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Date: Wed, 6 May 2020 12:51:56 +0300
From: Maxim Mikityanskiy <maximmi@...lanox.com>
To: Björn Töpel <bjorn.topel@...il.com>,
Björn Töpel <bjorn.topel@...el.com>
Cc: ast@...nel.org, daniel@...earbox.net, davem@...emloft.net,
kuba@...nel.org, hawk@...nel.org, john.fastabend@...il.com,
netdev@...r.kernel.org, bpf@...r.kernel.org,
magnus.karlsson@...el.com, jonathan.lemon@...il.com,
maciej.fijalkowski@...el.com
Subject: Re: [RFC PATCH bpf-next 04/13] xsk: introduce AF_XDP buffer
allocation API
On 2020-05-04 14:37, Björn Töpel wrote:
> From: Björn Töpel <bjorn.topel@...el.com>
>
> 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.
>
> Signed-off-by: Björn Töpel <bjorn.topel@...el.com>
> ---
> include/net/xdp.h | 4 +-
> include/net/xdp_sock.h | 2 +
> include/net/xdp_sock_drv.h | 132 +++++++++++
> include/net/xsk_buff_pool.h | 54 +++++
> include/trace/events/xdp.h | 3 +-
> net/core/xdp.c | 14 +-
> net/xdp/Makefile | 1 +
> net/xdp/xdp_umem.c | 19 +-
> net/xdp/xsk.c | 147 +++++-------
> net/xdp/xsk_buff_pool.c | 451 ++++++++++++++++++++++++++++++++++++
> net/xdp/xsk_diag.c | 2 +-
> net/xdp/xsk_queue.h | 59 +++--
> 12 files changed, 769 insertions(+), 119 deletions(-)
> create mode 100644 include/net/xsk_buff_pool.h
> create mode 100644 net/xdp/xsk_buff_pool.c
>
> diff --git a/include/net/xdp.h b/include/net/xdp.h
> index 3cc6d5d84aa4..83173e4d306c 100644
> --- a/include/net/xdp.h
> +++ b/include/net/xdp.h
> @@ -38,6 +38,7 @@ 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,
> };
>
> @@ -101,7 +102,8 @@ 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 */
> diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
> index 425a42c54b95..117cc1e2ca38 100644
> --- a/include/net/xdp_sock.h
> +++ b/include/net/xdp_sock.h
> @@ -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;
> unsigned long address;
> refcount_t users;
> diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
> index 98dd6962e6d4..232f2e3f01ac 100644
> --- a/include/net/xdp_sock_drv.h
> +++ b/include/net/xdp_sock_drv.h
> @@ -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
>
> @@ -96,6 +97,77 @@ static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address,
> return address + offset;
> }
>
> +static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem)
> +{
> + return umem->chunk_size - umem->headroom - XDP_PACKET_HEADROOM;
> +}
> +
> +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 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)
> @@ -202,6 +274,66 @@ static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle,
> 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 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 */
> diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
> new file mode 100644
> index 000000000000..9abef166441d
> --- /dev/null
> +++ b/include/net/xsk_buff_pool.h
> @@ -0,0 +1,54 @@
> +/* 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;
> + 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);
> +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_ */
> diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
> index b95d65e8c628..48547a12fa27 100644
> --- a/include/trace/events/xdp.h
> +++ b/include/trace/events/xdp.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);
> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 4c7ea85486af..89053ef8333b 100644
> --- a/net/core/xdp.c
> +++ b/net/core/xdp.c
> @@ -16,6 +16,7 @@
> #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
> @@ -360,7 +361,7 @@ 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;
> @@ -389,6 +390,11 @@ 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;
I remember I asked about it, but not sure what we decided here.
xdp_return_buff is the only way to get in this new case, and it's called
only from XSK flows. Maybe it would make sense to kill this case and
xdp_return_buff, and call xsk_buff_free directly? It'll save some time
that we waste in switch-case, a function call and two parameters of
__xdp_return - should make everything faster. Do you think it makes sense?
> default:
> /* Not possible, checked in xdp_rxq_info_reg_mem_model() */
> break;
> @@ -397,19 +403,19 @@ 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);
>
> diff --git a/net/xdp/Makefile b/net/xdp/Makefile
> index 90b5460d6166..30cdc4315f42 100644
> --- a/net/xdp/Makefile
> +++ b/net/xdp/Makefile
> @@ -1,3 +1,4 @@
> # 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
> diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
> index ed7a6060f73c..0bc8a50d553f 100644
> --- a/net/xdp/xdp_umem.c
> +++ b/net/xdp/xdp_umem.c
> @@ -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);
>
> @@ -391,6 +391,7 @@ 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;
> @@ -416,11 +417,21 @@ 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:
> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index a5cf3280f88e..df36c12236c3 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -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;
> }
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> new file mode 100644
> index 000000000000..30cb2de77a03
> --- /dev/null
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -0,0 +1,451 @@
> +// 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 "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;
> + 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 xp_check_cheap_dma(struct xsk_buff_pool *pool)
> +{
> + const struct dma_map_ops *ops = get_dma_ops(pool->dev);
> + phys_addr_t paddr;
> + u32 i;
> +
> + if (ops) {
> + return !ops->sync_single_for_cpu &&
> + !ops->sync_single_for_device;
> + }
> +
> + if (!dma_is_direct(ops))
> + return false;
> +
> +#if defined(CONFIG_SWIOTLB)
> + 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
> +
> + 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
> + }
> + 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->dma = (pool->dma_pages[addr >> PAGE_SHIFT] &
> + ~XSK_NEXT_PG_CONTIG_MASK) +
> + (addr & ~PAGE_MASK) +
> + 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);
> +
> +void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
> +{
> + size_t size;
> +
> + if (xskb->pool->cheap_dma)
> + return;
> +
> + size = xskb->xdp.data_end - xskb->xdp.data;
> + dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
> + size, 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);
> diff --git a/net/xdp/xsk_diag.c b/net/xdp/xsk_diag.c
> index f59791ba43a0..0163b26aaf63 100644
> --- a/net/xdp/xsk_diag.c
> +++ b/net/xdp/xsk_diag.c
> @@ -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;
> diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
> index aa3dd35cbfb6..db25da8fb2b9 100644
> --- a/net/xdp/xsk_queue.h
> +++ b/net/xdp/xsk_queue.h
> @@ -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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