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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/iommu/ipmmu-vmsa.c
Initial import
Diffstat (limited to 'drivers/iommu/ipmmu-vmsa.c')
-rw-r--r--drivers/iommu/ipmmu-vmsa.c895
1 files changed, 895 insertions, 0 deletions
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
new file mode 100644
index 000000000..1a67c531a
--- /dev/null
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -0,0 +1,895 @@
+/*
+ * 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/of.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include <asm/dma-iommu.h>
+#include <asm/pgalloc.h>
+
+#include "io-pgtable.h"
+
+struct ipmmu_vmsa_device {
+ struct device *dev;
+ void __iomem *base;
+ struct list_head list;
+
+ unsigned int num_utlbs;
+
+ struct dma_iommu_mapping *mapping;
+};
+
+struct ipmmu_vmsa_domain {
+ struct ipmmu_vmsa_device *mmu;
+ struct iommu_domain io_domain;
+
+ struct io_pgtable_cfg cfg;
+ struct io_pgtable_ops *iop;
+
+ unsigned int context_id;
+ spinlock_t lock; /* Protects mappings */
+};
+
+struct ipmmu_vmsa_archdata {
+ struct ipmmu_vmsa_device *mmu;
+ unsigned int *utlbs;
+ unsigned int num_utlbs;
+};
+
+static DEFINE_SPINLOCK(ipmmu_devices_lock);
+static LIST_HEAD(ipmmu_devices);
+
+static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
+{
+ return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
+}
+
+#define TLB_LOOP_TIMEOUT 100 /* 100us */
+
+/* -----------------------------------------------------------------------------
+ * Registers Definition
+ */
+
+#define IM_NS_ALIAS_OFFSET 0x800
+
+#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
+
+/* -----------------------------------------------------------------------------
+ * 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,
+ unsigned int utlb)
+{
+ struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+ /*
+ * TODO: Reference-count the microTLB as several bus masters can be
+ * connected to the same microTLB.
+ */
+
+ /* TODO: What should we set the ASID to ? */
+ ipmmu_write(mmu, IMUASID(utlb), 0);
+ /* TODO: Do we need to flush the microTLB ? */
+ ipmmu_write(mmu, IMUCTR(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,
+ unsigned int utlb)
+{
+ struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+ ipmmu_write(mmu, IMUCTR(utlb), 0);
+}
+
+static void ipmmu_tlb_flush_all(void *cookie)
+{
+ struct ipmmu_vmsa_domain *domain = cookie;
+
+ ipmmu_tlb_invalidate(domain);
+}
+
+static void ipmmu_tlb_add_flush(unsigned long iova, size_t size, bool leaf,
+ void *cookie)
+{
+ /* The hardware doesn't support selective TLB flush. */
+}
+
+static void ipmmu_flush_pgtable(void *ptr, size_t size, void *cookie)
+{
+ unsigned long offset = (unsigned long)ptr & ~PAGE_MASK;
+ struct ipmmu_vmsa_domain *domain = cookie;
+
+ /*
+ * TODO: Add support for coherent walk through CCI with DVM and remove
+ * cache handling.
+ */
+ dma_map_page(domain->mmu->dev, virt_to_page(ptr), offset, size,
+ DMA_TO_DEVICE);
+}
+
+static struct iommu_gather_ops ipmmu_gather_ops = {
+ .tlb_flush_all = ipmmu_tlb_flush_all,
+ .tlb_add_flush = ipmmu_tlb_add_flush,
+ .tlb_sync = ipmmu_tlb_flush_all,
+ .flush_pgtable = ipmmu_flush_pgtable,
+};
+
+/* -----------------------------------------------------------------------------
+ * Domain/Context Management
+ */
+
+static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
+{
+ phys_addr_t ttbr;
+
+ /*
+ * Allocate the page table operations.
+ *
+ * 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.
+ */
+ domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
+ domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
+ domain->cfg.ias = 32;
+ domain->cfg.oas = 40;
+ domain->cfg.tlb = &ipmmu_gather_ops;
+
+ domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
+ domain);
+ if (!domain->iop)
+ return -EINVAL;
+
+ /*
+ * TODO: When adding support for multiple contexts, find an unused
+ * context.
+ */
+ domain->context_id = 0;
+
+ /* TTBR0 */
+ ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
+ 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 */
+ ipmmu_ctx_write(domain, IMMAIR0, domain->cfg.arm_lpae_s1_cfg.mair[0]);
+
+ /* 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 = to_vmsa_domain(io_domain);
+
+ return ipmmu_domain_irq(domain);
+}
+
+/* -----------------------------------------------------------------------------
+ * IOMMU Operations
+ */
+
+static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
+{
+ struct ipmmu_vmsa_domain *domain;
+
+ if (type != IOMMU_DOMAIN_UNMANAGED)
+ return NULL;
+
+ domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+ if (!domain)
+ return NULL;
+
+ spin_lock_init(&domain->lock);
+
+ return &domain->io_domain;
+}
+
+static void ipmmu_domain_free(struct iommu_domain *io_domain)
+{
+ struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
+
+ /*
+ * Free the domain resources. We assume that all devices have already
+ * been detached.
+ */
+ ipmmu_domain_destroy_context(domain);
+ free_io_pgtable_ops(domain->iop);
+ kfree(domain);
+}
+
+static int ipmmu_attach_device(struct iommu_domain *io_domain,
+ struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+ struct ipmmu_vmsa_device *mmu = archdata->mmu;
+ struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
+ unsigned long flags;
+ unsigned int i;
+ 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;
+
+ for (i = 0; i < archdata->num_utlbs; ++i)
+ ipmmu_utlb_enable(domain, archdata->utlbs[i]);
+
+ return 0;
+}
+
+static void ipmmu_detach_device(struct iommu_domain *io_domain,
+ struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+ struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
+ unsigned int i;
+
+ for (i = 0; i < archdata->num_utlbs; ++i)
+ ipmmu_utlb_disable(domain, archdata->utlbs[i]);
+
+ /*
+ * 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 = to_vmsa_domain(io_domain);
+
+ if (!domain)
+ return -ENODEV;
+
+ return domain->iop->map(domain->iop, 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 = to_vmsa_domain(io_domain);
+
+ return domain->iop->unmap(domain->iop, iova, size);
+}
+
+static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
+ dma_addr_t iova)
+{
+ struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
+
+ /* TODO: Is locking needed ? */
+
+ return domain->iop->iova_to_phys(domain->iop, iova);
+}
+
+static int ipmmu_find_utlbs(struct ipmmu_vmsa_device *mmu, struct device *dev,
+ unsigned int *utlbs, unsigned int num_utlbs)
+{
+ unsigned int i;
+
+ for (i = 0; i < num_utlbs; ++i) {
+ struct of_phandle_args args;
+ int ret;
+
+ ret = of_parse_phandle_with_args(dev->of_node, "iommus",
+ "#iommu-cells", i, &args);
+ if (ret < 0)
+ return ret;
+
+ of_node_put(args.np);
+
+ if (args.np != mmu->dev->of_node || args.args_count != 1)
+ return -EINVAL;
+
+ utlbs[i] = args.args[0];
+ }
+
+ return 0;
+}
+
+static int ipmmu_add_device(struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata;
+ struct ipmmu_vmsa_device *mmu;
+ struct iommu_group *group = NULL;
+ unsigned int *utlbs;
+ unsigned int i;
+ int num_utlbs;
+ int ret = -ENODEV;
+
+ 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. */
+
+ num_utlbs = of_count_phandle_with_args(dev->of_node, "iommus",
+ "#iommu-cells");
+ if (num_utlbs < 0)
+ return -ENODEV;
+
+ utlbs = kcalloc(num_utlbs, sizeof(*utlbs), GFP_KERNEL);
+ if (!utlbs)
+ return -ENOMEM;
+
+ spin_lock(&ipmmu_devices_lock);
+
+ list_for_each_entry(mmu, &ipmmu_devices, list) {
+ ret = ipmmu_find_utlbs(mmu, dev, utlbs, num_utlbs);
+ if (!ret) {
+ /*
+ * TODO Take a reference to the MMU to protect
+ * against device removal.
+ */
+ break;
+ }
+ }
+
+ spin_unlock(&ipmmu_devices_lock);
+
+ if (ret < 0)
+ return -ENODEV;
+
+ for (i = 0; i < num_utlbs; ++i) {
+ if (utlbs[i] >= mmu->num_utlbs) {
+ ret = -EINVAL;
+ goto error;
+ }
+ }
+
+ /* 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");
+ ret = PTR_ERR(group);
+ goto error;
+ }
+
+ 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");
+ group = NULL;
+ goto error;
+ }
+
+ archdata = kzalloc(sizeof(*archdata), GFP_KERNEL);
+ if (!archdata) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ archdata->mmu = mmu;
+ archdata->utlbs = utlbs;
+ archdata->num_utlbs = num_utlbs;
+ dev->archdata.iommu = archdata;
+
+ /*
+ * 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);
+ if (IS_ERR(mapping)) {
+ dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
+ ret = PTR_ERR(mapping);
+ goto error;
+ }
+
+ 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:
+ arm_iommu_release_mapping(mmu->mapping);
+
+ kfree(dev->archdata.iommu);
+ kfree(utlbs);
+
+ dev->archdata.iommu = NULL;
+
+ if (!IS_ERR_OR_NULL(group))
+ iommu_group_remove_device(dev);
+
+ return ret;
+}
+
+static void ipmmu_remove_device(struct device *dev)
+{
+ struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
+
+ arm_iommu_detach_device(dev);
+ iommu_group_remove_device(dev);
+
+ kfree(archdata->utlbs);
+ kfree(archdata);
+
+ dev->archdata.iommu = NULL;
+}
+
+static const struct iommu_ops ipmmu_ops = {
+ .domain_alloc = ipmmu_domain_alloc,
+ .domain_free = ipmmu_domain_free,
+ .attach_dev = ipmmu_attach_device,
+ .detach_dev = ipmmu_detach_device,
+ .map = ipmmu_map,
+ .unmap = ipmmu_unmap,
+ .map_sg = default_iommu_map_sg,
+ .iova_to_phys = ipmmu_iova_to_phys,
+ .add_device = ipmmu_add_device,
+ .remove_device = ipmmu_remove_device,
+ .pgsize_bitmap = SZ_1G | SZ_2M | 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 (!IS_ENABLED(CONFIG_OF) && !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->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);
+
+ /*
+ * The IPMMU has two register banks, for secure and non-secure modes.
+ * The bank mapped at the beginning of the IPMMU address space
+ * corresponds to the running mode of the CPU. When running in secure
+ * mode the non-secure register bank is also available at an offset.
+ *
+ * Secure mode operation isn't clearly documented and is thus currently
+ * not implemented in the driver. Furthermore, preliminary tests of
+ * non-secure operation with the main register bank were not successful.
+ * Offset the registers base unconditionally to point to the non-secure
+ * alias space for now.
+ */
+ mmu->base += IM_NS_ALIAS_OFFSET;
+
+ 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 ret;
+ }
+
+ 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 const struct of_device_id ipmmu_of_ids[] = {
+ { .compatible = "renesas,ipmmu-vmsa", },
+ { }
+};
+
+static struct platform_driver ipmmu_driver = {
+ .driver = {
+ .name = "ipmmu-vmsa",
+ .of_match_table = of_match_ptr(ipmmu_of_ids),
+ },
+ .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");