[PATCH v3 virtio 1/8] virtio: allow caller to override device id and DMA mask
From: Shannon Nelson <hidden>
Date: 2023-03-22 19:11:02
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
To allow a bit of flexibility with various virtio based devices, allow the caller to specify a different device id and DMA mask. This adds fields to struct XXX to specify an override device id check and a DMA mask. Signed-off-by: Shannon Nelson <redacted> --- drivers/virtio/virtio_pci_modern_dev.c | 36 +++++++++++++++++--------- include/linux/virtio_pci_modern.h | 6 +++++ 2 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
index 869cb46bef96..6ad1bb9ae8fa 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c@@ -221,18 +221,25 @@ int vp_modern_probe(struct virtio_pci_modern_device *mdev) check_offsets(); - /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */ - if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f) - return -ENODEV; - - if (pci_dev->device < 0x1040) { - /* Transitional devices: use the PCI subsystem device id as - * virtio device id, same as legacy driver always did. - */ - mdev->id.device = pci_dev->subsystem_device; + if (mdev->device_id_check_override) { + err = mdev->device_id_check_override(pci_dev); + if (err) + return err; + mdev->id.device = pci_dev->device; } else { - /* Modern devices: simply use PCI device id, but start from 0x1040. */ - mdev->id.device = pci_dev->device - 0x1040; + /* We only own devices >= 0x1000 and <= 0x107f: leave the rest. */ + if (pci_dev->device < 0x1000 || pci_dev->device > 0x107f) + return -ENODEV; + + if (pci_dev->device < 0x1040) { + /* Transitional devices: use the PCI subsystem device id as + * virtio device id, same as legacy driver always did. + */ + mdev->id.device = pci_dev->subsystem_device; + } else { + /* Modern devices: simply use PCI device id, but start from 0x1040. */ + mdev->id.device = pci_dev->device - 0x1040; + } } mdev->id.vendor = pci_dev->subsystem_vendor;
@@ -260,7 +267,12 @@ 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)); + if (mdev->dma_mask_override) + err = dma_set_mask_and_coherent(&pci_dev->dev, + mdev->dma_mask_override); + else + err = dma_set_mask_and_coherent(&pci_dev->dev, + 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 c4eeb79b0139..84765bbd8dc5 100644
--- a/include/linux/virtio_pci_modern.h
+++ b/include/linux/virtio_pci_modern.h@@ -38,6 +38,12 @@ struct virtio_pci_modern_device { int modern_bars; struct virtio_device_id id; + + /* alt. check for vendor virtio device, return 0 or -ERRNO */ + int (*device_id_check_override)(struct pci_dev *pdev); + + /* alt. mask for devices with limited DMA space */ + u64 dma_mask_override; }; /*
--
2.17.1