[RFC PATCH net-next v7 06/14] page_pool: convert to use netmem

From: Mina Almasry
Date: Tue Mar 26 2024 - 18:54:31 EST

Abstrace the memory type from the page_pool so we can later add support
for new memory types. Convert the page_pool to use the new netmem type
abstraction, rather than use struct page directly.

As of this patch the netmem type is a no-op abstraction: it's always a
struct page underneath. All the page pool internals are converted to
use struct netmem instead of struct page, and the page pool now exports
2 APIs:

1. The existing struct page API.
2. The new struct netmem API.

Keeping the existing API is transitional; we do not want to refactor all
the current drivers using the page pool at once.

The netmem abstraction is currently a no-op. The page_pool uses
page_to_netmem() to convert allocated pages to netmem, and uses
netmem_to_page() to convert the netmem back to pages to pass to mm APIs,

Follow up patches to this series add non-paged netmem support to the
page_pool. This change is factored out on its own to limit the code
churn to this 1 patch, for ease of code review.

Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>

---

v6:

- Rebased on top of the merged netmem_ref type.

To: linux-mm@xxxxxxxxx
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>

---
include/linux/skbuff.h | 4 +-
include/net/netmem.h | 15 ++
include/net/page_pool/helpers.h | 122 +++++++++----
include/net/page_pool/types.h | 17 +-
include/trace/events/page_pool.h | 29 +--
net/bpf/test_run.c | 5 +-
net/core/page_pool.c | 303 +++++++++++++++++--------------
net/core/skbuff.c | 7 +-
8 files changed, 302 insertions(+), 200 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b945af8a6208..78659c8efa4e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3521,7 +3521,7 @@ int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
unsigned int headroom);
int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
struct bpf_prog *prog);
-bool napi_pp_put_page(struct page *page, bool napi_safe);
+bool napi_pp_put_page(netmem_ref netmem, bool napi_safe);

static inline void
skb_page_unref(const struct sk_buff *skb, struct page *page, bool napi_safe)
@@ -3539,7 +3539,7 @@ napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe)
struct page *page = skb_frag_page(frag);

#ifdef CONFIG_PAGE_POOL
- if (recycle && napi_pp_put_page(page, napi_safe))
+ if (recycle && napi_pp_put_page(page_to_netmem(page), napi_safe))
return;
#endif
put_page(page);
diff --git a/include/net/netmem.h b/include/net/netmem.h
index ca17ea1d33f8..21f53b29e5fe 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -88,4 +88,19 @@ static inline netmem_ref page_to_netmem(struct page *page)
return (__force netmem_ref)page;
}

+static inline int netmem_ref_count(netmem_ref netmem)
+{
+ return page_ref_count(netmem_to_page(netmem));
+}
+
+static inline unsigned long netmem_to_pfn(netmem_ref netmem)
+{
+ return page_to_pfn(netmem_to_page(netmem));
+}
+
+static inline netmem_ref netmem_compound_head(netmem_ref netmem)
+{
+ return page_to_netmem(compound_head(netmem_to_page(netmem)));
+}
+
#endif /* _NET_NETMEM_H */
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index 1d397c1a0043..61814f91a458 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -53,6 +53,8 @@
#define _NET_PAGE_POOL_HELPERS_H

#include <net/page_pool/types.h>
+#include <net/net_debug.h>
+#include <net/netmem.h>

#ifdef CONFIG_PAGE_POOL_STATS
/* Deprecated driver-facing API, use netlink instead */
@@ -101,7 +103,7 @@ static inline struct page *page_pool_dev_alloc_pages(struct page_pool *pool)
* Get a page fragment from the page allocator or page_pool caches.
*
* Return:
- * Return allocated page fragment, otherwise return NULL.
+ * Return allocated page fragment, otherwise return 0.
*/
static inline struct page *page_pool_dev_alloc_frag(struct page_pool *pool,
unsigned int *offset,
@@ -112,22 +114,22 @@ static inline struct page *page_pool_dev_alloc_frag(struct page_pool *pool,
return page_pool_alloc_frag(pool, offset, size, gfp);
}

-static inline struct page *page_pool_alloc(struct page_pool *pool,
- unsigned int *offset,
- unsigned int *size, gfp_t gfp)
+static inline netmem_ref page_pool_alloc(struct page_pool *pool,
+ unsigned int *offset,
+ unsigned int *size, gfp_t gfp)
{
unsigned int max_size = PAGE_SIZE << pool->p.order;
- struct page *page;
+ netmem_ref netmem;

if ((*size << 1) > max_size) {
*size = max_size;
*offset = 0;
- return page_pool_alloc_pages(pool, gfp);
+ return page_pool_alloc_netmem(pool, gfp);
}

- page = page_pool_alloc_frag(pool, offset, *size, gfp);
- if (unlikely(!page))
- return NULL;
+ netmem = page_pool_alloc_frag_netmem(pool, offset, *size, gfp);
+ if (unlikely(!netmem))
+ return 0;

/* There is very likely not enough space for another fragment, so append
* the remaining size to the current fragment to avoid truesize
@@ -138,7 +140,7 @@ static inline struct page *page_pool_alloc(struct page_pool *pool,
pool->frag_offset = max_size;
}

- return page;
+ return netmem;
}

/**
@@ -152,7 +154,7 @@ static inline struct page *page_pool_alloc(struct page_pool *pool,
* utilization and performance penalty.
*
* Return:
- * Return allocated page or page fragment, otherwise return NULL.
+ * Return allocated page or page fragment, otherwise return 0.
*/
static inline struct page *page_pool_dev_alloc(struct page_pool *pool,
unsigned int *offset,
@@ -160,7 +162,7 @@ static inline struct page *page_pool_dev_alloc(struct page_pool *pool,
{
gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN);

- return page_pool_alloc(pool, offset, size, gfp);
+ return netmem_to_page(page_pool_alloc(pool, offset, size, gfp));
}

static inline void *page_pool_alloc_va(struct page_pool *pool,
@@ -170,9 +172,10 @@ static inline void *page_pool_alloc_va(struct page_pool *pool,
struct page *page;

/* Mask off __GFP_HIGHMEM to ensure we can use page_address() */
- page = page_pool_alloc(pool, &offset, size, gfp & ~__GFP_HIGHMEM);
+ page = netmem_to_page(
+ page_pool_alloc(pool, &offset, size, gfp & ~__GFP_HIGHMEM));
if (unlikely(!page))
- return NULL;
+ return 0;

return page_address(page) + offset;
}
@@ -187,7 +190,7 @@ static inline void *page_pool_alloc_va(struct page_pool *pool,
* it returns va of the allocated page or page fragment.
*
* Return:
- * Return the va for the allocated page or page fragment, otherwise return NULL.
+ * Return the va for the allocated page or page fragment, otherwise return 0.
*/
static inline void *page_pool_dev_alloc_va(struct page_pool *pool,
unsigned int *size)
@@ -210,6 +213,11 @@ inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
return pool->p.dma_dir;
}

+static inline void page_pool_fragment_netmem(netmem_ref netmem, long nr)
+{
+ atomic_long_set(&netmem_to_page(netmem)->pp_ref_count, nr);
+}
+
/**
* page_pool_fragment_page() - split a fresh page into fragments
* @page: page to split
@@ -230,11 +238,12 @@ inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
*/
static inline void page_pool_fragment_page(struct page *page, long nr)
{
- atomic_long_set(&page->pp_ref_count, nr);
+ page_pool_fragment_netmem(page_to_netmem(page), nr);
}

-static inline long page_pool_unref_page(struct page *page, long nr)
+static inline long page_pool_unref_netmem(netmem_ref netmem, long nr)
{
+ struct page *page = netmem_to_page(netmem);
long ret;

/* If nr == pp_ref_count then we have cleared all remaining
@@ -277,15 +286,41 @@ static inline long page_pool_unref_page(struct page *page, long nr)
return ret;
}

+static inline long page_pool_unref_page(struct page *page, long nr)
+{
+ return page_pool_unref_netmem(page_to_netmem(page), nr);
+}
+
+static inline void page_pool_ref_netmem(netmem_ref netmem)
+{
+ atomic_long_inc(&netmem_to_page(netmem)->pp_ref_count);
+}
+
static inline void page_pool_ref_page(struct page *page)
{
- atomic_long_inc(&page->pp_ref_count);
+ page_pool_ref_netmem(page_to_netmem(page));
}

-static inline bool page_pool_is_last_ref(struct page *page)
+static inline bool page_pool_is_last_ref(netmem_ref netmem)
{
/* If page_pool_unref_page() returns 0, we were the last user */
- return page_pool_unref_page(page, 1) == 0;
+ return page_pool_unref_netmem(netmem, 1) == 0;
+}
+
+static inline void page_pool_put_netmem(struct page_pool *pool,
+ netmem_ref netmem,
+ unsigned int dma_sync_size,
+ bool allow_direct)
+{
+ /* When page_pool isn't compiled-in, net/core/xdp.c doesn't
+ * allow registering MEM_TYPE_PAGE_POOL, but shield linker.
+ */
+#ifdef CONFIG_PAGE_POOL
+ if (!page_pool_is_last_ref(netmem))
+ return;
+
+ page_pool_put_unrefed_netmem(pool, netmem, dma_sync_size, allow_direct);
+#endif
}

/**
@@ -306,15 +341,15 @@ static inline void page_pool_put_page(struct page_pool *pool,
unsigned int dma_sync_size,
bool allow_direct)
{
- /* When page_pool isn't compiled-in, net/core/xdp.c doesn't
- * allow registering MEM_TYPE_PAGE_POOL, but shield linker.
- */
-#ifdef CONFIG_PAGE_POOL
- if (!page_pool_is_last_ref(page))
- return;
+ page_pool_put_netmem(pool, page_to_netmem(page), dma_sync_size,
+ allow_direct);
+}

- page_pool_put_unrefed_page(pool, page, dma_sync_size, allow_direct);
-#endif
+static inline void page_pool_put_full_netmem(struct page_pool *pool,
+ netmem_ref netmem,
+ bool allow_direct)
+{
+ page_pool_put_netmem(pool, netmem, -1, allow_direct);
}

/**
@@ -329,7 +364,7 @@ static inline void page_pool_put_page(struct page_pool *pool,
static inline void page_pool_put_full_page(struct page_pool *pool,
struct page *page, bool allow_direct)
{
- page_pool_put_page(pool, page, -1, allow_direct);
+ page_pool_put_netmem(pool, page_to_netmem(page), -1, allow_direct);
}

/**
@@ -363,6 +398,18 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
page_pool_put_page(pool, virt_to_head_page(va), -1, allow_direct);
}

+static inline dma_addr_t page_pool_get_dma_addr_netmem(netmem_ref netmem)
+{
+ struct page *page = netmem_to_page(netmem);
+
+ dma_addr_t ret = page->dma_addr;
+
+ if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
+ ret <<= PAGE_SHIFT;
+
+ return ret;
+}
+
/**
* page_pool_get_dma_addr() - Retrieve the stored DMA address.
* @page: page allocated from a page pool
@@ -372,16 +419,14 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
*/
static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
{
- dma_addr_t ret = page->dma_addr;
-
- if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
- ret <<= PAGE_SHIFT;
-
- return ret;
+ return page_pool_get_dma_addr_netmem(page_to_netmem(page));
}

-static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
+static inline bool page_pool_set_dma_addr_netmem(netmem_ref netmem,
+ dma_addr_t addr)
{
+ struct page *page = netmem_to_page(netmem);
+
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
page->dma_addr = addr >> PAGE_SHIFT;

@@ -395,6 +440,11 @@ static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
return false;
}

+static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
+{
+ return page_pool_set_dma_addr_netmem(page_to_netmem(page), addr);
+}
+
static inline bool page_pool_put(struct page_pool *pool)
{
return refcount_dec_and_test(&pool->user_cnt);
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 07e6afafedbe..0d164624f16d 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -40,7 +40,7 @@
#define PP_ALLOC_CACHE_REFILL 64
struct pp_alloc_cache {
u32 count;
- struct page *cache[PP_ALLOC_CACHE_SIZE];
+ netmem_ref cache[PP_ALLOC_CACHE_SIZE];
};

/**
@@ -73,7 +73,7 @@ struct page_pool_params {
struct_group_tagged(page_pool_params_slow, slow,
struct net_device *netdev;
/* private: used by test code only */
- void (*init_callback)(struct page *page, void *arg);
+ void (*init_callback)(netmem_ref netmem, void *arg);
void *init_arg;
);
};
@@ -131,8 +131,8 @@ struct page_pool_stats {
struct memory_provider_ops {
int (*init)(struct page_pool *pool);
void (*destroy)(struct page_pool *pool);
- struct page *(*alloc_pages)(struct page_pool *pool, gfp_t gfp);
- bool (*release_page)(struct page_pool *pool, struct page *page);
+ netmem_ref (*alloc_pages)(struct page_pool *pool, gfp_t gfp);
+ bool (*release_page)(struct page_pool *pool, netmem_ref netmem);
};

struct pp_memory_provider_params {
@@ -147,7 +147,7 @@ struct page_pool {
bool has_init_callback;

long frag_users;
- struct page *frag_page;
+ netmem_ref frag_page;
unsigned int frag_offset;
u32 pages_state_hold_cnt;

@@ -219,8 +219,12 @@ struct page_pool {
};

struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
+netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp);
struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
unsigned int size, gfp_t gfp);
+netmem_ref page_pool_alloc_frag_netmem(struct page_pool *pool,
+ unsigned int *offset, unsigned int size,
+ gfp_t gfp);
struct page_pool *page_pool_create(const struct page_pool_params *params);
struct page_pool *page_pool_create_percpu(const struct page_pool_params *params,
int cpuid);
@@ -250,6 +254,9 @@ static inline void page_pool_put_page_bulk(struct page_pool *pool, void **data,
}
#endif

+void page_pool_put_unrefed_netmem(struct page_pool *pool, netmem_ref netmem,
+ unsigned int dma_sync_size,
+ bool allow_direct);
void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
unsigned int dma_sync_size,
bool allow_direct);
diff --git a/include/trace/events/page_pool.h b/include/trace/events/page_pool.h
index 6834356b2d2a..c5b6383ff276 100644
--- a/include/trace/events/page_pool.h
+++ b/include/trace/events/page_pool.h
@@ -42,51 +42,52 @@ TRACE_EVENT(page_pool_release,
TRACE_EVENT(page_pool_state_release,

TP_PROTO(const struct page_pool *pool,
- const struct page *page, u32 release),
+ netmem_ref netmem, u32 release),

- TP_ARGS(pool, page, release),
+ TP_ARGS(pool, netmem, release),

TP_STRUCT__entry(
__field(const struct page_pool *, pool)
- __field(const struct page *, page)
+ __field(netmem_ref, netmem)
__field(u32, release)
__field(unsigned long, pfn)
),

TP_fast_assign(
__entry->pool = pool;
- __entry->page = page;
+ __entry->netmem = netmem;
__entry->release = release;
- __entry->pfn = page_to_pfn(page);
+ __entry->pfn = netmem_to_pfn(netmem);
),

- TP_printk("page_pool=%p page=%p pfn=0x%lx release=%u",
- __entry->pool, __entry->page, __entry->pfn, __entry->release)
+ TP_printk("page_pool=%p netmem=%lu pfn=0x%lx release=%u",
+ __entry->pool, (__force unsigned long)__entry->netmem,
+ __entry->pfn, __entry->release)
);

TRACE_EVENT(page_pool_state_hold,

TP_PROTO(const struct page_pool *pool,
- const struct page *page, u32 hold),
+ netmem_ref netmem, u32 hold),

- TP_ARGS(pool, page, hold),
+ TP_ARGS(pool, netmem, hold),

TP_STRUCT__entry(
__field(const struct page_pool *, pool)
- __field(const struct page *, page)
+ __field(netmem_ref, netmem)
__field(u32, hold)
__field(unsigned long, pfn)
),

TP_fast_assign(
__entry->pool = pool;
- __entry->page = page;
+ __entry->netmem = netmem;
__entry->hold = hold;
- __entry->pfn = page_to_pfn(page);
+ __entry->pfn = netmem_to_pfn(netmem);
),

- TP_printk("page_pool=%p page=%p pfn=0x%lx hold=%u",
- __entry->pool, __entry->page, __entry->pfn, __entry->hold)
+ TP_printk("page_pool=%p netmem=%lu pfn=0x%lx hold=%u",
+ __entry->pool, __entry->netmem, __entry->pfn, __entry->hold)
);

TRACE_EVENT(page_pool_update_nid,
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 61efeadaff8d..fc300e807e1d 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -127,9 +127,10 @@ struct xdp_test_data {
#define TEST_XDP_FRAME_SIZE (PAGE_SIZE - sizeof(struct xdp_page_head))
#define TEST_XDP_MAX_BATCH 256

-static void xdp_test_run_init_page(struct page *page, void *arg)
+static void xdp_test_run_init_page(netmem_ref netmem, void *arg)
{
- struct xdp_page_head *head = phys_to_virt(page_to_phys(page));
+ struct xdp_page_head *head =
+ phys_to_virt(page_to_phys(netmem_to_page(netmem)));
struct xdp_buff *new_ctx, *orig_ctx;
u32 headroom = XDP_PACKET_HEADROOM;
struct xdp_test_data *xdp = arg;
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 795b7ff1c01f..c8125be3a6e2 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -329,19 +329,18 @@ struct page_pool *page_pool_create(const struct page_pool_params *params)
}
EXPORT_SYMBOL(page_pool_create);

-static void page_pool_return_page(struct page_pool *pool, struct page *page);
+static void page_pool_return_page(struct page_pool *pool, netmem_ref netmem);

-noinline
-static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
+static noinline netmem_ref page_pool_refill_alloc_cache(struct page_pool *pool)
{
struct ptr_ring *r = &pool->ring;
- struct page *page;
+ netmem_ref netmem;
int pref_nid; /* preferred NUMA node */

/* Quicker fallback, avoid locks when ring is empty */
if (__ptr_ring_empty(r)) {
alloc_stat_inc(pool, empty);
- return NULL;
+ return 0;
}

/* Softirq guarantee CPU and thus NUMA node is stable. This,
@@ -356,56 +355,56 @@ static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)

/* Refill alloc array, but only if NUMA match */
do {
- page = __ptr_ring_consume(r);
- if (unlikely(!page))
+ netmem = (__force netmem_ref)__ptr_ring_consume(r);
+ if (unlikely(!netmem))
break;

- if (likely(page_to_nid(page) == pref_nid)) {
- pool->alloc.cache[pool->alloc.count++] = page;
+ if (likely(page_to_nid(netmem_to_page(netmem)) == pref_nid)) {
+ pool->alloc.cache[pool->alloc.count++] = netmem;
} else {
/* NUMA mismatch;
* (1) release 1 page to page-allocator and
* (2) break out to fallthrough to alloc_pages_node.
* This limit stress on page buddy alloactor.
*/
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
alloc_stat_inc(pool, waive);
- page = NULL;
+ netmem = 0;
break;
}
} while (pool->alloc.count < PP_ALLOC_CACHE_REFILL);

/* Return last page */
if (likely(pool->alloc.count > 0)) {
- page = pool->alloc.cache[--pool->alloc.count];
+ netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, refill);
}

- return page;
+ return netmem;
}

/* fast path */
-static struct page *__page_pool_get_cached(struct page_pool *pool)
+static netmem_ref __page_pool_get_cached(struct page_pool *pool)
{
- struct page *page;
+ netmem_ref netmem;

/* Caller MUST guarantee safe non-concurrent access, e.g. softirq */
if (likely(pool->alloc.count)) {
/* Fast-path */
- page = pool->alloc.cache[--pool->alloc.count];
+ netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, fast);
} else {
- page = page_pool_refill_alloc_cache(pool);
+ netmem = page_pool_refill_alloc_cache(pool);
}

- return page;
+ return netmem;
}

static void page_pool_dma_sync_for_device(struct page_pool *pool,
- struct page *page,
+ netmem_ref netmem,
unsigned int dma_sync_size)
{
- dma_addr_t dma_addr = page_pool_get_dma_addr(page);
+ dma_addr_t dma_addr = page_pool_get_dma_addr_netmem(netmem);

dma_sync_size = min(dma_sync_size, pool->p.max_len);
dma_sync_single_range_for_device(pool->p.dev, dma_addr,
@@ -413,7 +412,7 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool,
pool->p.dma_dir);
}

-static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
+static bool page_pool_dma_map(struct page_pool *pool, netmem_ref netmem)
{
dma_addr_t dma;

@@ -422,18 +421,18 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
* into page private data (i.e 32bit cpu with 64bit DMA caps)
* This mapping is kept for lifetime of page, until leaving pool.
*/
- dma = dma_map_page_attrs(pool->p.dev, page, 0,
- (PAGE_SIZE << pool->p.order),
- pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC |
- DMA_ATTR_WEAK_ORDERING);
+ dma = dma_map_page_attrs(pool->p.dev, netmem_to_page(netmem), 0,
+ (PAGE_SIZE << pool->p.order), pool->p.dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC |
+ DMA_ATTR_WEAK_ORDERING);
if (dma_mapping_error(pool->p.dev, dma))
return false;

- if (page_pool_set_dma_addr(page, dma))
+ if (page_pool_set_dma_addr_netmem(netmem, dma))
goto unmap_failed;

if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
- page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
+ page_pool_dma_sync_for_device(pool, netmem, pool->p.max_len);

return true;

@@ -445,9 +444,10 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
return false;
}

-static void page_pool_set_pp_info(struct page_pool *pool,
- struct page *page)
+static void page_pool_set_pp_info(struct page_pool *pool, netmem_ref netmem)
{
+ struct page *page = netmem_to_page(netmem);
+
page->pp = pool;
page->pp_magic |= PP_SIGNATURE;

@@ -457,13 +457,15 @@ static void page_pool_set_pp_info(struct page_pool *pool,
* is dirtying the same cache line as the page->pp_magic above, so
* the overhead is negligible.
*/
- page_pool_fragment_page(page, 1);
+ page_pool_fragment_netmem(netmem, 1);
if (pool->has_init_callback)
- pool->slow.init_callback(page, pool->slow.init_arg);
+ pool->slow.init_callback(netmem, pool->slow.init_arg);
}

-static void page_pool_clear_pp_info(struct page *page)
+static void page_pool_clear_pp_info(netmem_ref netmem)
{
+ struct page *page = netmem_to_page(netmem);
+
page->pp_magic = 0;
page->pp = NULL;
}
@@ -479,34 +481,34 @@ static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
return NULL;

if ((pool->p.flags & PP_FLAG_DMA_MAP) &&
- unlikely(!page_pool_dma_map(pool, page))) {
+ unlikely(!page_pool_dma_map(pool, page_to_netmem(page)))) {
put_page(page);
return NULL;
}

alloc_stat_inc(pool, slow_high_order);
- page_pool_set_pp_info(pool, page);
+ 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, pool->pages_state_hold_cnt);
+ trace_page_pool_state_hold(pool, page_to_netmem(page),
+ pool->pages_state_hold_cnt);
return page;
}

/* slow path */
-noinline
-static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
- gfp_t gfp)
+static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
+ gfp_t gfp)
{
const int bulk = PP_ALLOC_CACHE_REFILL;
unsigned int pp_flags = pool->p.flags;
unsigned int pp_order = pool->p.order;
- struct page *page;
+ netmem_ref netmem;
int i, nr_pages;

/* Don't support bulk alloc for high-order pages */
if (unlikely(pp_order))
- return __page_pool_alloc_page_order(pool, gfp);
+ return page_to_netmem(__page_pool_alloc_page_order(pool, gfp));

/* Unnecessary as alloc cache is empty, but guarantees zero count */
if (unlikely(pool->alloc.count > 0))
@@ -515,60 +517,67 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
/* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */
memset(&pool->alloc.cache, 0, sizeof(void *) * bulk);

- nr_pages = alloc_pages_bulk_array_node(gfp, pool->p.nid, bulk,
- pool->alloc.cache);
+ nr_pages = alloc_pages_bulk_array_node(gfp,
+ pool->p.nid, bulk,
+ (struct page **)pool->alloc.cache);
if (unlikely(!nr_pages))
- return NULL;
+ return 0;

/* Pages have been filled into alloc.cache array, but count is zero and
* page element have not been (possibly) DMA mapped.
*/
for (i = 0; i < nr_pages; i++) {
- page = pool->alloc.cache[i];
+ netmem = pool->alloc.cache[i];
if ((pp_flags & PP_FLAG_DMA_MAP) &&
- unlikely(!page_pool_dma_map(pool, page))) {
- put_page(page);
+ unlikely(!page_pool_dma_map(pool, netmem))) {
+ put_page(netmem_to_page(netmem));
continue;
}

- page_pool_set_pp_info(pool, page);
- pool->alloc.cache[pool->alloc.count++] = page;
+ 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++;
- trace_page_pool_state_hold(pool, page,
+ trace_page_pool_state_hold(pool, netmem,
pool->pages_state_hold_cnt);
}

/* Return last page */
if (likely(pool->alloc.count > 0)) {
- page = pool->alloc.cache[--pool->alloc.count];
+ netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, slow);
} else {
- page = NULL;
+ netmem = 0;
}

/* When page just alloc'ed is should/must have refcnt 1. */
- return page;
+ return netmem;
}

/* For using page_pool replace: alloc_pages() API calls, but provide
* synchronization guarantee for allocation side.
*/
-struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
+netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp)
{
- struct page *page;
+ netmem_ref netmem;

/* Fast-path: Get a page from cache */
- page = __page_pool_get_cached(pool);
- if (page)
- return page;
+ netmem = __page_pool_get_cached(pool);
+ if (netmem)
+ return netmem;

/* Slow-path: cache empty, do real allocation */
if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_ops)
- page = pool->mp_ops->alloc_pages(pool, gfp);
+ netmem = pool->mp_ops->alloc_pages(pool, gfp);
else
- page = __page_pool_alloc_pages_slow(pool, gfp);
- return page;
+ netmem = __page_pool_alloc_pages_slow(pool, gfp);
+ return netmem;
+}
+EXPORT_SYMBOL(page_pool_alloc_netmem);
+
+struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
+{
+ return netmem_to_page(page_pool_alloc_netmem(pool, gfp));
}
EXPORT_SYMBOL(page_pool_alloc_pages);

@@ -596,8 +605,8 @@ s32 page_pool_inflight(const struct page_pool *pool, bool strict)
return inflight;
}

-static __always_inline
-void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
+static __always_inline void __page_pool_release_page_dma(struct page_pool *pool,
+ netmem_ref netmem)
{
dma_addr_t dma;

@@ -607,13 +616,13 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
*/
return;

- dma = page_pool_get_dma_addr(page);
+ 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(page, 0);
+ page_pool_set_dma_addr_netmem(netmem, 0);
}

/* Disconnects a page (from a page_pool). API users can have a need
@@ -621,26 +630,26 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
* a regular page (that will eventually be returned to the normal
* page-allocator via put_page).
*/
-void page_pool_return_page(struct page_pool *pool, struct page *page)
+void page_pool_return_page(struct page_pool *pool, netmem_ref netmem)
{
int count;
bool put;

put = true;
if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_ops)
- put = pool->mp_ops->release_page(pool, page);
+ put = pool->mp_ops->release_page(pool, netmem);
else
- __page_pool_release_page_dma(pool, page);
+ __page_pool_release_page_dma(pool, netmem);

/* This may be the last page returned, releasing the pool, so
* it is not safe to reference pool afterwards.
*/
count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
- trace_page_pool_state_release(pool, page, count);
+ trace_page_pool_state_release(pool, netmem, count);

if (put) {
- page_pool_clear_pp_info(page);
- put_page(page);
+ page_pool_clear_pp_info(netmem);
+ put_page(netmem_to_page(netmem));
}
/* An optimization would be to call __free_pages(page, pool->p.order)
* knowing page is not part of page-cache (thus avoiding a
@@ -648,14 +657,14 @@ void page_pool_return_page(struct page_pool *pool, struct page *page)
*/
}

-static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
+static bool page_pool_recycle_in_ring(struct page_pool *pool, netmem_ref netmem)
{
int ret;
/* BH protection not needed if current is softirq */
if (in_softirq())
- ret = ptr_ring_produce(&pool->ring, page);
+ ret = ptr_ring_produce(&pool->ring, (__force void *)netmem);
else
- ret = ptr_ring_produce_bh(&pool->ring, page);
+ ret = ptr_ring_produce_bh(&pool->ring, (__force void *)netmem);

if (!ret) {
recycle_stat_inc(pool, ring);
@@ -670,7 +679,7 @@ static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
*
* Caller must provide appropriate safe context.
*/
-static bool page_pool_recycle_in_cache(struct page *page,
+static bool page_pool_recycle_in_cache(netmem_ref netmem,
struct page_pool *pool)
{
if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) {
@@ -679,14 +688,15 @@ static bool page_pool_recycle_in_cache(struct page *page,
}

/* Caller MUST have verified/know (page_ref_count(page) == 1) */
- pool->alloc.cache[pool->alloc.count++] = page;
+ pool->alloc.cache[pool->alloc.count++] = netmem;
recycle_stat_inc(pool, cached);
return true;
}

-static bool __page_pool_page_can_be_recycled(const struct page *page)
+static bool __page_pool_page_can_be_recycled(netmem_ref netmem)
{
- return page_ref_count(page) == 1 && !page_is_pfmemalloc(page);
+ return page_ref_count(netmem_to_page(netmem)) == 1 &&
+ !page_is_pfmemalloc(netmem_to_page(netmem));
}

/* If the page refcnt == 1, this will try to recycle the page.
@@ -695,8 +705,8 @@ static bool __page_pool_page_can_be_recycled(const struct page *page)
* If the page refcnt != 1, then the page will be returned to memory
* subsystem.
*/
-static __always_inline struct page *
-__page_pool_put_page(struct page_pool *pool, struct page *page,
+static __always_inline netmem_ref
+__page_pool_put_page(struct page_pool *pool, netmem_ref netmem,
unsigned int dma_sync_size, bool allow_direct)
{
lockdep_assert_no_hardirq();
@@ -710,19 +720,19 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* page is NOT reusable when allocated when system is under
* some pressure. (page_is_pfmemalloc)
*/
- if (likely(__page_pool_page_can_be_recycled(page))) {
+ if (likely(__page_pool_page_can_be_recycled(netmem))) {
/* Read barrier done in page_ref_count / READ_ONCE */

if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
- page_pool_dma_sync_for_device(pool, page,
+ page_pool_dma_sync_for_device(pool, netmem,
dma_sync_size);

if (allow_direct && in_softirq() &&
- page_pool_recycle_in_cache(page, pool))
- return NULL;
+ page_pool_recycle_in_cache(netmem, pool))
+ return 0;

/* Page found as candidate for recycling */
- return page;
+ return netmem;
}
/* Fallback/non-XDP mode: API user have elevated refcnt.
*
@@ -738,21 +748,30 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* will be invoking put_page.
*/
recycle_stat_inc(pool, released_refcnt);
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);

- return NULL;
+ return 0;
}

-void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
- unsigned int dma_sync_size, bool allow_direct)
+void page_pool_put_unrefed_netmem(struct page_pool *pool, netmem_ref netmem,
+ unsigned int dma_sync_size, bool allow_direct)
{
- page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct);
- if (page && !page_pool_recycle_in_ring(pool, page)) {
+ netmem =
+ __page_pool_put_page(pool, netmem, dma_sync_size, allow_direct);
+ if (netmem && !page_pool_recycle_in_ring(pool, netmem)) {
/* Cache full, fallback to free pages */
recycle_stat_inc(pool, ring_full);
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
}
}
+EXPORT_SYMBOL(page_pool_put_unrefed_netmem);
+
+void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
+ unsigned int dma_sync_size, bool allow_direct)
+{
+ page_pool_put_unrefed_netmem(pool, page_to_netmem(page), dma_sync_size,
+ allow_direct);
+}
EXPORT_SYMBOL(page_pool_put_unrefed_page);

/**
@@ -777,16 +796,16 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
bool in_softirq;

for (i = 0; i < count; i++) {
- struct page *page = virt_to_head_page(data[i]);
+ netmem_ref netmem = page_to_netmem(virt_to_head_page(data[i]));

/* It is not the last user for the page frag case */
- if (!page_pool_is_last_ref(page))
+ if (!page_pool_is_last_ref(netmem))
continue;

- page = __page_pool_put_page(pool, page, -1, false);
+ netmem = __page_pool_put_page(pool, netmem, -1, false);
/* Approved for bulk recycling in ptr_ring cache */
- if (page)
- data[bulk_len++] = page;
+ if (netmem)
+ data[bulk_len++] = (__force void *)netmem;
}

if (unlikely(!bulk_len))
@@ -812,100 +831,108 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
* since put_page() with refcnt == 1 can be an expensive operation
*/
for (; i < bulk_len; i++)
- page_pool_return_page(pool, data[i]);
+ page_pool_return_page(pool, (__force netmem_ref)data[i]);
}
EXPORT_SYMBOL(page_pool_put_page_bulk);

-static struct page *page_pool_drain_frag(struct page_pool *pool,
- struct page *page)
+static netmem_ref page_pool_drain_frag(struct page_pool *pool,
+ netmem_ref netmem)
{
long drain_count = BIAS_MAX - pool->frag_users;

/* Some user is still using the page frag */
- if (likely(page_pool_unref_page(page, drain_count)))
- return NULL;
+ if (likely(page_pool_unref_netmem(netmem, drain_count)))
+ return 0;

- if (__page_pool_page_can_be_recycled(page)) {
+ if (__page_pool_page_can_be_recycled(netmem)) {
if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
- page_pool_dma_sync_for_device(pool, page, -1);
+ page_pool_dma_sync_for_device(pool, netmem, -1);

- return page;
+ return netmem;
}

- page_pool_return_page(pool, page);
- return NULL;
+ page_pool_return_page(pool, netmem);
+ return 0;
}

static void page_pool_free_frag(struct page_pool *pool)
{
long drain_count = BIAS_MAX - pool->frag_users;
- struct page *page = pool->frag_page;
+ netmem_ref netmem = pool->frag_page;

- pool->frag_page = NULL;
+ pool->frag_page = 0;

- if (!page || page_pool_unref_page(page, drain_count))
+ if (!netmem || page_pool_unref_netmem(netmem, drain_count))
return;

- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
}

-struct page *page_pool_alloc_frag(struct page_pool *pool,
- unsigned int *offset,
- unsigned int size, gfp_t gfp)
+netmem_ref page_pool_alloc_frag_netmem(struct page_pool *pool,
+ unsigned int *offset, unsigned int size,
+ gfp_t gfp)
{
unsigned int max_size = PAGE_SIZE << pool->p.order;
- struct page *page = pool->frag_page;
+ netmem_ref netmem = pool->frag_page;

if (WARN_ON(size > max_size))
- return NULL;
+ return 0;

size = ALIGN(size, dma_get_cache_alignment());
*offset = pool->frag_offset;

- if (page && *offset + size > max_size) {
- page = page_pool_drain_frag(pool, page);
- if (page) {
+ if (netmem && *offset + size > max_size) {
+ netmem = page_pool_drain_frag(pool, netmem);
+ if (netmem) {
alloc_stat_inc(pool, fast);
goto frag_reset;
}
}

- if (!page) {
- page = page_pool_alloc_pages(pool, gfp);
- if (unlikely(!page)) {
- pool->frag_page = NULL;
- return NULL;
+ if (!netmem) {
+ netmem = page_pool_alloc_netmem(pool, gfp);
+ if (unlikely(!netmem)) {
+ pool->frag_page = 0;
+ return 0;
}

- pool->frag_page = page;
+ pool->frag_page = netmem;

frag_reset:
pool->frag_users = 1;
*offset = 0;
pool->frag_offset = size;
- page_pool_fragment_page(page, BIAS_MAX);
- return page;
+ page_pool_fragment_netmem(netmem, BIAS_MAX);
+ return netmem;
}

pool->frag_users++;
pool->frag_offset = *offset + size;
alloc_stat_inc(pool, fast);
- return page;
+ return netmem;
+}
+EXPORT_SYMBOL(page_pool_alloc_frag_netmem);
+
+struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
+ unsigned int size, gfp_t gfp)
+{
+ return netmem_to_page(page_pool_alloc_frag_netmem(pool, offset, size,
+ gfp));
}
EXPORT_SYMBOL(page_pool_alloc_frag);

static void page_pool_empty_ring(struct page_pool *pool)
{
- struct page *page;
+ netmem_ref netmem;

/* Empty recycle ring */
- while ((page = ptr_ring_consume_bh(&pool->ring))) {
+ while ((netmem = (__force netmem_ref)ptr_ring_consume_bh(&pool->ring))) {
/* Verify the refcnt invariant of cached pages */
- if (!(page_ref_count(page) == 1))
+ if (!(page_ref_count(netmem_to_page(netmem)) == 1))
pr_crit("%s() page_pool refcnt %d violation\n",
- __func__, page_ref_count(page));
+ __func__, netmem_ref_count(netmem));

- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
}
}

@@ -927,7 +954,7 @@ static void __page_pool_destroy(struct page_pool *pool)

static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
{
- struct page *page;
+ netmem_ref netmem;

if (pool->destroy_cnt)
return;
@@ -937,8 +964,8 @@ static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
* call concurrently.
*/
while (pool->alloc.count) {
- page = pool->alloc.cache[--pool->alloc.count];
- page_pool_return_page(pool, page);
+ netmem = pool->alloc.cache[--pool->alloc.count];
+ page_pool_return_page(pool, netmem);
}
}

@@ -1044,15 +1071,15 @@ EXPORT_SYMBOL(page_pool_destroy);
/* Caller must provide appropriate safe context, e.g. NAPI. */
void page_pool_update_nid(struct page_pool *pool, int new_nid)
{
- struct page *page;
+ netmem_ref netmem;

trace_page_pool_update_nid(pool, new_nid);
pool->p.nid = new_nid;

/* Flush pool alloc cache, as refill will check NUMA node */
while (pool->alloc.count) {
- page = pool->alloc.cache[--pool->alloc.count];
- page_pool_return_page(pool, page);
+ netmem = pool->alloc.cache[--pool->alloc.count];
+ page_pool_return_page(pool, netmem);
}
}
EXPORT_SYMBOL(page_pool_update_nid);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 17617c29be2d..7193ee9737a0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1005,8 +1005,9 @@ int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
EXPORT_SYMBOL(skb_cow_data_for_xdp);

#if IS_ENABLED(CONFIG_PAGE_POOL)
-bool napi_pp_put_page(struct page *page, bool napi_safe)
+bool napi_pp_put_page(netmem_ref netmem, bool napi_safe)
{
+ struct page *page = netmem_to_page(netmem);
bool allow_direct = false;
struct page_pool *pp;

@@ -1043,7 +1044,7 @@ bool napi_pp_put_page(struct page *page, bool napi_safe)
* The page will be returned to the pool here regardless of the
* 'flipped' fragment being in use or not.
*/
- page_pool_put_full_page(pp, page, allow_direct);
+ page_pool_put_full_netmem(pp, page_to_netmem(page), allow_direct);

return true;
}
@@ -1054,7 +1055,7 @@ static bool skb_pp_recycle(struct sk_buff *skb, void *data, bool napi_safe)
{
if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle)
return false;
- return napi_pp_put_page(virt_to_page(data), napi_safe);
+ return napi_pp_put_page(page_to_netmem(virt_to_page(data)), napi_safe);
}

/**
--
2.44.0.396.g6e790dbe36-goog