blob: beb8bb079023cc555a2eeab4d73b1b62d261ad1f [file] [log] [blame]
// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/* Google virtual Ethernet (gve) driver
*
* Copyright (C) 2015-2021 Google, Inc.
*/
#include "gve.h"
#include "gve_dqo.h"
#include "gve_adminq.h"
#include "gve_utils.h"
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/ip6_checksum.h>
#include <net/ipv6.h>
#include <net/tcp.h>
static int gve_buf_ref_cnt(struct gve_rx_buf_state_dqo *bs)
{
return page_count(bs->page_info.page) - bs->page_info.pagecnt_bias;
}
static void gve_free_page_dqo(struct gve_priv *priv,
struct gve_rx_buf_state_dqo *bs)
{
page_ref_sub(bs->page_info.page, bs->page_info.pagecnt_bias - 1);
gve_free_page(&priv->pdev->dev, bs->page_info.page, bs->addr,
DMA_FROM_DEVICE);
bs->page_info.page = NULL;
}
static struct gve_rx_buf_state_dqo *gve_alloc_buf_state(struct gve_rx_ring *rx)
{
struct gve_rx_buf_state_dqo *buf_state;
s16 buffer_id;
buffer_id = rx->dqo.free_buf_states;
if (unlikely(buffer_id == -1))
return NULL;
buf_state = &rx->dqo.buf_states[buffer_id];
/* Remove buf_state from free list */
rx->dqo.free_buf_states = buf_state->next;
/* Point buf_state to itself to mark it as allocated */
buf_state->next = buffer_id;
return buf_state;
}
static bool gve_buf_state_is_allocated(struct gve_rx_ring *rx,
struct gve_rx_buf_state_dqo *buf_state)
{
s16 buffer_id = buf_state - rx->dqo.buf_states;
return buf_state->next == buffer_id;
}
static void gve_free_buf_state(struct gve_rx_ring *rx,
struct gve_rx_buf_state_dqo *buf_state)
{
s16 buffer_id = buf_state - rx->dqo.buf_states;
buf_state->next = rx->dqo.free_buf_states;
rx->dqo.free_buf_states = buffer_id;
}
static struct gve_rx_buf_state_dqo *
gve_dequeue_buf_state(struct gve_rx_ring *rx, struct gve_index_list *list)
{
struct gve_rx_buf_state_dqo *buf_state;
s16 buffer_id;
buffer_id = list->head;
if (unlikely(buffer_id == -1))
return NULL;
buf_state = &rx->dqo.buf_states[buffer_id];
/* Remove buf_state from list */
list->head = buf_state->next;
if (buf_state->next == -1)
list->tail = -1;
/* Point buf_state to itself to mark it as allocated */
buf_state->next = buffer_id;
return buf_state;
}
static void gve_enqueue_buf_state(struct gve_rx_ring *rx,
struct gve_index_list *list,
struct gve_rx_buf_state_dqo *buf_state)
{
s16 buffer_id = buf_state - rx->dqo.buf_states;
buf_state->next = -1;
if (list->head == -1) {
list->head = buffer_id;
list->tail = buffer_id;
} else {
int tail = list->tail;
rx->dqo.buf_states[tail].next = buffer_id;
list->tail = buffer_id;
}
}
static struct gve_rx_buf_state_dqo *
gve_get_recycled_buf_state(struct gve_rx_ring *rx)
{
struct gve_rx_buf_state_dqo *buf_state;
int i;
/* Recycled buf states are immediately usable. */
buf_state = gve_dequeue_buf_state(rx, &rx->dqo.recycled_buf_states);
if (likely(buf_state))
return buf_state;
if (unlikely(rx->dqo.used_buf_states.head == -1))
return NULL;
/* Used buf states are only usable when ref count reaches 0, which means
* no SKBs refer to them.
*
* Search a limited number before giving up.
*/
for (i = 0; i < 5; i++) {
buf_state = gve_dequeue_buf_state(rx, &rx->dqo.used_buf_states);
if (gve_buf_ref_cnt(buf_state) == 0)
return buf_state;
gve_enqueue_buf_state(rx, &rx->dqo.used_buf_states, buf_state);
}
/* If there are no free buf states discard an entry from
* `used_buf_states` so it can be used.
*/
if (unlikely(rx->dqo.free_buf_states == -1)) {
buf_state = gve_dequeue_buf_state(rx, &rx->dqo.used_buf_states);
if (gve_buf_ref_cnt(buf_state) == 0)
return buf_state;
gve_free_page_dqo(rx->gve, buf_state);
gve_free_buf_state(rx, buf_state);
}
return NULL;
}
static int gve_alloc_page_dqo(struct gve_priv *priv,
struct gve_rx_buf_state_dqo *buf_state)
{
int err;
err = gve_alloc_page(priv, &priv->pdev->dev, &buf_state->page_info.page,
&buf_state->addr, DMA_FROM_DEVICE);
if (err)
return err;
buf_state->page_info.page_offset = 0;
buf_state->page_info.page_address =
page_address(buf_state->page_info.page);
buf_state->last_single_ref_offset = 0;
/* The page already has 1 ref. */
page_ref_add(buf_state->page_info.page, INT_MAX - 1);
buf_state->page_info.pagecnt_bias = INT_MAX;
return 0;
}
static void gve_rx_free_ring_dqo(struct gve_priv *priv, int idx)
{
struct gve_rx_ring *rx = &priv->rx[idx];
struct device *hdev = &priv->pdev->dev;
size_t completion_queue_slots;
size_t buffer_queue_slots;
size_t size;
int i;
completion_queue_slots = rx->dqo.complq.mask + 1;
buffer_queue_slots = rx->dqo.bufq.mask + 1;
gve_rx_remove_from_block(priv, idx);
if (rx->q_resources) {
dma_free_coherent(hdev, sizeof(*rx->q_resources),
rx->q_resources, rx->q_resources_bus);
rx->q_resources = NULL;
}
for (i = 0; i < rx->dqo.num_buf_states; i++) {
struct gve_rx_buf_state_dqo *bs = &rx->dqo.buf_states[i];
if (bs->page_info.page)
gve_free_page_dqo(priv, bs);
}
if (rx->dqo.bufq.desc_ring) {
size = sizeof(rx->dqo.bufq.desc_ring[0]) * buffer_queue_slots;
dma_free_coherent(hdev, size, rx->dqo.bufq.desc_ring,
rx->dqo.bufq.bus);
rx->dqo.bufq.desc_ring = NULL;
}
if (rx->dqo.complq.desc_ring) {
size = sizeof(rx->dqo.complq.desc_ring[0]) *
completion_queue_slots;
dma_free_coherent(hdev, size, rx->dqo.complq.desc_ring,
rx->dqo.complq.bus);
rx->dqo.complq.desc_ring = NULL;
}
kvfree(rx->dqo.buf_states);
rx->dqo.buf_states = NULL;
netif_dbg(priv, drv, priv->dev, "freed rx ring %d\n", idx);
}
static int gve_rx_alloc_ring_dqo(struct gve_priv *priv, int idx)
{
struct gve_rx_ring *rx = &priv->rx[idx];
struct device *hdev = &priv->pdev->dev;
size_t size;
int i;
const u32 buffer_queue_slots =
priv->options_dqo_rda.rx_buff_ring_entries;
const u32 completion_queue_slots = priv->rx_desc_cnt;
netif_dbg(priv, drv, priv->dev, "allocating rx ring DQO\n");
memset(rx, 0, sizeof(*rx));
rx->gve = priv;
rx->q_num = idx;
rx->dqo.bufq.mask = buffer_queue_slots - 1;
rx->dqo.complq.num_free_slots = completion_queue_slots;
rx->dqo.complq.mask = completion_queue_slots - 1;
rx->ctx.skb_head = NULL;
rx->ctx.skb_tail = NULL;
rx->dqo.num_buf_states = min_t(s16, S16_MAX, buffer_queue_slots * 4);
rx->dqo.buf_states = kvcalloc(rx->dqo.num_buf_states,
sizeof(rx->dqo.buf_states[0]),
GFP_KERNEL);
if (!rx->dqo.buf_states)
return -ENOMEM;
/* Set up linked list of buffer IDs */
for (i = 0; i < rx->dqo.num_buf_states - 1; i++)
rx->dqo.buf_states[i].next = i + 1;
rx->dqo.buf_states[rx->dqo.num_buf_states - 1].next = -1;
rx->dqo.recycled_buf_states.head = -1;
rx->dqo.recycled_buf_states.tail = -1;
rx->dqo.used_buf_states.head = -1;
rx->dqo.used_buf_states.tail = -1;
/* Allocate RX completion queue */
size = sizeof(rx->dqo.complq.desc_ring[0]) *
completion_queue_slots;
rx->dqo.complq.desc_ring =
dma_alloc_coherent(hdev, size, &rx->dqo.complq.bus, GFP_KERNEL);
if (!rx->dqo.complq.desc_ring)
goto err;
/* Allocate RX buffer queue */
size = sizeof(rx->dqo.bufq.desc_ring[0]) * buffer_queue_slots;
rx->dqo.bufq.desc_ring =
dma_alloc_coherent(hdev, size, &rx->dqo.bufq.bus, GFP_KERNEL);
if (!rx->dqo.bufq.desc_ring)
goto err;
rx->q_resources = dma_alloc_coherent(hdev, sizeof(*rx->q_resources),
&rx->q_resources_bus, GFP_KERNEL);
if (!rx->q_resources)
goto err;
gve_rx_add_to_block(priv, idx);
return 0;
err:
gve_rx_free_ring_dqo(priv, idx);
return -ENOMEM;
}
void gve_rx_write_doorbell_dqo(const struct gve_priv *priv, int queue_idx)
{
const struct gve_rx_ring *rx = &priv->rx[queue_idx];
u64 index = be32_to_cpu(rx->q_resources->db_index);
iowrite32(rx->dqo.bufq.tail, &priv->db_bar2[index]);
}
int gve_rx_alloc_rings_dqo(struct gve_priv *priv)
{
int err = 0;
int i;
for (i = 0; i < priv->rx_cfg.num_queues; i++) {
err = gve_rx_alloc_ring_dqo(priv, i);
if (err) {
netif_err(priv, drv, priv->dev,
"Failed to alloc rx ring=%d: err=%d\n",
i, err);
goto err;
}
}
return 0;
err:
for (i--; i >= 0; i--)
gve_rx_free_ring_dqo(priv, i);
return err;
}
void gve_rx_free_rings_dqo(struct gve_priv *priv)
{
int i;
for (i = 0; i < priv->rx_cfg.num_queues; i++)
gve_rx_free_ring_dqo(priv, i);
}
void gve_rx_post_buffers_dqo(struct gve_rx_ring *rx)
{
struct gve_rx_compl_queue_dqo *complq = &rx->dqo.complq;
struct gve_rx_buf_queue_dqo *bufq = &rx->dqo.bufq;
struct gve_priv *priv = rx->gve;
u32 num_avail_slots;
u32 num_full_slots;
u32 num_posted = 0;
num_full_slots = (bufq->tail - bufq->head) & bufq->mask;
num_avail_slots = bufq->mask - num_full_slots;
num_avail_slots = min_t(u32, num_avail_slots, complq->num_free_slots);
while (num_posted < num_avail_slots) {
struct gve_rx_desc_dqo *desc = &bufq->desc_ring[bufq->tail];
struct gve_rx_buf_state_dqo *buf_state;
buf_state = gve_get_recycled_buf_state(rx);
if (unlikely(!buf_state)) {
buf_state = gve_alloc_buf_state(rx);
if (unlikely(!buf_state))
break;
if (unlikely(gve_alloc_page_dqo(priv, buf_state))) {
u64_stats_update_begin(&rx->statss);
rx->rx_buf_alloc_fail++;
u64_stats_update_end(&rx->statss);
gve_free_buf_state(rx, buf_state);
break;
}
}
desc->buf_id = cpu_to_le16(buf_state - rx->dqo.buf_states);
desc->buf_addr = cpu_to_le64(buf_state->addr +
buf_state->page_info.page_offset);
bufq->tail = (bufq->tail + 1) & bufq->mask;
complq->num_free_slots--;
num_posted++;
if ((bufq->tail & (GVE_RX_BUF_THRESH_DQO - 1)) == 0)
gve_rx_write_doorbell_dqo(priv, rx->q_num);
}
rx->fill_cnt += num_posted;
}
static void gve_try_recycle_buf(struct gve_priv *priv, struct gve_rx_ring *rx,
struct gve_rx_buf_state_dqo *buf_state)
{
const int data_buffer_size = priv->data_buffer_size_dqo;
int pagecount;
/* Can't reuse if we only fit one buffer per page */
if (data_buffer_size * 2 > PAGE_SIZE)
goto mark_used;
pagecount = gve_buf_ref_cnt(buf_state);
/* Record the offset when we have a single remaining reference.
*
* When this happens, we know all of the other offsets of the page are
* usable.
*/
if (pagecount == 1) {
buf_state->last_single_ref_offset =
buf_state->page_info.page_offset;
}
/* Use the next buffer sized chunk in the page. */
buf_state->page_info.page_offset += data_buffer_size;
buf_state->page_info.page_offset &= (PAGE_SIZE - 1);
/* If we wrap around to the same offset without ever dropping to 1
* reference, then we don't know if this offset was ever freed.
*/
if (buf_state->page_info.page_offset ==
buf_state->last_single_ref_offset) {
goto mark_used;
}
gve_enqueue_buf_state(rx, &rx->dqo.recycled_buf_states, buf_state);
return;
mark_used:
gve_enqueue_buf_state(rx, &rx->dqo.used_buf_states, buf_state);
}
static void gve_rx_skb_csum(struct sk_buff *skb,
const struct gve_rx_compl_desc_dqo *desc,
struct gve_ptype ptype)
{
skb->ip_summed = CHECKSUM_NONE;
/* HW did not identify and process L3 and L4 headers. */
if (unlikely(!desc->l3_l4_processed))
return;
if (ptype.l3_type == GVE_L3_TYPE_IPV4) {
if (unlikely(desc->csum_ip_err || desc->csum_external_ip_err))
return;
} else if (ptype.l3_type == GVE_L3_TYPE_IPV6) {
/* Checksum should be skipped if this flag is set. */
if (unlikely(desc->ipv6_ex_add))
return;
}
if (unlikely(desc->csum_l4_err))
return;
switch (ptype.l4_type) {
case GVE_L4_TYPE_TCP:
case GVE_L4_TYPE_UDP:
case GVE_L4_TYPE_ICMP:
case GVE_L4_TYPE_SCTP:
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
default:
break;
}
}
static void gve_rx_skb_hash(struct sk_buff *skb,
const struct gve_rx_compl_desc_dqo *compl_desc,
struct gve_ptype ptype)
{
enum pkt_hash_types hash_type = PKT_HASH_TYPE_L2;
if (ptype.l4_type != GVE_L4_TYPE_UNKNOWN)
hash_type = PKT_HASH_TYPE_L4;
else if (ptype.l3_type != GVE_L3_TYPE_UNKNOWN)
hash_type = PKT_HASH_TYPE_L3;
skb_set_hash(skb, le32_to_cpu(compl_desc->hash), hash_type);
}
static void gve_rx_free_skb(struct gve_rx_ring *rx)
{
if (!rx->ctx.skb_head)
return;
dev_kfree_skb_any(rx->ctx.skb_head);
rx->ctx.skb_head = NULL;
rx->ctx.skb_tail = NULL;
}
/* Chains multi skbs for single rx packet.
* Returns 0 if buffer is appended, -1 otherwise.
*/
static int gve_rx_append_frags(struct napi_struct *napi,
struct gve_rx_buf_state_dqo *buf_state,
u16 buf_len, struct gve_rx_ring *rx,
struct gve_priv *priv)
{
int num_frags = skb_shinfo(rx->ctx.skb_tail)->nr_frags;
if (unlikely(num_frags == MAX_SKB_FRAGS)) {
struct sk_buff *skb;
skb = napi_alloc_skb(napi, 0);
if (!skb)
return -1;
skb_shinfo(rx->ctx.skb_tail)->frag_list = skb;
rx->ctx.skb_tail = skb;
num_frags = 0;
}
if (rx->ctx.skb_tail != rx->ctx.skb_head) {
rx->ctx.skb_head->len += buf_len;
rx->ctx.skb_head->data_len += buf_len;
rx->ctx.skb_head->truesize += priv->data_buffer_size_dqo;
}
skb_add_rx_frag(rx->ctx.skb_tail, num_frags,
buf_state->page_info.page,
buf_state->page_info.page_offset,
buf_len, priv->data_buffer_size_dqo);
gve_dec_pagecnt_bias(&buf_state->page_info);
return 0;
}
/* Returns 0 if descriptor is completed successfully.
* Returns -EINVAL if descriptor is invalid.
* Returns -ENOMEM if data cannot be copied to skb.
*/
static int gve_rx_dqo(struct napi_struct *napi, struct gve_rx_ring *rx,
const struct gve_rx_compl_desc_dqo *compl_desc,
int queue_idx)
{
const u16 buffer_id = le16_to_cpu(compl_desc->buf_id);
const bool eop = compl_desc->end_of_packet != 0;
struct gve_rx_buf_state_dqo *buf_state;
struct gve_priv *priv = rx->gve;
u16 buf_len;
if (unlikely(buffer_id >= rx->dqo.num_buf_states)) {
net_err_ratelimited("%s: Invalid RX buffer_id=%u\n",
priv->dev->name, buffer_id);
return -EINVAL;
}
buf_state = &rx->dqo.buf_states[buffer_id];
if (unlikely(!gve_buf_state_is_allocated(rx, buf_state))) {
net_err_ratelimited("%s: RX buffer_id is not allocated: %u\n",
priv->dev->name, buffer_id);
return -EINVAL;
}
if (unlikely(compl_desc->rx_error)) {
gve_enqueue_buf_state(rx, &rx->dqo.recycled_buf_states,
buf_state);
return -EINVAL;
}
buf_len = compl_desc->packet_len;
/* Page might have not been used for awhile and was likely last written
* by a different thread.
*/
prefetch(buf_state->page_info.page);
/* Sync the portion of dma buffer for CPU to read. */
dma_sync_single_range_for_cpu(&priv->pdev->dev, buf_state->addr,
buf_state->page_info.page_offset,
buf_len, DMA_FROM_DEVICE);
/* Append to current skb if one exists. */
if (rx->ctx.skb_head) {
if (unlikely(gve_rx_append_frags(napi, buf_state, buf_len, rx,
priv)) != 0) {
goto error;
}
gve_try_recycle_buf(priv, rx, buf_state);
return 0;
}
if (eop && buf_len <= priv->rx_copybreak) {
rx->ctx.skb_head = gve_rx_copy(priv->dev, napi,
&buf_state->page_info, buf_len, 0, NULL);
if (unlikely(!rx->ctx.skb_head))
goto error;
rx->ctx.skb_tail = rx->ctx.skb_head;
u64_stats_update_begin(&rx->statss);
rx->rx_copied_pkt++;
rx->rx_copybreak_pkt++;
u64_stats_update_end(&rx->statss);
gve_enqueue_buf_state(rx, &rx->dqo.recycled_buf_states,
buf_state);
return 0;
}
rx->ctx.skb_head = napi_get_frags(napi);
if (unlikely(!rx->ctx.skb_head))
goto error;
rx->ctx.skb_tail = rx->ctx.skb_head;
skb_add_rx_frag(rx->ctx.skb_head, 0, buf_state->page_info.page,
buf_state->page_info.page_offset, buf_len,
priv->data_buffer_size_dqo);
gve_dec_pagecnt_bias(&buf_state->page_info);
gve_try_recycle_buf(priv, rx, buf_state);
return 0;
error:
gve_enqueue_buf_state(rx, &rx->dqo.recycled_buf_states, buf_state);
return -ENOMEM;
}
static int gve_rx_complete_rsc(struct sk_buff *skb,
const struct gve_rx_compl_desc_dqo *desc,
struct gve_ptype ptype)
{
struct skb_shared_info *shinfo = skb_shinfo(skb);
/* Only TCP is supported right now. */
if (ptype.l4_type != GVE_L4_TYPE_TCP)
return -EINVAL;
switch (ptype.l3_type) {
case GVE_L3_TYPE_IPV4:
shinfo->gso_type = SKB_GSO_TCPV4;
break;
case GVE_L3_TYPE_IPV6:
shinfo->gso_type = SKB_GSO_TCPV6;
break;
default:
return -EINVAL;
}
shinfo->gso_size = le16_to_cpu(desc->rsc_seg_len);
return 0;
}
/* Returns 0 if skb is completed successfully, -1 otherwise. */
static int gve_rx_complete_skb(struct gve_rx_ring *rx, struct napi_struct *napi,
const struct gve_rx_compl_desc_dqo *desc,
netdev_features_t feat)
{
struct gve_ptype ptype =
rx->gve->ptype_lut_dqo->ptypes[desc->packet_type];
int err;
skb_record_rx_queue(rx->ctx.skb_head, rx->q_num);
if (feat & NETIF_F_RXHASH)
gve_rx_skb_hash(rx->ctx.skb_head, desc, ptype);
if (feat & NETIF_F_RXCSUM)
gve_rx_skb_csum(rx->ctx.skb_head, desc, ptype);
/* RSC packets must set gso_size otherwise the TCP stack will complain
* that packets are larger than MTU.
*/
if (desc->rsc) {
err = gve_rx_complete_rsc(rx->ctx.skb_head, desc, ptype);
if (err < 0)
return err;
}
if (skb_headlen(rx->ctx.skb_head) == 0)
napi_gro_frags(napi);
else
napi_gro_receive(napi, rx->ctx.skb_head);
return 0;
}
int gve_rx_poll_dqo(struct gve_notify_block *block, int budget)
{
struct napi_struct *napi = &block->napi;
netdev_features_t feat = napi->dev->features;
struct gve_rx_ring *rx = block->rx;
struct gve_rx_compl_queue_dqo *complq = &rx->dqo.complq;
u32 work_done = 0;
u64 bytes = 0;
int err;
while (work_done < budget) {
struct gve_rx_compl_desc_dqo *compl_desc =
&complq->desc_ring[complq->head];
u32 pkt_bytes;
/* No more new packets */
if (compl_desc->generation == complq->cur_gen_bit)
break;
/* Prefetch the next two descriptors. */
prefetch(&complq->desc_ring[(complq->head + 1) & complq->mask]);
prefetch(&complq->desc_ring[(complq->head + 2) & complq->mask]);
/* Do not read data until we own the descriptor */
dma_rmb();
err = gve_rx_dqo(napi, rx, compl_desc, rx->q_num);
if (err < 0) {
gve_rx_free_skb(rx);
u64_stats_update_begin(&rx->statss);
if (err == -ENOMEM)
rx->rx_skb_alloc_fail++;
else if (err == -EINVAL)
rx->rx_desc_err_dropped_pkt++;
u64_stats_update_end(&rx->statss);
}
complq->head = (complq->head + 1) & complq->mask;
complq->num_free_slots++;
/* When the ring wraps, the generation bit is flipped. */
complq->cur_gen_bit ^= (complq->head == 0);
/* Receiving a completion means we have space to post another
* buffer on the buffer queue.
*/
{
struct gve_rx_buf_queue_dqo *bufq = &rx->dqo.bufq;
bufq->head = (bufq->head + 1) & bufq->mask;
}
/* Free running counter of completed descriptors */
rx->cnt++;
if (!rx->ctx.skb_head)
continue;
if (!compl_desc->end_of_packet)
continue;
work_done++;
pkt_bytes = rx->ctx.skb_head->len;
/* The ethernet header (first ETH_HLEN bytes) is snipped off
* by eth_type_trans.
*/
if (skb_headlen(rx->ctx.skb_head))
pkt_bytes += ETH_HLEN;
/* gve_rx_complete_skb() will consume skb if successful */
if (gve_rx_complete_skb(rx, napi, compl_desc, feat) != 0) {
gve_rx_free_skb(rx);
u64_stats_update_begin(&rx->statss);
rx->rx_desc_err_dropped_pkt++;
u64_stats_update_end(&rx->statss);
continue;
}
bytes += pkt_bytes;
rx->ctx.skb_head = NULL;
rx->ctx.skb_tail = NULL;
}
gve_rx_post_buffers_dqo(rx);
u64_stats_update_begin(&rx->statss);
rx->rpackets += work_done;
rx->rbytes += bytes;
u64_stats_update_end(&rx->statss);
return work_done;
}