Commit 2b43470a authored by Björn Töpel's avatar Björn Töpel Committed by Alexei Starovoitov

xsk: Introduce AF_XDP buffer allocation API

In order to simplify AF_XDP zero-copy enablement for NIC driver
developers, a new AF_XDP buffer allocation API is added. The
implementation is based on a single core (single producer/consumer)
buffer pool for the AF_XDP UMEM.

A buffer is allocated using the xsk_buff_alloc() function, and
returned using xsk_buff_free(). If a buffer is disassociated with the
pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is
said to be released. Currently, the release function is only used by
the AF_XDP internals and not visible to the driver.

Drivers using this API should register the XDP memory model with the
new MEM_TYPE_XSK_BUFF_POOL type.

The API is defined in net/xdp_sock_drv.h.

The buffer type is struct xdp_buff, and follows the lifetime of
regular xdp_buffs, i.e.  the lifetime of an xdp_buff is restricted to
a NAPI context. In other words, the API is not replacing xdp_frames.

In addition to introducing the API and implementations, the AF_XDP
core is migrated to use the new APIs.

rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test
         robot)
         Added headroom/chunk size getter. (Maxim/Björn)

v1->v2: Swapped SoBs. (Maxim)

v2->v3: Initialize struct xdp_buff member frame_sz. (Björn)
        Add API to query the DMA address of a frame. (Maxim)
        Do DMA sync for CPU till the end of the frame to handle
        possible growth (frame_sz). (Maxim)
Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarMaxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com
parent 89e4a376
......@@ -40,6 +40,7 @@ enum xdp_mem_type {
MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */
MEM_TYPE_PAGE_POOL,
MEM_TYPE_ZERO_COPY,
MEM_TYPE_XSK_BUFF_POOL,
MEM_TYPE_MAX,
};
......@@ -119,7 +120,8 @@ struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
int metasize;
int headroom;
if (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY)
if (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY ||
xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL)
return xdp_convert_zc_to_xdp_frame(xdp);
/* Assure headroom is available for storing info */
......
......@@ -31,11 +31,13 @@ struct xdp_umem_fq_reuse {
struct xdp_umem {
struct xsk_queue *fq;
struct xsk_queue *cq;
struct xsk_buff_pool *pool;
struct xdp_umem_page *pages;
u64 chunk_mask;
u64 size;
u32 headroom;
u32 chunk_size_nohr;
u32 chunk_size;
struct user_struct *user;
refcount_t users;
struct work_struct work;
......
......@@ -7,6 +7,7 @@
#define _LINUX_XDP_SOCK_DRV_H
#include <net/xdp_sock.h>
#include <net/xsk_buff_pool.h>
#ifdef CONFIG_XDP_SOCKETS
......@@ -101,6 +102,94 @@ static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem)
return umem->chunk_size_nohr;
}
static inline u32 xsk_umem_get_headroom(struct xdp_umem *umem)
{
return XDP_PACKET_HEADROOM + umem->headroom;
}
static inline u32 xsk_umem_get_chunk_size(struct xdp_umem *umem)
{
return umem->chunk_size;
}
static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem)
{
return xsk_umem_get_chunk_size(umem) - xsk_umem_get_headroom(umem);
}
static inline void xsk_buff_set_rxq_info(struct xdp_umem *umem,
struct xdp_rxq_info *rxq)
{
xp_set_rxq_info(umem->pool, rxq);
}
static inline void xsk_buff_dma_unmap(struct xdp_umem *umem,
unsigned long attrs)
{
xp_dma_unmap(umem->pool, attrs);
}
static inline int xsk_buff_dma_map(struct xdp_umem *umem, struct device *dev,
unsigned long attrs)
{
return xp_dma_map(umem->pool, dev, attrs, umem->pgs, umem->npgs);
}
static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
return xp_get_dma(xskb);
}
static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
return xp_get_frame_dma(xskb);
}
static inline struct xdp_buff *xsk_buff_alloc(struct xdp_umem *umem)
{
return xp_alloc(umem->pool);
}
static inline bool xsk_buff_can_alloc(struct xdp_umem *umem, u32 count)
{
return xp_can_alloc(umem->pool, count);
}
static inline void xsk_buff_free(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
xp_free(xskb);
}
static inline dma_addr_t xsk_buff_raw_get_dma(struct xdp_umem *umem, u64 addr)
{
return xp_raw_get_dma(umem->pool, addr);
}
static inline void *xsk_buff_raw_get_data(struct xdp_umem *umem, u64 addr)
{
return xp_raw_get_data(umem->pool, addr);
}
static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
xp_dma_sync_for_cpu(xskb);
}
static inline void xsk_buff_raw_dma_sync_for_device(struct xdp_umem *umem,
dma_addr_t dma,
size_t size)
{
xp_dma_sync_for_device(umem->pool, dma, size);
}
#else
static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
......@@ -212,6 +301,81 @@ static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem)
return 0;
}
static inline u32 xsk_umem_get_headroom(struct xdp_umem *umem)
{
return 0;
}
static inline u32 xsk_umem_get_chunk_size(struct xdp_umem *umem)
{
return 0;
}
static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem)
{
return 0;
}
static inline void xsk_buff_set_rxq_info(struct xdp_umem *umem,
struct xdp_rxq_info *rxq)
{
}
static inline void xsk_buff_dma_unmap(struct xdp_umem *umem,
unsigned long attrs)
{
}
static inline int xsk_buff_dma_map(struct xdp_umem *umem, struct device *dev,
unsigned long attrs)
{
return 0;
}
static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
{
return 0;
}
static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
{
return 0;
}
static inline struct xdp_buff *xsk_buff_alloc(struct xdp_umem *umem)
{
return NULL;
}
static inline bool xsk_buff_can_alloc(struct xdp_umem *umem, u32 count)
{
return false;
}
static inline void xsk_buff_free(struct xdp_buff *xdp)
{
}
static inline dma_addr_t xsk_buff_raw_get_dma(struct xdp_umem *umem, u64 addr)
{
return 0;
}
static inline void *xsk_buff_raw_get_data(struct xdp_umem *umem, u64 addr)
{
return NULL;
}
static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
{
}
static inline void xsk_buff_raw_dma_sync_for_device(struct xdp_umem *umem,
dma_addr_t dma,
size_t size)
{
}
#endif /* CONFIG_XDP_SOCKETS */
#endif /* _LINUX_XDP_SOCK_DRV_H */
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright(c) 2020 Intel Corporation. */
#ifndef XSK_BUFF_POOL_H_
#define XSK_BUFF_POOL_H_
#include <linux/types.h>
#include <linux/dma-mapping.h>
#include <net/xdp.h>
struct xsk_buff_pool;
struct xdp_rxq_info;
struct xsk_queue;
struct xdp_desc;
struct device;
struct page;
struct xdp_buff_xsk {
struct xdp_buff xdp;
dma_addr_t dma;
dma_addr_t frame_dma;
struct xsk_buff_pool *pool;
bool unaligned;
u64 orig_addr;
struct list_head free_list_node;
};
/* AF_XDP core. */
struct xsk_buff_pool *xp_create(struct page **pages, u32 nr_pages, u32 chunks,
u32 chunk_size, u32 headroom, u64 size,
bool unaligned);
void xp_set_fq(struct xsk_buff_pool *pool, struct xsk_queue *fq);
void xp_destroy(struct xsk_buff_pool *pool);
void xp_release(struct xdp_buff_xsk *xskb);
u64 xp_get_handle(struct xdp_buff_xsk *xskb);
bool xp_validate_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc);
/* AF_XDP, and XDP core. */
void xp_free(struct xdp_buff_xsk *xskb);
/* AF_XDP ZC drivers, via xdp_sock_buff.h */
void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq);
int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
unsigned long attrs, struct page **pages, u32 nr_pages);
void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs);
struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool);
bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count);
void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr);
dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr);
dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb);
dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb);
void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb);
void xp_dma_sync_for_device(struct xsk_buff_pool *pool, dma_addr_t dma,
size_t size);
#endif /* XSK_BUFF_POOL_H_ */
......@@ -287,7 +287,8 @@ TRACE_EVENT(xdp_devmap_xmit,
FN(PAGE_SHARED) \
FN(PAGE_ORDER0) \
FN(PAGE_POOL) \
FN(ZERO_COPY)
FN(ZERO_COPY) \
FN(XSK_BUFF_POOL)
#define __MEM_TYPE_TP_FN(x) \
TRACE_DEFINE_ENUM(MEM_TYPE_##x);
......
......@@ -17,6 +17,7 @@
#include <net/xdp.h>
#include <net/xdp_priv.h> /* struct xdp_mem_allocator */
#include <trace/events/xdp.h>
#include <net/xdp_sock_drv.h>
#define REG_STATE_NEW 0x0
#define REG_STATE_REGISTERED 0x1
......@@ -361,7 +362,7 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
* of xdp_frames/pages in those cases.
*/
static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
unsigned long handle)
unsigned long handle, struct xdp_buff *xdp)
{
struct xdp_mem_allocator *xa;
struct page *page;
......@@ -390,6 +391,11 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
xa->zc_alloc->free(xa->zc_alloc, handle);
rcu_read_unlock();
break;
case MEM_TYPE_XSK_BUFF_POOL:
/* NB! Only valid from an xdp_buff! */
xsk_buff_free(xdp);
break;
default:
/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
break;
......@@ -398,19 +404,19 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
void xdp_return_frame(struct xdp_frame *xdpf)
{
__xdp_return(xdpf->data, &xdpf->mem, false, 0);
__xdp_return(xdpf->data, &xdpf->mem, false, 0, NULL);
}
EXPORT_SYMBOL_GPL(xdp_return_frame);
void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
{
__xdp_return(xdpf->data, &xdpf->mem, true, 0);
__xdp_return(xdpf->data, &xdpf->mem, true, 0, NULL);
}
EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
void xdp_return_buff(struct xdp_buff *xdp)
{
__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle);
__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle, xdp);
}
EXPORT_SYMBOL_GPL(xdp_return_buff);
......
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_XDP_SOCKETS) += xsk.o xdp_umem.o xsk_queue.o xskmap.o
obj-$(CONFIG_XDP_SOCKETS) += xsk_buff_pool.o
obj-$(CONFIG_XDP_SOCKETS_DIAG) += xsk_diag.o
......@@ -245,7 +245,7 @@ static void xdp_umem_release(struct xdp_umem *umem)
}
xsk_reuseq_destroy(umem);
xp_destroy(umem->pool);
xdp_umem_unmap_pages(umem);
xdp_umem_unpin_pages(umem);
......@@ -390,6 +390,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
umem->size = size;
umem->headroom = headroom;
umem->chunk_size_nohr = chunk_size - headroom;
umem->chunk_size = chunk_size;
umem->npgs = size / PAGE_SIZE;
umem->pgs = NULL;
umem->user = NULL;
......@@ -415,11 +416,21 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
}
err = xdp_umem_map_pages(umem);
if (!err)
return 0;
if (err)
goto out_pages;
kvfree(umem->pages);
umem->pool = xp_create(umem->pgs, umem->npgs, chunks, chunk_size,
headroom, size, unaligned_chunks);
if (!umem->pool) {
err = -ENOMEM;
goto out_unmap;
}
return 0;
out_unmap:
xdp_umem_unmap_pages(umem);
out_pages:
kvfree(umem->pages);
out_pin:
xdp_umem_unpin_pages(umem);
out_account:
......
......@@ -117,76 +117,67 @@ bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
}
EXPORT_SYMBOL(xsk_umem_uses_need_wakeup);
/* If a buffer crosses a page boundary, we need to do 2 memcpy's, one for
* each page. This is only required in copy mode.
*/
static void __xsk_rcv_memcpy(struct xdp_umem *umem, u64 addr, void *from_buf,
u32 len, u32 metalen)
static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
{
void *to_buf = xdp_umem_get_data(umem, addr);
addr = xsk_umem_add_offset_to_addr(addr);
if (xskq_cons_crosses_non_contig_pg(umem, addr, len + metalen)) {
void *next_pg_addr = umem->pages[(addr >> PAGE_SHIFT) + 1].addr;
u64 page_start = addr & ~(PAGE_SIZE - 1);
u64 first_len = PAGE_SIZE - (addr - page_start);
memcpy(to_buf, from_buf, first_len);
memcpy(next_pg_addr, from_buf + first_len,
len + metalen - first_len);
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
u64 addr;
int err;
return;
addr = xp_get_handle(xskb);
err = xskq_prod_reserve_desc(xs->rx, addr, len);
if (err) {
xs->rx_dropped++;
return err;
}
memcpy(to_buf, from_buf, len + metalen);
xp_release(xskb);
return 0;
}
static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len)
{
u64 offset = xs->umem->headroom;
u64 addr, memcpy_addr;
void *from_buf;
void *from_buf, *to_buf;
u32 metalen;
int err;
if (!xskq_cons_peek_addr(xs->umem->fq, &addr, xs->umem) ||
len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) {
xs->rx_dropped++;
return -ENOSPC;
}
if (unlikely(xdp_data_meta_unsupported(xdp))) {
from_buf = xdp->data;
if (unlikely(xdp_data_meta_unsupported(from))) {
from_buf = from->data;
to_buf = to->data;
metalen = 0;
} else {
from_buf = xdp->data_meta;
metalen = xdp->data - xdp->data_meta;
from_buf = from->data_meta;
metalen = from->data - from->data_meta;
to_buf = to->data - metalen;
}
memcpy_addr = xsk_umem_adjust_offset(xs->umem, addr, offset);
__xsk_rcv_memcpy(xs->umem, memcpy_addr, from_buf, len, metalen);
offset += metalen;
addr = xsk_umem_adjust_offset(xs->umem, addr, offset);
err = xskq_prod_reserve_desc(xs->rx, addr, len);
if (!err) {
xskq_cons_release(xs->umem->fq);
xdp_return_buff(xdp);
return 0;
}
xs->rx_dropped++;
return err;
memcpy(to_buf, from_buf, len + metalen);
}
static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len)
static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len,
bool explicit_free)
{
int err = xskq_prod_reserve_desc(xs->rx, xdp->handle, len);
struct xdp_buff *xsk_xdp;
int err;
if (err)
if (len > xsk_umem_get_rx_frame_size(xs->umem)) {
xs->rx_dropped++;
return -ENOSPC;
}
xsk_xdp = xsk_buff_alloc(xs->umem);
if (!xsk_xdp) {
xs->rx_dropped++;
return -ENOSPC;
}
return err;
xsk_copy_xdp(xsk_xdp, xdp, len);
err = __xsk_rcv_zc(xs, xsk_xdp, len);
if (err) {
xsk_buff_free(xsk_xdp);
return err;
}
if (explicit_free)
xdp_return_buff(xdp);
return 0;
}
static bool xsk_is_bound(struct xdp_sock *xs)
......@@ -199,7 +190,8 @@ static bool xsk_is_bound(struct xdp_sock *xs)
return false;
}
static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp,
bool explicit_free)
{
u32 len;
......@@ -211,8 +203,10 @@ static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
len = xdp->data_end - xdp->data;
return (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) ?
__xsk_rcv_zc(xs, xdp, len) : __xsk_rcv(xs, xdp, len);
return xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY ||
xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ?
__xsk_rcv_zc(xs, xdp, len) :
__xsk_rcv(xs, xdp, len, explicit_free);
}
static void xsk_flush(struct xdp_sock *xs)
......@@ -224,46 +218,11 @@ static void xsk_flush(struct xdp_sock *xs)
int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
u32 metalen = xdp->data - xdp->data_meta;
u32 len = xdp->data_end - xdp->data;
u64 offset = xs->umem->headroom;
void *buffer;
u64 addr;
int err;
spin_lock_bh(&xs->rx_lock);
if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) {
err = -EINVAL;
goto out_unlock;
}
if (!xskq_cons_peek_addr(xs->umem->fq, &addr, xs->umem) ||
len > xs->umem->chunk_size_nohr - XDP_PACKET_HEADROOM) {
err = -ENOSPC;
goto out_drop;
}
addr = xsk_umem_adjust_offset(xs->umem, addr, offset);
buffer = xdp_umem_get_data(xs->umem, addr);
memcpy(buffer, xdp->data_meta, len + metalen);
addr = xsk_umem_adjust_offset(xs->umem, addr, metalen);
err = xskq_prod_reserve_desc(xs->rx, addr, len);
if (err)
goto out_drop;
xskq_cons_release(xs->umem->fq);
xskq_prod_submit(xs->rx);
spin_unlock_bh(&xs->rx_lock);
xs->sk.sk_data_ready(&xs->sk);
return 0;
out_drop:
xs->rx_dropped++;
out_unlock:
err = xsk_rcv(xs, xdp, false);
xsk_flush(xs);
spin_unlock_bh(&xs->rx_lock);
return err;
}
......@@ -273,7 +232,7 @@ int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list);
int err;
err = xsk_rcv(xs, xdp);
err = xsk_rcv(xs, xdp, true);
if (err)
return err;
......@@ -404,7 +363,7 @@ static int xsk_generic_xmit(struct sock *sk)
skb_put(skb, len);
addr = desc.addr;
buffer = xdp_umem_get_data(xs->umem, addr);
buffer = xsk_buff_raw_get_data(xs->umem, addr);
err = skb_store_bits(skb, 0, buffer, len);
/* This is the backpressure mechanism for the Tx path.
* Reserve space in the completion queue and only proceed
......@@ -860,6 +819,8 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
q = (optname == XDP_UMEM_FILL_RING) ? &xs->umem->fq :
&xs->umem->cq;
err = xsk_init_queue(entries, q, true);
if (optname == XDP_UMEM_FILL_RING)
xp_set_fq(xs->umem->pool, *q);
mutex_unlock(&xs->mutex);
return err;
}
......
// SPDX-License-Identifier: GPL-2.0
#include <net/xsk_buff_pool.h>
#include <net/xdp_sock.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/swiotlb.h>
#include "xsk_queue.h"
struct xsk_buff_pool {
struct xsk_queue *fq;
struct list_head free_list;
dma_addr_t *dma_pages;
struct xdp_buff_xsk *heads;
u64 chunk_mask;
u64 addrs_cnt;
u32 free_list_cnt;
u32 dma_pages_cnt;
u32 heads_cnt;
u32 free_heads_cnt;
u32 headroom;
u32 chunk_size;
u32 frame_len;
bool cheap_dma;
bool unaligned;
void *addrs;
struct device *dev;
struct xdp_buff_xsk *free_heads[];
};
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->cheap_dma = true;
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;
}
}
static bool __maybe_unused xp_check_swiotlb_dma(struct xsk_buff_pool *pool)
{
#if defined(CONFIG_SWIOTLB)
phys_addr_t paddr;
u32 i;
for (i = 0; i < pool->dma_pages_cnt; i++) {
paddr = dma_to_phys(pool->dev, pool->dma_pages[i]);
if (is_swiotlb_buffer(paddr))
return false;
}
#endif
return true;
}
static bool xp_check_cheap_dma(struct xsk_buff_pool *pool)
{
#if defined(CONFIG_HAS_DMA)
const struct dma_map_ops *ops = get_dma_ops(pool->dev);
if (ops) {
return !ops->sync_single_for_cpu &&
!ops->sync_single_for_device;
}
if (!dma_is_direct(ops))
return false;
if (!xp_check_swiotlb_dma(pool))
return false;
if (!dev_is_dma_coherent(pool->dev)) {
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE)
return false;
#endif
}
#endif
return true;
}
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;
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;
}
pool->dma_pages[i] = dma;
}
if (pool->unaligned)
xp_check_dma_contiguity(pool);
pool->dev = dev;
pool->cheap_dma = xp_check_cheap_dma(pool);
return 0;
}
EXPORT_SYMBOL(xp_dma_map);
static bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool,
u64 addr, u32 len)
{
bool cross_pg = (addr & (PAGE_SIZE - 1)) + len > PAGE_SIZE;
if (pool->dma_pages_cnt && cross_pg) {
return !(pool->dma_pages[addr >> PAGE_SHIFT] &
XSK_NEXT_PG_CONTIG_MASK);
}
return false;
}
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);
}
void xp_release(struct xdp_buff_xsk *xskb)
{
xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
}
static u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr)
{
return addr & pool->chunk_mask;
}
static u64 xp_unaligned_extract_addr(u64 addr)
{
return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
}
static u64 xp_unaligned_extract_offset(u64 addr)
{
return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
}
static u64 xp_unaligned_add_offset_to_addr(u64 addr)
{
return xp_unaligned_extract_addr(addr) +
xp_unaligned_extract_offset(addr);
}
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)) {
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->cheap_dma) {
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);
static bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
struct xdp_desc *desc)
{
u64 chunk, chunk_end;
chunk = xp_aligned_extract_addr(pool, desc->addr);
chunk_end = xp_aligned_extract_addr(pool, desc->addr + desc->len);
if (chunk != chunk_end)
return false;
if (chunk >= pool->addrs_cnt)
return false;
if (desc->options)
return false;
return true;
}
static bool xp_unaligned_validate_desc(struct xsk_buff_pool *pool,
struct xdp_desc *desc)
{
u64 addr, base_addr;
base_addr = xp_unaligned_extract_addr(desc->addr);
addr = xp_unaligned_add_offset_to_addr(desc->addr);
if (desc->len > pool->chunk_size)
return false;
if (base_addr >= pool->addrs_cnt || addr >= pool->addrs_cnt ||
xp_desc_crosses_non_contig_pg(pool, addr, desc->len))
return false;
if (desc->options)
return false;
return true;
}
bool xp_validate_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
{
return pool->unaligned ? xp_unaligned_validate_desc(pool, desc) :
xp_aligned_validate_desc(pool, desc);
}
u64 xp_get_handle(struct xdp_buff_xsk *xskb)
{
u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start;
offset += xskb->pool->headroom;
if (!xskb->pool->unaligned)
return xskb->orig_addr + offset;
return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
}
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);
dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb)
{
return xskb->dma;
}
EXPORT_SYMBOL(xp_get_dma);
dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb)
{
return xskb->frame_dma;
}
EXPORT_SYMBOL(xp_get_frame_dma);
void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
{
if (xskb->pool->cheap_dma)
return;
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);
void xp_dma_sync_for_device(struct xsk_buff_pool *pool, dma_addr_t dma,
size_t size)
{
if (pool->cheap_dma)
return;
dma_sync_single_range_for_device(pool->dev, dma, 0,
size, DMA_BIDIRECTIONAL);
}
EXPORT_SYMBOL(xp_dma_sync_for_device);
......@@ -56,7 +56,7 @@ static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
du.id = umem->id;
du.size = umem->size;
du.num_pages = umem->npgs;
du.chunk_size = umem->chunk_size_nohr + umem->headroom;
du.chunk_size = umem->chunk_size;
du.headroom = umem->headroom;
du.ifindex = umem->dev ? umem->dev->ifindex : 0;
du.queue_id = umem->queue_id;
......
......@@ -9,6 +9,7 @@
#include <linux/types.h>
#include <linux/if_xdp.h>
#include <net/xdp_sock.h>
#include <net/xsk_buff_pool.h>
#include "xsk.h"
......@@ -172,31 +173,45 @@ static inline bool xskq_cons_read_addr(struct xsk_queue *q, u64 *addr,
return false;
}
static inline bool xskq_cons_is_valid_desc(struct xsk_queue *q,
struct xdp_desc *d,
struct xdp_umem *umem)
static inline bool xskq_cons_read_addr_aligned(struct xsk_queue *q, u64 *addr)
{
if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG) {
if (!xskq_cons_is_valid_unaligned(q, d->addr, d->len, umem))
return false;
struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
if (d->len > umem->chunk_size_nohr || d->options) {
q->invalid_descs++;
return false;
}
while (q->cached_cons != q->cached_prod) {
u32 idx = q->cached_cons & q->ring_mask;
*addr = ring->desc[idx];
if (xskq_cons_is_valid_addr(q, *addr))
return true;
q->cached_cons++;
}
return false;
}
static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr)
{
struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
if (q->cached_cons != q->cached_prod) {
u32 idx = q->cached_cons & q->ring_mask;
*addr = ring->desc[idx];
return true;
}
if (!xskq_cons_is_valid_addr(q, d->addr))
return false;
return false;
}
if (((d->addr + d->len) & q->chunk_mask) != (d->addr & q->chunk_mask) ||
d->options) {
static inline bool xskq_cons_is_valid_desc(struct xsk_queue *q,
struct xdp_desc *d,
struct xdp_umem *umem)
{
if (!xp_validate_desc(umem->pool, d)) {
q->invalid_descs++;
return false;
}
return true;
}
......@@ -260,6 +275,20 @@ static inline bool xskq_cons_peek_addr(struct xsk_queue *q, u64 *addr,
return xskq_cons_read_addr(q, addr, umem);
}
static inline bool xskq_cons_peek_addr_aligned(struct xsk_queue *q, u64 *addr)
{
if (q->cached_prod == q->cached_cons)
xskq_cons_get_entries(q);
return xskq_cons_read_addr_aligned(q, addr);
}
static inline bool xskq_cons_peek_addr_unchecked(struct xsk_queue *q, u64 *addr)
{
if (q->cached_prod == q->cached_cons)
xskq_cons_get_entries(q);
return xskq_cons_read_addr_unchecked(q, addr);
}
static inline bool xskq_cons_peek_desc(struct xsk_queue *q,
struct xdp_desc *desc,
struct xdp_umem *umem)
......
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