cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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xsk_buff_pool.h (6610B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2/* Copyright(c) 2020 Intel Corporation. */
      3
      4#ifndef XSK_BUFF_POOL_H_
      5#define XSK_BUFF_POOL_H_
      6
      7#include <linux/if_xdp.h>
      8#include <linux/types.h>
      9#include <linux/dma-mapping.h>
     10#include <linux/bpf.h>
     11#include <net/xdp.h>
     12
     13struct xsk_buff_pool;
     14struct xdp_rxq_info;
     15struct xsk_queue;
     16struct xdp_desc;
     17struct xdp_umem;
     18struct xdp_sock;
     19struct device;
     20struct page;
     21
     22struct xdp_buff_xsk {
     23	struct xdp_buff xdp;
     24	dma_addr_t dma;
     25	dma_addr_t frame_dma;
     26	struct xsk_buff_pool *pool;
     27	u64 orig_addr;
     28	struct list_head free_list_node;
     29};
     30
     31struct xsk_dma_map {
     32	dma_addr_t *dma_pages;
     33	struct device *dev;
     34	struct net_device *netdev;
     35	refcount_t users;
     36	struct list_head list; /* Protected by the RTNL_LOCK */
     37	u32 dma_pages_cnt;
     38	bool dma_need_sync;
     39};
     40
     41struct xsk_buff_pool {
     42	/* Members only used in the control path first. */
     43	struct device *dev;
     44	struct net_device *netdev;
     45	struct list_head xsk_tx_list;
     46	/* Protects modifications to the xsk_tx_list */
     47	spinlock_t xsk_tx_list_lock;
     48	refcount_t users;
     49	struct xdp_umem *umem;
     50	struct work_struct work;
     51	struct list_head free_list;
     52	u32 heads_cnt;
     53	u16 queue_id;
     54
     55	/* Data path members as close to free_heads at the end as possible. */
     56	struct xsk_queue *fq ____cacheline_aligned_in_smp;
     57	struct xsk_queue *cq;
     58	/* For performance reasons, each buff pool has its own array of dma_pages
     59	 * even when they are identical.
     60	 */
     61	dma_addr_t *dma_pages;
     62	struct xdp_buff_xsk *heads;
     63	struct xdp_desc *tx_descs;
     64	u64 chunk_mask;
     65	u64 addrs_cnt;
     66	u32 free_list_cnt;
     67	u32 dma_pages_cnt;
     68	u32 free_heads_cnt;
     69	u32 headroom;
     70	u32 chunk_size;
     71	u32 chunk_shift;
     72	u32 frame_len;
     73	u8 cached_need_wakeup;
     74	bool uses_need_wakeup;
     75	bool dma_need_sync;
     76	bool unaligned;
     77	void *addrs;
     78	/* Mutual exclusion of the completion ring in the SKB mode. Two cases to protect:
     79	 * NAPI TX thread and sendmsg error paths in the SKB destructor callback and when
     80	 * sockets share a single cq when the same netdev and queue id is shared.
     81	 */
     82	spinlock_t cq_lock;
     83	struct xdp_buff_xsk *free_heads[];
     84};
     85
     86/* Masks for xdp_umem_page flags.
     87 * The low 12-bits of the addr will be 0 since this is the page address, so we
     88 * can use them for flags.
     89 */
     90#define XSK_NEXT_PG_CONTIG_SHIFT 0
     91#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
     92
     93/* AF_XDP core. */
     94struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
     95						struct xdp_umem *umem);
     96int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
     97		  u16 queue_id, u16 flags);
     98int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem,
     99			 struct net_device *dev, u16 queue_id);
    100int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs);
    101void xp_destroy(struct xsk_buff_pool *pool);
    102void xp_get_pool(struct xsk_buff_pool *pool);
    103bool xp_put_pool(struct xsk_buff_pool *pool);
    104void xp_clear_dev(struct xsk_buff_pool *pool);
    105void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
    106void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
    107
    108/* AF_XDP, and XDP core. */
    109void xp_free(struct xdp_buff_xsk *xskb);
    110
    111static inline void xp_init_xskb_addr(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
    112				     u64 addr)
    113{
    114	xskb->orig_addr = addr;
    115	xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
    116}
    117
    118static inline void xp_init_xskb_dma(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
    119				    dma_addr_t *dma_pages, u64 addr)
    120{
    121	xskb->frame_dma = (dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) +
    122		(addr & ~PAGE_MASK);
    123	xskb->dma = xskb->frame_dma + pool->headroom + XDP_PACKET_HEADROOM;
    124}
    125
    126/* AF_XDP ZC drivers, via xdp_sock_buff.h */
    127void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq);
    128int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
    129	       unsigned long attrs, struct page **pages, u32 nr_pages);
    130void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs);
    131struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool);
    132u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max);
    133bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count);
    134void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr);
    135dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr);
    136static inline dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb)
    137{
    138	return xskb->dma;
    139}
    140
    141static inline dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb)
    142{
    143	return xskb->frame_dma;
    144}
    145
    146void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb);
    147static inline void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
    148{
    149	xp_dma_sync_for_cpu_slow(xskb);
    150}
    151
    152void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
    153				 size_t size);
    154static inline void xp_dma_sync_for_device(struct xsk_buff_pool *pool,
    155					  dma_addr_t dma, size_t size)
    156{
    157	if (!pool->dma_need_sync)
    158		return;
    159
    160	xp_dma_sync_for_device_slow(pool, dma, size);
    161}
    162
    163/* Masks for xdp_umem_page flags.
    164 * The low 12-bits of the addr will be 0 since this is the page address, so we
    165 * can use them for flags.
    166 */
    167#define XSK_NEXT_PG_CONTIG_SHIFT 0
    168#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
    169
    170static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool,
    171						 u64 addr, u32 len)
    172{
    173	bool cross_pg = (addr & (PAGE_SIZE - 1)) + len > PAGE_SIZE;
    174
    175	if (likely(!cross_pg))
    176		return false;
    177
    178	if (pool->dma_pages_cnt) {
    179		return !(pool->dma_pages[addr >> PAGE_SHIFT] &
    180			 XSK_NEXT_PG_CONTIG_MASK);
    181	}
    182
    183	/* skb path */
    184	return addr + len > pool->addrs_cnt;
    185}
    186
    187static inline u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr)
    188{
    189	return addr & pool->chunk_mask;
    190}
    191
    192static inline u64 xp_unaligned_extract_addr(u64 addr)
    193{
    194	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
    195}
    196
    197static inline u64 xp_unaligned_extract_offset(u64 addr)
    198{
    199	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
    200}
    201
    202static inline u64 xp_unaligned_add_offset_to_addr(u64 addr)
    203{
    204	return xp_unaligned_extract_addr(addr) +
    205		xp_unaligned_extract_offset(addr);
    206}
    207
    208static inline u32 xp_aligned_extract_idx(struct xsk_buff_pool *pool, u64 addr)
    209{
    210	return xp_aligned_extract_addr(pool, addr) >> pool->chunk_shift;
    211}
    212
    213static inline void xp_release(struct xdp_buff_xsk *xskb)
    214{
    215	if (xskb->pool->unaligned)
    216		xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
    217}
    218
    219static inline u64 xp_get_handle(struct xdp_buff_xsk *xskb)
    220{
    221	u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start;
    222
    223	offset += xskb->pool->headroom;
    224	if (!xskb->pool->unaligned)
    225		return xskb->orig_addr + offset;
    226	return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
    227}
    228
    229#endif /* XSK_BUFF_POOL_H_ */