netdev: netdevice devmem allocator

Implement netdev devmem allocator. The allocator takes a given struct
netdev_dmabuf_binding as input and allocates net_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 net_iov
struct.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-5-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Mina Almasry 2024-09-10 17:14:48 +00:00 committed by Jakub Kicinski
parent 170aafe35c
commit 28c5c74eea
2 changed files with 75 additions and 0 deletions

View File

@ -34,6 +34,14 @@ static void net_devmem_dmabuf_free_chunk_owner(struct gen_pool *genpool,
kfree(owner);
}
static dma_addr_t net_devmem_get_dma_addr(const struct net_iov *niov)
{
struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
return owner->base_dma_addr +
((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT);
}
void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding)
{
size_t size, avail;
@ -56,6 +64,39 @@ void __net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding)
kfree(binding);
}
struct net_iov *
net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding)
{
struct dmabuf_genpool_chunk_owner *owner;
unsigned long dma_addr;
struct net_iov *niov;
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;
niov = &owner->niovs[index];
return niov;
}
void net_devmem_free_dmabuf(struct net_iov *niov)
{
struct net_devmem_dmabuf_binding *binding = net_iov_binding(niov);
unsigned long dma_addr = net_devmem_get_dma_addr(niov);
if (WARN_ON(!gen_pool_has_addr(binding->chunk_pool, dma_addr,
PAGE_SIZE)))
return;
gen_pool_free(binding->chunk_pool, dma_addr, PAGE_SIZE);
}
void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding)
{
struct netdev_rx_queue *rxq;

View File

@ -74,6 +74,23 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
struct netlink_ext_ack *extack);
void dev_dmabuf_uninstall(struct net_device *dev);
static inline struct dmabuf_genpool_chunk_owner *
net_iov_owner(const struct net_iov *niov)
{
return niov->owner;
}
static inline unsigned int net_iov_idx(const struct net_iov *niov)
{
return niov - net_iov_owner(niov)->niovs;
}
static inline struct net_devmem_dmabuf_binding *
net_iov_binding(const struct net_iov *niov)
{
return net_iov_owner(niov)->binding;
}
static inline void
net_devmem_dmabuf_binding_get(struct net_devmem_dmabuf_binding *binding)
{
@ -89,7 +106,13 @@ net_devmem_dmabuf_binding_put(struct net_devmem_dmabuf_binding *binding)
__net_devmem_dmabuf_binding_free(binding);
}
struct net_iov *
net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding);
void net_devmem_free_dmabuf(struct net_iov *ppiov);
#else
struct net_devmem_dmabuf_binding;
static inline void
__net_devmem_dmabuf_binding_free(struct net_devmem_dmabuf_binding *binding)
{
@ -119,6 +142,17 @@ net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
static inline void dev_dmabuf_uninstall(struct net_device *dev)
{
}
static inline struct net_iov *
net_devmem_alloc_dmabuf(struct net_devmem_dmabuf_binding *binding)
{
return NULL;
}
static inline void net_devmem_free_dmabuf(struct net_iov *ppiov)
{
}
#endif
#endif /* _NET_DEVMEM_H */