Messages in this thread Patch in this message | | | From | Tomasz Jeznach <> | Subject | [PATCH 10/11] RISC-V: drivers/iommu/riscv: Add MSI identity remapping | Date | Wed, 19 Jul 2023 12:33:54 -0700 |
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This change provides basic identity mapping support to excercise MSI_FLAT hardware capability.
Signed-off-by: Tomasz Jeznach <tjeznach@rivosinc.com> --- drivers/iommu/riscv/iommu.c | 81 +++++++++++++++++++++++++++++++++++++ drivers/iommu/riscv/iommu.h | 3 ++ 2 files changed, 84 insertions(+)
diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c index 6042c35be3ca..7b3e3e135cf6 100644 --- a/drivers/iommu/riscv/iommu.c +++ b/drivers/iommu/riscv/iommu.c @@ -61,6 +61,9 @@ MODULE_PARM_DESC(priq_length, "Page request interface queue length."); #define RISCV_IOMMU_MAX_PSCID (1U << 20) static DEFINE_IDA(riscv_iommu_pscids); +/* TODO: Enable MSI remapping */ +#define RISCV_IMSIC_BASE 0x28000000 + /* 1 second */ #define RISCV_IOMMU_TIMEOUT riscv_timebase @@ -932,6 +935,72 @@ static irqreturn_t riscv_iommu_priq_process(int irq, void *data) * Endpoint management */ +static int riscv_iommu_enable_ir(struct riscv_iommu_endpoint *ep) +{ + struct riscv_iommu_device *iommu = ep->iommu; + struct iommu_resv_region *entry; + struct irq_domain *msi_domain; + u64 val; + int i; + + /* Initialize MSI remapping */ + if (!ep->dc || !(iommu->cap & RISCV_IOMMU_CAP_MSI_FLAT)) + return 0; + + ep->msi_root = (struct riscv_iommu_msi_pte *)get_zeroed_page(GFP_KERNEL); + if (!ep->msi_root) + return -ENOMEM; + + for (i = 0; i < 256; i++) { + ep->msi_root[i].pte = RISCV_IOMMU_MSI_PTE_V | + FIELD_PREP(RISCV_IOMMU_MSI_PTE_M, 3) | + phys_to_ppn(RISCV_IMSIC_BASE + i * PAGE_SIZE); + } + + entry = iommu_alloc_resv_region(RISCV_IMSIC_BASE, PAGE_SIZE * 256, 0, + IOMMU_RESV_SW_MSI, GFP_KERNEL); + if (entry) + list_add_tail(&entry->list, &ep->regions); + + val = virt_to_pfn(ep->msi_root) | + FIELD_PREP(RISCV_IOMMU_DC_MSIPTP_MODE, RISCV_IOMMU_DC_MSIPTP_MODE_FLAT); + ep->dc->msiptp = cpu_to_le64(val); + + /* Single page of MSIPTP, 256 IMSIC files */ + ep->dc->msi_addr_mask = cpu_to_le64(255); + ep->dc->msi_addr_pattern = cpu_to_le64(RISCV_IMSIC_BASE >> 12); + wmb(); + + /* set msi domain for the device as isolated. hack. */ + msi_domain = dev_get_msi_domain(ep->dev); + if (msi_domain) { + msi_domain->flags |= IRQ_DOMAIN_FLAG_ISOLATED_MSI; + } + + dev_dbg(ep->dev, "RV-IR enabled\n"); + + ep->ir_enabled = true; + + return 0; +} + +static void riscv_iommu_disable_ir(struct riscv_iommu_endpoint *ep) +{ + if (!ep->ir_enabled) + return; + + ep->dc->msi_addr_pattern = 0ULL; + ep->dc->msi_addr_mask = 0ULL; + ep->dc->msiptp = 0ULL; + wmb(); + + dev_dbg(ep->dev, "RV-IR disabled\n"); + + free_pages((unsigned long)ep->msi_root, 0); + ep->msi_root = NULL; + ep->ir_enabled = false; +} + /* Endpoint features/capabilities */ static void riscv_iommu_disable_ep(struct riscv_iommu_endpoint *ep) { @@ -1226,6 +1295,7 @@ static struct iommu_device *riscv_iommu_probe_device(struct device *dev) mutex_init(&ep->lock); INIT_LIST_HEAD(&ep->domain); + INIT_LIST_HEAD(&ep->regions); if (dev_is_pci(dev)) { ep->devid = pci_dev_id(to_pci_dev(dev)); @@ -1248,6 +1318,7 @@ static struct iommu_device *riscv_iommu_probe_device(struct device *dev) dev_iommu_priv_set(dev, ep); riscv_iommu_add_device(iommu, dev); riscv_iommu_enable_ep(ep); + riscv_iommu_enable_ir(ep); return &iommu->iommu; } @@ -1279,6 +1350,7 @@ static void riscv_iommu_release_device(struct device *dev) riscv_iommu_iodir_inv_devid(iommu, ep->devid); } + riscv_iommu_disable_ir(ep); riscv_iommu_disable_ep(ep); /* Remove endpoint from IOMMU tracking structures */ @@ -1301,6 +1373,15 @@ static struct iommu_group *riscv_iommu_device_group(struct device *dev) static void riscv_iommu_get_resv_regions(struct device *dev, struct list_head *head) { + struct iommu_resv_region *entry, *new_entry; + struct riscv_iommu_endpoint *ep = dev_iommu_priv_get(dev); + + list_for_each_entry(entry, &ep->regions, list) { + new_entry = kmemdup(entry, sizeof(*entry), GFP_KERNEL); + if (new_entry) + list_add_tail(&new_entry->list, head); + } + iommu_dma_get_resv_regions(dev, head); } diff --git a/drivers/iommu/riscv/iommu.h b/drivers/iommu/riscv/iommu.h index 83e8d00fd0f8..55418a1144fb 100644 --- a/drivers/iommu/riscv/iommu.h +++ b/drivers/iommu/riscv/iommu.h @@ -117,14 +117,17 @@ struct riscv_iommu_endpoint { struct riscv_iommu_dc *dc; /* device context pointer */ struct riscv_iommu_pc *pc; /* process context root, valid if pasid_enabled is true */ struct riscv_iommu_device *iommu; /* parent iommu device */ + struct riscv_iommu_msi_pte *msi_root; /* interrupt re-mapping */ struct mutex lock; struct list_head domain; /* endpoint attached managed domain */ + struct list_head regions; /* reserved regions, interrupt remapping window */ /* end point info bits */ unsigned pasid_bits; unsigned pasid_feat; bool pasid_enabled; + bool ir_enabled; }; /* Helper functions and macros */ -- 2.34.1
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