[PATCH v13 3/6] iommu: Add verisilicon IOMMU driver

Benjamin Gaignard
2026-02-16T09:51:53Z

The Verisilicon IOMMU hardware block can be found in combination
with Verisilicon hardware video codecs (encoders or decoders) on
different SoCs.
Enable it will allow us to use non contiguous memory allocators
for Verisilicon video codecs.
If both decoder and this iommu driver are compiled has modules
there is undefined symboles issues so this iommu driver could
only be compiled has built-in.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
MAINTAINERS | 8 +
drivers/iommu/Kconfig | 11 +
drivers/iommu/Makefile | 1 +
drivers/iommu/vsi-iommu.c | 794 ++++++++++++++++++++++++++++++++++++++
include/linux/vsi-iommu.h | 21 +
5 files changed, 835 insertions(+)
create mode 100644 drivers/iommu/vsi-iommu.c
create mode 100644 include/linux/vsi-iommu.h

diff --git a/MAINTAINERS b/MAINTAINERS
index e08767323763..28b53efe2c66 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27348,6 +27348,14 @@ F: drivers/media/v4l2-core/v4l2-isp.c
F: include/media/v4l2-isp.h
F: include/uapi/linux/media/v4l2-isp.h

+VERISILICON IOMMU DRIVER
+M: Benjamin Gaignard <benjamin.gaignard@collabora.com>
+L: iommu@lists.linux.dev
+S: Maintained
+F: Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml
+F: drivers/iommu/vsi-iommu.c
+F: include/linux/vsi-iommu.h
+
VF610 NAND DRIVER
M: Stefan Agner <stefan@agner.ch>
L: linux-mtd@lists.infradead.org
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 99095645134f..cfa712d2d035 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -384,6 +384,17 @@ config SPRD_IOMMU

Say Y here if you want to use the multimedia devices listed above.

+config VSI_IOMMU
+ bool "Verisilicon IOMMU Support"
+ depends on (ARCH_ROCKCHIP && ARM64) || COMPILE_TEST
+ select IOMMU_API
+ help
+ Support for IOMMUs used by Verisilicon sub-systems like video
+ decoders or encoder hardware blocks.
+
+ Say Y here if you want to use this IOMMU in front of these
+ hardware blocks.
+
endif # IOMMU_SUPPORT

source "drivers/iommu/generic_pt/Kconfig"
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 8e8843316c4b..f4043350d023 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -36,3 +36,4 @@ obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o
obj-$(CONFIG_IOMMU_IOPF) += io-pgfault.o
obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
obj-$(CONFIG_APPLE_DART) += apple-dart.o
+obj-$(CONFIG_VSI_IOMMU) += vsi-iommu.o
diff --git a/drivers/iommu/vsi-iommu.c b/drivers/iommu/vsi-iommu.c
new file mode 100644
index 000000000000..5c7fc6ebd0cd
--- /dev/null
+++ b/drivers/iommu/vsi-iommu.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2025 Collabora Ltd.
+ *
+ * IOMMU API for Verisilicon
+ *
+ * Module Authors: Yandong Lin <yandong.lin@rock-chips.com>
+ * Simon Xue <xxm@rock-chips.com>
+ * Benjamin Gaignard <benjamin.gaignard@collabora.com>
+ *
+ * This hardware block is using a 2 pages tables allocation structure.
+ * That make very similar to Rockhip iommu hardware blocks but it has
+ * it own driver because the registers offset and configuration bits
+ * are completely different. An additional reason is that this hardware
+ * has been developed by Verisilicon to be used by their hardware video
+ * decoders and not for a general purpose like Rockchip iommus.
+ */
+
+#include <linux/clk.h>
+#include <linux/compiler.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_iommu.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/vsi-iommu.h>
+
+#include "iommu-pages.h"
+
+struct vsi_iommu {
+ struct device *dev;
+ void __iomem *regs;
+ struct clk_bulk_data *clocks;
+ int num_clocks;
+ struct iommu_device iommu;
+ struct list_head node; /* entry in vsi_iommu_domain.iommus */
+ struct iommu_domain *domain; /* domain to which iommu is attached */
+ spinlock_t lock; /* lock to protect vsi_iommu fields */
+ int irq;
+};
+
+struct vsi_iommu_domain {
+ struct list_head iommus;
+ struct device *dev;
+ u32 *dt;
+ dma_addr_t dt_dma;
+ struct iommu_domain domain;
+ u64 *pta;
+ dma_addr_t pta_dma;
+ spinlock_t lock; /* lock to protect vsi_iommu_domain fields */
+};
+
+static struct iommu_domain vsi_identity_domain;
+
+#define NUM_DT_ENTRIES 1024
+#define NUM_PT_ENTRIES 1024
+#define PT_SIZE (NUM_PT_ENTRIES * sizeof(u32))
+
+#define SPAGE_SIZE BIT(12)
+
+/* vsi iommu regs address */
+#define VSI_MMU_CONFIG1_BASE 0x1ac
+#define VSI_MMU_AHB_EXCEPTION_BASE 0x380
+#define VSI_MMU_AHB_CONTROL_BASE 0x388
+#define VSI_MMU_AHB_TLB_ARRAY_BASE_L_BASE 0x38C
+
+/* MMU register offsets */
+#define VSI_MMU_FLUSH_BASE 0x184
+#define VSI_MMU_BIT_FLUSH BIT(4)
+
+#define VSI_MMU_PAGE_FAULT_ADDR 0x380
+#define VSI_MMU_STATUS_BASE 0x384 /* IRQ status */
+
+#define VSI_MMU_BIT_ENABLE BIT(0)
+
+#define VSI_MMU_OUT_OF_BOUND BIT(28)
+/* Irq mask */
+#define VSI_MMU_IRQ_MASK 0x7
+
+#define VSI_DTE_PT_ADDRESS_MASK 0xffffffc0
+#define VSI_DTE_PT_VALID BIT(0)
+
+#define VSI_PAGE_DESC_LO_MASK 0xfffff000
+#define VSI_PAGE_DESC_HI_MASK GENMASK_ULL(39, 32)
+#define VSI_PAGE_DESC_HI_SHIFT (32 - 4)
+
+static inline phys_addr_t vsi_dte_pt_address(u32 dte)
+{
+ return (phys_addr_t)dte & VSI_DTE_PT_ADDRESS_MASK;
+}
+
+static inline u32 vsi_mk_dte(u32 dte)
+{
+ return (phys_addr_t)dte | VSI_DTE_PT_VALID;
+}
+
+#define VSI_PTE_PAGE_WRITABLE BIT(2)
+#define VSI_PTE_PAGE_VALID BIT(0)
+
+static inline phys_addr_t vsi_pte_page_address(u64 pte)
+{
+ return ((pte << VSI_PAGE_DESC_HI_SHIFT) & VSI_PAGE_DESC_HI_MASK) |
+ (pte & VSI_PAGE_DESC_LO_MASK);
+}
+
+static u32 vsi_mk_pte(phys_addr_t page, int prot)
+{
+ u32 flags = 0;
+
+ flags |= (prot & IOMMU_WRITE) ? VSI_PTE_PAGE_WRITABLE : 0;
+
+ page = (page & VSI_PAGE_DESC_LO_MASK) |
+ ((page & VSI_PAGE_DESC_HI_MASK) >> VSI_PAGE_DESC_HI_SHIFT);
+
+ return page | flags | VSI_PTE_PAGE_VALID;
+}
+
+#define VSI_DTE_PT_VALID BIT(0)
+
+static inline bool vsi_dte_is_pt_valid(u32 dte)
+{
+ return dte & VSI_DTE_PT_VALID;
+}
+
+static inline bool vsi_pte_is_page_valid(u32 pte)
+{
+ return pte & VSI_PTE_PAGE_VALID;
+}
+
+static u32 vsi_mk_pte_invalid(u32 pte)
+{
+ return pte & ~VSI_PTE_PAGE_VALID;
+}
+
+#define VSI_MASTER_TLB_MASK GENMASK_ULL(31, 10)
+/* mode 0 : 4k */
+#define VSI_PTA_4K_MODE 0
+
+static u64 vsi_mk_pta(dma_addr_t dt_dma)
+{
+ u64 val = (dt_dma & VSI_MASTER_TLB_MASK) | VSI_PTA_4K_MODE;
+
+ return val;
+}
+
+static struct vsi_iommu_domain *to_vsi_domain(struct iommu_domain *dom)
+{
+ return container_of(dom, struct vsi_iommu_domain, domain);
+}
+
+static inline void vsi_table_flush(struct vsi_iommu_domain *vsi_domain, dma_addr_t dma,
+ unsigned int count)
+{
+ size_t size = count * sizeof(u32); /* count of u32 entry */
+
+ dma_sync_single_for_device(vsi_domain->dev, dma, size, DMA_TO_DEVICE);
+}
+
+#define VSI_IOVA_DTE_MASK 0xffc00000
+#define VSI_IOVA_DTE_SHIFT 22
+#define VSI_IOVA_PTE_MASK 0x003ff000
+#define VSI_IOVA_PTE_SHIFT 12
+#define VSI_IOVA_PAGE_MASK 0x00000fff
+#define VSI_IOVA_PAGE_SHIFT 0
+
+static u32 vsi_iova_dte_index(u32 iova)
+{
+ return (iova & VSI_IOVA_DTE_MASK) >> VSI_IOVA_DTE_SHIFT;
+}
+
+static u32 vsi_iova_pte_index(u32 iova)
+{
+ return (iova & VSI_IOVA_PTE_MASK) >> VSI_IOVA_PTE_SHIFT;
+}
+
+static u32 vsi_iova_page_offset(u32 iova)
+{
+ return (iova & VSI_IOVA_PAGE_MASK) >> VSI_IOVA_PAGE_SHIFT;
+}
+
+static irqreturn_t vsi_iommu_irq(int irq, void *dev_id)
+{
+ struct vsi_iommu *iommu = dev_id;
+ unsigned long flags;
+ dma_addr_t iova;
+ u32 status;
+
+ if (pm_runtime_resume_and_get(iommu->dev) < 0)
+ return IRQ_NONE;
+
+ spin_lock_irqsave(&iommu->lock, flags);
+
+ status = readl(iommu->regs + VSI_MMU_STATUS_BASE);
+ if (status & VSI_MMU_IRQ_MASK) {
+ dev_err(iommu->dev, "unexpected int_status=%08x\n", status);
+ iova = readl(iommu->regs + VSI_MMU_PAGE_FAULT_ADDR);
+ report_iommu_fault(iommu->domain, iommu->dev, iova, status);
+ }
+ writel(0, iommu->regs + VSI_MMU_STATUS_BASE);
+
+ spin_unlock_irqrestore(&iommu->lock, flags);
+ pm_runtime_put_autosuspend(iommu->dev);
+
+ return IRQ_HANDLED;
+}
+
+static struct vsi_iommu *vsi_iommu_get_from_dev(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct device *iommu_dev = bus_find_device_by_fwnode(&platform_bus_type,
+ fwspec->iommu_fwnode);
+
+ put_device(iommu_dev);
+
+ return iommu_dev ? dev_get_drvdata(iommu_dev) : NULL;
+}
+
+static struct iommu_domain *vsi_iommu_domain_alloc_paging(struct device *dev)
+{
+ struct vsi_iommu *iommu = dev_iommu_priv_get(dev);
+ struct vsi_iommu_domain *vsi_domain;
+
+ vsi_domain = kzalloc(sizeof(*vsi_domain), GFP_KERNEL);
+ if (!vsi_domain)
+ return NULL;
+
+ vsi_domain->dev = iommu->dev;
+ spin_lock_init(&vsi_domain->lock);
+
+ /*
+ * iommu use a 2 level pagetable.
+ * Each level1 (dt) and level2 (pt) table has 1024 4-byte entries.
+ * Allocate one 4 KiB page for each table.
+ */
+ vsi_domain->dt = iommu_alloc_pages_sz(GFP_KERNEL | GFP_DMA32,
+ SPAGE_SIZE);
+ if (!vsi_domain->dt)
+ goto err_free_domain;
+
+ vsi_domain->dt_dma = dma_map_single(vsi_domain->dev, vsi_domain->dt,
+ SPAGE_SIZE, DMA_TO_DEVICE);
+ if (dma_mapping_error(vsi_domain->dev, vsi_domain->dt_dma)) {
+ dev_err(dev, "DMA map error for DT\n");
+ goto err_free_dt;
+ }
+
+ vsi_domain->pta = iommu_alloc_pages_sz(GFP_KERNEL | GFP_DMA32,
+ SPAGE_SIZE);
+ if (!vsi_domain->pta)
+ goto err_unmap_dt;
+
+ vsi_domain->pta[0] = vsi_mk_pta(vsi_domain->dt_dma);
+ vsi_domain->pta_dma = dma_map_single(vsi_domain->dev, vsi_domain->pta,
+ SPAGE_SIZE, DMA_TO_DEVICE);
+ if (dma_mapping_error(vsi_domain->dev, vsi_domain->pta_dma)) {
+ dev_err(dev, "DMA map error for PTA\n");
+ goto err_free_pta;
+ }
+
+ INIT_LIST_HEAD(&vsi_domain->iommus);
+
+ vsi_domain->domain.geometry.aperture_start = 0;
+ vsi_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
+ vsi_domain->domain.geometry.force_aperture = true;
+ vsi_domain->domain.pgsize_bitmap = SZ_4K;
+
+ return &vsi_domain->domain;
+
+err_free_pta:
+ iommu_free_pages(vsi_domain->pta);
+err_unmap_dt:
+ dma_unmap_single(vsi_domain->dev, vsi_domain->dt_dma,
+ SPAGE_SIZE, DMA_TO_DEVICE);
+err_free_dt:
+ iommu_free_pages(vsi_domain->dt);
+err_free_domain:
+ kfree(vsi_domain);
+
+ return NULL;
+}
+
+static phys_addr_t vsi_iommu_iova_to_phys(struct iommu_domain *domain,
+ dma_addr_t iova)
+{
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+ phys_addr_t pt_phys, phys = 0;
+ unsigned long flags;
+ u32 dte, pte;
+ u32 *page_table;
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+ dte = vsi_domain->dt[vsi_iova_dte_index(iova)];
+ if (!vsi_dte_is_pt_valid(dte))
+ goto unlock;
+
+ pt_phys = vsi_dte_pt_address(dte);
+ page_table = (u32 *)phys_to_virt(pt_phys);
+ pte = page_table[vsi_iova_pte_index(iova)];
+ if (!vsi_pte_is_page_valid(pte))
+ goto unlock;
+
+ phys = vsi_pte_page_address(pte) + vsi_iova_page_offset(iova);
+
+unlock:
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+ return phys;
+}
+
+static size_t vsi_iommu_unmap_iova(struct vsi_iommu_domain *vsi_domain,
+ u32 *pte_addr, dma_addr_t pte_dma,
+ size_t size)
+{
+ unsigned int pte_count;
+ unsigned int pte_total = size / SPAGE_SIZE;
+
+ for (pte_count = 0;
+ pte_count < pte_total && pte_count < NUM_PT_ENTRIES; pte_count++) {
+ u32 pte = pte_addr[pte_count];
+
+ if (!vsi_pte_is_page_valid(pte))
+ break;
+
+ pte_addr[pte_count] = vsi_mk_pte_invalid(pte);
+ }
+
+ vsi_table_flush(vsi_domain, pte_dma, pte_total);
+
+ return pte_count * SPAGE_SIZE;
+}
+
+static int vsi_iommu_map_iova(struct vsi_iommu_domain *vsi_domain, u32 *pte_addr,
+ dma_addr_t pte_dma, dma_addr_t iova,
+ phys_addr_t paddr, size_t size, int prot)
+{
+ unsigned int pte_count;
+ unsigned int pte_total = size / SPAGE_SIZE;
+
+ for (pte_count = 0;
+ pte_count < pte_total && pte_count < NUM_PT_ENTRIES; pte_count++) {
+ u32 pte = pte_addr[pte_count];
+
+ if (vsi_pte_is_page_valid(pte))
+ return (pte_count - 1) * SPAGE_SIZE;
+
+ pte_addr[pte_count] = vsi_mk_pte(paddr, prot);
+
+ paddr += SPAGE_SIZE;
+ }
+
+ vsi_table_flush(vsi_domain, pte_dma, pte_total);
+
+ return 0;
+}
+
+static size_t vsi_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
+ size_t size, size_t count, struct iommu_iotlb_gather *gather)
+{
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+ dma_addr_t pte_dma, iova = (dma_addr_t)_iova;
+ unsigned long flags;
+ phys_addr_t pt_phys;
+ u32 dte;
+ u32 *pte_addr;
+ size_t unmap_size = 0;
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+
+ dte = vsi_domain->dt[vsi_iova_dte_index(iova)];
+ /* Just return 0 if iova is unmapped */
+ if (!vsi_dte_is_pt_valid(dte))
+ goto unlock;
+
+ pt_phys = vsi_dte_pt_address(dte);
+ pte_addr = (u32 *)phys_to_virt(pt_phys) + vsi_iova_pte_index(iova);
+ pte_dma = pt_phys + vsi_iova_pte_index(iova) * sizeof(u32);
+ unmap_size = vsi_iommu_unmap_iova(vsi_domain, pte_addr, pte_dma, size);
+
+unlock:
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+
+ return unmap_size;
+}
+
+static u32 *vsi_dte_get_page_table(struct vsi_iommu_domain *vsi_domain,
+ dma_addr_t iova, gfp_t gfp)
+{
+ u32 *page_table, *dte_addr;
+ u32 dte_index, dte;
+ phys_addr_t pt_phys;
+ dma_addr_t pt_dma;
+ gfp_t flags;
+
+ dte_index = vsi_iova_dte_index(iova);
+ dte_addr = &vsi_domain->dt[dte_index];
+ dte = *dte_addr;
+ if (vsi_dte_is_pt_valid(dte))
+ goto done;
+
+ /* Do not allow to sleep while allocating the buffer */
+ flags = (gfp & ~GFP_KERNEL) | GFP_ATOMIC | GFP_DMA32;
+ page_table = iommu_alloc_pages_sz(flags, PAGE_SIZE);
+ if (!page_table)
+ return ERR_PTR(-ENOMEM);
+
+ pt_dma = dma_map_single(vsi_domain->dev, page_table, PAGE_SIZE, DMA_TO_DEVICE);
+ if (dma_mapping_error(vsi_domain->dev, pt_dma)) {
+ dev_err(vsi_domain->dev, "DMA mapping error while allocating page table\n");
+ iommu_free_pages(page_table);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ dte = vsi_mk_dte(pt_dma);
+ *dte_addr = dte;
+
+ vsi_table_flush(vsi_domain,
+ vsi_domain->dt_dma + dte_index * sizeof(u32), 1);
+done:
+ pt_phys = vsi_dte_pt_address(dte);
+ return (u32 *)phys_to_virt(pt_phys);
+}
+
+static int vsi_iommu_map(struct iommu_domain *domain, unsigned long _iova,
+ phys_addr_t paddr, size_t size, size_t count,
+ int prot, gfp_t gfp, size_t *mapped)
+{
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+ dma_addr_t pte_dma, iova = (dma_addr_t)_iova;
+ u32 *page_table, *pte_addr;
+ u32 dte, pte_index;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+
+ page_table = vsi_dte_get_page_table(vsi_domain, iova, gfp);
+ if (IS_ERR(page_table)) {
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+ return PTR_ERR(page_table);
+ }
+
+ dte = vsi_domain->dt[vsi_iova_dte_index(iova)];
+ pte_index = vsi_iova_pte_index(iova);
+ pte_addr = &page_table[pte_index];
+ pte_dma = vsi_dte_pt_address(dte) + pte_index * sizeof(u32);
+ ret = vsi_iommu_map_iova(vsi_domain, pte_addr, pte_dma, iova,
+ paddr, size, prot);
+ if (!ret)
+ *mapped = size;
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+
+ return ret;
+}
+
+static void vsi_iommu_disable(struct vsi_iommu *iommu)
+{
+ writel(0, iommu->regs + VSI_MMU_AHB_CONTROL_BASE);
+}
+
+static int vsi_iommu_identity_attach(struct iommu_domain *domain,
+ struct device *dev, struct iommu_domain *old)
+{
+ struct vsi_iommu *iommu = dev_iommu_priv_get(dev);
+ unsigned long flags;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(iommu->dev);
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irqsave(&iommu->lock, flags);
+ if (iommu->domain == domain)
+ goto unlock;
+
+ vsi_iommu_disable(iommu);
+ list_del_init(&iommu->node);
+
+ iommu->domain = domain;
+
+unlock:
+ spin_unlock_irqrestore(&iommu->lock, flags);
+ pm_runtime_put_autosuspend(iommu->dev);
+ return 0;
+}
+
+static const struct iommu_domain_ops vsi_identity_ops = {
+ .attach_dev = vsi_iommu_identity_attach,
+};
+
+static struct iommu_domain vsi_identity_domain = {
+ .type = IOMMU_DOMAIN_IDENTITY,
+ .ops = &vsi_identity_ops,
+};
+
+static void vsi_iommu_enable(struct vsi_iommu *iommu, struct iommu_domain *domain)
+{
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+
+ if (domain == &vsi_identity_domain)
+ return;
+
+ writel(vsi_domain->pta_dma, iommu->regs + VSI_MMU_AHB_TLB_ARRAY_BASE_L_BASE);
+ writel(VSI_MMU_OUT_OF_BOUND, iommu->regs + VSI_MMU_CONFIG1_BASE);
+ writel(VSI_MMU_BIT_ENABLE, iommu->regs + VSI_MMU_AHB_EXCEPTION_BASE);
+ writel(VSI_MMU_BIT_ENABLE, iommu->regs + VSI_MMU_AHB_CONTROL_BASE);
+}
+
+/**
+ * vsi_iommu_restore_ctx - Restore iommu context for AV1 decoder
+ *
+ * @domain: iommu domain attached to AV1 video decoder
+ *
+ * AV1 stateless decoder could decode multiple bistreams at same
+ * time and before decoding a frame it is needed to restore the iommu
+ * table to avoid mixing decode contexts.
+ */
+void vsi_iommu_restore_ctx(struct iommu_domain *domain)
+{
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+ struct list_head *pos;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+
+ list_for_each(pos, &vsi_domain->iommus) {
+ struct vsi_iommu *iommu;
+
+ iommu = list_entry(pos, struct vsi_iommu, node);
+ if (!iommu)
+ continue;
+
+ spin_lock(&iommu->lock);
+
+ writel(VSI_MMU_BIT_FLUSH, iommu->regs + VSI_MMU_FLUSH_BASE);
+ writel(0, iommu->regs + VSI_MMU_FLUSH_BASE);
+
+ spin_unlock(&iommu->lock);
+ }
+
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+}
+EXPORT_SYMBOL_GPL(vsi_iommu_restore_ctx);
+
+static int vsi_iommu_attach_device(struct iommu_domain *domain,
+ struct device *dev, struct iommu_domain *old)
+{
+ struct vsi_iommu *iommu = dev_iommu_priv_get(dev);
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+ unsigned long flags, flags2;
+ int ret = 0;
+
+ ret = pm_runtime_resume_and_get(iommu->dev);
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+ spin_lock_irqsave(&iommu->lock, flags2);
+
+ vsi_iommu_enable(iommu, domain);
+ writel(VSI_MMU_BIT_FLUSH, iommu->regs + VSI_MMU_FLUSH_BASE);
+ writel(0, iommu->regs + VSI_MMU_FLUSH_BASE);
+
+ list_del_init(&iommu->node);
+ list_add_tail(&iommu->node, &vsi_domain->iommus);
+
+ iommu->domain = domain;
+
+ spin_unlock_irqrestore(&iommu->lock, flags2);
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+ pm_runtime_put_autosuspend(iommu->dev);
+ return ret;
+}
+
+static void vsi_iommu_domain_free(struct iommu_domain *domain)
+{
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(domain);
+ unsigned long flags;
+ int i;
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+
+ WARN_ON(!list_empty(&vsi_domain->iommus));
+
+ for (i = 0; i < NUM_DT_ENTRIES; i++) {
+ u32 dte = vsi_domain->dt[i];
+
+ if (vsi_dte_is_pt_valid(dte)) {
+ phys_addr_t pt_phys = vsi_dte_pt_address(dte);
+ u32 *page_table = phys_to_virt(pt_phys);
+
+ dma_unmap_single(vsi_domain->dev, pt_phys,
+ SPAGE_SIZE, DMA_TO_DEVICE);
+ iommu_free_pages(page_table);
+ }
+ }
+
+ dma_unmap_single(vsi_domain->dev, vsi_domain->dt_dma,
+ SPAGE_SIZE, DMA_TO_DEVICE);
+ iommu_free_pages(vsi_domain->dt);
+
+ dma_unmap_single(vsi_domain->dev, vsi_domain->pta_dma,
+ SPAGE_SIZE, DMA_TO_DEVICE);
+ iommu_free_pages(vsi_domain->pta);
+
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+
+ kfree(vsi_domain);
+}
+
+static struct iommu_device *vsi_iommu_probe_device(struct device *dev)
+{
+ struct vsi_iommu *iommu = vsi_iommu_get_from_dev(dev);
+ struct device_link *link;
+
+ link = device_link_add(dev, iommu->dev,
+ DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME);
+ if (!link)
+ dev_err(dev, "Unable to link %s\n", dev_name(iommu->dev));
+
+ dev_iommu_priv_set(dev, iommu);
+ return &iommu->iommu;
+}
+
+static void vsi_iommu_release_device(struct device *dev)
+{
+ struct vsi_iommu *iommu = dev_iommu_priv_get(dev);
+
+ device_link_remove(dev, iommu->dev);
+}
+
+static int vsi_iommu_of_xlate(struct device *dev, const struct of_phandle_args *args)
+{
+ return iommu_fwspec_add_ids(dev, args->args, 1);
+}
+
+static const struct iommu_ops vsi_iommu_ops = {
+ .identity_domain = &vsi_identity_domain,
+ .release_domain = &vsi_identity_domain,
+ .domain_alloc_paging = vsi_iommu_domain_alloc_paging,
+ .of_xlate = vsi_iommu_of_xlate,
+ .probe_device = vsi_iommu_probe_device,
+ .release_device = vsi_iommu_release_device,
+ .device_group = generic_single_device_group,
+ .owner = THIS_MODULE,
+ .default_domain_ops = &(const struct iommu_domain_ops) {
+ .attach_dev = vsi_iommu_attach_device,
+ .map_pages = vsi_iommu_map,
+ .unmap_pages = vsi_iommu_unmap,
+ .iova_to_phys = vsi_iommu_iova_to_phys,
+ .free = vsi_iommu_domain_free,
+ }
+};
+
+static const struct of_device_id vsi_iommu_dt_ids[] = {
+ {
+ .compatible = "verisilicon,iommu-1.2",
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, vsi_iommu_dt_ids);
+
+static int vsi_iommu_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct vsi_iommu *iommu;
+ int err;
+
+ iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
+ if (!iommu)
+ return -ENOMEM;
+
+ iommu->dev = dev;
+ spin_lock_init(&iommu->lock);
+ INIT_LIST_HEAD(&iommu->node);
+
+ iommu->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(iommu->regs))
+ return -ENOMEM;
+
+ iommu->num_clocks = devm_clk_bulk_get_all(dev, &iommu->clocks);
+ if (iommu->num_clocks < 0)
+ return iommu->num_clocks;
+
+ err = clk_bulk_prepare(iommu->num_clocks, iommu->clocks);
+ if (err)
+ return err;
+
+ iommu->irq = platform_get_irq(pdev, 0);
+ if (iommu->irq < 0)
+ return iommu->irq;
+
+ err = devm_request_irq(iommu->dev, iommu->irq, vsi_iommu_irq,
+ IRQF_SHARED, dev_name(dev), iommu);
+ if (err)
+ goto err_unprepare_clocks;
+
+ dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ platform_set_drvdata(pdev, iommu);
+
+ pm_runtime_set_autosuspend_delay(dev, 100);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_enable(dev);
+
+ err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev));
+ if (err)
+ goto err_runtime_disable;
+
+ err = iommu_device_register(&iommu->iommu, &vsi_iommu_ops, dev);
+ if (err)
+ goto err_remove_sysfs;
+
+ return 0;
+
+err_remove_sysfs:
+ iommu_device_sysfs_remove(&iommu->iommu);
+err_runtime_disable:
+ pm_runtime_disable(dev);
+err_unprepare_clocks:
+ clk_bulk_unprepare(iommu->num_clocks, iommu->clocks);
+ return err;
+}
+
+static void vsi_iommu_shutdown(struct platform_device *pdev)
+{
+ struct vsi_iommu *iommu = platform_get_drvdata(pdev);
+
+ disable_irq(iommu->irq);
+ pm_runtime_force_suspend(&pdev->dev);
+}
+
+static int __maybe_unused vsi_iommu_suspend(struct device *dev)
+{
+ struct vsi_iommu *iommu = dev_get_drvdata(dev);
+
+ vsi_iommu_disable(iommu);
+
+ clk_bulk_disable(iommu->num_clocks, iommu->clocks);
+
+ return 0;
+}
+
+static int __maybe_unused vsi_iommu_resume(struct device *dev)
+{
+ struct vsi_iommu *iommu = dev_get_drvdata(dev);
+ unsigned long flags, flags2;
+ int ret;
+
+ ret = clk_bulk_enable(iommu->num_clocks, iommu->clocks);
+ if (ret)
+ return ret;
+
+ if (iommu->domain) {
+ struct vsi_iommu_domain *vsi_domain = to_vsi_domain(iommu->domain);
+
+ spin_lock_irqsave(&vsi_domain->lock, flags);
+ spin_lock_irqsave(&iommu->lock, flags2);
+ vsi_iommu_enable(iommu, iommu->domain);
+ spin_unlock_irqrestore(&iommu->lock, flags2);
+ spin_unlock_irqrestore(&vsi_domain->lock, flags);
+ }
+
+ return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(vsi_iommu_pm_ops,
+ vsi_iommu_suspend, vsi_iommu_resume,
+ NULL);
+
+static struct platform_driver rockchip_vsi_iommu_driver = {
+ .probe = vsi_iommu_probe,
+ .shutdown = vsi_iommu_shutdown,
+ .driver = {
+ .name = "vsi_iommu",
+ .of_match_table = vsi_iommu_dt_ids,
+ .pm = pm_sleep_ptr(&vsi_iommu_pm_ops),
+ .suppress_bind_attrs = true,
+ },
+};
+module_platform_driver(rockchip_vsi_iommu_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@collabora.com>");
+MODULE_DESCRIPTION("Verisilicon IOMMU driver");
diff --git a/include/linux/vsi-iommu.h b/include/linux/vsi-iommu.h
new file mode 100644
index 000000000000..81a80f9219f4
--- /dev/null
+++ b/include/linux/vsi-iommu.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * verisilicon iommu: simple virtual address space management
+ *
+ * Copyright (c) 2025, Collabora
+ *
+ * Written by Benjamin Gaignard <benjamin.gaignard@collabora.com>
+ */
+
+#ifndef _VSI_IOMMU_H_
+#define _VSI_IOMMU_H_
+
+struct iommu_domain;
+
+#if IS_ENABLED(CONFIG_VSI_IOMMU)
+void vsi_iommu_restore_ctx(struct iommu_domain *domain);
+#else
+static inline void vsi_iommu_restore_ctx(struct iommu_domain *domain) {}
+#endif
+
+#endif
--
2.43.0