[linux-2.6-block.git] / net / core / xdp.c

/* net/core/xdp.c
 *
 * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
 * Released under terms in GPL version 2.  See COPYING.
 */
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/rhashtable.h>
#include <net/page_pool.h>

#include <net/xdp.h>

#define REG_STATE_NEW		0x0
#define REG_STATE_REGISTERED	0x1
#define REG_STATE_UNREGISTERED	0x2
#define REG_STATE_UNUSED	0x3

static DEFINE_IDA(mem_id_pool);
static DEFINE_MUTEX(mem_id_lock);
#define MEM_ID_MAX 0xFFFE
#define MEM_ID_MIN 1
static int mem_id_next = MEM_ID_MIN;

static bool mem_id_init; /* false */
static struct rhashtable *mem_id_ht;

struct xdp_mem_allocator {
	struct xdp_mem_info mem;
	union {
		void *allocator;
		struct page_pool *page_pool;
		struct zero_copy_allocator *zc_alloc;
	};
	struct rhash_head node;
	struct rcu_head rcu;
};

static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
{
	const u32 *k = data;
	const u32 key = *k;

	BUILD_BUG_ON(FIELD_SIZEOF(struct xdp_mem_allocator, mem.id)
		     != sizeof(u32));

	/* Use cyclic increasing ID as direct hash key */
	return key;
}

static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg,
			  const void *ptr)
{
	const struct xdp_mem_allocator *xa = ptr;
	u32 mem_id = *(u32 *)arg->key;

	return xa->mem.id != mem_id;
}

static const struct rhashtable_params mem_id_rht_params = {
	.nelem_hint = 64,
	.head_offset = offsetof(struct xdp_mem_allocator, node),
	.key_offset  = offsetof(struct xdp_mem_allocator, mem.id),
	.key_len = FIELD_SIZEOF(struct xdp_mem_allocator, mem.id),
	.max_size = MEM_ID_MAX,
	.min_size = 8,
	.automatic_shrinking = true,
	.hashfn    = xdp_mem_id_hashfn,
	.obj_cmpfn = xdp_mem_id_cmp,
};

static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu)
{
	struct xdp_mem_allocator *xa;

	xa = container_of(rcu, struct xdp_mem_allocator, rcu);

	/* Allow this ID to be reused */
	ida_simple_remove(&mem_id_pool, xa->mem.id);

	/* Notice, driver is expected to free the *allocator,
	 * e.g. page_pool, and MUST also use RCU free.
	 */

	/* Poison memory */
	xa->mem.id = 0xFFFF;
	xa->mem.type = 0xF0F0;
	xa->allocator = (void *)0xDEAD9001;

	kfree(xa);
}

void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
{
	struct xdp_mem_allocator *xa;
	int id = xdp_rxq->mem.id;

	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
		WARN(1, "Missing register, driver bug");
		return;
	}

	if (xdp_rxq->mem.type != MEM_TYPE_PAGE_POOL &&
	    xdp_rxq->mem.type != MEM_TYPE_ZERO_COPY) {
		return;
	}

	if (id == 0)
		return;

	mutex_lock(&mem_id_lock);

	xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params);
	if (xa && !rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
		call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);

	mutex_unlock(&mem_id_lock);
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model);

void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
{
	/* Simplify driver cleanup code paths, allow unreg "unused" */
	if (xdp_rxq->reg_state == REG_STATE_UNUSED)
		return;

	WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG");

	xdp_rxq_info_unreg_mem_model(xdp_rxq);

	xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
	xdp_rxq->dev = NULL;

	/* Reset mem info to defaults */
	xdp_rxq->mem.id = 0;
	xdp_rxq->mem.type = 0;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);

static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
{
	memset(xdp_rxq, 0, sizeof(*xdp_rxq));
}

/* Returns 0 on success, negative on failure */
int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
		     struct net_device *dev, u32 queue_index)
{
	if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
		WARN(1, "Driver promised not to register this");
		return -EINVAL;
	}

	if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
		WARN(1, "Missing unregister, handled but fix driver");
		xdp_rxq_info_unreg(xdp_rxq);
	}

	if (!dev) {
		WARN(1, "Missing net_device from driver");
		return -ENODEV;
	}

	/* State either UNREGISTERED or NEW */
	xdp_rxq_info_init(xdp_rxq);
	xdp_rxq->dev = dev;
	xdp_rxq->queue_index = queue_index;

	xdp_rxq->reg_state = REG_STATE_REGISTERED;
	return 0;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_reg);

void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
{
	xdp_rxq->reg_state = REG_STATE_UNUSED;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);

bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
{
	return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);

static int __mem_id_init_hash_table(void)
{
	struct rhashtable *rht;
	int ret;

	if (unlikely(mem_id_init))
		return 0;

	rht = kzalloc(sizeof(*rht), GFP_KERNEL);
	if (!rht)
		return -ENOMEM;

	ret = rhashtable_init(rht, &mem_id_rht_params);
	if (ret < 0) {
		kfree(rht);
		return ret;
	}
	mem_id_ht = rht;
	smp_mb(); /* mutex lock should provide enough pairing */
	mem_id_init = true;

	return 0;
}

/* Allocate a cyclic ID that maps to allocator pointer.
 * See: https://www.kernel.org/doc/html/latest/core-api/idr.html
 *
 * Caller must lock mem_id_lock.
 */
static int __mem_id_cyclic_get(gfp_t gfp)
{
	int retries = 1;
	int id;

again:
	id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp);
	if (id < 0) {
		if (id == -ENOSPC) {
			/* Cyclic allocator, reset next id */
			if (retries--) {
				mem_id_next = MEM_ID_MIN;
				goto again;
			}
		}
		return id; /* errno */
	}
	mem_id_next = id + 1;

	return id;
}

static bool __is_supported_mem_type(enum xdp_mem_type type)
{
	if (type == MEM_TYPE_PAGE_POOL)
		return is_page_pool_compiled_in();

	if (type >= MEM_TYPE_MAX)
		return false;

	return true;
}

int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
			       enum xdp_mem_type type, void *allocator)
{
	struct xdp_mem_allocator *xdp_alloc;
	gfp_t gfp = GFP_KERNEL;
	int id, errno, ret;
	void *ptr;

	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
		WARN(1, "Missing register, driver bug");
		return -EFAULT;
	}

	if (!__is_supported_mem_type(type))
		return -EOPNOTSUPP;

	xdp_rxq->mem.type = type;

	if (!allocator) {
		if (type == MEM_TYPE_PAGE_POOL || type == MEM_TYPE_ZERO_COPY)
			return -EINVAL; /* Setup time check page_pool req */
		return 0;
	}

	/* Delay init of rhashtable to save memory if feature isn't used */
	if (!mem_id_init) {
		mutex_lock(&mem_id_lock);
		ret = __mem_id_init_hash_table();
		mutex_unlock(&mem_id_lock);
		if (ret < 0) {
			WARN_ON(1);
			return ret;
		}
	}

	xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);
	if (!xdp_alloc)
		return -ENOMEM;

	mutex_lock(&mem_id_lock);
	id = __mem_id_cyclic_get(gfp);
	if (id < 0) {
		errno = id;
		goto err;
	}
	xdp_rxq->mem.id = id;
	xdp_alloc->mem  = xdp_rxq->mem;
	xdp_alloc->allocator = allocator;

	/* Insert allocator into ID lookup table */
	ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
	if (IS_ERR(ptr)) {
		errno = PTR_ERR(ptr);
		goto err;
	}

	mutex_unlock(&mem_id_lock);

	return 0;
err:
	mutex_unlock(&mem_id_lock);
	kfree(xdp_alloc);
	return errno;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);

/* XDP RX runs under NAPI protection, and in different delivery error
 * scenarios (e.g. queue full), it is possible to return the xdp_frame
 * while still leveraging this protection.  The @napi_direct boolian
 * is used for those calls sites.  Thus, allowing for faster recycling
 * of xdp_frames/pages in those cases.
 */
static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
			 unsigned long handle)
{
	struct xdp_mem_allocator *xa;
	struct page *page;

	switch (mem->type) {
	case MEM_TYPE_PAGE_POOL:
		rcu_read_lock();
		/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
		page = virt_to_head_page(data);
		if (xa) {
			napi_direct &= !xdp_return_frame_no_direct();
			page_pool_put_page(xa->page_pool, page, napi_direct);
		} else {
			put_page(page);
		}
		rcu_read_unlock();
		break;
	case MEM_TYPE_PAGE_SHARED:
		page_frag_free(data);
		break;
	case MEM_TYPE_PAGE_ORDER0:
		page = virt_to_page(data); /* Assumes order0 page*/
		put_page(page);
		break;
	case MEM_TYPE_ZERO_COPY:
		/* NB! Only valid from an xdp_buff! */
		rcu_read_lock();
		/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
		xa->zc_alloc->free(xa->zc_alloc, handle);
		rcu_read_unlock();
	default:
		/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
		break;
	}
}

void xdp_return_frame(struct xdp_frame *xdpf)
{
	__xdp_return(xdpf->data, &xdpf->mem, false, 0);
}
EXPORT_SYMBOL_GPL(xdp_return_frame);

void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
{
	__xdp_return(xdpf->data, &xdpf->mem, true, 0);
}
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);
}
EXPORT_SYMBOL_GPL(xdp_return_buff);

int xdp_attachment_query(struct xdp_attachment_info *info,
			 struct netdev_bpf *bpf)
{
	bpf->prog_id = info->prog ? info->prog->aux->id : 0;
	bpf->prog_flags = info->prog ? info->flags : 0;
	return 0;
}
EXPORT_SYMBOL_GPL(xdp_attachment_query);

bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
			     struct netdev_bpf *bpf)
{
	if (info->prog && (bpf->flags ^ info->flags) & XDP_FLAGS_MODES) {
		NL_SET_ERR_MSG(bpf->extack,
			       "program loaded with different flags");
		return false;
	}
	return true;
}
EXPORT_SYMBOL_GPL(xdp_attachment_flags_ok);

void xdp_attachment_setup(struct xdp_attachment_info *info,
			  struct netdev_bpf *bpf)
{
	if (info->prog)
		bpf_prog_put(info->prog);
	info->prog = bpf->prog;
	info->flags = bpf->flags;
}
EXPORT_SYMBOL_GPL(xdp_attachment_setup);

struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp)
{
	unsigned int metasize, totsize;
	void *addr, *data_to_copy;
	struct xdp_frame *xdpf;
	struct page *page;

	/* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */
	metasize = xdp_data_meta_unsupported(xdp) ? 0 :
		   xdp->data - xdp->data_meta;
	totsize = xdp->data_end - xdp->data + metasize;

	if (sizeof(*xdpf) + totsize > PAGE_SIZE)
		return NULL;

	page = dev_alloc_page();
	if (!page)
		return NULL;

	addr = page_to_virt(page);
	xdpf = addr;
	memset(xdpf, 0, sizeof(*xdpf));

	addr += sizeof(*xdpf);
	data_to_copy = metasize ? xdp->data_meta : xdp->data;
	memcpy(addr, data_to_copy, totsize);

	xdpf->data = addr + metasize;
	xdpf->len = totsize - metasize;
	xdpf->headroom = 0;
	xdpf->metasize = metasize;
	xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;

	xdp_return_buff(xdp);
	return xdpf;
}
EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);
Commit	Line	Data
aecd67b6 JDB	1	/* net/core/xdp.c
	2	*
	3	* Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
	4	* Released under terms in GPL version 2. See COPYING.
	5	*/
05296620 JK	6	#include <linux/bpf.h>
05296620 JK	7	#include <linux/filter.h>
aecd67b6 JDB	8	#include <linux/types.h>
aecd67b6 JDB	9	#include <linux/mm.h>
05296620	10	#include <linux/netdevice.h>
8d5d8852 JDB	11	#include <linux/slab.h>
	12	#include <linux/idr.h>
	13	#include <linux/rhashtable.h>
57d0a1c1	14	#include <net/page_pool.h>
aecd67b6 JDB	15
	16	#include <net/xdp.h>
	17
	18	#define REG_STATE_NEW 0x0
	19	#define REG_STATE_REGISTERED 0x1
	20	#define REG_STATE_UNREGISTERED 0x2
	21	#define REG_STATE_UNUSED 0x3
	22
8d5d8852 JDB	23	static DEFINE_IDA(mem_id_pool);
	24	static DEFINE_MUTEX(mem_id_lock);
	25	#define MEM_ID_MAX 0xFFFE
	26	#define MEM_ID_MIN 1
	27	static int mem_id_next = MEM_ID_MIN;
	28
	29	static bool mem_id_init; /* false */
	30	static struct rhashtable *mem_id_ht;
	31
	32	struct xdp_mem_allocator {
	33	struct xdp_mem_info mem;
57d0a1c1 JDB	34	union {
	35	void *allocator;
	36	struct page_pool *page_pool;
02b55e56	37	struct zero_copy_allocator *zc_alloc;
57d0a1c1	38	};
8d5d8852 JDB	39	struct rhash_head node;
	40	struct rcu_head rcu;
	41	};
	42
	43	static u32 xdp_mem_id_hashfn(const void *data, u32 len, u32 seed)
	44	{
	45	const u32 *k = data;
	46	const u32 key = *k;
	47
	48	BUILD_BUG_ON(FIELD_SIZEOF(struct xdp_mem_allocator, mem.id)
	49	!= sizeof(u32));
	50
9f9a7077 N	51	/* Use cyclic increasing ID as direct hash key */
9f9a7077 N	52	return key;
8d5d8852 JDB	53	}
	54
	55	static int xdp_mem_id_cmp(struct rhashtable_compare_arg *arg,
	56	const void *ptr)
	57	{
	58	const struct xdp_mem_allocator *xa = ptr;
	59	u32 mem_id = (u32 )arg->key;
	60
	61	return xa->mem.id != mem_id;
	62	}
	63
	64	static const struct rhashtable_params mem_id_rht_params = {
	65	.nelem_hint = 64,
	66	.head_offset = offsetof(struct xdp_mem_allocator, node),
	67	.key_offset = offsetof(struct xdp_mem_allocator, mem.id),
	68	.key_len = FIELD_SIZEOF(struct xdp_mem_allocator, mem.id),
	69	.max_size = MEM_ID_MAX,
	70	.min_size = 8,
	71	.automatic_shrinking = true,
	72	.hashfn = xdp_mem_id_hashfn,
	73	.obj_cmpfn = xdp_mem_id_cmp,
	74	};
	75
	76	static void __xdp_mem_allocator_rcu_free(struct rcu_head *rcu)
	77	{
	78	struct xdp_mem_allocator *xa;
	79
	80	xa = container_of(rcu, struct xdp_mem_allocator, rcu);
	81
	82	/* Allow this ID to be reused */
	83	ida_simple_remove(&mem_id_pool, xa->mem.id);
	84
57d0a1c1 JDB	85	/* Notice, driver is expected to free the *allocator,
	86	* e.g. page_pool, and MUST also use RCU free.
	87	*/
8d5d8852 JDB	88
	89	/* Poison memory */
	90	xa->mem.id = 0xFFFF;
	91	xa->mem.type = 0xF0F0;
	92	xa->allocator = (void *)0xDEAD9001;
	93
	94	kfree(xa);
	95	}
	96
dce5bd61	97	void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
8d5d8852 JDB	98	{
	99	struct xdp_mem_allocator *xa;
	100	int id = xdp_rxq->mem.id;
8d5d8852	101
dce5bd61 BT	102	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
	103	WARN(1, "Missing register, driver bug");
	104	return;
	105	}
	106
	107	if (xdp_rxq->mem.type != MEM_TYPE_PAGE_POOL &&
	108	xdp_rxq->mem.type != MEM_TYPE_ZERO_COPY) {
	109	return;
	110	}
	111
8d5d8852 JDB	112	if (id == 0)
	113	return;
	114
	115	mutex_lock(&mem_id_lock);
	116
21b172ee TT	117	xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params);
	118	if (xa && !rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
	119	call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
8d5d8852 JDB	120
	121	mutex_unlock(&mem_id_lock);
	122	}
dce5bd61	123	EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg_mem_model);
8d5d8852	124
aecd67b6 JDB	125	void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
	126	{
	127	/* Simplify driver cleanup code paths, allow unreg "unused" */
	128	if (xdp_rxq->reg_state == REG_STATE_UNUSED)
	129	return;
	130
	131	WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG");
	132
dce5bd61	133	xdp_rxq_info_unreg_mem_model(xdp_rxq);
8d5d8852	134
aecd67b6 JDB	135	xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
aecd67b6 JDB	136	xdp_rxq->dev = NULL;
8d5d8852 JDB	137
	138	/* Reset mem info to defaults */
	139	xdp_rxq->mem.id = 0;
	140	xdp_rxq->mem.type = 0;
aecd67b6 JDB	141	}
	142	EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);
	143
	144	static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
	145	{
	146	memset(xdp_rxq, 0, sizeof(*xdp_rxq));
	147	}
	148
	149	/* Returns 0 on success, negative on failure */
	150	int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
	151	struct net_device *dev, u32 queue_index)
	152	{
	153	if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
	154	WARN(1, "Driver promised not to register this");
	155	return -EINVAL;
	156	}
	157
	158	if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
	159	WARN(1, "Missing unregister, handled but fix driver");
	160	xdp_rxq_info_unreg(xdp_rxq);
	161	}
	162
	163	if (!dev) {
	164	WARN(1, "Missing net_device from driver");
	165	return -ENODEV;
	166	}
	167
	168	/* State either UNREGISTERED or NEW */
	169	xdp_rxq_info_init(xdp_rxq);
	170	xdp_rxq->dev = dev;
	171	xdp_rxq->queue_index = queue_index;
	172
	173	xdp_rxq->reg_state = REG_STATE_REGISTERED;
	174	return 0;
	175	}
	176	EXPORT_SYMBOL_GPL(xdp_rxq_info_reg);
	177
	178	void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
	179	{
	180	xdp_rxq->reg_state = REG_STATE_UNUSED;
	181	}
	182	EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);
c0124f32 JDB	183
	184	bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
	185	{
	186	return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
	187	}
	188	EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);
5ab073ff	189
8d5d8852 JDB	190	static int __mem_id_init_hash_table(void)
	191	{
	192	struct rhashtable *rht;
	193	int ret;
	194
	195	if (unlikely(mem_id_init))
	196	return 0;
	197
	198	rht = kzalloc(sizeof(*rht), GFP_KERNEL);
	199	if (!rht)
	200	return -ENOMEM;
	201
	202	ret = rhashtable_init(rht, &mem_id_rht_params);
	203	if (ret < 0) {
	204	kfree(rht);
	205	return ret;
	206	}
	207	mem_id_ht = rht;
	208	smp_mb(); /* mutex lock should provide enough pairing */
	209	mem_id_init = true;
	210
	211	return 0;
	212	}
	213
	214	/* Allocate a cyclic ID that maps to allocator pointer.
	215	* See: https://www.kernel.org/doc/html/latest/core-api/idr.html
	216	*
	217	* Caller must lock mem_id_lock.
	218	*/
	219	static int __mem_id_cyclic_get(gfp_t gfp)
	220	{
	221	int retries = 1;
	222	int id;
	223
	224	again:
	225	id = ida_simple_get(&mem_id_pool, mem_id_next, MEM_ID_MAX, gfp);
	226	if (id < 0) {
	227	if (id == -ENOSPC) {
	228	/* Cyclic allocator, reset next id */
	229	if (retries--) {
	230	mem_id_next = MEM_ID_MIN;
	231	goto again;
	232	}
	233	}
	234	return id; /* errno */
	235	}
	236	mem_id_next = id + 1;
	237
	238	return id;
	239	}
	240
57d0a1c1 JDB	241	static bool __is_supported_mem_type(enum xdp_mem_type type)
	242	{
	243	if (type == MEM_TYPE_PAGE_POOL)
	244	return is_page_pool_compiled_in();
	245
	246	if (type >= MEM_TYPE_MAX)
	247	return false;
	248
	249	return true;
	250	}
	251
5ab073ff JDB	252	int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
	253	enum xdp_mem_type type, void *allocator)
	254	{
8d5d8852 JDB	255	struct xdp_mem_allocator *xdp_alloc;
	256	gfp_t gfp = GFP_KERNEL;
	257	int id, errno, ret;
	258	void *ptr;
	259
	260	if (xdp_rxq->reg_state != REG_STATE_REGISTERED) {
	261	WARN(1, "Missing register, driver bug");
	262	return -EFAULT;
	263	}
	264
57d0a1c1 JDB	265	if (!__is_supported_mem_type(type))
57d0a1c1 JDB	266	return -EOPNOTSUPP;
5ab073ff JDB	267
	268	xdp_rxq->mem.type = type;
	269
57d0a1c1	270	if (!allocator) {
02b55e56	271	if (type == MEM_TYPE_PAGE_POOL \|\| type == MEM_TYPE_ZERO_COPY)
57d0a1c1	272	return -EINVAL; /* Setup time check page_pool req */
8d5d8852	273	return 0;
57d0a1c1	274	}
8d5d8852 JDB	275
	276	/* Delay init of rhashtable to save memory if feature isn't used */
	277	if (!mem_id_init) {
	278	mutex_lock(&mem_id_lock);
	279	ret = __mem_id_init_hash_table();
	280	mutex_unlock(&mem_id_lock);
	281	if (ret < 0) {
	282	WARN_ON(1);
	283	return ret;
	284	}
	285	}
	286
	287	xdp_alloc = kzalloc(sizeof(*xdp_alloc), gfp);
	288	if (!xdp_alloc)
	289	return -ENOMEM;
	290
	291	mutex_lock(&mem_id_lock);
	292	id = __mem_id_cyclic_get(gfp);
	293	if (id < 0) {
	294	errno = id;
	295	goto err;
	296	}
	297	xdp_rxq->mem.id = id;
	298	xdp_alloc->mem = xdp_rxq->mem;
	299	xdp_alloc->allocator = allocator;
	300
	301	/* Insert allocator into ID lookup table */
	302	ptr = rhashtable_insert_slow(mem_id_ht, &id, &xdp_alloc->node);
	303	if (IS_ERR(ptr)) {
	304	errno = PTR_ERR(ptr);
	305	goto err;
	306	}
	307
	308	mutex_unlock(&mem_id_lock);
5ab073ff	309
5ab073ff	310	return 0;
8d5d8852 JDB	311	err:
	312	mutex_unlock(&mem_id_lock);
	313	kfree(xdp_alloc);
	314	return errno;
5ab073ff JDB	315	}
5ab073ff JDB	316	EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
8d5d8852	317
389ab7f0 JDB	318	/* XDP RX runs under NAPI protection, and in different delivery error
	319	* scenarios (e.g. queue full), it is possible to return the xdp_frame
	320	* while still leveraging this protection. The @napi_direct boolian
	321	* is used for those calls sites. Thus, allowing for faster recycling
	322	* of xdp_frames/pages in those cases.
	323	*/
02b55e56 BT	324	static void __xdp_return(void data, struct xdp_mem_info mem, bool napi_direct,
02b55e56 BT	325	unsigned long handle)
8d5d8852	326	{
57d0a1c1 JDB	327	struct xdp_mem_allocator *xa;
	328	struct page *page;
	329
	330	switch (mem->type) {
	331	case MEM_TYPE_PAGE_POOL:
	332	rcu_read_lock();
	333	/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
	334	xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
	335	page = virt_to_head_page(data);
2539650f TM	336	if (xa) {
2539650f TM	337	napi_direct &= !xdp_return_frame_no_direct();
389ab7f0	338	page_pool_put_page(xa->page_pool, page, napi_direct);
2539650f	339	} else {
57d0a1c1	340	put_page(page);
2539650f	341	}
57d0a1c1 JDB	342	rcu_read_unlock();
	343	break;
	344	case MEM_TYPE_PAGE_SHARED:
8d5d8852	345	page_frag_free(data);
57d0a1c1 JDB	346	break;
	347	case MEM_TYPE_PAGE_ORDER0:
	348	page = virt_to_page(data); /* Assumes order0 page*/
8d5d8852	349	put_page(page);
57d0a1c1	350	break;
02b55e56 BT	351	case MEM_TYPE_ZERO_COPY:
	352	/* NB! Only valid from an xdp_buff! */
	353	rcu_read_lock();
	354	/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
	355	xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
eb91e4d4	356	xa->zc_alloc->free(xa->zc_alloc, handle);
02b55e56	357	rcu_read_unlock();
57d0a1c1 JDB	358	default:
	359	/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
	360	break;
8d5d8852 JDB	361	}
8d5d8852 JDB	362	}
c497176c BT	363
	364	void xdp_return_frame(struct xdp_frame *xdpf)
	365	{
02b55e56	366	__xdp_return(xdpf->data, &xdpf->mem, false, 0);
c497176c	367	}
8d5d8852	368	EXPORT_SYMBOL_GPL(xdp_return_frame);
c497176c	369
389ab7f0 JDB	370	void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
389ab7f0 JDB	371	{
02b55e56	372	__xdp_return(xdpf->data, &xdpf->mem, true, 0);
389ab7f0 JDB	373	}
	374	EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
	375
c497176c BT	376	void xdp_return_buff(struct xdp_buff *xdp)
c497176c BT	377	{
02b55e56	378	__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle);
c497176c BT	379	}
c497176c BT	380	EXPORT_SYMBOL_GPL(xdp_return_buff);
05296620 JK	381
	382	int xdp_attachment_query(struct xdp_attachment_info *info,
	383	struct netdev_bpf *bpf)
	384	{
	385	bpf->prog_id = info->prog ? info->prog->aux->id : 0;
	386	bpf->prog_flags = info->prog ? info->flags : 0;
	387	return 0;
	388	}
	389	EXPORT_SYMBOL_GPL(xdp_attachment_query);
	390
	391	bool xdp_attachment_flags_ok(struct xdp_attachment_info *info,
	392	struct netdev_bpf *bpf)
	393	{
	394	if (info->prog && (bpf->flags ^ info->flags) & XDP_FLAGS_MODES) {
	395	NL_SET_ERR_MSG(bpf->extack,
	396	"program loaded with different flags");
	397	return false;
	398	}
	399	return true;
	400	}
	401	EXPORT_SYMBOL_GPL(xdp_attachment_flags_ok);
	402
	403	void xdp_attachment_setup(struct xdp_attachment_info *info,
	404	struct netdev_bpf *bpf)
	405	{
	406	if (info->prog)
	407	bpf_prog_put(info->prog);
	408	info->prog = bpf->prog;
	409	info->flags = bpf->flags;
	410	}
	411	EXPORT_SYMBOL_GPL(xdp_attachment_setup);
b0d1beef BT	412
	413	struct xdp_frame xdp_convert_zc_to_xdp_frame(struct xdp_buff xdp)
	414	{
72962167	415	unsigned int metasize, totsize;
b0d1beef BT	416	void addr, data_to_copy;
	417	struct xdp_frame *xdpf;
	418	struct page *page;
	419
	420	/* Clone into a MEM_TYPE_PAGE_ORDER0 xdp_frame. */
	421	metasize = xdp_data_meta_unsupported(xdp) ? 0 :
	422	xdp->data - xdp->data_meta;
b0d1beef BT	423	totsize = xdp->data_end - xdp->data + metasize;
	424
	425	if (sizeof(*xdpf) + totsize > PAGE_SIZE)
	426	return NULL;
	427
	428	page = dev_alloc_page();
	429	if (!page)
	430	return NULL;
	431
	432	addr = page_to_virt(page);
	433	xdpf = addr;
	434	memset(xdpf, 0, sizeof(*xdpf));
	435
	436	addr += sizeof(*xdpf);
	437	data_to_copy = metasize ? xdp->data_meta : xdp->data;
	438	memcpy(addr, data_to_copy, totsize);
	439
	440	xdpf->data = addr + metasize;
	441	xdpf->len = totsize - metasize;
	442	xdpf->headroom = 0;
	443	xdpf->metasize = metasize;
	444	xdpf->mem.type = MEM_TYPE_PAGE_ORDER0;
	445
	446	xdp_return_buff(xdp);
	447	return xdpf;
	448	}
	449	EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame);