diff options
Diffstat (limited to 'drivers/uio/uio_pci_generic_sva.c')
| -rw-r--r-- | drivers/uio/uio_pci_generic_sva.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/uio/uio_pci_generic_sva.c b/drivers/uio/uio_pci_generic_sva.c new file mode 100644 index 000000000000..97e9ab9a081a --- /dev/null +++ b/drivers/uio/uio_pci_generic_sva.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * UIO PCI Express sva driver + * + * Copyright (c) 2025 Beijing Institute of Open Source Chip (BOSC) + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/uio_driver.h> +#include <linux/iommu.h> + +struct uio_pci_sva_dev { + struct pci_dev *pdev; + struct uio_info info; + struct iommu_sva *sva_handle; + int pasid; +}; + +static irqreturn_t irq_handler(int irq, struct uio_info *dev_info) +{ + return IRQ_HANDLED; +} + +static int uio_pci_sva_open(struct uio_info *info, struct inode *inode) +{ + struct iommu_sva *handle; + struct uio_pci_sva_dev *udev = info->priv; + struct iommu_domain *domain; + + if (!udev && !udev->pdev) + return -ENODEV; + + domain = iommu_get_domain_for_dev(&udev->pdev->dev); + if (domain) + iommu_detach_device(domain, &udev->pdev->dev); + + handle = iommu_sva_bind_device(&udev->pdev->dev, current->mm); + if (IS_ERR(handle)) + return -EINVAL; + + udev->pasid = iommu_sva_get_pasid(handle); + + udev->sva_handle = handle; + + return 0; +} + +static int uio_pci_sva_release(struct uio_info *info, struct inode *inode) +{ + struct uio_pci_sva_dev *udev = info->priv; + + if (!udev && !udev->pdev) + return -ENODEV; + + iommu_sva_unbind_device(udev->sva_handle); + + return 0; +} + +static int probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct uio_pci_sva_dev *udev; + int ret, i, irq = 0; + + ret = pci_enable_device(pdev); + if (ret) { + dev_err(&pdev->dev, "pci_enable_device failed: %d\n", ret); + return ret; + } + + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); + if (ret) + goto out_disable; + + pci_set_master(pdev); + + ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_MSI); + if (ret > 0) { + irq = pci_irq_vector(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "Failed to get MSI vector\n"); + ret = irq; + goto out_disable; + } + } else + dev_warn(&pdev->dev, + "No IRQ vectors available (%d), using polling\n", ret); + + udev = devm_kzalloc(&pdev->dev, sizeof(struct uio_pci_sva_dev), + GFP_KERNEL); + if (!udev) { + ret = -ENOMEM; + goto out_disable; + } + + udev->pdev = pdev; + udev->info.name = "uio_pci_sva"; + udev->info.version = "0.0.1"; + udev->info.open = uio_pci_sva_open; + udev->info.release = uio_pci_sva_release; + udev->info.irq = irq; + udev->info.handler = irq_handler; + udev->info.priv = udev; + + for (i = 0; i < MAX_UIO_MAPS; i++) { + struct resource *r = &pdev->resource[i]; + struct uio_mem *uiomem = &udev->info.mem[i]; + + if (r->flags != (IORESOURCE_SIZEALIGN | IORESOURCE_MEM)) + continue; + + if (uiomem >= &udev->info.mem[MAX_UIO_MAPS]) { + dev_warn(&pdev->dev, "Do not support more than %d iomem\n", + MAX_UIO_MAPS); + break; + } + + uiomem->memtype = UIO_MEM_PHYS; + uiomem->addr = r->start & PAGE_MASK; + uiomem->offs = r->start & ~PAGE_MASK; + uiomem->size = + (uiomem->offs + resource_size(r) + PAGE_SIZE - 1) & + PAGE_MASK; + uiomem->name = r->name; + } + + ret = devm_uio_register_device(&pdev->dev, &udev->info); + if (ret) { + dev_err(&pdev->dev, "Failed to register uio device\n"); + goto out_free; + } + + pci_set_drvdata(pdev, udev); + + return 0; + +out_free: + kfree(udev); +out_disable: + pci_disable_device(pdev); + + return ret; +} + +static void remove(struct pci_dev *pdev) +{ + struct uio_pci_sva_dev *udev = pci_get_drvdata(pdev); + + pci_release_regions(pdev); + pci_disable_device(pdev); + kfree(udev); +} + +static ssize_t pasid_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct uio_pci_sva_dev *udev = pci_get_drvdata(pdev); + + return sysfs_emit(buf, "%d\n", udev->pasid); +} +static DEVICE_ATTR_RO(pasid); + +static struct attribute *uio_pci_sva_attrs[] = { + &dev_attr_pasid.attr, + NULL +}; + +static const struct attribute_group uio_pci_sva_attr_group = { + .attrs = uio_pci_sva_attrs, +}; + +static const struct attribute_group *uio_pci_sva_attr_groups[] = { + &uio_pci_sva_attr_group, + NULL +}; + +static struct pci_driver uio_pci_generic_sva_driver = { + .name = "uio_pci_sva", + .dev_groups = uio_pci_sva_attr_groups, + .id_table = NULL, + .probe = probe, + .remove = remove, +}; + +module_pci_driver(uio_pci_generic_sva_driver); +MODULE_VERSION("0.0.01"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Yaxing Guo <guoyaxing@bosc.ac.cn>"); +MODULE_DESCRIPTION("Generic UIO sva driver for PCI"); |