[RFC,net-next,v5,05/14] netdev: netdevice devmem allocator
Commit Message
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>
---
v1:
- Rename devmem -> dmabuf (David).
---
include/net/devmem.h | 12 ++++++++++++
include/net/netmem.h | 26 ++++++++++++++++++++++++++
net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
3 files changed, 76 insertions(+)
Comments
On 12/18/23 02:40, Mina Almasry wrote:
> 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>
>
> ---
>
> v1:
> - Rename devmem -> dmabuf (David).
>
> ---
> include/net/devmem.h | 12 ++++++++++++
> include/net/netmem.h | 26 ++++++++++++++++++++++++++
> net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 76 insertions(+)
>
..
> diff --git a/include/net/netmem.h b/include/net/netmem.h
> index 45eb42d9990b..7fce2efc8707 100644
> --- a/include/net/netmem.h
> +++ b/include/net/netmem.h
> @@ -14,8 +14,34 @@
>
> struct net_iov {
> struct dmabuf_genpool_chunk_owner *owner;
> + unsigned long dma_addr;
> };
>
> +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 dma_addr_t net_iov_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);
Looks like it should have been niov->dma_addr
> +}
> +
> +static inline struct netdev_dmabuf_binding *
> +net_iov_binding(const struct net_iov *niov)
> +{
> + return net_iov_owner(niov)->binding;
> +}
> +
> /* netmem */
>
> struct netmem {
..
On Tue, Feb 13, 2024 at 5:24 AM Pavel Begunkov <asml.silence@gmail.com> wrote:
>
> On 12/18/23 02:40, Mina Almasry wrote:
> > 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>
> >
> > ---
> >
> > v1:
> > - Rename devmem -> dmabuf (David).
> >
> > ---
> > include/net/devmem.h | 12 ++++++++++++
> > include/net/netmem.h | 26 ++++++++++++++++++++++++++
> > net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 76 insertions(+)
> >
> ...
> > diff --git a/include/net/netmem.h b/include/net/netmem.h
> > index 45eb42d9990b..7fce2efc8707 100644
> > --- a/include/net/netmem.h
> > +++ b/include/net/netmem.h
> > @@ -14,8 +14,34 @@
> >
> > struct net_iov {
> > struct dmabuf_genpool_chunk_owner *owner;
> > + unsigned long dma_addr;
> > };
> >
> > +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 dma_addr_t net_iov_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);
>
> Looks like it should have been niov->dma_addr
>
Yes, indeed. Thanks for catching.
> > +}
> > +
> > +static inline struct netdev_dmabuf_binding *
> > +net_iov_binding(const struct net_iov *niov)
> > +{
> > + return net_iov_owner(niov)->binding;
> > +}
> > +
> > /* netmem */
> >
> > struct netmem {
> ...
>
> --
> Pavel Begunkov
@@ -67,6 +67,8 @@ struct dmabuf_genpool_chunk_owner {
};
#ifdef CONFIG_DMA_SHARED_BUFFER
+struct net_iov *netdev_alloc_dmabuf(struct netdev_dmabuf_binding *binding);
+void netdev_free_dmabuf(struct net_iov *ppiov);
void __netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding);
int netdev_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,
struct netdev_dmabuf_binding **out);
@@ -74,6 +76,16 @@ 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 net_iov *
+netdev_alloc_dmabuf(struct netdev_dmabuf_binding *binding)
+{
+ return NULL;
+}
+
+static inline void netdev_free_dmabuf(struct net_iov *ppiov)
+{
+}
+
static inline void
__netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding)
{
@@ -14,8 +14,34 @@
struct net_iov {
struct dmabuf_genpool_chunk_owner *owner;
+ unsigned long dma_addr;
};
+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 dma_addr_t net_iov_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);
+}
+
+static inline struct netdev_dmabuf_binding *
+net_iov_binding(const struct net_iov *niov)
+{
+ return net_iov_owner(niov)->binding;
+}
+
/* netmem */
struct netmem {
@@ -2119,6 +2119,44 @@ static int netdev_restart_rx_queue(struct net_device *dev, int rxq_idx)
return err;
}
+struct net_iov *netdev_alloc_dmabuf(struct netdev_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];
+
+ niov->pp_magic = 0;
+ niov->pp = NULL;
+ niov->dma_addr = 0;
+ atomic_long_set(&niov->pp_ref_count, 0);
+
+ netdev_dmabuf_binding_get(binding);
+
+ return niov;
+}
+
+void netdev_free_dmabuf(struct net_iov *niov)
+{
+ struct netdev_dmabuf_binding *binding = net_iov_binding(niov);
+ unsigned long dma_addr = net_iov_dma_addr(niov);
+
+ if (gen_pool_has_addr(binding->chunk_pool, dma_addr, PAGE_SIZE))
+ gen_pool_free(binding->chunk_pool, dma_addr, PAGE_SIZE);
+
+ netdev_dmabuf_binding_put(binding);
+}
+
/* Protected by rtnl_lock() */
static DEFINE_XARRAY_FLAGS(netdev_dmabuf_bindings, XA_FLAGS_ALLOC1);