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Message-ID: <20250212092552.1779679-3-linyunsheng@huawei.com>
Date: Wed, 12 Feb 2025 17:25:49 +0800
From: Yunsheng Lin <linyunsheng@...wei.com>
To: <davem@...emloft.net>, <kuba@...nel.org>, <pabeni@...hat.com>
CC: <zhangkun09@...wei.com>, <liuyonglong@...wei.com>,
<fanghaiqing@...wei.com>, Yunsheng Lin <linyunsheng@...wei.com>, Robin Murphy
<robin.murphy@....com>, Alexander Duyck <alexander.duyck@...il.com>, IOMMU
<iommu@...ts.linux.dev>, Andrew Morton <akpm@...ux-foundation.org>, Eric
Dumazet <edumazet@...gle.com>, Simon Horman <horms@...nel.org>, Jesper
Dangaard Brouer <hawk@...nel.org>, Ilias Apalodimas
<ilias.apalodimas@...aro.org>, <linux-mm@...ck.org>,
<linux-kernel@...r.kernel.org>, <netdev@...r.kernel.org>
Subject: [PATCH net-next v9 2/4] page_pool: fix IOMMU crash when driver has already unbound
Networking driver with page_pool support may hand over page
still with dma mapping to network stack and try to reuse that
page after network stack is done with it and passes it back
to page_pool to avoid the penalty of dma mapping/unmapping.
With all the caching in the network stack, some pages may be
held in the network stack without returning to the page_pool
soon enough, and with VF disable causing the driver unbound,
the page_pool does not stop the driver from doing it's
unbounding work, instead page_pool uses workqueue to check
if there is some pages coming back from the network stack
periodically, if there is any, it will do the dma unmmapping
related cleanup work.
As mentioned in [1], attempting DMA unmaps after the driver
has already unbound may leak resources or at worst corrupt
memory. Fundamentally, the page pool code cannot allow DMA
mappings to outlive the driver they belong to.
Currently it seems there are at least two cases that the page
is not released fast enough causing dma unmmapping done after
driver has already unbound:
1. ipv4 packet defragmentation timeout: this seems to cause
delay up to 30 secs.
2. skb_defer_free_flush(): this may cause infinite delay if
there is no triggering for net_rx_action().
In order not to call DMA APIs to do DMA unmmapping after driver
has already unbound and stall the unloading of the networking
driver, use some pre-allocated item blocks to record inflight
pages including the ones which are handed over to network stack,
so the page_pool can do the DMA unmmapping for those pages when
page_pool_destroy() is called. As the pre-allocated item blocks
need to be large enough to avoid performance degradation, add a
'item_fast_empty' stat to indicate the unavailability of the
pre-allocated item blocks.
By using the 'struct page_pool_item' referenced by page->pp_item,
page_pool is not only able to keep track of the inflight page to
do dma unmmaping if some pages are still handled in networking
stack when page_pool_destroy() is called, and networking stack is
also able to find the page_pool owning the page when returning
pages back into page_pool:
1. When a page is added to the page_pool, an item is deleted from
pool->hold_items and set the 'pp_netmem' pointing to that page
and set item->state and item->pp_netmem accordingly in order to
keep track of that page, refill from pool->release_items when
pool->hold_items is empty or use the item from pool->slow_items
when fast items run out.
2. When a page is released from the page_pool, it is able to tell
which page_pool this page belongs to by masking off the lower
bits of the pointer to page_pool_item *item, as the 'struct
page_pool_item_block' is stored in the top of a struct page. And
after clearing the pp_item->state', the item for the released page
is added back to pool->release_items so that it can be reused for
new pages or just free it when it is from the pool->slow_items.
3. When page_pool_destroy() is called, item->state is used to tell if
a specific item is being used/dma mapped or not by scanning all the
item blocks in pool->item_blocks, then item->netmem can be used to
do the dma unmmaping if the corresponding inflight page is dma
mapped.
The overhead of tracking of inflight pages is about 10ns~20ns,
which causes about 10% performance degradation for the test case
of time_bench_page_pool03_slow() in [2].
Note, the devmem patchset seems to make the bug harder to fix,
and may make backporting harder too. As there is no actual user
for the devmem and the fixing for devmem is unclear for now,
this patch does not consider fixing the case for devmem yet.
1. https://lore.kernel.org/lkml/8067f204-1380-4d37-8ffd-007fc6f26738@kernel.org/T/
2. https://github.com/netoptimizer/prototype-kernel
CC: Robin Murphy <robin.murphy@....com>
CC: Alexander Duyck <alexander.duyck@...il.com>
CC: IOMMU <iommu@...ts.linux.dev>
Fixes: f71fec47c2df ("page_pool: make sure struct device is stable")
Signed-off-by: Yunsheng Lin <linyunsheng@...wei.com>
Tested-by: Yonglong Liu <liuyonglong@...wei.com>
---
include/linux/mm_types.h | 2 +-
include/linux/skbuff.h | 1 +
include/net/netmem.h | 31 ++-
include/net/page_pool/helpers.h | 12 +-
include/net/page_pool/memory_provider.h | 2 +-
include/net/page_pool/types.h | 36 ++-
net/core/devmem.c | 6 +-
net/core/netmem_priv.h | 5 +-
net/core/page_pool.c | 289 +++++++++++++++++++++---
net/core/page_pool_priv.h | 10 +-
10 files changed, 341 insertions(+), 53 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 6b27db7f9496..c0353866a329 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -120,7 +120,7 @@ struct page {
* page_pool allocated pages.
*/
unsigned long pp_magic;
- struct page_pool *pp;
+ struct page_pool_item *pp_item;
unsigned long _pp_mapping_pad;
unsigned long dma_addr;
atomic_long_t pp_ref_count;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bb2b751d274a..a47a23527724 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -39,6 +39,7 @@
#include <net/net_debug.h>
#include <net/dropreason-core.h>
#include <net/netmem.h>
+#include <net/page_pool/types.h>
/**
* DOC: skb checksums
diff --git a/include/net/netmem.h b/include/net/netmem.h
index c61d5b21e7b4..a75fdb60ac3d 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -23,7 +23,7 @@ DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers);
struct net_iov {
unsigned long __unused_padding;
unsigned long pp_magic;
- struct page_pool *pp;
+ struct page_pool_item *pp_item;
struct net_iov_area *owner;
unsigned long dma_addr;
atomic_long_t pp_ref_count;
@@ -42,7 +42,7 @@ struct net_iov_area {
*
* struct {
* unsigned long pp_magic;
- * struct page_pool *pp;
+ * struct page_pool_item *pp_item;
* unsigned long _pp_mapping_pad;
* unsigned long dma_addr;
* atomic_long_t pp_ref_count;
@@ -58,7 +58,7 @@ struct net_iov_area {
static_assert(offsetof(struct page, pg) == \
offsetof(struct net_iov, iov))
NET_IOV_ASSERT_OFFSET(pp_magic, pp_magic);
-NET_IOV_ASSERT_OFFSET(pp, pp);
+NET_IOV_ASSERT_OFFSET(pp_item, pp_item);
NET_IOV_ASSERT_OFFSET(dma_addr, dma_addr);
NET_IOV_ASSERT_OFFSET(pp_ref_count, pp_ref_count);
#undef NET_IOV_ASSERT_OFFSET
@@ -86,6 +86,11 @@ static inline unsigned int net_iov_idx(const struct net_iov *niov)
*/
typedef unsigned long __bitwise netmem_ref;
+/* Mirror page_pool_item_block, see include/net/page_pool/types.h */
+struct netmem_item_block {
+ struct page_pool *pp;
+};
+
static inline bool netmem_is_net_iov(const netmem_ref netmem)
{
return (__force unsigned long)netmem & NET_IOV;
@@ -173,6 +178,15 @@ static inline struct net_iov *__netmem_clear_lsb(netmem_ref netmem)
return (struct net_iov *)((__force unsigned long)netmem & ~NET_IOV);
}
+static inline struct page_pool *
+netmem_pp_item_to_pp(struct page_pool_item *item)
+{
+ struct netmem_item_block *block;
+
+ block = (struct netmem_item_block *)((unsigned long)item & PAGE_MASK);
+ return block->pp;
+}
+
/**
* __netmem_get_pp - unsafely get pointer to the &page_pool backing @netmem
* @netmem: netmem reference to get the pointer from
@@ -186,12 +200,19 @@ static inline struct net_iov *__netmem_clear_lsb(netmem_ref netmem)
*/
static inline struct page_pool *__netmem_get_pp(netmem_ref netmem)
{
- return __netmem_to_page(netmem)->pp;
+ return netmem_pp_item_to_pp(__netmem_to_page(netmem)->pp_item);
+}
+
+static inline struct page_pool_item *netmem_get_pp_item(netmem_ref netmem)
+{
+ return __netmem_clear_lsb(netmem)->pp_item;
}
static inline struct page_pool *netmem_get_pp(netmem_ref netmem)
{
- return __netmem_clear_lsb(netmem)->pp;
+ struct page_pool_item *item = netmem_get_pp_item(netmem);
+
+ return netmem_pp_item_to_pp(item);
}
static inline atomic_long_t *netmem_get_pp_ref_count_ref(netmem_ref netmem)
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index ab91911af215..ac8c71841be5 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -83,9 +83,19 @@ static inline u64 *page_pool_ethtool_stats_get(u64 *data, const void *stats)
}
#endif
+static inline struct page_pool_item_block *
+page_pool_item_to_block(struct page_pool_item *item)
+{
+ return (struct page_pool_item_block *)((unsigned long)item & PAGE_MASK);
+}
+
static inline struct page_pool *page_pool_get_pp(struct page *page)
{
- return page->pp;
+ /* The size of item_block is always PAGE_SIZE, the address of item_block
+ * for a specific item can be calculated using 'item & PAGE_MASK', so
+ * that we can find the page_pool object it belongs to.
+ */
+ return page_pool_item_to_block(page->pp_item)->pp;
}
/**
diff --git a/include/net/page_pool/memory_provider.h b/include/net/page_pool/memory_provider.h
index b3e665897767..bcc72f340db9 100644
--- a/include/net/page_pool/memory_provider.h
+++ b/include/net/page_pool/memory_provider.h
@@ -20,7 +20,7 @@ struct memory_provider_ops {
bool net_mp_niov_set_dma_addr(struct net_iov *niov, dma_addr_t addr);
void net_mp_niov_set_page_pool(struct page_pool *pool, struct net_iov *niov);
-void net_mp_niov_clear_page_pool(struct net_iov *niov);
+void net_mp_niov_clear_page_pool(struct page_pool *pool, struct net_iov *niov);
int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
struct pp_memory_provider_params *p);
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 36eb57d73abc..c131e2725e9a 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -102,6 +102,7 @@ struct page_pool_params {
* @refill: an allocation which triggered a refill of the cache
* @waive: pages obtained from the ptr ring that cannot be added to
* the cache due to a NUMA mismatch
+ * @item_fast_empty: pre-allocated item cache is empty
*/
struct page_pool_alloc_stats {
u64 fast;
@@ -110,6 +111,7 @@ struct page_pool_alloc_stats {
u64 empty;
u64 refill;
u64 waive;
+ u64 item_fast_empty;
};
/**
@@ -142,6 +144,30 @@ struct page_pool_stats {
};
#endif
+struct page_pool_item {
+ unsigned long state;
+
+ union {
+ netmem_ref pp_netmem;
+ struct llist_node lentry;
+ };
+};
+
+/* The size of item_block is always PAGE_SIZE, so that the address of item_block
+ * for a specific item can be calculated using 'item & PAGE_MASK'
+ */
+struct page_pool_item_block {
+ struct page_pool *pp;
+ struct list_head list;
+ struct page_pool_item items[];
+};
+
+/* Ensure the offset of 'pp' field for both 'page_pool_item_block' and
+ * 'netmem_item_block' are the same.
+ */
+static_assert(offsetof(struct page_pool_item_block, pp) == \
+ offsetof(struct netmem_item_block, pp));
+
/* The whole frag API block must stay within one cacheline. On 32-bit systems,
* sizeof(long) == sizeof(int), so that the block size is ``3 * sizeof(long)``.
* On 64-bit systems, the actual size is ``2 * sizeof(long) + sizeof(int)``.
@@ -164,6 +190,7 @@ struct page_pool {
int cpuid;
u32 pages_state_hold_cnt;
+ struct llist_head hold_items;
bool has_init_callback:1; /* slow::init_callback is set */
bool dma_map:1; /* Perform DMA mapping */
@@ -227,13 +254,20 @@ struct page_pool {
#endif
atomic_t pages_state_release_cnt;
+ /* Synchronizate dma unmapping operation in page_pool_return_page() with
+ * page_pool_destory() when destroy_cnt is non-zero.
+ */
+ spinlock_t item_lock;
+ struct list_head item_blocks;
+ struct llist_head release_items;
+
/* A page_pool is strictly tied to a single RX-queue being
* protected by NAPI, due to above pp_alloc_cache. This
* refcnt serves purpose is to simplify drivers error handling.
*/
refcount_t user_cnt;
- u64 destroy_cnt;
+ unsigned long destroy_cnt;
/* Slow/Control-path information follows */
struct page_pool_params_slow slow;
diff --git a/net/core/devmem.c b/net/core/devmem.c
index 7c6e0b5b6acb..d0ddbf2f7a6a 100644
--- a/net/core/devmem.c
+++ b/net/core/devmem.c
@@ -32,7 +32,7 @@ static const struct memory_provider_ops dmabuf_devmem_ops;
bool net_is_devmem_iov(struct net_iov *niov)
{
- return niov->pp->mp_ops == &dmabuf_devmem_ops;
+ return netmem_pp_item_to_pp(niov->pp_item)->mp_ops == &dmabuf_devmem_ops;
}
static void net_devmem_dmabuf_free_chunk_owner(struct gen_pool *genpool,
@@ -95,7 +95,7 @@ net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding)
niov = &owner->area.niovs[index];
niov->pp_magic = 0;
- niov->pp = NULL;
+ niov->pp_item = NULL;
atomic_long_set(&niov->pp_ref_count, 0);
return niov;
@@ -383,7 +383,7 @@ bool mp_dmabuf_devmem_release_page(struct page_pool *pool, netmem_ref netmem)
if (WARN_ON_ONCE(refcount != 1))
return false;
- page_pool_clear_pp_info(netmem);
+ page_pool_clear_pp_info(pool, netmem);
net_devmem_free_dmabuf(netmem_to_net_iov(netmem));
diff --git a/net/core/netmem_priv.h b/net/core/netmem_priv.h
index 7eadb8393e00..3173f6070cf7 100644
--- a/net/core/netmem_priv.h
+++ b/net/core/netmem_priv.h
@@ -18,9 +18,10 @@ static inline void netmem_clear_pp_magic(netmem_ref netmem)
__netmem_clear_lsb(netmem)->pp_magic = 0;
}
-static inline void netmem_set_pp(netmem_ref netmem, struct page_pool *pool)
+static inline void netmem_set_pp_item(netmem_ref netmem,
+ struct page_pool_item *item)
{
- __netmem_clear_lsb(netmem)->pp = pool;
+ __netmem_clear_lsb(netmem)->pp_item = item;
}
static inline void netmem_set_dma_addr(netmem_ref netmem,
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 1c6fec08bc43..508dd51b1a9a 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -63,6 +63,7 @@ static const char pp_stats[][ETH_GSTRING_LEN] = {
"rx_pp_alloc_empty",
"rx_pp_alloc_refill",
"rx_pp_alloc_waive",
+ "rx_pp_alloc_item_fast_empty",
"rx_pp_recycle_cached",
"rx_pp_recycle_cache_full",
"rx_pp_recycle_ring",
@@ -96,6 +97,7 @@ bool page_pool_get_stats(const struct page_pool *pool,
stats->alloc_stats.empty += pool->alloc_stats.empty;
stats->alloc_stats.refill += pool->alloc_stats.refill;
stats->alloc_stats.waive += pool->alloc_stats.waive;
+ stats->alloc_stats.item_fast_empty += pool->alloc_stats.item_fast_empty;
for_each_possible_cpu(cpu) {
const struct page_pool_recycle_stats *pcpu =
@@ -141,6 +143,7 @@ u64 *page_pool_ethtool_stats_get(u64 *data, const void *stats)
*data++ = pool_stats->alloc_stats.empty;
*data++ = pool_stats->alloc_stats.refill;
*data++ = pool_stats->alloc_stats.waive;
+ *data++ = pool_stats->alloc_stats.item_fast_empty;
*data++ = pool_stats->recycle_stats.cached;
*data++ = pool_stats->recycle_stats.cache_full;
*data++ = pool_stats->recycle_stats.ring;
@@ -333,6 +336,214 @@ static void page_pool_uninit(struct page_pool *pool)
#endif
}
+#define PAGE_POOL_ITEM_USED 0
+#define PAGE_POOL_ITEM_MAPPED 1
+
+#define ITEMS_PER_PAGE ((PAGE_SIZE - \
+ offsetof(struct page_pool_item_block, items)) / \
+ sizeof(struct page_pool_item))
+
+#if defined(CONFIG_DEBUG_NET)
+#define page_pool_item_set_used(item) \
+ __set_bit(PAGE_POOL_ITEM_USED, &(item)->state)
+
+#define page_pool_item_clear_used(item) \
+ __clear_bit(PAGE_POOL_ITEM_USED, &(item)->state)
+
+#define page_pool_item_is_used(item) \
+ test_bit(PAGE_POOL_ITEM_USED, &(item)->state)
+#else
+#define page_pool_item_set_used(item)
+#define page_pool_item_clear_used(item)
+#define page_pool_item_is_used(item) false
+#endif
+
+#define page_pool_item_set_mapped(item) \
+ __set_bit(PAGE_POOL_ITEM_MAPPED, &(item)->state)
+
+/* Only clear_mapped and is_mapped need to be atomic as they can be
+ * called concurrently.
+ */
+#define page_pool_item_clear_mapped(item) \
+ clear_bit(PAGE_POOL_ITEM_MAPPED, &(item)->state)
+
+#define page_pool_item_is_mapped(item) \
+ test_bit(PAGE_POOL_ITEM_MAPPED, &(item)->state)
+
+static __always_inline void __page_pool_release_page_dma(struct page_pool *pool,
+ netmem_ref netmem)
+{
+ struct page_pool_item *item;
+ bool destroyed;
+ dma_addr_t dma;
+
+ if (!pool->dma_map)
+ /* Always account for inflight pages, even if we didn't
+ * map them
+ */
+ return;
+
+ /* Paired with the rcu synchronization in page_pool_destroy() to ensure
+ * synchronize dma unmapping operation between page_pool_destroy() and
+ * page being released to page_pool from networking by using a spinlock
+ * when pool->destroy_cnt is non-zero.
+ */
+ rcu_read_lock();
+ destroyed = !!READ_ONCE(pool->destroy_cnt);
+ item = netmem_get_pp_item(netmem);
+
+ /* To catch the case of item state not setting up correctly as dma
+ * unmapping is always needed when page_pool_destory() is not called
+ * yet.
+ */
+ DEBUG_NET_WARN_ON_ONCE(!destroyed &&
+ !page_pool_item_is_mapped(item));
+ if (unlikely(destroyed)) {
+ spin_lock_bh(&pool->item_lock);
+
+ if (!page_pool_item_is_mapped(item))
+ goto out_unlock;
+ }
+
+ dma = page_pool_get_dma_addr_netmem(netmem);
+
+ /* When page is unmapped, it cannot be returned to our pool */
+ dma_unmap_page_attrs(pool->p.dev, dma,
+ PAGE_SIZE << pool->p.order, pool->p.dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
+ page_pool_set_dma_addr_netmem(netmem, 0);
+ page_pool_item_clear_mapped(item);
+
+out_unlock:
+ if (unlikely(destroyed))
+ spin_unlock_bh(&pool->item_lock);
+
+ rcu_read_unlock();
+}
+
+static void page_pool_item_uninit(struct page_pool *pool)
+{
+ while (!list_empty(&pool->item_blocks)) {
+ struct page_pool_item_block *block;
+
+ block = list_first_entry(&pool->item_blocks,
+ struct page_pool_item_block,
+ list);
+ list_del(&block->list);
+ put_page(virt_to_page(block));
+ }
+}
+
+static int page_pool_item_init(struct page_pool *pool)
+{
+#define PAGE_POOL_MIN_INFLIGHT_ITEMS 512
+ struct page_pool_item_block *block;
+ int item_cnt;
+
+ INIT_LIST_HEAD(&pool->item_blocks);
+ spin_lock_init(&pool->item_lock);
+ init_llist_head(&pool->hold_items);
+ init_llist_head(&pool->release_items);
+
+ item_cnt = pool->p.pool_size * 2 + PP_ALLOC_CACHE_SIZE +
+ PAGE_POOL_MIN_INFLIGHT_ITEMS;
+ for (; item_cnt > 0; item_cnt -= ITEMS_PER_PAGE) {
+ struct page *page;
+ unsigned int i;
+
+ page = alloc_pages_node(pool->p.nid, GFP_KERNEL | __GFP_ZERO,
+ 0);
+ if (!page) {
+ page_pool_item_uninit(pool);
+ return -ENOMEM;
+ }
+
+ block = page_address(page);
+ block->pp = pool;
+ list_add(&block->list, &pool->item_blocks);
+
+ for (i = 0; i < ITEMS_PER_PAGE; i++)
+ __llist_add(&block->items[i].lentry, &pool->hold_items);
+ }
+
+ return 0;
+}
+
+static void page_pool_item_unmap(struct page_pool *pool)
+{
+ struct page_pool_item_block *block;
+
+ if (!pool->dma_map || pool->mp_priv)
+ return;
+
+ /* Paired with rcu read lock in __page_pool_release_page_dma() to
+ * synchronize dma unmapping operations.
+ */
+ synchronize_net();
+
+ list_for_each_entry(block, &pool->item_blocks, list) {
+ struct page_pool_item *items = block->items;
+ int i;
+
+ for (i = 0; i < ITEMS_PER_PAGE; i++) {
+ struct page_pool_item *item = &items[i];
+
+ if (!page_pool_item_is_mapped(item))
+ continue;
+
+ __page_pool_release_page_dma(pool, item->pp_netmem);
+ }
+ }
+}
+
+static struct page_pool_item *page_pool_fast_item_alloc(struct page_pool *pool)
+{
+ struct llist_node *first = pool->hold_items.first;
+
+ if (unlikely(!first)) {
+ first = llist_del_all(&pool->release_items);
+
+ if (unlikely(!first)) {
+ alloc_stat_inc(pool, item_fast_empty);
+ return NULL;
+ }
+ }
+
+ pool->hold_items.first = first->next;
+ return llist_entry(first, struct page_pool_item, lentry);
+}
+
+static bool page_pool_set_item_info(struct page_pool *pool, netmem_ref netmem)
+{
+ struct page_pool_item *item = page_pool_fast_item_alloc(pool);
+
+ if (likely(item)) {
+ item->pp_netmem = netmem;
+ page_pool_item_set_used(item);
+ netmem_set_pp_item(netmem, item);
+ }
+
+ return !!item;
+}
+
+static void page_pool_fast_item_free(struct page_pool *pool,
+ struct page_pool_item *item)
+{
+ llist_add(&item->lentry, &pool->release_items);
+}
+
+static void page_pool_clear_item_info(struct page_pool *pool, netmem_ref netmem)
+{
+ struct page_pool_item *item = netmem_get_pp_item(netmem);
+
+ DEBUG_NET_WARN_ON_ONCE(item->pp_netmem != netmem);
+ DEBUG_NET_WARN_ON_ONCE(page_pool_item_is_mapped(item));
+ DEBUG_NET_WARN_ON_ONCE(!page_pool_item_is_used(item));
+ page_pool_item_clear_used(item);
+ netmem_set_pp_item(netmem, NULL);
+ page_pool_fast_item_free(pool, item);
+}
+
/**
* page_pool_create_percpu() - create a page pool for a given cpu.
* @params: parameters, see struct page_pool_params
@@ -352,12 +563,18 @@ page_pool_create_percpu(const struct page_pool_params *params, int cpuid)
if (err < 0)
goto err_free;
- err = page_pool_list(pool);
+ err = page_pool_item_init(pool);
if (err)
goto err_uninit;
+ err = page_pool_list(pool);
+ if (err)
+ goto err_item_uninit;
+
return pool;
+err_item_uninit:
+ page_pool_item_uninit(pool);
err_uninit:
page_pool_uninit(pool);
err_free:
@@ -472,6 +689,7 @@ page_pool_dma_sync_for_device(const struct page_pool *pool,
static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem)
{
+ struct page_pool_item *item;
dma_addr_t dma;
/* Setup DMA mapping: use 'struct page' area for storing DMA-addr
@@ -489,6 +707,9 @@ static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem)
if (page_pool_set_dma_addr_netmem(netmem, dma))
goto unmap_failed;
+ item = netmem_get_pp_item(netmem);
+ DEBUG_NET_WARN_ON_ONCE(page_pool_item_is_mapped(item));
+ page_pool_item_set_mapped(item);
page_pool_dma_sync_for_device(pool, netmem, pool->p.max_len);
return true;
@@ -511,19 +732,24 @@ static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
if (unlikely(!page))
return NULL;
- if (pool->dma_map && unlikely(!page_pool_dma_map(pool, page_to_netmem(page)))) {
- put_page(page);
- return NULL;
- }
+ if (unlikely(!page_pool_set_pp_info(pool, page_to_netmem(page))))
+ goto err_alloc;
+
+ if (pool->dma_map && unlikely(!page_pool_dma_map(pool, page_to_netmem(page))))
+ goto err_set_info;
alloc_stat_inc(pool, slow_high_order);
- page_pool_set_pp_info(pool, page_to_netmem(page));
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
trace_page_pool_state_hold(pool, page_to_netmem(page),
pool->pages_state_hold_cnt);
return page;
+err_set_info:
+ page_pool_clear_pp_info(pool, page_to_netmem(page));
+err_alloc:
+ put_page(page);
+ return NULL;
}
/* slow path */
@@ -557,12 +783,18 @@ static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
*/
for (i = 0; i < nr_pages; i++) {
netmem = pool->alloc.cache[i];
+
+ if (unlikely(!page_pool_set_pp_info(pool, netmem))) {
+ put_page(netmem_to_page(netmem));
+ continue;
+ }
+
if (dma_map && unlikely(!page_pool_dma_map(pool, netmem))) {
+ page_pool_clear_pp_info(pool, netmem);
put_page(netmem_to_page(netmem));
continue;
}
- page_pool_set_pp_info(pool, netmem);
pool->alloc.cache[pool->alloc.count++] = netmem;
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
@@ -634,9 +866,11 @@ s32 page_pool_inflight(const struct page_pool *pool, bool strict)
return inflight;
}
-void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem)
+bool page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem)
{
- netmem_set_pp(netmem, pool);
+ if (unlikely(!page_pool_set_item_info(pool, netmem)))
+ return false;
+
netmem_or_pp_magic(netmem, PP_SIGNATURE);
/* Ensuring all pages have been split into one fragment initially:
@@ -648,32 +882,14 @@ void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem)
page_pool_fragment_netmem(netmem, 1);
if (pool->has_init_callback)
pool->slow.init_callback(netmem, pool->slow.init_arg);
-}
-void page_pool_clear_pp_info(netmem_ref netmem)
-{
- netmem_clear_pp_magic(netmem);
- netmem_set_pp(netmem, NULL);
+ return true;
}
-static __always_inline void __page_pool_release_page_dma(struct page_pool *pool,
- netmem_ref netmem)
+void page_pool_clear_pp_info(struct page_pool *pool, netmem_ref netmem)
{
- dma_addr_t dma;
-
- if (!pool->dma_map)
- /* Always account for inflight pages, even if we didn't
- * map them
- */
- return;
-
- dma = page_pool_get_dma_addr_netmem(netmem);
-
- /* When page is unmapped, it cannot be returned to our pool */
- dma_unmap_page_attrs(pool->p.dev, dma,
- PAGE_SIZE << pool->p.order, pool->p.dma_dir,
- DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
- page_pool_set_dma_addr_netmem(netmem, 0);
+ netmem_clear_pp_magic(netmem);
+ page_pool_clear_item_info(pool, netmem);
}
/* Disconnects a page (from a page_pool). API users can have a need
@@ -699,7 +915,7 @@ void page_pool_return_page(struct page_pool *pool, netmem_ref netmem)
trace_page_pool_state_release(pool, netmem, count);
if (put) {
- page_pool_clear_pp_info(netmem);
+ page_pool_clear_pp_info(pool, netmem);
put_page(netmem_to_page(netmem));
}
/* An optimization would be to call __free_pages(page, pool->p.order)
@@ -1053,6 +1269,7 @@ static void __page_pool_destroy(struct page_pool *pool)
if (pool->disconnect)
pool->disconnect(pool);
+ page_pool_item_uninit(pool);
page_pool_unlist(pool);
page_pool_uninit(pool);
@@ -1084,7 +1301,7 @@ static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
static void page_pool_scrub(struct page_pool *pool)
{
page_pool_empty_alloc_cache_once(pool);
- pool->destroy_cnt++;
+ WRITE_ONCE(pool->destroy_cnt, pool->destroy_cnt + 1);
/* No more consumers should exist, but producers could still
* be in-flight.
@@ -1170,6 +1387,8 @@ void page_pool_destroy(struct page_pool *pool)
if (!page_pool_release(pool))
return;
+ page_pool_item_unmap(pool);
+
page_pool_detached(pool);
pool->defer_start = jiffies;
pool->defer_warn = jiffies + DEFER_WARN_INTERVAL;
@@ -1216,9 +1435,9 @@ void net_mp_niov_set_page_pool(struct page_pool *pool, struct net_iov *niov)
/* Disassociate a niov from a page pool. Should only be used in the
* ->release_netmem() path.
*/
-void net_mp_niov_clear_page_pool(struct net_iov *niov)
+void net_mp_niov_clear_page_pool(struct page_pool *pool, struct net_iov *niov)
{
netmem_ref netmem = net_iov_to_netmem(niov);
- page_pool_clear_pp_info(netmem);
+ page_pool_clear_pp_info(pool, netmem);
}
diff --git a/net/core/page_pool_priv.h b/net/core/page_pool_priv.h
index 2fb06d5f6d55..a5df5ab14ead 100644
--- a/net/core/page_pool_priv.h
+++ b/net/core/page_pool_priv.h
@@ -38,16 +38,18 @@ static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
}
#if defined(CONFIG_PAGE_POOL)
-void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem);
-void page_pool_clear_pp_info(netmem_ref netmem);
+bool page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem);
+void page_pool_clear_pp_info(struct page_pool *pool, netmem_ref netmem);
int page_pool_check_memory_provider(struct net_device *dev,
struct netdev_rx_queue *rxq);
#else
-static inline void page_pool_set_pp_info(struct page_pool *pool,
+static inline bool page_pool_set_pp_info(struct page_pool *pool,
netmem_ref netmem)
{
+ return true;
}
-static inline void page_pool_clear_pp_info(netmem_ref netmem)
+static inline void page_pool_clear_pp_info(struct page_pool *pool,
+ netmem_ref netmem)
{
}
static inline int page_pool_check_memory_provider(struct net_device *dev,
--
2.33.0
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