blob: 9f52e72ff641d91bbeb43f2efe8d12c5a5184204 [file] [log] [blame]
// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/* Google virtual Ethernet (gve) driver
*
* Copyright (C) 2015-2019 Google, Inc.
*/
#include "gve.h"
#include "gve_adminq.h"
#include <linux/etherdevice.h>
static void gve_rx_remove_from_block(struct gve_priv *priv, int queue_idx)
{
struct gve_notify_block *block =
&priv->ntfy_blocks[gve_rx_idx_to_ntfy(priv, queue_idx)];
block->rx = NULL;
}
static void gve_rx_free_ring(struct gve_priv *priv, int idx)
{
struct gve_rx_ring *rx = &priv->rx[idx];
struct device *dev = &priv->pdev->dev;
size_t bytes;
u32 slots;
gve_rx_remove_from_block(priv, idx);
bytes = sizeof(struct gve_rx_desc) * priv->rx_desc_cnt;
dma_free_coherent(dev, bytes, rx->desc.desc_ring, rx->desc.bus);
rx->desc.desc_ring = NULL;
dma_free_coherent(dev, sizeof(*rx->q_resources),
rx->q_resources, rx->q_resources_bus);
rx->q_resources = NULL;
gve_unassign_qpl(priv, rx->data.qpl->id);
rx->data.qpl = NULL;
kvfree(rx->data.page_info);
slots = rx->mask + 1;
bytes = sizeof(*rx->data.data_ring) * slots;
dma_free_coherent(dev, bytes, rx->data.data_ring,
rx->data.data_bus);
rx->data.data_ring = NULL;
netif_dbg(priv, drv, priv->dev, "freed rx ring %d\n", idx);
}
static void gve_setup_rx_buffer(struct gve_rx_slot_page_info *page_info,
struct gve_rx_data_slot *slot,
dma_addr_t addr, struct page *page)
{
page_info->page = page;
page_info->page_offset = 0;
page_info->page_address = page_address(page);
slot->qpl_offset = cpu_to_be64(addr);
}
static int gve_prefill_rx_pages(struct gve_rx_ring *rx)
{
struct gve_priv *priv = rx->gve;
u32 slots;
int i;
/* Allocate one page per Rx queue slot. Each page is split into two
* packet buffers, when possible we "page flip" between the two.
*/
slots = rx->mask + 1;
rx->data.page_info = kvzalloc(slots *
sizeof(*rx->data.page_info), GFP_KERNEL);
if (!rx->data.page_info)
return -ENOMEM;
rx->data.qpl = gve_assign_rx_qpl(priv);
for (i = 0; i < slots; i++) {
struct page *page = rx->data.qpl->pages[i];
dma_addr_t addr = i * PAGE_SIZE;
gve_setup_rx_buffer(&rx->data.page_info[i],
&rx->data.data_ring[i], addr, page);
}
return slots;
}
static void gve_rx_add_to_block(struct gve_priv *priv, int queue_idx)
{
u32 ntfy_idx = gve_rx_idx_to_ntfy(priv, queue_idx);
struct gve_notify_block *block = &priv->ntfy_blocks[ntfy_idx];
struct gve_rx_ring *rx = &priv->rx[queue_idx];
block->rx = rx;
rx->ntfy_id = ntfy_idx;
}
static int gve_rx_alloc_ring(struct gve_priv *priv, int idx)
{
struct gve_rx_ring *rx = &priv->rx[idx];
struct device *hdev = &priv->pdev->dev;
u32 slots, npages;
int filled_pages;
size_t bytes;
int err;
netif_dbg(priv, drv, priv->dev, "allocating rx ring\n");
/* Make sure everything is zeroed to start with */
memset(rx, 0, sizeof(*rx));
rx->gve = priv;
rx->q_num = idx;
slots = priv->rx_pages_per_qpl;
rx->mask = slots - 1;
/* alloc rx data ring */
bytes = sizeof(*rx->data.data_ring) * slots;
rx->data.data_ring = dma_alloc_coherent(hdev, bytes,
&rx->data.data_bus,
GFP_KERNEL);
if (!rx->data.data_ring)
return -ENOMEM;
filled_pages = gve_prefill_rx_pages(rx);
if (filled_pages < 0) {
err = -ENOMEM;
goto abort_with_slots;
}
rx->fill_cnt = filled_pages;
/* Ensure data ring slots (packet buffers) are visible. */
dma_wmb();
/* Alloc gve_queue_resources */
rx->q_resources =
dma_alloc_coherent(hdev,
sizeof(*rx->q_resources),
&rx->q_resources_bus,
GFP_KERNEL);
if (!rx->q_resources) {
err = -ENOMEM;
goto abort_filled;
}
netif_dbg(priv, drv, priv->dev, "rx[%d]->data.data_bus=%lx\n", idx,
(unsigned long)rx->data.data_bus);
/* alloc rx desc ring */
bytes = sizeof(struct gve_rx_desc) * priv->rx_desc_cnt;
npages = bytes / PAGE_SIZE;
if (npages * PAGE_SIZE != bytes) {
err = -EIO;
goto abort_with_q_resources;
}
rx->desc.desc_ring = dma_alloc_coherent(hdev, bytes, &rx->desc.bus,
GFP_KERNEL);
if (!rx->desc.desc_ring) {
err = -ENOMEM;
goto abort_with_q_resources;
}
rx->mask = slots - 1;
rx->cnt = 0;
rx->desc.seqno = 1;
gve_rx_add_to_block(priv, idx);
return 0;
abort_with_q_resources:
dma_free_coherent(hdev, sizeof(*rx->q_resources),
rx->q_resources, rx->q_resources_bus);
rx->q_resources = NULL;
abort_filled:
kvfree(rx->data.page_info);
abort_with_slots:
bytes = sizeof(*rx->data.data_ring) * slots;
dma_free_coherent(hdev, bytes, rx->data.data_ring, rx->data.data_bus);
rx->data.data_ring = NULL;
return err;
}
int gve_rx_alloc_rings(struct gve_priv *priv)
{
int err = 0;
int i;
for (i = 0; i < priv->rx_cfg.num_queues; i++) {
err = gve_rx_alloc_ring(priv, i);
if (err) {
netif_err(priv, drv, priv->dev,
"Failed to alloc rx ring=%d: err=%d\n",
i, err);
break;
}
}
/* Unallocate if there was an error */
if (err) {
int j;
for (j = 0; j < i; j++)
gve_rx_free_ring(priv, j);
}
return err;
}
void gve_rx_free_rings(struct gve_priv *priv)
{
int i;
for (i = 0; i < priv->rx_cfg.num_queues; i++)
gve_rx_free_ring(priv, i);
}
void gve_rx_write_doorbell(struct gve_priv *priv, struct gve_rx_ring *rx)
{
u32 db_idx = be32_to_cpu(rx->q_resources->db_index);
iowrite32be(rx->fill_cnt, &priv->db_bar2[db_idx]);
}
static enum pkt_hash_types gve_rss_type(__be16 pkt_flags)
{
if (likely(pkt_flags & (GVE_RXF_TCP | GVE_RXF_UDP)))
return PKT_HASH_TYPE_L4;
if (pkt_flags & (GVE_RXF_IPV4 | GVE_RXF_IPV6))
return PKT_HASH_TYPE_L3;
return PKT_HASH_TYPE_L2;
}
static struct sk_buff *gve_rx_copy(struct net_device *dev,
struct napi_struct *napi,
struct gve_rx_slot_page_info *page_info,
u16 len)
{
struct sk_buff *skb = napi_alloc_skb(napi, len);
void *va = page_info->page_address + GVE_RX_PAD +
page_info->page_offset;
if (unlikely(!skb))
return NULL;
__skb_put(skb, len);
skb_copy_to_linear_data(skb, va, len);
skb->protocol = eth_type_trans(skb, dev);
return skb;
}
static struct sk_buff *gve_rx_add_frags(struct net_device *dev,
struct napi_struct *napi,
struct gve_rx_slot_page_info *page_info,
u16 len)
{
struct sk_buff *skb = napi_get_frags(napi);
if (unlikely(!skb))
return NULL;
skb_add_rx_frag(skb, 0, page_info->page,
page_info->page_offset +
GVE_RX_PAD, len, PAGE_SIZE / 2);
return skb;
}
static void gve_rx_flip_buff(struct gve_rx_slot_page_info *page_info,
struct gve_rx_data_slot *data_ring)
{
u64 addr = be64_to_cpu(data_ring->qpl_offset);
page_info->page_offset ^= PAGE_SIZE / 2;
addr ^= PAGE_SIZE / 2;
data_ring->qpl_offset = cpu_to_be64(addr);
}
static bool gve_rx(struct gve_rx_ring *rx, struct gve_rx_desc *rx_desc,
netdev_features_t feat, u32 idx)
{
struct gve_rx_slot_page_info *page_info;
struct gve_priv *priv = rx->gve;
struct napi_struct *napi = &priv->ntfy_blocks[rx->ntfy_id].napi;
struct net_device *dev = priv->dev;
struct sk_buff *skb;
int pagecount;
u16 len;
/* drop this packet */
if (unlikely(rx_desc->flags_seq & GVE_RXF_ERR))
return true;
len = be16_to_cpu(rx_desc->len) - GVE_RX_PAD;
page_info = &rx->data.page_info[idx];
dma_sync_single_for_cpu(&priv->pdev->dev, rx->data.qpl->page_buses[idx],
PAGE_SIZE, DMA_FROM_DEVICE);
/* gvnic can only receive into registered segments. If the buffer
* can't be recycled, our only choice is to copy the data out of
* it so that we can return it to the device.
*/
if (PAGE_SIZE == 4096) {
if (len <= priv->rx_copybreak) {
/* Just copy small packets */
skb = gve_rx_copy(dev, napi, page_info, len);
goto have_skb;
}
if (unlikely(!gve_can_recycle_pages(dev))) {
skb = gve_rx_copy(dev, napi, page_info, len);
goto have_skb;
}
pagecount = page_count(page_info->page);
if (pagecount == 1) {
/* No part of this page is used by any SKBs; we attach
* the page fragment to a new SKB and pass it up the
* stack.
*/
skb = gve_rx_add_frags(dev, napi, page_info, len);
if (!skb)
return true;
/* Make sure the kernel stack can't release the page */
get_page(page_info->page);
/* "flip" to other packet buffer on this page */
gve_rx_flip_buff(page_info, &rx->data.data_ring[idx]);
} else if (pagecount >= 2) {
/* We have previously passed the other half of this
* page up the stack, but it has not yet been freed.
*/
skb = gve_rx_copy(dev, napi, page_info, len);
} else {
WARN(pagecount < 1, "Pagecount should never be < 1");
return false;
}
} else {
skb = gve_rx_copy(dev, napi, page_info, len);
}
have_skb:
/* We didn't manage to allocate an skb but we haven't had any
* reset worthy failures.
*/
if (!skb)
return true;
if (likely(feat & NETIF_F_RXCSUM)) {
/* NIC passes up the partial sum */
if (rx_desc->csum)
skb->ip_summed = CHECKSUM_COMPLETE;
else
skb->ip_summed = CHECKSUM_NONE;
skb->csum = csum_unfold(rx_desc->csum);
}
/* parse flags & pass relevant info up */
if (likely(feat & NETIF_F_RXHASH) &&
gve_needs_rss(rx_desc->flags_seq))
skb_set_hash(skb, be32_to_cpu(rx_desc->rss_hash),
gve_rss_type(rx_desc->flags_seq));
if (skb_is_nonlinear(skb))
napi_gro_frags(napi);
else
napi_gro_receive(napi, skb);
return true;
}
static bool gve_rx_work_pending(struct gve_rx_ring *rx)
{
struct gve_rx_desc *desc;
__be16 flags_seq;
u32 next_idx;
next_idx = rx->cnt & rx->mask;
desc = rx->desc.desc_ring + next_idx;
flags_seq = desc->flags_seq;
/* Make sure we have synchronized the seq no with the device */
smp_rmb();
return (GVE_SEQNO(flags_seq) == rx->desc.seqno);
}
bool gve_clean_rx_done(struct gve_rx_ring *rx, int budget,
netdev_features_t feat)
{
struct gve_priv *priv = rx->gve;
struct gve_rx_desc *desc;
u32 cnt = rx->cnt;
u32 idx = cnt & rx->mask;
u32 work_done = 0;
u64 bytes = 0;
desc = rx->desc.desc_ring + idx;
while ((GVE_SEQNO(desc->flags_seq) == rx->desc.seqno) &&
work_done < budget) {
netif_info(priv, rx_status, priv->dev,
"[%d] idx=%d desc=%p desc->flags_seq=0x%x\n",
rx->q_num, idx, desc, desc->flags_seq);
netif_info(priv, rx_status, priv->dev,
"[%d] seqno=%d rx->desc.seqno=%d\n",
rx->q_num, GVE_SEQNO(desc->flags_seq),
rx->desc.seqno);
bytes += be16_to_cpu(desc->len) - GVE_RX_PAD;
if (!gve_rx(rx, desc, feat, idx))
gve_schedule_reset(priv);
cnt++;
idx = cnt & rx->mask;
desc = rx->desc.desc_ring + idx;
rx->desc.seqno = gve_next_seqno(rx->desc.seqno);
work_done++;
}
if (!work_done)
return false;
u64_stats_update_begin(&rx->statss);
rx->rpackets += work_done;
rx->rbytes += bytes;
u64_stats_update_end(&rx->statss);
rx->cnt = cnt;
rx->fill_cnt += work_done;
gve_rx_write_doorbell(priv, rx);
return gve_rx_work_pending(rx);
}
bool gve_rx_poll(struct gve_notify_block *block, int budget)
{
struct gve_rx_ring *rx = block->rx;
netdev_features_t feat;
bool repoll = false;
feat = block->napi.dev->features;
/* If budget is 0, do all the work */
if (budget == 0)
budget = INT_MAX;
if (budget > 0)
repoll |= gve_clean_rx_done(rx, budget, feat);
else
repoll |= gve_rx_work_pending(rx);
return repoll;
}