drivers/iommu/riscv/iommu-pci.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 /*
   4  * Copyright © 2022-2024 Rivos Inc.
   5  * Copyright © 2023 FORTH-ICS/CARV
   6  *
   7  * RISCV IOMMU as a PCIe device
   8  *
   9  * Authors
  10  *      Tomasz Jeznach <tjeznach@rivosinc.com>
  11  *      Nick Kossifidis <mick@ics.forth.gr>
  12  */
  13
  14 #include <linux/compiler.h>
  15 #include <linux/init.h>
  16 #include <linux/iommu.h>
  17 #include <linux/kernel.h>
  18 #include <linux/pci.h>
  19
  20 #include "iommu-bits.h"
  21 #include "iommu.h"
  22
  23 /* QEMU RISC-V IOMMU implementation */
  24 #define PCI_DEVICE_ID_REDHAT_RISCV_IOMMU     0x0014
  25
  26 /* Rivos Inc. assigned PCI Vendor and Device IDs */
  27 #ifndef PCI_VENDOR_ID_RIVOS
  28 #define PCI_VENDOR_ID_RIVOS                  0x1efd
  29 #endif
  30
  31 #define PCI_DEVICE_ID_RIVOS_RISCV_IOMMU_GA   0x0008
  32
  33 static int riscv_iommu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
  34 {
  35         struct device *dev = &pdev->dev;
  36         struct riscv_iommu_device *iommu;
  37         int rc, vec;
  38
  39         rc = pcim_enable_device(pdev);
  40         if (rc)
  41                 return rc;
  42
  43         if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM))
  44                 return -ENODEV;
  45
  46         if (pci_resource_len(pdev, 0) < RISCV_IOMMU_REG_SIZE)
  47                 return -ENODEV;
  48
  49         rc = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
  50         if (rc)
  51                 return dev_err_probe(dev, rc, "pcim_iomap_regions failed\n");
  52
  53         iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
  54         if (!iommu)
  55                 return -ENOMEM;
  56
  57         iommu->dev = dev;
  58         iommu->reg = pcim_iomap_table(pdev)[0];
  59
  60         pci_set_master(pdev);
  61         dev_set_drvdata(dev, iommu);
  62
  63         /* Check device reported capabilities / features. */
  64         iommu->caps = riscv_iommu_readq(iommu, RISCV_IOMMU_REG_CAPABILITIES);
  65         iommu->fctl = riscv_iommu_readl(iommu, RISCV_IOMMU_REG_FCTL);
  66
  67         /* The PCI driver only uses MSIs, make sure the IOMMU supports this */
  68         switch (FIELD_GET(RISCV_IOMMU_CAPABILITIES_IGS, iommu->caps)) {
  69         case RISCV_IOMMU_CAPABILITIES_IGS_MSI:
  70         case RISCV_IOMMU_CAPABILITIES_IGS_BOTH:
  71                 break;
  72         default:
  73                 return dev_err_probe(dev, -ENODEV,
  74                                      "unable to use message-signaled interrupts\n");
  75         }
  76
  77         /* Allocate and assign IRQ vectors for the various events */
  78         rc = pci_alloc_irq_vectors(pdev, 1, RISCV_IOMMU_INTR_COUNT,
  79                                    PCI_IRQ_MSIX | PCI_IRQ_MSI);
  80         if (rc <= 0)
  81                 return dev_err_probe(dev, -ENODEV,
  82                                      "unable to allocate irq vectors\n");
  83
  84         iommu->irqs_count = rc;
  85         for (vec = 0; vec < iommu->irqs_count; vec++)
  86                 iommu->irqs[vec] = msi_get_virq(dev, vec);
  87
  88         /* Enable message-signaled interrupts, fctl.WSI */
  89         if (iommu->fctl & RISCV_IOMMU_FCTL_WSI) {
  90                 iommu->fctl ^= RISCV_IOMMU_FCTL_WSI;
  91                 riscv_iommu_writel(iommu, RISCV_IOMMU_REG_FCTL, iommu->fctl);
  92         }
  93
  94         return riscv_iommu_init(iommu);
  95 }
  96
  97 static void riscv_iommu_pci_remove(struct pci_dev *pdev)
  98 {
  99         struct riscv_iommu_device *iommu = dev_get_drvdata(&pdev->dev);
 100
 101         riscv_iommu_remove(iommu);
 102 }
 103
 104 static const struct pci_device_id riscv_iommu_pci_tbl[] = {
 105         {PCI_VDEVICE(REDHAT, PCI_DEVICE_ID_REDHAT_RISCV_IOMMU), 0},
 106         {PCI_VDEVICE(RIVOS, PCI_DEVICE_ID_RIVOS_RISCV_IOMMU_GA), 0},
 107         {0,}
 108 };
 109
 110 static struct pci_driver riscv_iommu_pci_driver = {
 111         .name = KBUILD_MODNAME,
 112         .id_table = riscv_iommu_pci_tbl,
 113         .probe = riscv_iommu_pci_probe,
 114         .remove = riscv_iommu_pci_remove,
 115         .driver = {
 116                 .suppress_bind_attrs = true,
 117         },
 118 };
 119
 120 builtin_pci_driver(riscv_iommu_pci_driver);