OpenCloudOS-Kernel/net/xdp/xsk_buff_pool.c

685 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <net/xsk_buff_pool.h>
#include <net/xdp_sock.h>
#include <net/xdp_sock_drv.h>
#include "xsk_queue.h"
#include "xdp_umem.h"
#include "xsk.h"
void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
{
unsigned long flags;
if (!xs->tx)
return;
spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
list_add_rcu(&xs->tx_list, &pool->xsk_tx_list);
spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
}
void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
{
unsigned long flags;
if (!xs->tx)
return;
spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
list_del_rcu(&xs->tx_list);
spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
}
void xp_destroy(struct xsk_buff_pool *pool)
{
if (!pool)
return;
kvfree(pool->tx_descs);
kvfree(pool->heads);
kvfree(pool);
}
int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs)
{
pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs),
GFP_KERNEL);
if (!pool->tx_descs)
return -ENOMEM;
return 0;
}
struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
struct xdp_umem *umem)
{
bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
struct xsk_buff_pool *pool;
struct xdp_buff_xsk *xskb;
u32 i, entries;
entries = unaligned ? umem->chunks : 0;
pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL);
if (!pool)
goto out;
pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
if (!pool->heads)
goto out;
if (xs->tx)
if (xp_alloc_tx_descs(pool, xs))
goto out;
pool->chunk_mask = ~((u64)umem->chunk_size - 1);
pool->addrs_cnt = umem->size;
pool->heads_cnt = umem->chunks;
pool->free_heads_cnt = umem->chunks;
pool->headroom = umem->headroom;
pool->chunk_size = umem->chunk_size;
pool->chunk_shift = ffs(umem->chunk_size) - 1;
pool->unaligned = unaligned;
pool->frame_len = umem->chunk_size - umem->headroom -
XDP_PACKET_HEADROOM;
pool->umem = umem;
pool->addrs = umem->addrs;
INIT_LIST_HEAD(&pool->free_list);
INIT_LIST_HEAD(&pool->xsk_tx_list);
spin_lock_init(&pool->xsk_tx_list_lock);
spin_lock_init(&pool->cq_lock);
refcount_set(&pool->users, 1);
pool->fq = xs->fq_tmp;
pool->cq = xs->cq_tmp;
for (i = 0; i < pool->free_heads_cnt; i++) {
xskb = &pool->heads[i];
xskb->pool = pool;
xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
INIT_LIST_HEAD(&xskb->free_list_node);
if (pool->unaligned)
pool->free_heads[i] = xskb;
else
xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
}
return pool;
out:
xp_destroy(pool);
return NULL;
}
void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
{
u32 i;
for (i = 0; i < pool->heads_cnt; i++)
pool->heads[i].xdp.rxq = rxq;
}
EXPORT_SYMBOL(xp_set_rxq_info);
static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
{
struct netdev_bpf bpf;
int err;
ASSERT_RTNL();
if (pool->umem->zc) {
bpf.command = XDP_SETUP_XSK_POOL;
bpf.xsk.pool = NULL;
bpf.xsk.queue_id = pool->queue_id;
err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
if (err)
WARN(1, "Failed to disable zero-copy!\n");
}
}
#define NETDEV_XDP_ACT_ZC (NETDEV_XDP_ACT_BASIC | \
NETDEV_XDP_ACT_REDIRECT | \
NETDEV_XDP_ACT_XSK_ZEROCOPY)
int xp_assign_dev(struct xsk_buff_pool *pool,
struct net_device *netdev, u16 queue_id, u16 flags)
{
bool force_zc, force_copy;
struct netdev_bpf bpf;
int err = 0;
ASSERT_RTNL();
force_zc = flags & XDP_ZEROCOPY;
force_copy = flags & XDP_COPY;
if (force_zc && force_copy)
return -EINVAL;
if (xsk_get_pool_from_qid(netdev, queue_id))
return -EBUSY;
pool->netdev = netdev;
pool->queue_id = queue_id;
err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
if (err)
return err;
if (flags & XDP_USE_NEED_WAKEUP)
pool->uses_need_wakeup = true;
/* Tx needs to be explicitly woken up the first time. Also
* for supporting drivers that do not implement this
* feature. They will always have to call sendto() or poll().
*/
pool->cached_need_wakeup = XDP_WAKEUP_TX;
dev_hold(netdev);
if (force_copy)
/* For copy-mode, we are done. */
return 0;
if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) {
err = -EOPNOTSUPP;
goto err_unreg_pool;
}
bpf.command = XDP_SETUP_XSK_POOL;
bpf.xsk.pool = pool;
bpf.xsk.queue_id = queue_id;
err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
if (err)
goto err_unreg_pool;
if (!pool->dma_pages) {
WARN(1, "Driver did not DMA map zero-copy buffers");
err = -EINVAL;
goto err_unreg_xsk;
}
pool->umem->zc = true;
return 0;
err_unreg_xsk:
xp_disable_drv_zc(pool);
err_unreg_pool:
if (!force_zc)
err = 0; /* fallback to copy mode */
if (err) {
xsk_clear_pool_at_qid(netdev, queue_id);
dev_put(netdev);
}
return err;
}
int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
struct net_device *dev, u16 queue_id)
{
u16 flags;
struct xdp_umem *umem = umem_xs->umem;
/* One fill and completion ring required for each queue id. */
if (!pool->fq || !pool->cq)
return -EINVAL;
flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
if (umem_xs->pool->uses_need_wakeup)
flags |= XDP_USE_NEED_WAKEUP;
return xp_assign_dev(pool, dev, queue_id, flags);
}
void xp_clear_dev(struct xsk_buff_pool *pool)
{
if (!pool->netdev)
return;
xp_disable_drv_zc(pool);
xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
dev_put(pool->netdev);
pool->netdev = NULL;
}
static void xp_release_deferred(struct work_struct *work)
{
struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
work);
rtnl_lock();
xp_clear_dev(pool);
rtnl_unlock();
if (pool->fq) {
xskq_destroy(pool->fq);
pool->fq = NULL;
}
if (pool->cq) {
xskq_destroy(pool->cq);
pool->cq = NULL;
}
xdp_put_umem(pool->umem, false);
xp_destroy(pool);
}
void xp_get_pool(struct xsk_buff_pool *pool)
{
refcount_inc(&pool->users);
}
bool xp_put_pool(struct xsk_buff_pool *pool)
{
if (!pool)
return false;
if (refcount_dec_and_test(&pool->users)) {
INIT_WORK(&pool->work, xp_release_deferred);
schedule_work(&pool->work);
return true;
}
return false;
}
static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
{
struct xsk_dma_map *dma_map;
list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
if (dma_map->netdev == pool->netdev)
return dma_map;
}
return NULL;
}
static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
u32 nr_pages, struct xdp_umem *umem)
{
struct xsk_dma_map *dma_map;
dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
if (!dma_map)
return NULL;
dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
if (!dma_map->dma_pages) {
kfree(dma_map);
return NULL;
}
dma_map->netdev = netdev;
dma_map->dev = dev;
dma_map->dma_need_sync = false;
dma_map->dma_pages_cnt = nr_pages;
refcount_set(&dma_map->users, 1);
list_add(&dma_map->list, &umem->xsk_dma_list);
return dma_map;
}
static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
{
list_del(&dma_map->list);
kvfree(dma_map->dma_pages);
kfree(dma_map);
}
static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
{
dma_addr_t *dma;
u32 i;
for (i = 0; i < dma_map->dma_pages_cnt; i++) {
dma = &dma_map->dma_pages[i];
if (*dma) {
*dma &= ~XSK_NEXT_PG_CONTIG_MASK;
dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
DMA_BIDIRECTIONAL, attrs);
*dma = 0;
}
}
xp_destroy_dma_map(dma_map);
}
void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
{
struct xsk_dma_map *dma_map;
if (pool->dma_pages_cnt == 0)
return;
dma_map = xp_find_dma_map(pool);
if (!dma_map) {
WARN(1, "Could not find dma_map for device");
return;
}
if (!refcount_dec_and_test(&dma_map->users))
return;
__xp_dma_unmap(dma_map, attrs);
kvfree(pool->dma_pages);
pool->dma_pages_cnt = 0;
pool->dev = NULL;
}
EXPORT_SYMBOL(xp_dma_unmap);
static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
{
u32 i;
for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
else
dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
}
}
static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
{
if (!pool->unaligned) {
u32 i;
for (i = 0; i < pool->heads_cnt; i++) {
struct xdp_buff_xsk *xskb = &pool->heads[i];
xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
}
}
pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
if (!pool->dma_pages)
return -ENOMEM;
pool->dev = dma_map->dev;
pool->dma_pages_cnt = dma_map->dma_pages_cnt;
pool->dma_need_sync = dma_map->dma_need_sync;
memcpy(pool->dma_pages, dma_map->dma_pages,
pool->dma_pages_cnt * sizeof(*pool->dma_pages));
return 0;
}
int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
unsigned long attrs, struct page **pages, u32 nr_pages)
{
struct xsk_dma_map *dma_map;
dma_addr_t dma;
int err;
u32 i;
dma_map = xp_find_dma_map(pool);
if (dma_map) {
err = xp_init_dma_info(pool, dma_map);
if (err)
return err;
refcount_inc(&dma_map->users);
return 0;
}
dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
if (!dma_map)
return -ENOMEM;
for (i = 0; i < dma_map->dma_pages_cnt; i++) {
dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
DMA_BIDIRECTIONAL, attrs);
if (dma_mapping_error(dev, dma)) {
__xp_dma_unmap(dma_map, attrs);
return -ENOMEM;
}
if (dma_need_sync(dev, dma))
dma_map->dma_need_sync = true;
dma_map->dma_pages[i] = dma;
}
if (pool->unaligned)
xp_check_dma_contiguity(dma_map);
err = xp_init_dma_info(pool, dma_map);
if (err) {
__xp_dma_unmap(dma_map, attrs);
return err;
}
return 0;
}
EXPORT_SYMBOL(xp_dma_map);
static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
u64 addr)
{
return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
}
static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
{
*addr = xp_unaligned_extract_addr(*addr);
if (*addr >= pool->addrs_cnt ||
*addr + pool->chunk_size > pool->addrs_cnt ||
xp_addr_crosses_non_contig_pg(pool, *addr))
return false;
return true;
}
static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
{
*addr = xp_aligned_extract_addr(pool, *addr);
return *addr < pool->addrs_cnt;
}
static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
{
struct xdp_buff_xsk *xskb;
u64 addr;
bool ok;
if (pool->free_heads_cnt == 0)
return NULL;
for (;;) {
if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
pool->fq->queue_empty_descs++;
return NULL;
}
ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
xp_check_aligned(pool, &addr);
if (!ok) {
pool->fq->invalid_descs++;
xskq_cons_release(pool->fq);
continue;
}
break;
}
if (pool->unaligned) {
xskb = pool->free_heads[--pool->free_heads_cnt];
xp_init_xskb_addr(xskb, pool, addr);
if (pool->dma_pages_cnt)
xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
} else {
xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
}
xskq_cons_release(pool->fq);
return xskb;
}
struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
{
struct xdp_buff_xsk *xskb;
if (!pool->free_list_cnt) {
xskb = __xp_alloc(pool);
if (!xskb)
return NULL;
} else {
pool->free_list_cnt--;
xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
free_list_node);
list_del_init(&xskb->free_list_node);
}
xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
xskb->xdp.data_meta = xskb->xdp.data;
if (pool->dma_need_sync) {
dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
pool->frame_len,
DMA_BIDIRECTIONAL);
}
return &xskb->xdp;
}
EXPORT_SYMBOL(xp_alloc);
static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
{
u32 i, cached_cons, nb_entries;
if (max > pool->free_heads_cnt)
max = pool->free_heads_cnt;
max = xskq_cons_nb_entries(pool->fq, max);
cached_cons = pool->fq->cached_cons;
nb_entries = max;
i = max;
while (i--) {
struct xdp_buff_xsk *xskb;
u64 addr;
bool ok;
__xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
xp_check_aligned(pool, &addr);
if (unlikely(!ok)) {
pool->fq->invalid_descs++;
nb_entries--;
continue;
}
if (pool->unaligned) {
xskb = pool->free_heads[--pool->free_heads_cnt];
xp_init_xskb_addr(xskb, pool, addr);
if (pool->dma_pages_cnt)
xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
} else {
xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
}
*xdp = &xskb->xdp;
xdp++;
}
xskq_cons_release_n(pool->fq, max);
return nb_entries;
}
static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
{
struct xdp_buff_xsk *xskb;
u32 i;
nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
i = nb_entries;
while (i--) {
xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
list_del_init(&xskb->free_list_node);
*xdp = &xskb->xdp;
xdp++;
}
pool->free_list_cnt -= nb_entries;
return nb_entries;
}
u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
{
u32 nb_entries1 = 0, nb_entries2;
if (unlikely(pool->dma_need_sync)) {
struct xdp_buff *buff;
/* Slow path */
buff = xp_alloc(pool);
if (buff)
*xdp = buff;
return !!buff;
}
if (unlikely(pool->free_list_cnt)) {
nb_entries1 = xp_alloc_reused(pool, xdp, max);
if (nb_entries1 == max)
return nb_entries1;
max -= nb_entries1;
xdp += nb_entries1;
}
nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
if (!nb_entries2)
pool->fq->queue_empty_descs++;
return nb_entries1 + nb_entries2;
}
EXPORT_SYMBOL(xp_alloc_batch);
bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
{
if (pool->free_list_cnt >= count)
return true;
return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
}
EXPORT_SYMBOL(xp_can_alloc);
void xp_free(struct xdp_buff_xsk *xskb)
{
if (!list_empty(&xskb->free_list_node))
return;
xskb->pool->free_list_cnt++;
list_add(&xskb->free_list_node, &xskb->pool->free_list);
}
EXPORT_SYMBOL(xp_free);
void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
{
addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
return pool->addrs + addr;
}
EXPORT_SYMBOL(xp_raw_get_data);
dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
{
addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
return (pool->dma_pages[addr >> PAGE_SHIFT] &
~XSK_NEXT_PG_CONTIG_MASK) +
(addr & ~PAGE_MASK);
}
EXPORT_SYMBOL(xp_raw_get_dma);
void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
{
dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
xskb->pool->frame_len, DMA_BIDIRECTIONAL);
}
EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
size_t size)
{
dma_sync_single_range_for_device(pool->dev, dma, 0,
size, DMA_BIDIRECTIONAL);
}
EXPORT_SYMBOL(xp_dma_sync_for_device_slow);