consume_skb_any(tx_buffer->skb);
/* unmap skb header data */
dma_unmap_single(tx_ring->dev,
dma_unmap_addr(tx_buffer, dma),
dma_unmap_len(tx_buffer, len),
DMA_TO_DEVICE);
/* clear tx_buffer data */
tx_buffer->skb = NULL;
dma_unmap_len_set(tx_buffer, len, 0);
/* unmap remaining buffers */
while (tx_desc != eop_desc) {
tx_buffer++;
tx_desc++;
i++;
if (unlikely(!i)) {
i -= tx_ring->count;
tx_buffer = tx_ring->tx_buffer;
tx_desc = FM10K_TX_DESC(tx_ring, 0);
}
/* unmap any remaining paged data */
if (dma_unmap_len(tx_buffer, len)) {
dma_unmap_page(tx_ring->dev,
dma_unmap_addr(tx_buffer, dma),
dma_unmap_len(tx_buffer, len),
DMA_TO_DEVICE);
dma_unmap_len_set(tx_buffer, len, 0);
}
}
/* move us one more past the eop_desc for start of next pkt */
tx_buffer++;
tx_desc++;
i++;
if (unlikely(!i)) {
i -= tx_ring->count;
tx_buffer = tx_ring->tx_buffer;
tx_desc = FM10K_TX_DESC(tx_ring, 0);
}
/* issue prefetch for next Tx descriptor */
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.packets += total_packets;
u64_stats_update_end(&tx_ring->syncp);
q_vector->tx.total_bytes += total_bytes;
q_vector->tx.total_packets += total_packets;
if (check_for_tx_hang(tx_ring) && fm10k_check_tx_hang(tx_ring)) {
/* schedule immediate reset if we believe we hung */
struct fm10k_hw *hw = &interface->hw;
netif_err(interface, drv, tx_ring->netdev,
"Detected Tx Unit Hang\n"
" Tx Queue <%d>\n"
" TDH, TDT <%x>, <%x>\n"
" next_to_use <%x>\n"
" next_to_clean <%x>\n",
tx_ring->queue_index,
fm10k_read_reg(hw, FM10K_TDH(tx_ring->reg_idx)),
fm10k_read_reg(hw, FM10K_TDT(tx_ring->reg_idx)),
tx_ring->next_to_use, i);
netif_stop_subqueue(tx_ring->netdev,
tx_ring->queue_index);
netif_info(interface, probe, tx_ring->netdev,
"tx hang %d detected on queue %d, resetting interface\n",
interface->tx_timeout_count + 1,
tx_ring->queue_index);
fm10k_tx_timeout_reset(interface);
/* the netdev is about to reset, no point in enabling stuff */
return true;
}
/* notify netdev of completed buffers */
netdev_tx_completed_queue(txring_txq(tx_ring),
total_packets, total_bytes);
#define TX_WAKE_THRESHOLD min_t(u16, FM10K_MIN_TXD - 1, DESC_NEEDED * 2)
if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
(fm10k_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->queue_index) &&
!test_bit(__FM10K_DOWN, &interface->state)) {
netif_wake_subqueue(tx_ring->netdev,
tx_ring->queue_index);
++tx_ring->tx_stats.restart_queue;
}
}
return !!budget;
}
/**
* fm10k_update_itr - update the dynamic ITR value based on packet size
*
* Stores a new ITR value based on strictly on packet size. The
* divisors and thresholds used by this function were determined based
* on theoretical maximum wire speed and testing data, in order to
* minimize response time while increasing bulk throughput.
*
* @ring_container: Container for rings to have ITR updated
**/
static void fm10k_update_itr(struct fm10k_ring_container *ring_container)
{
unsigned int avg_wire_size, packets;
/* Only update ITR if we are using adaptive setting */
if (!(ring_container->itr & FM10K_ITR_ADAPTIVE))
goto clear_counts;
packets = ring_container->total_packets;
if (!packets)
goto clear_counts;
avg_wire_size = ring_container->total_bytes / packets;
/* Add 24 bytes to size to account for CRC, preamble, and gap */
avg_wire_size += 24;
/* Don't starve jumbo frames */
if (avg_wire_size > 3000)
avg_wire_size = 3000;
/* Give a little boost to mid-size frames */
if ((avg_wire_size > 300) && (avg_wire_size < 1200))
avg_wire_size /= 3;
else
avg_wire_size /= 2;
/* write back value and retain adaptive flag */
ring_container->itr = avg_wire_size | FM10K_ITR_ADAPTIVE;
clear_counts:
ring_container->total_bytes = 0;
ring_container->total_packets = 0;
}
static void fm10k_qv_enable(struct fm10k_q_vector *q_vector)
{
/* Enable auto-mask and clear the current mask */
u32 itr = FM10K_ITR_ENABLE;
/* Update Tx ITR */
fm10k_update_itr(&q_vector->tx);
/* Update Rx ITR */
fm10k_update_itr(&q_vector->rx);
/* Store Tx itr in timer slot 0 */
itr |= (q_vector->tx.itr & FM10K_ITR_MAX);
/* Shift Rx itr to timer slot 1 */
itr |= (q_vector->rx.itr & FM10K_ITR_MAX) << FM10K_ITR_INTERVAL1_SHIFT;
/* Write the final value to the ITR register */
writel(itr, q_vector->itr);
}
static int fm10k_poll(struct napi_struct *napi, int budget)
{
struct fm10k_q_vector *q_vector =
container_of(napi, struct fm10k_q_vector, napi);
struct fm10k_ring *ring;
int per_ring_budget;
bool clean_complete = true;
fm10k_for_each_ring(ring, q_vector->tx)
clean_complete &= fm10k_clean_tx_irq(q_vector, ring);
/* attempt to distribute budget to each queue fairly, but don't
* allow the budget to go below 1 because we'll exit polling
*/
if (q_vector->rx.count > 1)
per_ring_budget = max(budget/q_vector->rx.count, 1);
else
per_ring_budget = budget;
fm10k_for_each_ring(ring, q_vector->rx)
clean_complete &= fm10k_clean_rx_irq(q_vector, ring,
per_ring_budget);
/* If all work not completed, return budget and keep polling */
if (!clean_complete)
return budget;
/* all work done, exit the polling mode */
napi_complete(napi);
/* re-enable the q_vector */
fm10k_qv_enable(q_vector);
return 0;
}
/**
* fm10k_set_num_queues: Allocate queues for device, feature dependent
* @interface: board private structure to initialize
*
* This is the top level queue allocation routine. The order here is very
* important, starting with the "most" number of features turned on at once,
* and ending with the smallest set of features. This way large combinations
* can be allocated if they're turned on, and smaller combinations are the
* fallthrough conditions.
*
**/
static void fm10k_set_num_queues(struct fm10k_intfc *interface)
{
/* Start with base case */
interface->num_rx_queues = 1;
interface->num_tx_queues = 1;
}
/**
* fm10k_alloc_q_vector - Allocate memory for a single interrupt vector
* @interface: board private structure to initialize
* @v_count: q_vectors allocated on interface, used for ring interleaving
* @v_idx: index of vector in interface struct
* @txr_count: total number of Tx rings to allocate
* @txr_idx: index of first Tx ring to allocate
* @rxr_count: total number of Rx rings to allocate
* @rxr_idx: index of first Rx ring to allocate
*
* We allocate one q_vector. If allocation fails we return -ENOMEM.
**/
static int fm10k_alloc_q_vector(struct fm10k_intfc *interface,
unsigned int v_count, unsigned int v_idx,
unsigned int txr_count, unsigned int txr_idx,
unsigned int rxr_count, unsigned int rxr_idx)
{
struct fm10k_q_vector *q_vector;
struct fm10k_ring *ring;
int ring_count, size;
ring_count = txr_count + rxr_count;
size = sizeof(struct fm10k_q_vector) +
(sizeof(struct fm10k_ring) * ring_count);
/* allocate q_vector and rings */
q_vector = kzalloc(size, GFP_KERNEL);
if (!q_vector)
return -ENOMEM;
/* initialize NAPI */
netif_napi_add(interface->netdev, &q_vector->napi,
fm10k_poll, NAPI_POLL_WEIGHT);
/* tie q_vector and interface together */
interface->q_vector[v_idx] = q_vector;
q_vector->interface = interface;
q_vector->v_idx = v_idx;
/* initialize pointer to rings */
ring = q_vector->ring;
/* save Tx ring container info */
q_vector->tx.ring = ring;
q_vector->tx.work_limit = FM10K_DEFAULT_TX_WORK;
q_vector->tx.itr = interface->tx_itr;
q_vector->tx.count = txr_count;
while (txr_count) {
/* assign generic ring traits */
ring->dev = &interface->pdev->dev;
ring->netdev = interface->netdev;
/* configure backlink on ring */
ring->q_vector = q_vector;
/* apply Tx specific ring traits */
ring->count = interface->tx_ring_count;
ring->queue_index = txr_idx;
/* assign ring to interface */
interface->tx_ring[txr_idx] = ring;
/* update count and index */
txr_count--;
txr_idx += v_count;
/* push pointer to next ring */
ring++;
}
/* save Rx ring container info */
q_vector->rx.ring = ring;
q_vector->rx.itr = interface->rx_itr;
q_vector->rx.count = rxr_count;
while (rxr_count) {
/* assign generic ring traits */
ring->dev = &interface->pdev->dev;
ring->netdev = interface->netdev;
/* configure backlink on ring */
ring->q_vector = q_vector;
/* apply Rx specific ring traits */
ring->count = interface->rx_ring_count;
ring->queue_index = rxr_idx;
/* assign ring to interface */
interface->rx_ring[rxr_idx] = ring;
/* update count and index */
rxr_count--;
rxr_idx += v_count;
/* push pointer to next ring */
ring++;
}
return 0;
}
/**
* fm10k_free_q_vector - Free memory allocated for specific interrupt vector
* @interface: board private structure to initialize
* @v_idx: Index of vector to be freed
*
* This function frees the memory allocated to the q_vector. In addition if
* NAPI is enabled it will delete any references to the NAPI struct prior
* to freeing the q_vector.
**/
static void fm10k_free_q_vector(struct fm10k_intfc *interface, int v_idx)
{
struct fm10k_q_vector *q_vector = interface->q_vector[v_idx];
struct fm10k_ring *ring;
fm10k_for_each_ring(ring, q_vector->tx)
interface->tx_ring[ring->queue_index] = NULL;
fm10k_for_each_ring(ring, q_vector->rx)
interface->rx_ring[ring->queue_index] = NULL;
interface->q_vector[v_idx] = NULL;
netif_napi_del(&q_vector->napi);
kfree_rcu(q_vector, rcu);
}
/**
* fm10k_alloc_q_vectors - Allocate memory for interrupt vectors
* @interface: board private structure to initialize
*
* We allocate one q_vector per queue interrupt. If allocation fails we
* return -ENOMEM.
**/
static int fm10k_alloc_q_vectors(struct fm10k_intfc *interface)
{
unsigned int q_vectors = interface->num_q_vectors;
unsigned int rxr_remaining = interface->num_rx_queues;
unsigned int txr_remaining = interface->num_tx_queues;
unsigned int rxr_idx = 0, txr_idx = 0, v_idx = 0;
int err;
if (q_vectors >= (rxr_remaining + txr_remaining)) {
for (; rxr_remaining; v_idx++) {
err = fm10k_alloc_q_vector(interface, q_vectors, v_idx,
0, 0, 1, rxr_idx);
if (err)
goto err_out;
/* update counts and index */
rxr_remaining--;
rxr_idx++;
}
}
for (; v_idx < q_vectors; v_idx++) {
int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors - v_idx);
int tqpv = DIV_ROUND_UP(txr_remaining, q_vectors - v_idx);
err = fm10k_alloc_q_vector(interface, q_vectors, v_idx,
tqpv, txr_idx,
rqpv, rxr_idx);
if (err)
goto err_out;
/* update counts and index */
rxr_remaining -= rqpv;
txr_remaining -= tqpv;
rxr_idx++;
txr_idx++;
}
return 0;
err_out:
interface->num_tx_queues = 0;
interface->num_rx_queues = 0;
interface->num_q_vectors = 0;
while (v_idx--)
fm10k_free_q_vector(interface, v_idx);
return -ENOMEM;
}
/**
* fm10k_free_q_vectors - Free memory allocated for interrupt vectors
* @interface: board private structure to initialize
*
* This function frees the memory allocated to the q_vectors. In addition if
* NAPI is enabled it will delete any references to the NAPI struct prior
* to freeing the q_vector.
**/
static void fm10k_free_q_vectors(struct fm10k_intfc *interface)
{
int v_idx = interface->num_q_vectors;
interface->num_tx_queues = 0;
interface->num_rx_queues = 0;
interface->num_q_vectors = 0;
while (v_idx--)
fm10k_free_q_vector(interface, v_idx);
}
/**
* f10k_reset_msix_capability - reset MSI-X capability
* @interface: board private structure to initialize
*
* Reset the MSI-X capability back to its starting state
**/
static void fm10k_reset_msix_capability(struct fm10k_intfc *interface)
{
pci_disable_msix(interface->pdev);
kfree(interface->msix_entries);
interface->msix_entries = NULL;
}
/**
* f10k_init_msix_capability - configure MSI-X capability
* @interface: board private structure to initialize
*
* Attempt to configure the interrupts using the best available
* capabilities of the hardware and the kernel.
**/
static int fm10k_init_msix_capability(struct fm10k_intfc *interface)
{
struct fm10k_hw *hw = &interface->hw;
int v_budget, vector;
/* It's easy to be greedy for MSI-X vectors, but it really
* doesn't do us much good if we have a lot more vectors
* than CPU's. So let's be conservative and only ask for
* (roughly) the same number of vectors as there are CPU's.
* the default is to use pairs of vectors
*/
v_budget = max(interface->num_rx_queues, interface->num_tx_queues);
v_budget = min_t(u16, v_budget, num_online_cpus());
/* account for vectors not related to queues */
v_budget += NON_Q_VECTORS(hw);
/* At the same time, hardware can only support a maximum of
* hw.mac->max_msix_vectors vectors. With features
* such as RSS and VMDq, we can easily surpass the number of Rx and Tx
* descriptor queues supported by our device. Thus, we cap it off in
* those rare cases where the cpu count also exceeds our vector limit.
*/
v_budget = min_t(int, v_budget, hw->mac.max_msix_vectors);
/* A failure in MSI-X entry allocation is fatal. */
interface->msix_entries = kcalloc(v_budget, sizeof(struct msix_entry),
GFP_KERNEL);
if (!interface->msix_entries)
return -ENOMEM;
/* populate entry values */
for (vector = 0; vector < v_budget; vector++)
interface->msix_entries[vector].entry = vector;
/* Attempt to enable MSI-X with requested value */
v_budget = pci_enable_msix_range(interface->pdev,
interface->msix_entries,
MIN_MSIX_COUNT(hw),
v_budget);
if (v_budget < 0) {
kfree(interface->msix_entries);
interface->msix_entries = NULL;
return -ENOMEM;
}
/* record the number of queues available for q_vectors */
interface->num_q_vectors = v_budget - NON_Q_VECTORS(hw);
return 0;
}
static void fm10k_init_reta(struct fm10k_intfc *interface)
{
u16 i, rss_i = interface->ring_feature[RING_F_RSS].indices;
u32 reta, base;
/* If the netdev is initialized we have to maintain table if possible */
if (interface->netdev->reg_state) {
for (i = FM10K_RETA_SIZE; i--;) {
reta = interface->reta[i];
if ((((reta << 24) >> 24) < rss_i) &&
(((reta << 16) >> 24) < rss_i) &&
(((reta << 8) >> 24) < rss_i) &&
(((reta) >> 24) < rss_i))
continue;
goto repopulate_reta;
}
/* do nothing if all of the elements are in bounds */
return;
}
repopulate_reta:
/* Populate the redirection table 4 entries at a time. To do this
* we are generating the results for n and n+2 and then interleaving
* those with the results with n+1 and n+3.
*/
for (i = FM10K_RETA_SIZE; i--;) {
/* first pass generates n and n+2 */
base = ((i * 0x00040004) + 0x00020000) * rss_i;
reta = (base & 0x3F803F80) >> 7;
/* second pass generates n+1 and n+3 */
base += 0x00010001 * rss_i;
reta |= (base & 0x3F803F80) << 1;
interface->reta[i] = reta;
}
}
/**
* fm10k_init_queueing_scheme - Determine proper queueing scheme
* @interface: board private structure to initialize
*
* We determine which queueing scheme to use based on...
* - Hardware queue count (num_*_queues)
* - defined by miscellaneous hardware support/features (RSS, etc.)
**/
int fm10k_init_queueing_scheme(struct fm10k_intfc *interface)
{
int err;
/* Number of supported queues */
fm10k_set_num_queues(interface);
/* Configure MSI-X capability */
err = fm10k_init_msix_capability(interface);
if (err) {
dev_err(&interface->pdev->dev,
"Unable to initialize MSI-X capability\n");
return err;
}
/* Allocate memory for queues */
err = fm10k_alloc_q_vectors(interface);
if (err)
return err;
/* Initialize RSS redirection table */
fm10k_init_reta(interface);
return 0;
}
/**
* fm10k_clear_queueing_scheme - Clear the current queueing scheme settings
* @interface: board private structure to clear queueing scheme on
*
* We go through and clear queueing specific resources and reset the structure
* to pre-load conditions
**/
void fm10k_clear_queueing_scheme(struct fm10k_intfc *interface)
{
fm10k_free_q_vectors(interface);
fm10k_reset_msix_capability(interface);
}
