iommu: Add driver for Renesas VMSA-compatible IPMMU

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

4 files changed, 1107 insertions, 0 deletions

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index df56e4c74a7e..a22b537caacd 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -272,6 +272,18 @@ config SHMOBILE_IOMMU_L1SIZE
         default 256 if SHMOBILE_IOMMU_ADDRSIZE_64MB
         default 128 if SHMOBILE_IOMMU_ADDRSIZE_32MB
 
+config IPMMU_VMSA
+        bool "Renesas VMSA-compatible IPMMU"
+        depends on ARM_LPAE
+        depends on ARCH_SHMOBILE || COMPILE_TEST
+        select IOMMU_API
+        select ARM_DMA_USE_IOMMU
+        help
+          Support for the Renesas VMSA-compatible IPMMU Renesas found in the
+          R-Mobile APE6 and R-Car H2/M2 SoCs.
+
+          If unsure, say N.
+
 config SPAPR_TCE_IOMMU
         bool "sPAPR TCE IOMMU Support"
         depends on PPC_POWERNV || PPC_PSERIES
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 5d58bf16e9e3..8893bad048e0 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_AMD_IOMMU_V2) += amd_iommu_v2.o
 obj-$(CONFIG_ARM_SMMU) += arm-smmu.o
 obj-$(CONFIG_DMAR_TABLE) += dmar.o
 obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
+obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
 obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
 obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
 obj-$(CONFIG_OMAP_IOMMU) += omap-iommu2.o
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
new file mode 100644
index 000000000000..b084530babf4
--- /dev/null
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -0,0 +1,1070 @@
+/*
+ * IPMMU VMSA
+ *
+ * Copyright (C) 2014 Renesas Electronics Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/platform_data/ipmmu-vmsa.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include <asm/dma-iommu.h>
+#include <asm/pgalloc.h>
+
+struct ipmmu_vmsa_device {
+        struct device *dev;
+        void __iomem *base;
+        struct list_head list;
+
+        const struct ipmmu_vmsa_platform_data *pdata;
+        unsigned int num_utlbs;
+
+        struct dma_iommu_mapping *mapping;
+};
+
+struct ipmmu_vmsa_domain {
+        struct ipmmu_vmsa_device *mmu;
+        struct iommu_domain *io_domain;
+
+        unsigned int context_id;
+        spinlock_t lock;                        /* Protects mappings */
+        pgd_t *pgd;
+};
+
+static DEFINE_SPINLOCK(ipmmu_devices_lock);
+static LIST_HEAD(ipmmu_devices);
+
+#define TLB_LOOP_TIMEOUT                100     /* 100us */
+
+/* -----------------------------------------------------------------------------
+ * Registers Definition
+ */
+
+#define IM_CTX_SIZE                     0x40
+
+#define IMCTR                           0x0000
+#define IMCTR_TRE                       (1 << 17)
+#define IMCTR_AFE                       (1 << 16)
+#define IMCTR_RTSEL_MASK                (3 << 4)
+#define IMCTR_RTSEL_SHIFT               4
+#define IMCTR_TREN                      (1 << 3)
+#define IMCTR_INTEN                     (1 << 2)
+#define IMCTR_FLUSH                     (1 << 1)
+#define IMCTR_MMUEN                     (1 << 0)
+
+#define IMCAAR                          0x0004
+
+#define IMTTBCR                         0x0008
+#define IMTTBCR_EAE                     (1 << 31)
+#define IMTTBCR_PMB                     (1 << 30)
+#define IMTTBCR_SH1_NON_SHAREABLE       (0 << 28)
+#define IMTTBCR_SH1_OUTER_SHAREABLE     (2 << 28)
+#define IMTTBCR_SH1_INNER_SHAREABLE     (3 << 28)
+#define IMTTBCR_SH1_MASK                (3 << 28)
+#define IMTTBCR_ORGN1_NC                (0 << 26)
+#define IMTTBCR_ORGN1_WB_WA             (1 << 26)
+#define IMTTBCR_ORGN1_WT                (2 << 26)
+#define IMTTBCR_ORGN1_WB                (3 << 26)
+#define IMTTBCR_ORGN1_MASK              (3 << 26)
+#define IMTTBCR_IRGN1_NC                (0 << 24)
+#define IMTTBCR_IRGN1_WB_WA             (1 << 24)
+#define IMTTBCR_IRGN1_WT                (2 << 24)
+#define IMTTBCR_IRGN1_WB                (3 << 24)
+#define IMTTBCR_IRGN1_MASK              (3 << 24)
+#define IMTTBCR_TSZ1_MASK               (7 << 16)
+#define IMTTBCR_TSZ1_SHIFT              16
+#define IMTTBCR_SH0_NON_SHAREABLE       (0 << 12)
+#define IMTTBCR_SH0_OUTER_SHAREABLE     (2 << 12)
+#define IMTTBCR_SH0_INNER_SHAREABLE     (3 << 12)
+#define IMTTBCR_SH0_MASK                (3 << 12)
+#define IMTTBCR_ORGN0_NC                (0 << 10)
+#define IMTTBCR_ORGN0_WB_WA             (1 << 10)
+#define IMTTBCR_ORGN0_WT                (2 << 10)
+#define IMTTBCR_ORGN0_WB                (3 << 10)
+#define IMTTBCR_ORGN0_MASK              (3 << 10)
+#define IMTTBCR_IRGN0_NC                (0 << 8)
+#define IMTTBCR_IRGN0_WB_WA             (1 << 8)
+#define IMTTBCR_IRGN0_WT                (2 << 8)
+#define IMTTBCR_IRGN0_WB                (3 << 8)
+#define IMTTBCR_IRGN0_MASK              (3 << 8)
+#define IMTTBCR_SL0_LVL_2               (0 << 4)
+#define IMTTBCR_SL0_LVL_1               (1 << 4)
+#define IMTTBCR_TSZ0_MASK               (7 << 0)
+#define IMTTBCR_TSZ0_SHIFT              O
+
+#define IMBUSCR                         0x000c
+#define IMBUSCR_DVM                     (1 << 2)
+#define IMBUSCR_BUSSEL_SYS              (0 << 0)
+#define IMBUSCR_BUSSEL_CCI              (1 << 0)
+#define IMBUSCR_BUSSEL_IMCAAR           (2 << 0)
+#define IMBUSCR_BUSSEL_CCI_IMCAAR       (3 << 0)
+#define IMBUSCR_BUSSEL_MASK             (3 << 0)
+
+#define IMTTLBR0                        0x0010
+#define IMTTUBR0                        0x0014
+#define IMTTLBR1                        0x0018
+#define IMTTUBR1                        0x001c
+
+#define IMSTR                           0x0020
+#define IMSTR_ERRLVL_MASK               (3 << 12)
+#define IMSTR_ERRLVL_SHIFT              12
+#define IMSTR_ERRCODE_TLB_FORMAT        (1 << 8)
+#define IMSTR_ERRCODE_ACCESS_PERM       (4 << 8)
+#define IMSTR_ERRCODE_SECURE_ACCESS     (5 << 8)
+#define IMSTR_ERRCODE_MASK              (7 << 8)
+#define IMSTR_MHIT                      (1 << 4)
+#define IMSTR_ABORT                     (1 << 2)
+#define IMSTR_PF                        (1 << 1)
+#define IMSTR_TF                        (1 << 0)
+
+#define IMMAIR0                         0x0028
+#define IMMAIR1                         0x002c
+#define IMMAIR_ATTR_MASK                0xff
+#define IMMAIR_ATTR_DEVICE              0x04
+#define IMMAIR_ATTR_NC                  0x44
+#define IMMAIR_ATTR_WBRWA               0xff
+#define IMMAIR_ATTR_SHIFT(n)            ((n) << 3)
+#define IMMAIR_ATTR_IDX_NC              0
+#define IMMAIR_ATTR_IDX_WBRWA           1
+#define IMMAIR_ATTR_IDX_DEV             2
+
+#define IMEAR                           0x0030
+
+#define IMPCTR                          0x0200
+#define IMPSTR                          0x0208
+#define IMPEAR                          0x020c
+#define IMPMBA(n)                       (0x0280 + ((n) * 4))
+#define IMPMBD(n)                       (0x02c0 + ((n) * 4))
+
+#define IMUCTR(n)                       (0x0300 + ((n) * 16))
+#define IMUCTR_FIXADDEN                 (1 << 31)
+#define IMUCTR_FIXADD_MASK              (0xff << 16)
+#define IMUCTR_FIXADD_SHIFT             16
+#define IMUCTR_TTSEL_MMU(n)             ((n) << 4)
+#define IMUCTR_TTSEL_PMB                (8 << 4)
+#define IMUCTR_TTSEL_MASK               (15 << 4)
+#define IMUCTR_FLUSH                    (1 << 1)
+#define IMUCTR_MMUEN                    (1 << 0)
+
+#define IMUASID(n)                      (0x0308 + ((n) * 16))
+#define IMUASID_ASID8_MASK              (0xff << 8)
+#define IMUASID_ASID8_SHIFT             8
+#define IMUASID_ASID0_MASK              (0xff << 0)
+#define IMUASID_ASID0_SHIFT             0
+
+/* -----------------------------------------------------------------------------
+ * Page Table Bits
+ */
+
+/*
+ * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory access,
+ * Long-descriptor format" that the NStable bit being set in a table descriptor
+ * will result in the NStable and NS bits of all child entries being ignored and
+ * considered as being set. The IPMMU seems not to comply with this, as it
+ * generates a secure access page fault if any of the NStable and NS bits isn't
+ * set when running in non-secure mode.
+ */
+#ifndef PMD_NSTABLE
+#define PMD_NSTABLE                     (_AT(pmdval_t, 1) << 63)
+#endif
+
+#define ARM_VMSA_PTE_XN                 (((pteval_t)3) << 53)
+#define ARM_VMSA_PTE_CONT               (((pteval_t)1) << 52)
+#define ARM_VMSA_PTE_AF                 (((pteval_t)1) << 10)
+#define ARM_VMSA_PTE_SH_NS              (((pteval_t)0) << 8)
+#define ARM_VMSA_PTE_SH_OS              (((pteval_t)2) << 8)
+#define ARM_VMSA_PTE_SH_IS              (((pteval_t)3) << 8)
+#define ARM_VMSA_PTE_NS                 (((pteval_t)1) << 5)
+#define ARM_VMSA_PTE_PAGE               (((pteval_t)3) << 0)
+
+/* Stage-1 PTE */
+#define ARM_VMSA_PTE_AP_UNPRIV          (((pteval_t)1) << 6)
+#define ARM_VMSA_PTE_AP_RDONLY          (((pteval_t)2) << 6)
+#define ARM_VMSA_PTE_ATTRINDX_SHIFT     2
+#define ARM_VMSA_PTE_nG                 (((pteval_t)1) << 11)
+
+/* Stage-2 PTE */
+#define ARM_VMSA_PTE_HAP_FAULT          (((pteval_t)0) << 6)
+#define ARM_VMSA_PTE_HAP_READ           (((pteval_t)1) << 6)
+#define ARM_VMSA_PTE_HAP_WRITE          (((pteval_t)2) << 6)
+#define ARM_VMSA_PTE_MEMATTR_OIWB       (((pteval_t)0xf) << 2)
+#define ARM_VMSA_PTE_MEMATTR_NC         (((pteval_t)0x5) << 2)
+#define ARM_VMSA_PTE_MEMATTR_DEV        (((pteval_t)0x1) << 2)
+
+/* -----------------------------------------------------------------------------
+ * Read/Write Access
+ */
+
+static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
+{
+        return ioread32(mmu->base + offset);
+}
+
+static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
+                        u32 data)
+{
+        iowrite32(data, mmu->base + offset);
+}
+
+static u32 ipmmu_ctx_read(struct ipmmu_vmsa_domain *domain, unsigned int reg)
+{
+        return ipmmu_read(domain->mmu, domain->context_id * IM_CTX_SIZE + reg);
+}
+
+static void ipmmu_ctx_write(struct ipmmu_vmsa_domain *domain, unsigned int reg,
+                            u32 data)
+{
+        ipmmu_write(domain->mmu, domain->context_id * IM_CTX_SIZE + reg, data);
+}
+
+/* -----------------------------------------------------------------------------
+ * TLB and microTLB Management
+ */
+
+/* Wait for any pending TLB invalidations to complete */
+static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
+{
+        unsigned int count = 0;
+
+        while (ipmmu_ctx_read(domain, IMCTR) & IMCTR_FLUSH) {
+                cpu_relax();
+                if (++count == TLB_LOOP_TIMEOUT) {
+                        dev_err_ratelimited(domain->mmu->dev,
+                        "TLB sync timed out -- MMU may be deadlocked\n");
+                        return;
+                }
+                udelay(1);
+        }
+}
+
+static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
+{
+        u32 reg;
+
+        reg = ipmmu_ctx_read(domain, IMCTR);
+        reg |= IMCTR_FLUSH;
+        ipmmu_ctx_write(domain, IMCTR, reg);
+
+        ipmmu_tlb_sync(domain);
+}
+
+/*
+ * Enable MMU translation for the microTLB.
+ */
+static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
+                              const struct ipmmu_vmsa_master *master)
+{
+        struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+        /* TODO: What should we set the ASID to ? */
+        ipmmu_write(mmu, IMUASID(master->utlb), 0);
+        /* TODO: Do we need to flush the microTLB ? */
+        ipmmu_write(mmu, IMUCTR(master->utlb),
+                    IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_FLUSH |
+                    IMUCTR_MMUEN);
+}
+
+/*
+ * Disable MMU translation for the microTLB.
+ */
+static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
+                               const struct ipmmu_vmsa_master *master)
+{
+        struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+        ipmmu_write(mmu, IMUCTR(master->utlb), 0);
+}
+
+static void ipmmu_flush_pgtable(struct ipmmu_vmsa_device *mmu, void *addr,
+                                size_t size)
+{
+        unsigned long offset = (unsigned long)addr & ~PAGE_MASK;
+
+        /*
+         * TODO: Add support for coherent walk through CCI with DVM and remove
+         * cache handling.
+         */
+        dma_map_page(mmu->dev, virt_to_page(addr), offset, size, DMA_TO_DEVICE);
+}
+
+/* -----------------------------------------------------------------------------
+ * Domain/Context Management
+ */
+
+static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
+{
+        phys_addr_t ttbr;
+        u32 reg;
+
+        /*
+         * TODO: When adding support for multiple contexts, find an unused
+         * context.
+         */
+        domain->context_id = 0;
+
+        /* TTBR0 */
+        ipmmu_flush_pgtable(domain->mmu, domain->pgd,
+                            PTRS_PER_PGD * sizeof(*domain->pgd));
+        ttbr = __pa(domain->pgd);
+        ipmmu_ctx_write(domain, IMTTLBR0, ttbr);
+        ipmmu_ctx_write(domain, IMTTUBR0, ttbr >> 32);
+
+        /*
+         * TTBCR
+         * We use long descriptors with inner-shareable WBWA tables and allocate
+         * the whole 32-bit VA space to TTBR0.
+         */
+        ipmmu_ctx_write(domain, IMTTBCR, IMTTBCR_EAE |
+                        IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
+                        IMTTBCR_IRGN0_WB_WA | IMTTBCR_SL0_LVL_1);
+
+        /*
+         * MAIR0
+         * We need three attributes only, non-cacheable, write-back read/write
+         * allocate and device memory.
+         */
+        reg = (IMMAIR_ATTR_NC << IMMAIR_ATTR_SHIFT(IMMAIR_ATTR_IDX_NC))
+            | (IMMAIR_ATTR_WBRWA << IMMAIR_ATTR_SHIFT(IMMAIR_ATTR_IDX_WBRWA))
+            | (IMMAIR_ATTR_DEVICE << IMMAIR_ATTR_SHIFT(IMMAIR_ATTR_IDX_DEV));
+        ipmmu_ctx_write(domain, IMMAIR0, reg);
+
+        /* IMBUSCR */
+        ipmmu_ctx_write(domain, IMBUSCR,
+                        ipmmu_ctx_read(domain, IMBUSCR) &
+                        ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
+
+        /*
+         * IMSTR
+         * Clear all interrupt flags.
+         */
+        ipmmu_ctx_write(domain, IMSTR, ipmmu_ctx_read(domain, IMSTR));
+
+        /*
+         * IMCTR
+         * Enable the MMU and interrupt generation. The long-descriptor
+         * translation table format doesn't use TEX remapping. Don't enable AF
+         * software management as we have no use for it. Flush the TLB as
+         * required when modifying the context registers.
+         */
+        ipmmu_ctx_write(domain, IMCTR, IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
+
+        return 0;
+}
+
+static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
+{
+        /*
+         * Disable the context. Flush the TLB as required when modifying the
+         * context registers.
+         *
+         * TODO: Is TLB flush really needed ?
+         */
+        ipmmu_ctx_write(domain, IMCTR, IMCTR_FLUSH);
+        ipmmu_tlb_sync(domain);
+}
+
+/* -----------------------------------------------------------------------------
+ * Fault Handling
+ */
+
+static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
+{
+        const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
+        struct ipmmu_vmsa_device *mmu = domain->mmu;
+        u32 status;
+        u32 iova;
+
+        status = ipmmu_ctx_read(domain, IMSTR);
+        if (!(status & err_mask))
+                return IRQ_NONE;
+
+        iova = ipmmu_ctx_read(domain, IMEAR);
+
+        /*
+         * Clear the error status flags. Unlike traditional interrupt flag
+         * registers that must be cleared by writing 1, this status register
+         * seems to require 0. The error address register must be read before,
+         * otherwise its value will be 0.
+         */
+        ipmmu_ctx_write(domain, IMSTR, 0);
+
+        /* Log fatal errors. */
+        if (status & IMSTR_MHIT)
+                dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%08x\n",
+                                    iova);
+        if (status & IMSTR_ABORT)
+                dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%08x\n",
+                                    iova);
+
+        if (!(status & (IMSTR_PF | IMSTR_TF)))
+                return IRQ_NONE;
+
+        /*
+         * Try to handle page faults and translation faults.
+         *
+         * TODO: We need to look up the faulty device based on the I/O VA. Use
+         * the IOMMU device for now.
+         */
+        if (!report_iommu_fault(domain->io_domain, mmu->dev, iova, 0))
+                return IRQ_HANDLED;
+
+        dev_err_ratelimited(mmu->dev,
+                            "Unhandled fault: status 0x%08x iova 0x%08x\n",
+                            status, iova);
+
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t ipmmu_irq(int irq, void *dev)
+{
+        struct ipmmu_vmsa_device *mmu = dev;
+        struct iommu_domain *io_domain;
+        struct ipmmu_vmsa_domain *domain;
+
+        if (!mmu->mapping)
+                return IRQ_NONE;
+
+        io_domain = mmu->mapping->domain;
+        domain = io_domain->priv;
+
+        return ipmmu_domain_irq(domain);
+}
+
+/* -----------------------------------------------------------------------------
+ * Page Table Management
+ */
+
+static void ipmmu_free_ptes(pmd_t *pmd)
+{
+        pgtable_t table = pmd_pgtable(*pmd);
+        __free_page(table);
+}
+
+static void ipmmu_free_pmds(pud_t *pud)
+{
+        pmd_t *pmd, *pmd_base = pmd_offset(pud, 0);
+        unsigned int i;
+
+        pmd = pmd_base;
+        for (i = 0; i < PTRS_PER_PMD; ++i) {
+                if (pmd_none(*pmd))
+                        continue;
+
+                ipmmu_free_ptes(pmd);
+                pmd++;
+        }
+
+        pmd_free(NULL, pmd_base);
+}
+
+static void ipmmu_free_puds(pgd_t *pgd)
+{
+        pud_t *pud, *pud_base = pud_offset(pgd, 0);
+        unsigned int i;
+
+        pud = pud_base;
+        for (i = 0; i < PTRS_PER_PUD; ++i) {
+                if (pud_none(*pud))
+                        continue;
+
+                ipmmu_free_pmds(pud);
+                pud++;
+        }
+
+        pud_free(NULL, pud_base);
+}
+
+static void ipmmu_free_pgtables(struct ipmmu_vmsa_domain *domain)
+{
+        pgd_t *pgd, *pgd_base = domain->pgd;
+        unsigned int i;
+
+        /*
+         * Recursively free the page tables for this domain. We don't care about
+         * speculative TLB filling, because the TLB will be nuked next time this
+         * context bank is re-allocated and no devices currently map to these
+         * tables.
+         */
+        pgd = pgd_base;
+        for (i = 0; i < PTRS_PER_PGD; ++i) {
+                if (pgd_none(*pgd))
+                        continue;
+                ipmmu_free_puds(pgd);
+                pgd++;
+        }
+
+        kfree(pgd_base);
+}
+
+/*
+ * We can't use the (pgd|pud|pmd|pte)_populate or the set_(pgd|pud|pmd|pte)
+ * functions as they would flush the CPU TLB.
+ */
+
+static int ipmmu_alloc_init_pte(struct ipmmu_vmsa_device *mmu, pmd_t *pmd,
+                                unsigned long addr, unsigned long end,
+                                phys_addr_t phys, int prot)
+{
+        unsigned long pfn = __phys_to_pfn(phys);
+        pteval_t pteval = ARM_VMSA_PTE_PAGE | ARM_VMSA_PTE_NS | ARM_VMSA_PTE_AF
+                        | ARM_VMSA_PTE_XN;
+        pte_t *pte, *start;
+
+        if (pmd_none(*pmd)) {
+                /* Allocate a new set of tables */
+                pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
+                if (!pte)
+                        return -ENOMEM;
+
+                ipmmu_flush_pgtable(mmu, pte, PAGE_SIZE);
+                *pmd = __pmd(__pa(pte) | PMD_NSTABLE | PMD_TYPE_TABLE);
+                ipmmu_flush_pgtable(mmu, pmd, sizeof(*pmd));
+
+                pte += pte_index(addr);
+        } else
+                pte = pte_offset_kernel(pmd, addr);
+
+        pteval |= ARM_VMSA_PTE_AP_UNPRIV | ARM_VMSA_PTE_nG;
+        if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
+                pteval |= ARM_VMSA_PTE_AP_RDONLY;
+
+        if (prot & IOMMU_CACHE)
+                pteval |= (IMMAIR_ATTR_IDX_WBRWA <<
+                           ARM_VMSA_PTE_ATTRINDX_SHIFT);
+
+        /* If no access, create a faulting entry to avoid TLB fills */
+        if (prot & IOMMU_EXEC)
+                pteval &= ~ARM_VMSA_PTE_XN;
+        else if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
+                pteval &= ~ARM_VMSA_PTE_PAGE;
+
+        pteval |= ARM_VMSA_PTE_SH_IS;
+        start = pte;
+
+        /* Install the page table entries. */
+        do {
+                *pte++ = pfn_pte(pfn++, __pgprot(pteval));
+                addr += PAGE_SIZE;
+        } while (addr != end);
+
+        ipmmu_flush_pgtable(mmu, start, sizeof(*pte) * (pte - start));
+        return 0;
+}
+
+static int ipmmu_alloc_init_pmd(struct ipmmu_vmsa_device *mmu, pud_t *pud,
+                                unsigned long addr, unsigned long end,
+                                phys_addr_t phys, int prot)
+{
+        unsigned long next;
+        pmd_t *pmd;
+        int ret;
+
+#ifndef __PAGETABLE_PMD_FOLDED
+        if (pud_none(*pud)) {
+                pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC);
+                if (!pmd)
+                        return -ENOMEM;
+
+                ipmmu_flush_pgtable(mmu, pmd, PAGE_SIZE);
+                *pud = __pud(__pa(pmd) | PMD_NSTABLE | PMD_TYPE_TABLE);
+                ipmmu_flush_pgtable(mmu, pud, sizeof(*pud));
+
+                pmd += pmd_index(addr);
+        } else
+#endif
+                pmd = pmd_offset(pud, addr);
+
+        do {
+                next = pmd_addr_end(addr, end);
+                ret = ipmmu_alloc_init_pte(mmu, pmd, addr, end, phys, prot);
+                phys += next - addr;
+        } while (pmd++, addr = next, addr < end);
+
+        return ret;
+}
+
+static int ipmmu_alloc_init_pud(struct ipmmu_vmsa_device *mmu, pgd_t *pgd,
+                                unsigned long addr, unsigned long end,
+                                phys_addr_t phys, int prot)
+{
+        unsigned long next;
+        pud_t *pud;
+        int ret;
+
+#ifndef __PAGETABLE_PUD_FOLDED
+        if (pgd_none(*pgd)) {
+                pud = (pud_t *)get_zeroed_page(GFP_ATOMIC);
+                if (!pud)
+                        return -ENOMEM;
+
+                ipmmu_flush_pgtable(mmu, pud, PAGE_SIZE);
+                *pgd = __pgd(__pa(pud) | PMD_NSTABLE | PMD_TYPE_TABLE);
+                ipmmu_flush_pgtable(mmu, pgd, sizeof(*pgd));
+
+                pud += pud_index(addr);
+        } else
+#endif
+                pud = pud_offset(pgd, addr);
+
+        do {
+                next = pud_addr_end(addr, end);
+                ret = ipmmu_alloc_init_pmd(mmu, pud, addr, next, phys, prot);
+                phys += next - addr;
+        } while (pud++, addr = next, addr < end);
+
+        return ret;
+}
+
+static int ipmmu_handle_mapping(struct ipmmu_vmsa_domain *domain,
+                                unsigned long iova, phys_addr_t paddr,
+                                size_t size, int prot)
+{
+        struct ipmmu_vmsa_device *mmu = domain->mmu;
+        pgd_t *pgd = domain->pgd;
+        unsigned long flags;
+        unsigned long end;
+        int ret;
+
+        if (!pgd)
+                return -EINVAL;
+
+        if (size & ~PAGE_MASK)
+                return -EINVAL;
+
+        if (paddr & ~((1ULL << 40) - 1))
+                return -ERANGE;
+
+        spin_lock_irqsave(&domain->lock, flags);
+
+        pgd += pgd_index(iova);
+        end = iova + size;
+
+        do {
+                unsigned long next = pgd_addr_end(iova, end);
+
+                ret = ipmmu_alloc_init_pud(mmu, pgd, iova, next, paddr, prot);
+                if (ret)
+                        break;
+
+                paddr += next - iova;
+                iova = next;
+        } while (pgd++, iova != end);
+
+        spin_unlock_irqrestore(&domain->lock, flags);
+
+        ipmmu_tlb_invalidate(domain);
+
+        return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * IOMMU Operations
+ */
+
+static const struct ipmmu_vmsa_master *
+ipmmu_find_master(struct ipmmu_vmsa_device *ipmmu, struct device *dev)
+{
+        const struct ipmmu_vmsa_master *master = ipmmu->pdata->masters;
+        const char *devname = dev_name(dev);
+        unsigned int i;
+
+        for (i = 0; i < ipmmu->pdata->num_masters; ++i, ++master) {
+                if (strcmp(master->name, devname) == 0)
+                        return master;
+        }
+
+        return NULL;
+}
+
+static int ipmmu_domain_init(struct iommu_domain *io_domain)
+{
+        struct ipmmu_vmsa_domain *domain;
+
+        domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+        if (!domain)
+                return -ENOMEM;
+
+        spin_lock_init(&domain->lock);
+
+        domain->pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+        if (!domain->pgd) {
+                kfree(domain);
+                return -ENOMEM;
+        }
+
+        io_domain->priv = domain;
+        domain->io_domain = io_domain;
+
+        return 0;
+}
+
+static void ipmmu_domain_destroy(struct iommu_domain *io_domain)
+{
+        struct ipmmu_vmsa_domain *domain = io_domain->priv;
+
+        /*
+         * Free the domain resources. We assume that all devices have already
+         * been detached.
+         */
+        ipmmu_domain_destroy_context(domain);
+        ipmmu_free_pgtables(domain);
+        kfree(domain);
+}
+
+static int ipmmu_attach_device(struct iommu_domain *io_domain,
+                               struct device *dev)
+{
+        struct ipmmu_vmsa_device *mmu = dev->archdata.iommu;
+        struct ipmmu_vmsa_domain *domain = io_domain->priv;
+        const struct ipmmu_vmsa_master *master;
+        unsigned long flags;
+        int ret = 0;
+
+        if (!mmu) {
+                dev_err(dev, "Cannot attach to IPMMU\n");
+                return -ENXIO;
+        }
+
+        spin_lock_irqsave(&domain->lock, flags);
+
+        if (!domain->mmu) {
+                /* The domain hasn't been used yet, initialize it. */
+                domain->mmu = mmu;
+                ret = ipmmu_domain_init_context(domain);
+        } else if (domain->mmu != mmu) {
+                /*
+                 * Something is wrong, we can't attach two devices using
+                 * different IOMMUs to the same domain.
+                 */
+                dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
+                        dev_name(mmu->dev), dev_name(domain->mmu->dev));
+                ret = -EINVAL;
+        }
+
+        spin_unlock_irqrestore(&domain->lock, flags);
+
+        if (ret < 0)
+                return ret;
+
+        master = ipmmu_find_master(mmu, dev);
+        if (!master)
+                return -EINVAL;
+
+        ipmmu_utlb_enable(domain, master);
+
+        return 0;
+}
+
+static void ipmmu_detach_device(struct iommu_domain *io_domain,
+                                struct device *dev)
+{
+        struct ipmmu_vmsa_domain *domain = io_domain->priv;
+        const struct ipmmu_vmsa_master *master;
+
+        master = ipmmu_find_master(domain->mmu, dev);
+        if (!master)
+                return;
+
+        ipmmu_utlb_disable(domain, master);
+
+        /*
+         * TODO: Optimize by disabling the context when no device is attached.
+         */
+}
+
+static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
+                     phys_addr_t paddr, size_t size, int prot)
+{
+        struct ipmmu_vmsa_domain *domain = io_domain->priv;
+
+        if (!domain)
+                return -ENODEV;
+
+        return ipmmu_handle_mapping(domain, iova, paddr, size, prot);
+}
+
+static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
+                          size_t size)
+{
+        struct ipmmu_vmsa_domain *domain = io_domain->priv;
+        int ret;
+
+        ret = ipmmu_handle_mapping(domain, iova, 0, size, 0);
+        return ret ? 0 : size;
+}
+
+static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
+                                      dma_addr_t iova)
+{
+        struct ipmmu_vmsa_domain *domain = io_domain->priv;
+        pgd_t pgd;
+        pud_t pud;
+        pmd_t pmd;
+        pte_t pte;
+
+        /* TODO: Is locking needed ? */
+
+        if (!domain->pgd)
+                return 0;
+
+        pgd = *(domain->pgd + pgd_index(iova));
+        if (pgd_none(pgd))
+                return 0;
+
+        pud = *pud_offset(&pgd, iova);
+        if (pud_none(pud))
+                return 0;
+
+        pmd = *pmd_offset(&pud, iova);
+        if (pmd_none(pmd))
+                return 0;
+
+        pte = *(pmd_page_vaddr(pmd) + pte_index(iova));
+        if (pte_none(pte))
+                return 0;
+
+        return __pfn_to_phys(pte_pfn(pte)) | (iova & ~PAGE_MASK);
+}
+
+static int ipmmu_add_device(struct device *dev)
+{
+        const struct ipmmu_vmsa_master *master = NULL;
+        struct ipmmu_vmsa_device *mmu;
+        struct iommu_group *group;
+        int ret;
+
+        if (dev->archdata.iommu) {
+                dev_warn(dev, "IOMMU driver already assigned to device %s\n",
+                         dev_name(dev));
+                return -EINVAL;
+        }
+
+        /* Find the master corresponding to the device. */
+        spin_lock(&ipmmu_devices_lock);
+
+        list_for_each_entry(mmu, &ipmmu_devices, list) {
+                master = ipmmu_find_master(mmu, dev);
+                if (master) {
+                        /*
+                         * TODO Take a reference to the master to protect
+                         * against device removal.
+                         */
+                        break;
+                }
+        }
+
+        spin_unlock(&ipmmu_devices_lock);
+
+        if (!master)
+                return -ENODEV;
+
+        if (!master->utlb >= mmu->num_utlbs)
+                return -EINVAL;
+
+        /* Create a device group and add the device to it. */
+        group = iommu_group_alloc();
+        if (IS_ERR(group)) {
+                dev_err(dev, "Failed to allocate IOMMU group\n");
+                return PTR_ERR(group);
+        }
+
+        ret = iommu_group_add_device(group, dev);
+        iommu_group_put(group);
+
+        if (ret < 0) {
+                dev_err(dev, "Failed to add device to IPMMU group\n");
+                return ret;
+        }
+
+        dev->archdata.iommu = mmu;
+
+        /*
+         * Create the ARM mapping, used by the ARM DMA mapping core to allocate
+         * VAs. This will allocate a corresponding IOMMU domain.
+         *
+         * TODO:
+         * - Create one mapping per context (TLB).
+         * - Make the mapping size configurable ? We currently use a 2GB mapping
+         *   at a 1GB offset to ensure that NULL VAs will fault.
+         */
+        if (!mmu->mapping) {
+                struct dma_iommu_mapping *mapping;
+
+                mapping = arm_iommu_create_mapping(&platform_bus_type,
+                                                        SZ_1G, SZ_2G, 0);
+                if (IS_ERR(mapping)) {
+                        dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
+                        return PTR_ERR(mapping);
+                }
+
+                mmu->mapping = mapping;
+        }
+
+        /* Attach the ARM VA mapping to the device. */
+        ret = arm_iommu_attach_device(dev, mmu->mapping);
+        if (ret < 0) {
+                dev_err(dev, "Failed to attach device to VA mapping\n");
+                goto error;
+        }
+
+        return 0;
+
+error:
+        dev->archdata.iommu = NULL;
+        iommu_group_remove_device(dev);
+        return ret;
+}
+
+static void ipmmu_remove_device(struct device *dev)
+{
+        arm_iommu_detach_device(dev);
+        iommu_group_remove_device(dev);
+        dev->archdata.iommu = NULL;
+}
+
+static struct iommu_ops ipmmu_ops = {
+        .domain_init = ipmmu_domain_init,
+        .domain_destroy = ipmmu_domain_destroy,
+        .attach_dev = ipmmu_attach_device,
+        .detach_dev = ipmmu_detach_device,
+        .map = ipmmu_map,
+        .unmap = ipmmu_unmap,
+        .iova_to_phys = ipmmu_iova_to_phys,
+        .add_device = ipmmu_add_device,
+        .remove_device = ipmmu_remove_device,
+        .pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K,
+};
+
+/* -----------------------------------------------------------------------------
+ * Probe/remove and init
+ */
+
+static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
+{
+        unsigned int i;
+
+        /* Disable all contexts. */
+        for (i = 0; i < 4; ++i)
+                ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
+}
+
+static int ipmmu_probe(struct platform_device *pdev)
+{
+        struct ipmmu_vmsa_device *mmu;
+        struct resource *res;
+        int irq;
+        int ret;
+
+        if (!pdev->dev.platform_data) {
+                dev_err(&pdev->dev, "missing platform data\n");
+                return -EINVAL;
+        }
+
+        mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
+        if (!mmu) {
+                dev_err(&pdev->dev, "cannot allocate device data\n");
+                return -ENOMEM;
+        }
+
+        mmu->dev = &pdev->dev;
+        mmu->pdata = pdev->dev.platform_data;
+        mmu->num_utlbs = 32;
+
+        /* Map I/O memory and request IRQ. */
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        mmu->base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(mmu->base))
+                return PTR_ERR(mmu->base);
+
+        irq = platform_get_irq(pdev, 0);
+        if (irq < 0) {
+                dev_err(&pdev->dev, "no IRQ found\n");
+                return irq;
+        }
+
+        ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
+                               dev_name(&pdev->dev), mmu);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
+                return irq;
+        }
+
+        ipmmu_device_reset(mmu);
+
+        /*
+         * We can't create the ARM mapping here as it requires the bus to have
+         * an IOMMU, which only happens when bus_set_iommu() is called in
+         * ipmmu_init() after the probe function returns.
+         */
+
+        spin_lock(&ipmmu_devices_lock);
+        list_add(&mmu->list, &ipmmu_devices);
+        spin_unlock(&ipmmu_devices_lock);
+
+        platform_set_drvdata(pdev, mmu);
+
+        return 0;
+}
+
+static int ipmmu_remove(struct platform_device *pdev)
+{
+        struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
+
+        spin_lock(&ipmmu_devices_lock);
+        list_del(&mmu->list);
+        spin_unlock(&ipmmu_devices_lock);
+
+        arm_iommu_release_mapping(mmu->mapping);
+
+        ipmmu_device_reset(mmu);
+
+        return 0;
+}
+
+static struct platform_driver ipmmu_driver = {
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = "ipmmu-vmsa",
+        },
+        .probe = ipmmu_probe,
+        .remove = ipmmu_remove,
+};
+
+static int __init ipmmu_init(void)
+{
+        int ret;
+
+        ret = platform_driver_register(&ipmmu_driver);
+        if (ret < 0)
+                return ret;
+
+        if (!iommu_present(&platform_bus_type))
+                bus_set_iommu(&platform_bus_type, &ipmmu_ops);
+
+        return 0;
+}
+
+static void __exit ipmmu_exit(void)
+{
+        return platform_driver_unregister(&ipmmu_driver);
+}
+
+subsys_initcall(ipmmu_init);
+module_exit(ipmmu_exit);
+
+MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/ipmmu-vmsa.h b/include/linux/platform_data/ipmmu-vmsa.h
new file mode 100644
index 000000000000..5275b3ac6d37
--- /dev/null
+++ b/include/linux/platform_data/ipmmu-vmsa.h
@@ -0,0 +1,24 @@
+/*
+ * IPMMU VMSA Platform Data
+ *
+ * Copyright (C) 2014 Renesas Electronics Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#ifndef __IPMMU_VMSA_H__
+#define __IPMMU_VMSA_H__
+
+struct ipmmu_vmsa_master {
+        const char *name;
+        unsigned int utlb;
+};
+
+struct ipmmu_vmsa_platform_data {
+        const struct ipmmu_vmsa_master *masters;
+        unsigned int num_masters;
+};
+
+#endif /* __IPMMU_VMSA_H__ */