swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: d012a7190fc1fd72ed48911e77ca97ba4521bccd authored by Linus Torvalds on 23 August 2020, 21:08:43 UTC
Linux 5.9-rc2
Linux 5.9-rc2
Tip revision: d012a71
xsk_buff_pool.c
// SPDX-License-Identifier: GPL-2.0
#include <net/xsk_buff_pool.h>
#include <net/xdp_sock.h>
#include "xsk_queue.h"
static void xp_addr_unmap(struct xsk_buff_pool *pool)
{
vunmap(pool->addrs);
}
static int xp_addr_map(struct xsk_buff_pool *pool,
struct page **pages, u32 nr_pages)
{
pool->addrs = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
if (!pool->addrs)
return -ENOMEM;
return 0;
}
void xp_destroy(struct xsk_buff_pool *pool)
{
if (!pool)
return;
xp_addr_unmap(pool);
kvfree(pool->heads);
kvfree(pool);
}
struct xsk_buff_pool *xp_create(struct page **pages, u32 nr_pages, u32 chunks,
u32 chunk_size, u32 headroom, u64 size,
bool unaligned)
{
struct xsk_buff_pool *pool;
struct xdp_buff_xsk *xskb;
int err;
u32 i;
pool = kvzalloc(struct_size(pool, free_heads, chunks), GFP_KERNEL);
if (!pool)
goto out;
pool->heads = kvcalloc(chunks, sizeof(*pool->heads), GFP_KERNEL);
if (!pool->heads)
goto out;
pool->chunk_mask = ~((u64)chunk_size - 1);
pool->addrs_cnt = size;
pool->heads_cnt = chunks;
pool->free_heads_cnt = chunks;
pool->headroom = headroom;
pool->chunk_size = chunk_size;
pool->unaligned = unaligned;
pool->frame_len = chunk_size - headroom - XDP_PACKET_HEADROOM;
INIT_LIST_HEAD(&pool->free_list);
for (i = 0; i < pool->free_heads_cnt; i++) {
xskb = &pool->heads[i];
xskb->pool = pool;
xskb->xdp.frame_sz = chunk_size - headroom;
pool->free_heads[i] = xskb;
}
err = xp_addr_map(pool, pages, nr_pages);
if (!err)
return pool;
out:
xp_destroy(pool);
return NULL;
}
void xp_set_fq(struct xsk_buff_pool *pool, struct xsk_queue *fq)
{
pool->fq = fq;
}
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);
void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
{
dma_addr_t *dma;
u32 i;
if (pool->dma_pages_cnt == 0)
return;
for (i = 0; i < pool->dma_pages_cnt; i++) {
dma = &pool->dma_pages[i];
if (*dma) {
dma_unmap_page_attrs(pool->dev, *dma, PAGE_SIZE,
DMA_BIDIRECTIONAL, attrs);
*dma = 0;
}
}
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_buff_pool *pool)
{
u32 i;
for (i = 0; i < pool->dma_pages_cnt - 1; i++) {
if (pool->dma_pages[i] + PAGE_SIZE == pool->dma_pages[i + 1])
pool->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
else
pool->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
}
}
int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
unsigned long attrs, struct page **pages, u32 nr_pages)
{
dma_addr_t dma;
u32 i;
pool->dma_pages = kvcalloc(nr_pages, sizeof(*pool->dma_pages),
GFP_KERNEL);
if (!pool->dma_pages)
return -ENOMEM;
pool->dev = dev;
pool->dma_pages_cnt = nr_pages;
pool->dma_need_sync = false;
for (i = 0; i < pool->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(pool, attrs);
return -ENOMEM;
}
if (dma_need_sync(dev, dma))
pool->dma_need_sync = true;
pool->dma_pages[i] = dma;
}
if (pool->unaligned)
xp_check_dma_contiguity(pool);
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;
xskb = pool->free_heads[--pool->free_heads_cnt];
for (;;) {
if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
pool->fq->queue_empty_descs++;
xp_release(xskb);
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;
}
xskq_cons_release(pool->fq);
xskb->orig_addr = addr;
xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
if (pool->dma_pages_cnt) {
xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] &
~XSK_NEXT_PG_CONTIG_MASK) +
(addr & ~PAGE_MASK);
xskb->dma = xskb->frame_dma + pool->headroom +
XDP_PACKET_HEADROOM;
}
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(&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);
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)
{
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);