Implement netdev devmem allocator. The allocator takes a given struct
netdev_dmabuf_binding as input and allocates page_pool_iov from that
binding.
The allocation simply delegates to the binding's genpool for the
allocation logic and wraps the returned memory region in a page_pool_iov
struct.
page_pool_iov are refcounted and are freed back to the binding when the
refcount drops to 0.
Signed-off-by: Willem de Bruijn <will...@google.com>
Signed-off-by: Kaiyuan Zhang <kaiyu...@google.com>
Signed-off-by: Mina Almasry <almasrym...@google.com>
---
include/linux/netdevice.h | 13 ++++++++++++
include/net/page_pool/helpers.h | 28 +++++++++++++++++++++++++
net/core/dev.c | 37 +++++++++++++++++++++++++++++++++
3 files changed, 78 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index eeeda849115c..1c351c138a5b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -843,6 +843,9 @@ struct netdev_dmabuf_binding {
};
#ifdef CONFIG_DMA_SHARED_BUFFER
+struct page_pool_iov *
+netdev_alloc_devmem(struct netdev_dmabuf_binding *binding);
+void netdev_free_devmem(struct page_pool_iov *ppiov);
void __netdev_devmem_binding_free(struct netdev_dmabuf_binding *binding);
int netdev_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,
struct netdev_dmabuf_binding **out);
@@ -850,6 +853,16 @@ void netdev_unbind_dmabuf(struct netdev_dmabuf_binding
*binding);
int netdev_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
struct netdev_dmabuf_binding *binding);
#else
+static inline struct page_pool_iov *
+netdev_alloc_devmem(struct netdev_dmabuf_binding *binding)
+{
+ return NULL;
+}
+
+static inline void netdev_free_devmem(struct page_pool_iov *ppiov)
+{
+}
+
static inline void
__netdev_devmem_binding_free(struct netdev_dmabuf_binding *binding)
{
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index 4ebd544ae977..78cbb040af94 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -83,6 +83,34 @@ static inline u64 *page_pool_ethtool_stats_get(u64 *data,
void *stats)
}
#endif
+/* page_pool_iov support */
+
+static inline struct dmabuf_genpool_chunk_owner *
+page_pool_iov_owner(const struct page_pool_iov *ppiov)
+{
+ return ppiov->owner;
+}
+
+static inline unsigned int page_pool_iov_idx(const struct page_pool_iov *ppiov)
+{
+ return ppiov - page_pool_iov_owner(ppiov)->ppiovs;
+}
+
+static inline dma_addr_t
+page_pool_iov_dma_addr(const struct page_pool_iov *ppiov)
+{
+ struct dmabuf_genpool_chunk_owner *owner = page_pool_iov_owner(ppiov);
+
+ return owner->base_dma_addr +
+ ((dma_addr_t)page_pool_iov_idx(ppiov) << PAGE_SHIFT);
+}
+
+static inline struct netdev_dmabuf_binding *
+page_pool_iov_binding(const struct page_pool_iov *ppiov)
+{
+ return page_pool_iov_owner(ppiov)->binding;
+}
+
/**
* page_pool_dev_alloc_pages() - allocate a page.
* @pool: pool from which to allocate
diff --git a/net/core/dev.c b/net/core/dev.c
index c8c3709d42c8..2315bbc03ec8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -156,6 +156,7 @@
#include <linux/genalloc.h>
#include <linux/dma-buf.h>
#include <net/page_pool/types.h>
+#include <net/page_pool/helpers.h>
#include "dev.h"
#include "net-sysfs.h"
@@ -2077,6 +2078,42 @@ void __netdev_devmem_binding_free(struct
netdev_dmabuf_binding *binding)
kfree(binding);
}
+struct page_pool_iov *netdev_alloc_devmem(struct netdev_dmabuf_binding
*binding)
+{
+ struct dmabuf_genpool_chunk_owner *owner;
+ struct page_pool_iov *ppiov;
+ unsigned long dma_addr;
+ ssize_t offset;
+ ssize_t index;
+
+ dma_addr = gen_pool_alloc_owner(binding->chunk_pool, PAGE_SIZE,
+ (void **)&owner);
+ if (!dma_addr)
+ return NULL;
+
+ offset = dma_addr - owner->base_dma_addr;
+ index = offset / PAGE_SIZE;
+ ppiov = &owner->ppiovs[index];
+
+ netdev_devmem_binding_get(binding);
+
+ return ppiov;
+}
+
+void netdev_free_devmem(struct page_pool_iov *ppiov)
+{
+ struct netdev_dmabuf_binding *binding = page_pool_iov_binding(ppiov);
+
+ refcount_set(&ppiov->refcount, 1);
+
+ if (gen_pool_has_addr(binding->chunk_pool,
+ page_pool_iov_dma_addr(ppiov), PAGE_SIZE))
+ gen_pool_free(binding->chunk_pool,
+ page_pool_iov_dma_addr(ppiov), PAGE_SIZE);
+
+ netdev_devmem_binding_put(binding);
+}
+
void netdev_unbind_dmabuf(struct netdev_dmabuf_binding *binding)
{
struct netdev_rx_queue *rxq;
--
2.42.0.869.gea05f2083d-goog
