Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 216.228.112.34 as permitted sender) receiver=protection.outlook.com;
 client-ip=216.228.112.34; helo=mail.nvidia.com;
Date:   Wed, 21 Apr 2021 10:44:22 +0300
From:   Eli Cohen <elic@nvidia.com>
To:     Jason Wang <jasowang@redhat.com>
CC:     <mst@redhat.com>, <virtualization@lists.linux-foundation.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/7] virtio_pci_modern: introduce helper to map vq notify
 area
Message-ID: <20210421074422.GB97533@mtl-vdi-166.wap.labs.mlnx>
References: <20210415073147.19331-1-jasowang@redhat.com>
 <20210415073147.19331-2-jasowang@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20210415073147.19331-2-jasowang@redhat.com>
User-Agent: Mutt/1.9.5 (bf161cf53efb) (2018-04-13)
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Apr 2021 07:44:28.1603
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: ce51e9be-cc12-4e4d-ba55-08d904994ae5
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.112.34];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT016.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5201
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, Apr 15, 2021 at 03:31:41AM -0400, Jason Wang wrote:
> This patch factors out the logic of vq notify area mapping. Following
> patches will switch to use this common helpers for both virtio_pci
> library and virtio-pci vDPA driver.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Reviewed-by: Eli Cohen <elic@nvidia.com>

> ---
>  drivers/virtio/virtio_pci_modern_dev.c | 35 ++++++++++++++++++++++++++
>  include/linux/virtio_pci_modern.h      |  2 ++
>  2 files changed, 37 insertions(+)
> 
> diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
> index cbd667496bb1..28cb5847fafa 100644
> --- a/drivers/virtio/virtio_pci_modern_dev.c
> +++ b/drivers/virtio/virtio_pci_modern_dev.c
> @@ -593,6 +593,41 @@ u16 vp_modern_get_queue_notify_off(struct virtio_pci_modern_device *mdev,
>  }
>  EXPORT_SYMBOL_GPL(vp_modern_get_queue_notify_off);
>  
> +/*
> + * vp_modern_map_vq_notify - map notification area for a
> + * specific virtqueue
> + * @mdev: the modern virtio-pci device
> + * @index: the queue index
> + *
> + * Returns the address of the notification area
> + */
> +void *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
> +			      u16 index)
> +{
> +	u16 off = vp_modern_get_queue_notify_off(mdev, index);
> +
> +	if (mdev->notify_base) {
> +		/* offset should not wrap */
> +		if ((u64)off * mdev->notify_offset_multiplier + 2
> +			> mdev->notify_len) {
> +			dev_warn(&mdev->pci_dev->dev,
> +				 "bad notification offset %u (x %u) "
> +				 "for queue %u > %zd",
> +				 off, mdev->notify_offset_multiplier,
> +				 index, mdev->notify_len);
> +			return NULL;
> +		}
> +		return (void __force *)mdev->notify_base +
> +			off * mdev->notify_offset_multiplier;
> +	} else {
> +		return (void __force *)vp_modern_map_capability(mdev,
> +				       mdev->notify_map_cap, 2, 2,
> +				       off * mdev->notify_offset_multiplier, 2,
> +				       NULL);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(vp_modern_map_vq_notify);
> +
>  MODULE_VERSION("0.1");
>  MODULE_DESCRIPTION("Modern Virtio PCI Device");
>  MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
> diff --git a/include/linux/virtio_pci_modern.h b/include/linux/virtio_pci_modern.h
> index f26acbeec965..1b95d39b00fc 100644
> --- a/include/linux/virtio_pci_modern.h
> +++ b/include/linux/virtio_pci_modern.h
> @@ -106,6 +106,8 @@ void __iomem *vp_modern_map_capability(struct virtio_pci_modern_device *mdev, in
>  				       u32 align,
>  				       u32 start, u32 size,
>  				       size_t *len);
> +void *vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
> +                              u16 index);
>  int vp_modern_probe(struct virtio_pci_modern_device *mdev);
>  void vp_modern_remove(struct virtio_pci_modern_device *mdev);
>  #endif
> -- 
> 2.18.1
>