diff mbox series

[03/12] net: mana: Handle vport sharing between devices

Message ID 1652778276-2986-4-git-send-email-longli@linuxonhyperv.com (mailing list archive)
State Superseded
Delegated to: Jason Gunthorpe
Headers show
Series Introduce Microsoft Azure Network Adapter (MANA) RDMA driver | expand

Commit Message

Long Li May 17, 2022, 9:04 a.m. UTC 
From: Long Li <longli@microsoft.com>

For outgoing packets, the PF requires the VF to configure the vport with
corresponding protection domain and doorbell ID for the kernel or user
context. The vport can't be shared between different contexts.

Implement the logic to exclusively take over the vport by either the
Ethernet device or RDMA device.

Signed-off-by: Long Li <longli@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana.h    |  4 ++++
 drivers/net/ethernet/microsoft/mana/mana_en.c | 19 +++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

Comments

Stephen Hemminger May 17, 2022, 3:19 p.m. UTC | #1 
On Tue, 17 May 2022 02:04:27 -0700
longli@linuxonhyperv.com wrote:

> diff --git a/drivers/net/ethernet/microsoft/mana/mana.h b/drivers/net/ethernet/microsoft/mana/mana.h
> index 51bff91b63ee..26f14fcb6a61 100644
> --- a/drivers/net/ethernet/microsoft/mana/mana.h
> +++ b/drivers/net/ethernet/microsoft/mana/mana.h
> @@ -375,6 +375,7 @@ struct mana_port_context {
>  	unsigned int num_queues;
>  
>  	mana_handle_t port_handle;
> +	atomic_t port_use_count;

Could this be a refcount_t instead?
The refcount_t has protections against under/overflow.
Long Li May 17, 2022, 11:39 p.m. UTC | #2 
> Subject: Re: [PATCH 03/12] net: mana: Handle vport sharing between devices
> 
> On Tue, 17 May 2022 02:04:27 -0700
> longli@linuxonhyperv.com wrote:
> 
> > diff --git a/drivers/net/ethernet/microsoft/mana/mana.h
> b/drivers/net/ethernet/microsoft/mana/mana.h
> > index 51bff91b63ee..26f14fcb6a61 100644
> > --- a/drivers/net/ethernet/microsoft/mana/mana.h
> > +++ b/drivers/net/ethernet/microsoft/mana/mana.h
> > @@ -375,6 +375,7 @@ struct mana_port_context {
> >  	unsigned int num_queues;
> >
> >  	mana_handle_t port_handle;
> > +	atomic_t port_use_count;
> 
> Could this be a refcount_t instead?
> The refcount_t has protections against under/overflow.

Thanks for pointing this out. I will use refcount_t for v2.

Long
diff mbox series

Patch

diff --git a/drivers/net/ethernet/microsoft/mana/mana.h b/drivers/net/ethernet/microsoft/mana/mana.h
index 51bff91b63ee..26f14fcb6a61 100644
--- a/drivers/net/ethernet/microsoft/mana/mana.h
+++ b/drivers/net/ethernet/microsoft/mana/mana.h
@@ -375,6 +375,7 @@  struct mana_port_context {
 	unsigned int num_queues;
 
 	mana_handle_t port_handle;
+	atomic_t port_use_count;
 
 	u16 port_idx;
 
@@ -567,4 +568,7 @@  struct mana_adev {
 	struct gdma_dev *mdev;
 };
 
+int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
+		   u32 doorbell_pg_id);
+void mana_uncfg_vport(struct mana_port_context *apc);
 #endif /* _MANA_H */
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index c706bf943e49..4f7a50ace9f6 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -530,13 +530,25 @@  static int mana_query_vport_cfg(struct mana_port_context *apc, u32 vport_index,
 	return 0;
 }
 
-static int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
-			  u32 doorbell_pg_id)
+void mana_uncfg_vport(struct mana_port_context *apc)
+{
+	atomic_dec(&apc->port_use_count);
+}
+EXPORT_SYMBOL_GPL(mana_uncfg_vport);
+
+int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
+		   u32 doorbell_pg_id)
 {
 	struct mana_config_vport_resp resp = {};
 	struct mana_config_vport_req req = {};
 	int err;
 
+	/* Ethernet driver and IB driver can't take the port at the same time */
+	if (atomic_inc_return(&apc->port_use_count) != 1) {
+		atomic_dec(&apc->port_use_count);
+		return -ENODEV;
+	}
+
 	mana_gd_init_req_hdr(&req.hdr, MANA_CONFIG_VPORT_TX,
 			     sizeof(req), sizeof(resp));
 	req.vport = apc->port_handle;
@@ -566,6 +578,7 @@  static int mana_cfg_vport(struct mana_port_context *apc, u32 protection_dom_id,
 out:
 	return err;
 }
+EXPORT_SYMBOL_GPL(mana_cfg_vport);
 
 static int mana_cfg_vport_steering(struct mana_port_context *apc,
 				   enum TRI_STATE rx,
@@ -1678,6 +1691,8 @@  static void mana_destroy_vport(struct mana_port_context *apc)
 	}
 
 	mana_destroy_txq(apc);
+
+	mana_uncfg_vport(apc);
 }
 
 static int mana_create_vport(struct mana_port_context *apc,