From: Shannon Nelson Date: Fri, 19 May 2023 21:56:23 +0000 (-0700) Subject: virtio: allow caller to override device DMA mask in vp_modern X-Git-Tag: v6.5-rc1~70^2~36 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=5d7d82d39eb4cab2c7d0d85baaee0fc45d2c7900;p=linux-2.6-block.git virtio: allow caller to override device DMA mask in vp_modern To add a bit of vendor flexibility with various virtio based devices, allow the caller to specify a different DMA mask. This adds a dma_mask field to struct virtio_pci_modern_device. If defined by the driver, this mask will be used in a call to dma_set_mask_and_coherent() instead of the traditional DMA_BIT_MASK(64). This allows limiting the DMA space on vendor devices with address limitations. Signed-off-by: Shannon Nelson Acked-by: Jason Wang Message-Id: <20230519215632.12343-3-shannon.nelson@amd.com> Signed-off-by: Michael S. Tsirkin --- diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c index 9b2d6614de67..aad7d9296e77 100644 --- a/drivers/virtio/virtio_pci_modern_dev.c +++ b/drivers/virtio/virtio_pci_modern_dev.c @@ -268,7 +268,8 @@ int vp_modern_probe(struct virtio_pci_modern_device *mdev) return -EINVAL; } - err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64)); + err = dma_set_mask_and_coherent(&pci_dev->dev, + mdev->dma_mask ? : DMA_BIT_MASK(64)); if (err) err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32)); diff --git a/include/linux/virtio_pci_modern.h b/include/linux/virtio_pci_modern.h index e7b1db1dd0bb..067ac1d789bc 100644 --- a/include/linux/virtio_pci_modern.h +++ b/include/linux/virtio_pci_modern.h @@ -41,6 +41,9 @@ struct virtio_pci_modern_device { /* optional check for vendor virtio device, returns dev_id or -ERRNO */ int (*device_id_check)(struct pci_dev *pdev); + + /* optional mask for devices with limited DMA space */ + u64 dma_mask; }; /*