Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1599 insertions, 0 deletions

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
new file mode 100644
index 000000000..d2fb347aa
--- /dev/null
+++ b/drivers/iommu/omap-iommu.c
@@ -0,0 +1,1599 @@
+/*
+ * omap iommu: tlb and pagetable primitives
+ *
+ * Copyright (C) 2008-2010 Nokia Corporation
+ * Copyright (C) 2013-2017 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>,
+ *		Paul Mundt and Toshihiro Kobayashi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/iommu.h>
+#include <linux/omap-iommu.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_iommu.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include <linux/platform_data/iommu-omap.h>
+
+#include "omap-iopgtable.h"
+#include "omap-iommu.h"
+
+static const struct iommu_ops omap_iommu_ops;
+
+#define to_iommu(dev)							\
+	((struct omap_iommu *)platform_get_drvdata(to_platform_device(dev)))
+
+/* bitmap of the page sizes currently supported */
+#define OMAP_IOMMU_PGSIZES	(SZ_4K | SZ_64K | SZ_1M | SZ_16M)
+
+#define MMU_LOCK_BASE_SHIFT	10
+#define MMU_LOCK_BASE_MASK	(0x1f << MMU_LOCK_BASE_SHIFT)
+#define MMU_LOCK_BASE(x)	\
+	((x & MMU_LOCK_BASE_MASK) >> MMU_LOCK_BASE_SHIFT)
+
+#define MMU_LOCK_VICT_SHIFT	4
+#define MMU_LOCK_VICT_MASK	(0x1f << MMU_LOCK_VICT_SHIFT)
+#define MMU_LOCK_VICT(x)	\
+	((x & MMU_LOCK_VICT_MASK) >> MMU_LOCK_VICT_SHIFT)
+
+static struct platform_driver omap_iommu_driver;
+static struct kmem_cache *iopte_cachep;
+
+/**
+ * to_omap_domain - Get struct omap_iommu_domain from generic iommu_domain
+ * @dom:	generic iommu domain handle
+ **/
+static struct omap_iommu_domain *to_omap_domain(struct iommu_domain *dom)
+{
+	return container_of(dom, struct omap_iommu_domain, domain);
+}
+
+/**
+ * omap_iommu_save_ctx - Save registers for pm off-mode support
+ * @dev:	client device
+ **/
+void omap_iommu_save_ctx(struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+	struct omap_iommu *obj;
+	u32 *p;
+	int i;
+
+	if (!arch_data)
+		return;
+
+	while (arch_data->iommu_dev) {
+		obj = arch_data->iommu_dev;
+		p = obj->ctx;
+		for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
+			p[i] = iommu_read_reg(obj, i * sizeof(u32));
+			dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i,
+				p[i]);
+		}
+		arch_data++;
+	}
+}
+EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
+
+/**
+ * omap_iommu_restore_ctx - Restore registers for pm off-mode support
+ * @dev:	client device
+ **/
+void omap_iommu_restore_ctx(struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+	struct omap_iommu *obj;
+	u32 *p;
+	int i;
+
+	if (!arch_data)
+		return;
+
+	while (arch_data->iommu_dev) {
+		obj = arch_data->iommu_dev;
+		p = obj->ctx;
+		for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
+			iommu_write_reg(obj, p[i], i * sizeof(u32));
+			dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i,
+				p[i]);
+		}
+		arch_data++;
+	}
+}
+EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
+
+static void dra7_cfg_dspsys_mmu(struct omap_iommu *obj, bool enable)
+{
+	u32 val, mask;
+
+	if (!obj->syscfg)
+		return;
+
+	mask = (1 << (obj->id * DSP_SYS_MMU_CONFIG_EN_SHIFT));
+	val = enable ? mask : 0;
+	regmap_update_bits(obj->syscfg, DSP_SYS_MMU_CONFIG, mask, val);
+}
+
+static void __iommu_set_twl(struct omap_iommu *obj, bool on)
+{
+	u32 l = iommu_read_reg(obj, MMU_CNTL);
+
+	if (on)
+		iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
+	else
+		iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
+
+	l &= ~MMU_CNTL_MASK;
+	if (on)
+		l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
+	else
+		l |= (MMU_CNTL_MMU_EN);
+
+	iommu_write_reg(obj, l, MMU_CNTL);
+}
+
+static int omap2_iommu_enable(struct omap_iommu *obj)
+{
+	u32 l, pa;
+
+	if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd,  SZ_16K))
+		return -EINVAL;
+
+	pa = virt_to_phys(obj->iopgd);
+	if (!IS_ALIGNED(pa, SZ_16K))
+		return -EINVAL;
+
+	l = iommu_read_reg(obj, MMU_REVISION);
+	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
+		 (l >> 4) & 0xf, l & 0xf);
+
+	iommu_write_reg(obj, pa, MMU_TTB);
+
+	dra7_cfg_dspsys_mmu(obj, true);
+
+	if (obj->has_bus_err_back)
+		iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
+
+	__iommu_set_twl(obj, true);
+
+	return 0;
+}
+
+static void omap2_iommu_disable(struct omap_iommu *obj)
+{
+	u32 l = iommu_read_reg(obj, MMU_CNTL);
+
+	l &= ~MMU_CNTL_MASK;
+	iommu_write_reg(obj, l, MMU_CNTL);
+	dra7_cfg_dspsys_mmu(obj, false);
+
+	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
+}
+
+static int iommu_enable(struct omap_iommu *obj)
+{
+	int err;
+	struct platform_device *pdev = to_platform_device(obj->dev);
+	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+	if (pdata && pdata->deassert_reset) {
+		err = pdata->deassert_reset(pdev, pdata->reset_name);
+		if (err) {
+			dev_err(obj->dev, "deassert_reset failed: %d\n", err);
+			return err;
+		}
+	}
+
+	pm_runtime_get_sync(obj->dev);
+
+	err = omap2_iommu_enable(obj);
+
+	return err;
+}
+
+static void iommu_disable(struct omap_iommu *obj)
+{
+	struct platform_device *pdev = to_platform_device(obj->dev);
+	struct iommu_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+	omap2_iommu_disable(obj);
+
+	pm_runtime_put_sync(obj->dev);
+
+	if (pdata && pdata->assert_reset)
+		pdata->assert_reset(pdev, pdata->reset_name);
+}
+
+/*
+ *	TLB operations
+ */
+static u32 iotlb_cr_to_virt(struct cr_regs *cr)
+{
+	u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
+	u32 mask = get_cam_va_mask(cr->cam & page_size);
+
+	return cr->cam & mask;
+}
+
+static u32 get_iopte_attr(struct iotlb_entry *e)
+{
+	u32 attr;
+
+	attr = e->mixed << 5;
+	attr |= e->endian;
+	attr |= e->elsz >> 3;
+	attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
+			(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
+	return attr;
+}
+
+static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
+{
+	u32 status, fault_addr;
+
+	status = iommu_read_reg(obj, MMU_IRQSTATUS);
+	status &= MMU_IRQ_MASK;
+	if (!status) {
+		*da = 0;
+		return 0;
+	}
+
+	fault_addr = iommu_read_reg(obj, MMU_FAULT_AD);
+	*da = fault_addr;
+
+	iommu_write_reg(obj, status, MMU_IRQSTATUS);
+
+	return status;
+}
+
+void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
+{
+	u32 val;
+
+	val = iommu_read_reg(obj, MMU_LOCK);
+
+	l->base = MMU_LOCK_BASE(val);
+	l->vict = MMU_LOCK_VICT(val);
+}
+
+void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
+{
+	u32 val;
+
+	val = (l->base << MMU_LOCK_BASE_SHIFT);
+	val |= (l->vict << MMU_LOCK_VICT_SHIFT);
+
+	iommu_write_reg(obj, val, MMU_LOCK);
+}
+
+static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
+{
+	cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
+	cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
+}
+
+static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
+{
+	iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
+	iommu_write_reg(obj, cr->ram, MMU_RAM);
+
+	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
+	iommu_write_reg(obj, 1, MMU_LD_TLB);
+}
+
+/* only used in iotlb iteration for-loop */
+struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
+{
+	struct cr_regs cr;
+	struct iotlb_lock l;
+
+	iotlb_lock_get(obj, &l);
+	l.vict = n;
+	iotlb_lock_set(obj, &l);
+	iotlb_read_cr(obj, &cr);
+
+	return cr;
+}
+
+#ifdef PREFETCH_IOTLB
+static struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
+				      struct iotlb_entry *e)
+{
+	struct cr_regs *cr;
+
+	if (!e)
+		return NULL;
+
+	if (e->da & ~(get_cam_va_mask(e->pgsz))) {
+		dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
+			e->da);
+		return ERR_PTR(-EINVAL);
+	}
+
+	cr = kmalloc(sizeof(*cr), GFP_KERNEL);
+	if (!cr)
+		return ERR_PTR(-ENOMEM);
+
+	cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
+	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
+
+	return cr;
+}
+
+/**
+ * load_iotlb_entry - Set an iommu tlb entry
+ * @obj:	target iommu
+ * @e:		an iommu tlb entry info
+ **/
+static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
+{
+	int err = 0;
+	struct iotlb_lock l;
+	struct cr_regs *cr;
+
+	if (!obj || !obj->nr_tlb_entries || !e)
+		return -EINVAL;
+
+	pm_runtime_get_sync(obj->dev);
+
+	iotlb_lock_get(obj, &l);
+	if (l.base == obj->nr_tlb_entries) {
+		dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
+		err = -EBUSY;
+		goto out;
+	}
+	if (!e->prsvd) {
+		int i;
+		struct cr_regs tmp;
+
+		for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, tmp)
+			if (!iotlb_cr_valid(&tmp))
+				break;
+
+		if (i == obj->nr_tlb_entries) {
+			dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
+			err = -EBUSY;
+			goto out;
+		}
+
+		iotlb_lock_get(obj, &l);
+	} else {
+		l.vict = l.base;
+		iotlb_lock_set(obj, &l);
+	}
+
+	cr = iotlb_alloc_cr(obj, e);
+	if (IS_ERR(cr)) {
+		pm_runtime_put_sync(obj->dev);
+		return PTR_ERR(cr);
+	}
+
+	iotlb_load_cr(obj, cr);
+	kfree(cr);
+
+	if (e->prsvd)
+		l.base++;
+	/* increment victim for next tlb load */
+	if (++l.vict == obj->nr_tlb_entries)
+		l.vict = l.base;
+	iotlb_lock_set(obj, &l);
+out:
+	pm_runtime_put_sync(obj->dev);
+	return err;
+}
+
+#else /* !PREFETCH_IOTLB */
+
+static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
+{
+	return 0;
+}
+
+#endif /* !PREFETCH_IOTLB */
+
+static int prefetch_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
+{
+	return load_iotlb_entry(obj, e);
+}
+
+/**
+ * flush_iotlb_page - Clear an iommu tlb entry
+ * @obj:	target iommu
+ * @da:		iommu device virtual address
+ *
+ * Clear an iommu tlb entry which includes 'da' address.
+ **/
+static void flush_iotlb_page(struct omap_iommu *obj, u32 da)
+{
+	int i;
+	struct cr_regs cr;
+
+	pm_runtime_get_sync(obj->dev);
+
+	for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, cr) {
+		u32 start;
+		size_t bytes;
+
+		if (!iotlb_cr_valid(&cr))
+			continue;
+
+		start = iotlb_cr_to_virt(&cr);
+		bytes = iopgsz_to_bytes(cr.cam & 3);
+
+		if ((start <= da) && (da < start + bytes)) {
+			dev_dbg(obj->dev, "%s: %08x<=%08x(%x)\n",
+				__func__, start, da, bytes);
+			iotlb_load_cr(obj, &cr);
+			iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
+			break;
+		}
+	}
+	pm_runtime_put_sync(obj->dev);
+
+	if (i == obj->nr_tlb_entries)
+		dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
+}
+
+/**
+ * flush_iotlb_all - Clear all iommu tlb entries
+ * @obj:	target iommu
+ **/
+static void flush_iotlb_all(struct omap_iommu *obj)
+{
+	struct iotlb_lock l;
+
+	pm_runtime_get_sync(obj->dev);
+
+	l.base = 0;
+	l.vict = 0;
+	iotlb_lock_set(obj, &l);
+
+	iommu_write_reg(obj, 1, MMU_GFLUSH);
+
+	pm_runtime_put_sync(obj->dev);
+}
+
+/*
+ *	H/W pagetable operations
+ */
+static void flush_iopte_range(struct device *dev, dma_addr_t dma,
+			      unsigned long offset, int num_entries)
+{
+	size_t size = num_entries * sizeof(u32);
+
+	dma_sync_single_range_for_device(dev, dma, offset, size, DMA_TO_DEVICE);
+}
+
+static void iopte_free(struct omap_iommu *obj, u32 *iopte, bool dma_valid)
+{
+	dma_addr_t pt_dma;
+
+	/* Note: freed iopte's must be clean ready for re-use */
+	if (iopte) {
+		if (dma_valid) {
+			pt_dma = virt_to_phys(iopte);
+			dma_unmap_single(obj->dev, pt_dma, IOPTE_TABLE_SIZE,
+					 DMA_TO_DEVICE);
+		}
+
+		kmem_cache_free(iopte_cachep, iopte);
+	}
+}
+
+static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd,
+			dma_addr_t *pt_dma, u32 da)
+{
+	u32 *iopte;
+	unsigned long offset = iopgd_index(da) * sizeof(da);
+
+	/* a table has already existed */
+	if (*iopgd)
+		goto pte_ready;
+
+	/*
+	 * do the allocation outside the page table lock
+	 */
+	spin_unlock(&obj->page_table_lock);
+	iopte = kmem_cache_zalloc(iopte_cachep, GFP_KERNEL);
+	spin_lock(&obj->page_table_lock);
+
+	if (!*iopgd) {
+		if (!iopte)
+			return ERR_PTR(-ENOMEM);
+
+		*pt_dma = dma_map_single(obj->dev, iopte, IOPTE_TABLE_SIZE,
+					 DMA_TO_DEVICE);
+		if (dma_mapping_error(obj->dev, *pt_dma)) {
+			dev_err(obj->dev, "DMA map error for L2 table\n");
+			iopte_free(obj, iopte, false);
+			return ERR_PTR(-ENOMEM);
+		}
+
+		/*
+		 * we rely on dma address and the physical address to be
+		 * the same for mapping the L2 table
+		 */
+		if (WARN_ON(*pt_dma != virt_to_phys(iopte))) {
+			dev_err(obj->dev, "DMA translation error for L2 table\n");
+			dma_unmap_single(obj->dev, *pt_dma, IOPTE_TABLE_SIZE,
+					 DMA_TO_DEVICE);
+			iopte_free(obj, iopte, false);
+			return ERR_PTR(-ENOMEM);
+		}
+
+		*iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
+
+		flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
+		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
+	} else {
+		/* We raced, free the reduniovant table */
+		iopte_free(obj, iopte, false);
+	}
+
+pte_ready:
+	iopte = iopte_offset(iopgd, da);
+	*pt_dma = iopgd_page_paddr(iopgd);
+	dev_vdbg(obj->dev,
+		 "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
+		 __func__, da, iopgd, *iopgd, iopte, *iopte);
+
+	return iopte;
+}
+
+static int iopgd_alloc_section(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, da);
+	unsigned long offset = iopgd_index(da) * sizeof(da);
+
+	if ((da | pa) & ~IOSECTION_MASK) {
+		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
+			__func__, da, pa, IOSECTION_SIZE);
+		return -EINVAL;
+	}
+
+	*iopgd = (pa & IOSECTION_MASK) | prot | IOPGD_SECTION;
+	flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
+	return 0;
+}
+
+static int iopgd_alloc_super(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, da);
+	unsigned long offset = iopgd_index(da) * sizeof(da);
+	int i;
+
+	if ((da | pa) & ~IOSUPER_MASK) {
+		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
+			__func__, da, pa, IOSUPER_SIZE);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < 16; i++)
+		*(iopgd + i) = (pa & IOSUPER_MASK) | prot | IOPGD_SUPER;
+	flush_iopte_range(obj->dev, obj->pd_dma, offset, 16);
+	return 0;
+}
+
+static int iopte_alloc_page(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, da);
+	dma_addr_t pt_dma;
+	u32 *iopte = iopte_alloc(obj, iopgd, &pt_dma, da);
+	unsigned long offset = iopte_index(da) * sizeof(da);
+
+	if (IS_ERR(iopte))
+		return PTR_ERR(iopte);
+
+	*iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
+	flush_iopte_range(obj->dev, pt_dma, offset, 1);
+
+	dev_vdbg(obj->dev, "%s: da:%08x pa:%08x pte:%p *pte:%08x\n",
+		 __func__, da, pa, iopte, *iopte);
+
+	return 0;
+}
+
+static int iopte_alloc_large(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, da);
+	dma_addr_t pt_dma;
+	u32 *iopte = iopte_alloc(obj, iopgd, &pt_dma, da);
+	unsigned long offset = iopte_index(da) * sizeof(da);
+	int i;
+
+	if ((da | pa) & ~IOLARGE_MASK) {
+		dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
+			__func__, da, pa, IOLARGE_SIZE);
+		return -EINVAL;
+	}
+
+	if (IS_ERR(iopte))
+		return PTR_ERR(iopte);
+
+	for (i = 0; i < 16; i++)
+		*(iopte + i) = (pa & IOLARGE_MASK) | prot | IOPTE_LARGE;
+	flush_iopte_range(obj->dev, pt_dma, offset, 16);
+	return 0;
+}
+
+static int
+iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
+{
+	int (*fn)(struct omap_iommu *, u32, u32, u32);
+	u32 prot;
+	int err;
+
+	if (!obj || !e)
+		return -EINVAL;
+
+	switch (e->pgsz) {
+	case MMU_CAM_PGSZ_16M:
+		fn = iopgd_alloc_super;
+		break;
+	case MMU_CAM_PGSZ_1M:
+		fn = iopgd_alloc_section;
+		break;
+	case MMU_CAM_PGSZ_64K:
+		fn = iopte_alloc_large;
+		break;
+	case MMU_CAM_PGSZ_4K:
+		fn = iopte_alloc_page;
+		break;
+	default:
+		fn = NULL;
+		break;
+	}
+
+	if (WARN_ON(!fn))
+		return -EINVAL;
+
+	prot = get_iopte_attr(e);
+
+	spin_lock(&obj->page_table_lock);
+	err = fn(obj, e->da, e->pa, prot);
+	spin_unlock(&obj->page_table_lock);
+
+	return err;
+}
+
+/**
+ * omap_iopgtable_store_entry - Make an iommu pte entry
+ * @obj:	target iommu
+ * @e:		an iommu tlb entry info
+ **/
+static int
+omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
+{
+	int err;
+
+	flush_iotlb_page(obj, e->da);
+	err = iopgtable_store_entry_core(obj, e);
+	if (!err)
+		prefetch_iotlb_entry(obj, e);
+	return err;
+}
+
+/**
+ * iopgtable_lookup_entry - Lookup an iommu pte entry
+ * @obj:	target iommu
+ * @da:		iommu device virtual address
+ * @ppgd:	iommu pgd entry pointer to be returned
+ * @ppte:	iommu pte entry pointer to be returned
+ **/
+static void
+iopgtable_lookup_entry(struct omap_iommu *obj, u32 da, u32 **ppgd, u32 **ppte)
+{
+	u32 *iopgd, *iopte = NULL;
+
+	iopgd = iopgd_offset(obj, da);
+	if (!*iopgd)
+		goto out;
+
+	if (iopgd_is_table(*iopgd))
+		iopte = iopte_offset(iopgd, da);
+out:
+	*ppgd = iopgd;
+	*ppte = iopte;
+}
+
+static size_t iopgtable_clear_entry_core(struct omap_iommu *obj, u32 da)
+{
+	size_t bytes;
+	u32 *iopgd = iopgd_offset(obj, da);
+	int nent = 1;
+	dma_addr_t pt_dma;
+	unsigned long pd_offset = iopgd_index(da) * sizeof(da);
+	unsigned long pt_offset = iopte_index(da) * sizeof(da);
+
+	if (!*iopgd)
+		return 0;
+
+	if (iopgd_is_table(*iopgd)) {
+		int i;
+		u32 *iopte = iopte_offset(iopgd, da);
+
+		bytes = IOPTE_SIZE;
+		if (*iopte & IOPTE_LARGE) {
+			nent *= 16;
+			/* rewind to the 1st entry */
+			iopte = iopte_offset(iopgd, (da & IOLARGE_MASK));
+		}
+		bytes *= nent;
+		memset(iopte, 0, nent * sizeof(*iopte));
+		pt_dma = iopgd_page_paddr(iopgd);
+		flush_iopte_range(obj->dev, pt_dma, pt_offset, nent);
+
+		/*
+		 * do table walk to check if this table is necessary or not
+		 */
+		iopte = iopte_offset(iopgd, 0);
+		for (i = 0; i < PTRS_PER_IOPTE; i++)
+			if (iopte[i])
+				goto out;
+
+		iopte_free(obj, iopte, true);
+		nent = 1; /* for the next L1 entry */
+	} else {
+		bytes = IOPGD_SIZE;
+		if ((*iopgd & IOPGD_SUPER) == IOPGD_SUPER) {
+			nent *= 16;
+			/* rewind to the 1st entry */
+			iopgd = iopgd_offset(obj, (da & IOSUPER_MASK));
+		}
+		bytes *= nent;
+	}
+	memset(iopgd, 0, nent * sizeof(*iopgd));
+	flush_iopte_range(obj->dev, obj->pd_dma, pd_offset, nent);
+out:
+	return bytes;
+}
+
+/**
+ * iopgtable_clear_entry - Remove an iommu pte entry
+ * @obj:	target iommu
+ * @da:		iommu device virtual address
+ **/
+static size_t iopgtable_clear_entry(struct omap_iommu *obj, u32 da)
+{
+	size_t bytes;
+
+	spin_lock(&obj->page_table_lock);
+
+	bytes = iopgtable_clear_entry_core(obj, da);
+	flush_iotlb_page(obj, da);
+
+	spin_unlock(&obj->page_table_lock);
+
+	return bytes;
+}
+
+static void iopgtable_clear_entry_all(struct omap_iommu *obj)
+{
+	unsigned long offset;
+	int i;
+
+	spin_lock(&obj->page_table_lock);
+
+	for (i = 0; i < PTRS_PER_IOPGD; i++) {
+		u32 da;
+		u32 *iopgd;
+
+		da = i << IOPGD_SHIFT;
+		iopgd = iopgd_offset(obj, da);
+		offset = iopgd_index(da) * sizeof(da);
+
+		if (!*iopgd)
+			continue;
+
+		if (iopgd_is_table(*iopgd))
+			iopte_free(obj, iopte_offset(iopgd, 0), true);
+
+		*iopgd = 0;
+		flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
+	}
+
+	flush_iotlb_all(obj);
+
+	spin_unlock(&obj->page_table_lock);
+}
+
+/*
+ *	Device IOMMU generic operations
+ */
+static irqreturn_t iommu_fault_handler(int irq, void *data)
+{
+	u32 da, errs;
+	u32 *iopgd, *iopte;
+	struct omap_iommu *obj = data;
+	struct iommu_domain *domain = obj->domain;
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+
+	if (!omap_domain->dev)
+		return IRQ_NONE;
+
+	errs = iommu_report_fault(obj, &da);
+	if (errs == 0)
+		return IRQ_HANDLED;
+
+	/* Fault callback or TLB/PTE Dynamic loading */
+	if (!report_iommu_fault(domain, obj->dev, da, 0))
+		return IRQ_HANDLED;
+
+	iommu_write_reg(obj, 0, MMU_IRQENABLE);
+
+	iopgd = iopgd_offset(obj, da);
+
+	if (!iopgd_is_table(*iopgd)) {
+		dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:px%08x\n",
+			obj->name, errs, da, iopgd, *iopgd);
+		return IRQ_NONE;
+	}
+
+	iopte = iopte_offset(iopgd, da);
+
+	dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:0x%08x pte:0x%p *pte:0x%08x\n",
+		obj->name, errs, da, iopgd, *iopgd, iopte, *iopte);
+
+	return IRQ_NONE;
+}
+
+/**
+ * omap_iommu_attach() - attach iommu device to an iommu domain
+ * @obj:	target omap iommu device
+ * @iopgd:	page table
+ **/
+static int omap_iommu_attach(struct omap_iommu *obj, u32 *iopgd)
+{
+	int err;
+
+	spin_lock(&obj->iommu_lock);
+
+	obj->pd_dma = dma_map_single(obj->dev, iopgd, IOPGD_TABLE_SIZE,
+				     DMA_TO_DEVICE);
+	if (dma_mapping_error(obj->dev, obj->pd_dma)) {
+		dev_err(obj->dev, "DMA map error for L1 table\n");
+		err = -ENOMEM;
+		goto out_err;
+	}
+
+	obj->iopgd = iopgd;
+	err = iommu_enable(obj);
+	if (err)
+		goto out_err;
+	flush_iotlb_all(obj);
+
+	spin_unlock(&obj->iommu_lock);
+
+	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
+
+	return 0;
+
+out_err:
+	spin_unlock(&obj->iommu_lock);
+
+	return err;
+}
+
+/**
+ * omap_iommu_detach - release iommu device
+ * @obj:	target iommu
+ **/
+static void omap_iommu_detach(struct omap_iommu *obj)
+{
+	if (!obj || IS_ERR(obj))
+		return;
+
+	spin_lock(&obj->iommu_lock);
+
+	dma_unmap_single(obj->dev, obj->pd_dma, IOPGD_TABLE_SIZE,
+			 DMA_TO_DEVICE);
+	iommu_disable(obj);
+	obj->pd_dma = 0;
+	obj->iopgd = NULL;
+
+	spin_unlock(&obj->iommu_lock);
+
+	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
+}
+
+static bool omap_iommu_can_register(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+
+	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
+		return true;
+
+	/*
+	 * restrict IOMMU core registration only for processor-port MDMA MMUs
+	 * on DRA7 DSPs
+	 */
+	if ((!strcmp(dev_name(&pdev->dev), "40d01000.mmu")) ||
+	    (!strcmp(dev_name(&pdev->dev), "41501000.mmu")))
+		return true;
+
+	return false;
+}
+
+static int omap_iommu_dra7_get_dsp_system_cfg(struct platform_device *pdev,
+					      struct omap_iommu *obj)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int ret;
+
+	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
+		return 0;
+
+	if (!of_property_read_bool(np, "ti,syscon-mmuconfig")) {
+		dev_err(&pdev->dev, "ti,syscon-mmuconfig property is missing\n");
+		return -EINVAL;
+	}
+
+	obj->syscfg =
+		syscon_regmap_lookup_by_phandle(np, "ti,syscon-mmuconfig");
+	if (IS_ERR(obj->syscfg)) {
+		/* can fail with -EPROBE_DEFER */
+		ret = PTR_ERR(obj->syscfg);
+		return ret;
+	}
+
+	if (of_property_read_u32_index(np, "ti,syscon-mmuconfig", 1,
+				       &obj->id)) {
+		dev_err(&pdev->dev, "couldn't get the IOMMU instance id within subsystem\n");
+		return -EINVAL;
+	}
+
+	if (obj->id != 0 && obj->id != 1) {
+		dev_err(&pdev->dev, "invalid IOMMU instance id\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ *	OMAP Device MMU(IOMMU) detection
+ */
+static int omap_iommu_probe(struct platform_device *pdev)
+{
+	int err = -ENODEV;
+	int irq;
+	struct omap_iommu *obj;
+	struct resource *res;
+	struct device_node *of = pdev->dev.of_node;
+
+	if (!of) {
+		pr_err("%s: only DT-based devices are supported\n", __func__);
+		return -ENODEV;
+	}
+
+	obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
+	if (!obj)
+		return -ENOMEM;
+
+	obj->name = dev_name(&pdev->dev);
+	obj->nr_tlb_entries = 32;
+	err = of_property_read_u32(of, "ti,#tlb-entries", &obj->nr_tlb_entries);
+	if (err && err != -EINVAL)
+		return err;
+	if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
+		return -EINVAL;
+	if (of_find_property(of, "ti,iommu-bus-err-back", NULL))
+		obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN;
+
+	obj->dev = &pdev->dev;
+	obj->ctx = (void *)obj + sizeof(*obj);
+
+	spin_lock_init(&obj->iommu_lock);
+	spin_lock_init(&obj->page_table_lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	obj->regbase = devm_ioremap_resource(obj->dev, res);
+	if (IS_ERR(obj->regbase))
+		return PTR_ERR(obj->regbase);
+
+	err = omap_iommu_dra7_get_dsp_system_cfg(pdev, obj);
+	if (err)
+		return err;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENODEV;
+
+	err = devm_request_irq(obj->dev, irq, iommu_fault_handler, IRQF_SHARED,
+			       dev_name(obj->dev), obj);
+	if (err < 0)
+		return err;
+	platform_set_drvdata(pdev, obj);
+
+	if (omap_iommu_can_register(pdev)) {
+		obj->group = iommu_group_alloc();
+		if (IS_ERR(obj->group))
+			return PTR_ERR(obj->group);
+
+		err = iommu_device_sysfs_add(&obj->iommu, obj->dev, NULL,
+					     obj->name);
+		if (err)
+			goto out_group;
+
+		iommu_device_set_ops(&obj->iommu, &omap_iommu_ops);
+
+		err = iommu_device_register(&obj->iommu);
+		if (err)
+			goto out_sysfs;
+	}
+
+	pm_runtime_irq_safe(obj->dev);
+	pm_runtime_enable(obj->dev);
+
+	omap_iommu_debugfs_add(obj);
+
+	dev_info(&pdev->dev, "%s registered\n", obj->name);
+
+	return 0;
+
+out_sysfs:
+	iommu_device_sysfs_remove(&obj->iommu);
+out_group:
+	iommu_group_put(obj->group);
+	return err;
+}
+
+static int omap_iommu_remove(struct platform_device *pdev)
+{
+	struct omap_iommu *obj = platform_get_drvdata(pdev);
+
+	if (obj->group) {
+		iommu_group_put(obj->group);
+		obj->group = NULL;
+
+		iommu_device_sysfs_remove(&obj->iommu);
+		iommu_device_unregister(&obj->iommu);
+	}
+
+	omap_iommu_debugfs_remove(obj);
+
+	pm_runtime_disable(obj->dev);
+
+	dev_info(&pdev->dev, "%s removed\n", obj->name);
+	return 0;
+}
+
+static const struct of_device_id omap_iommu_of_match[] = {
+	{ .compatible = "ti,omap2-iommu" },
+	{ .compatible = "ti,omap4-iommu" },
+	{ .compatible = "ti,dra7-iommu"	},
+	{ .compatible = "ti,dra7-dsp-iommu" },
+	{},
+};
+
+static struct platform_driver omap_iommu_driver = {
+	.probe	= omap_iommu_probe,
+	.remove	= omap_iommu_remove,
+	.driver	= {
+		.name	= "omap-iommu",
+		.of_match_table = of_match_ptr(omap_iommu_of_match),
+	},
+};
+
+static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
+{
+	memset(e, 0, sizeof(*e));
+
+	e->da		= da;
+	e->pa		= pa;
+	e->valid	= MMU_CAM_V;
+	e->pgsz		= pgsz;
+	e->endian	= MMU_RAM_ENDIAN_LITTLE;
+	e->elsz		= MMU_RAM_ELSZ_8;
+	e->mixed	= 0;
+
+	return iopgsz_to_bytes(e->pgsz);
+}
+
+static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
+			  phys_addr_t pa, size_t bytes, int prot)
+{
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+	struct device *dev = omap_domain->dev;
+	struct omap_iommu_device *iommu;
+	struct omap_iommu *oiommu;
+	struct iotlb_entry e;
+	int omap_pgsz;
+	u32 ret = -EINVAL;
+	int i;
+
+	omap_pgsz = bytes_to_iopgsz(bytes);
+	if (omap_pgsz < 0) {
+		dev_err(dev, "invalid size to map: %d\n", bytes);
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "mapping da 0x%lx to pa %pa size 0x%x\n", da, &pa, bytes);
+
+	iotlb_init_entry(&e, da, pa, omap_pgsz);
+
+	iommu = omap_domain->iommus;
+	for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
+		oiommu = iommu->iommu_dev;
+		ret = omap_iopgtable_store_entry(oiommu, &e);
+		if (ret) {
+			dev_err(dev, "omap_iopgtable_store_entry failed: %d\n",
+				ret);
+			break;
+		}
+	}
+
+	if (ret) {
+		while (i--) {
+			iommu--;
+			oiommu = iommu->iommu_dev;
+			iopgtable_clear_entry(oiommu, da);
+		}
+	}
+
+	return ret;
+}
+
+static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
+			       size_t size)
+{
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+	struct device *dev = omap_domain->dev;
+	struct omap_iommu_device *iommu;
+	struct omap_iommu *oiommu;
+	bool error = false;
+	size_t bytes = 0;
+	int i;
+
+	dev_dbg(dev, "unmapping da 0x%lx size %u\n", da, size);
+
+	iommu = omap_domain->iommus;
+	for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
+		oiommu = iommu->iommu_dev;
+		bytes = iopgtable_clear_entry(oiommu, da);
+		if (!bytes)
+			error = true;
+	}
+
+	/*
+	 * simplify return - we are only checking if any of the iommus
+	 * reported an error, but not if all of them are unmapping the
+	 * same number of entries. This should not occur due to the
+	 * mirror programming.
+	 */
+	return error ? 0 : bytes;
+}
+
+static int omap_iommu_count(struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+	int count = 0;
+
+	while (arch_data->iommu_dev) {
+		count++;
+		arch_data++;
+	}
+
+	return count;
+}
+
+/* caller should call cleanup if this function fails */
+static int omap_iommu_attach_init(struct device *dev,
+				  struct omap_iommu_domain *odomain)
+{
+	struct omap_iommu_device *iommu;
+	int i;
+
+	odomain->num_iommus = omap_iommu_count(dev);
+	if (!odomain->num_iommus)
+		return -EINVAL;
+
+	odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu),
+				  GFP_ATOMIC);
+	if (!odomain->iommus)
+		return -ENOMEM;
+
+	iommu = odomain->iommus;
+	for (i = 0; i < odomain->num_iommus; i++, iommu++) {
+		iommu->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_ATOMIC);
+		if (!iommu->pgtable)
+			return -ENOMEM;
+
+		/*
+		 * should never fail, but please keep this around to ensure
+		 * we keep the hardware happy
+		 */
+		if (WARN_ON(!IS_ALIGNED((long)iommu->pgtable,
+					IOPGD_TABLE_SIZE)))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void omap_iommu_detach_fini(struct omap_iommu_domain *odomain)
+{
+	int i;
+	struct omap_iommu_device *iommu = odomain->iommus;
+
+	for (i = 0; iommu && i < odomain->num_iommus; i++, iommu++)
+		kfree(iommu->pgtable);
+
+	kfree(odomain->iommus);
+	odomain->num_iommus = 0;
+	odomain->iommus = NULL;
+}
+
+static int
+omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
+{
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+	struct omap_iommu_device *iommu;
+	struct omap_iommu *oiommu;
+	int ret = 0;
+	int i;
+
+	if (!arch_data || !arch_data->iommu_dev) {
+		dev_err(dev, "device doesn't have an associated iommu\n");
+		return -EINVAL;
+	}
+
+	spin_lock(&omap_domain->lock);
+
+	/* only a single client device can be attached to a domain */
+	if (omap_domain->dev) {
+		dev_err(dev, "iommu domain is already attached\n");
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ret = omap_iommu_attach_init(dev, omap_domain);
+	if (ret) {
+		dev_err(dev, "failed to allocate required iommu data %d\n",
+			ret);
+		goto init_fail;
+	}
+
+	iommu = omap_domain->iommus;
+	for (i = 0; i < omap_domain->num_iommus; i++, iommu++, arch_data++) {
+		/* configure and enable the omap iommu */
+		oiommu = arch_data->iommu_dev;
+		ret = omap_iommu_attach(oiommu, iommu->pgtable);
+		if (ret) {
+			dev_err(dev, "can't get omap iommu: %d\n", ret);
+			goto attach_fail;
+		}
+
+		oiommu->domain = domain;
+		iommu->iommu_dev = oiommu;
+	}
+
+	omap_domain->dev = dev;
+
+	goto out;
+
+attach_fail:
+	while (i--) {
+		iommu--;
+		arch_data--;
+		oiommu = iommu->iommu_dev;
+		omap_iommu_detach(oiommu);
+		iommu->iommu_dev = NULL;
+		oiommu->domain = NULL;
+	}
+init_fail:
+	omap_iommu_detach_fini(omap_domain);
+out:
+	spin_unlock(&omap_domain->lock);
+	return ret;
+}
+
+static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
+				   struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+	struct omap_iommu_device *iommu = omap_domain->iommus;
+	struct omap_iommu *oiommu;
+	int i;
+
+	if (!omap_domain->dev) {
+		dev_err(dev, "domain has no attached device\n");
+		return;
+	}
+
+	/* only a single device is supported per domain for now */
+	if (omap_domain->dev != dev) {
+		dev_err(dev, "invalid attached device\n");
+		return;
+	}
+
+	/*
+	 * cleanup in the reverse order of attachment - this addresses
+	 * any h/w dependencies between multiple instances, if any
+	 */
+	iommu += (omap_domain->num_iommus - 1);
+	arch_data += (omap_domain->num_iommus - 1);
+	for (i = 0; i < omap_domain->num_iommus; i++, iommu--, arch_data--) {
+		oiommu = iommu->iommu_dev;
+		iopgtable_clear_entry_all(oiommu);
+
+		omap_iommu_detach(oiommu);
+		iommu->iommu_dev = NULL;
+		oiommu->domain = NULL;
+	}
+
+	omap_iommu_detach_fini(omap_domain);
+
+	omap_domain->dev = NULL;
+}
+
+static void omap_iommu_detach_dev(struct iommu_domain *domain,
+				  struct device *dev)
+{
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+
+	spin_lock(&omap_domain->lock);
+	_omap_iommu_detach_dev(omap_domain, dev);
+	spin_unlock(&omap_domain->lock);
+}
+
+static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
+{
+	struct omap_iommu_domain *omap_domain;
+
+	if (type != IOMMU_DOMAIN_UNMANAGED)
+		return NULL;
+
+	omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
+	if (!omap_domain)
+		return NULL;
+
+	spin_lock_init(&omap_domain->lock);
+
+	omap_domain->domain.geometry.aperture_start = 0;
+	omap_domain->domain.geometry.aperture_end   = (1ULL << 32) - 1;
+	omap_domain->domain.geometry.force_aperture = true;
+
+	return &omap_domain->domain;
+}
+
+static void omap_iommu_domain_free(struct iommu_domain *domain)
+{
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+
+	/*
+	 * An iommu device is still attached
+	 * (currently, only one device can be attached) ?
+	 */
+	if (omap_domain->dev)
+		_omap_iommu_detach_dev(omap_domain, omap_domain->dev);
+
+	kfree(omap_domain);
+}
+
+static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
+					   dma_addr_t da)
+{
+	struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
+	struct omap_iommu_device *iommu = omap_domain->iommus;
+	struct omap_iommu *oiommu = iommu->iommu_dev;
+	struct device *dev = oiommu->dev;
+	u32 *pgd, *pte;
+	phys_addr_t ret = 0;
+
+	/*
+	 * all the iommus within the domain will have identical programming,
+	 * so perform the lookup using just the first iommu
+	 */
+	iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
+
+	if (pte) {
+		if (iopte_is_small(*pte))
+			ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
+		else if (iopte_is_large(*pte))
+			ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
+		else
+			dev_err(dev, "bogus pte 0x%x, da 0x%llx", *pte,
+				(unsigned long long)da);
+	} else {
+		if (iopgd_is_section(*pgd))
+			ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
+		else if (iopgd_is_super(*pgd))
+			ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
+		else
+			dev_err(dev, "bogus pgd 0x%x, da 0x%llx", *pgd,
+				(unsigned long long)da);
+	}
+
+	return ret;
+}
+
+static int omap_iommu_add_device(struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data, *tmp;
+	struct omap_iommu *oiommu;
+	struct iommu_group *group;
+	struct device_node *np;
+	struct platform_device *pdev;
+	int num_iommus, i;
+	int ret;
+
+	/*
+	 * Allocate the archdata iommu structure for DT-based devices.
+	 *
+	 * TODO: Simplify this when removing non-DT support completely from the
+	 * IOMMU users.
+	 */
+	if (!dev->of_node)
+		return 0;
+
+	/*
+	 * retrieve the count of IOMMU nodes using phandle size as element size
+	 * since #iommu-cells = 0 for OMAP
+	 */
+	num_iommus = of_property_count_elems_of_size(dev->of_node, "iommus",
+						     sizeof(phandle));
+	if (num_iommus < 0)
+		return 0;
+
+	arch_data = kcalloc(num_iommus + 1, sizeof(*arch_data), GFP_KERNEL);
+	if (!arch_data)
+		return -ENOMEM;
+
+	for (i = 0, tmp = arch_data; i < num_iommus; i++, tmp++) {
+		np = of_parse_phandle(dev->of_node, "iommus", i);
+		if (!np) {
+			kfree(arch_data);
+			return -EINVAL;
+		}
+
+		pdev = of_find_device_by_node(np);
+		if (WARN_ON(!pdev)) {
+			of_node_put(np);
+			kfree(arch_data);
+			return -EINVAL;
+		}
+
+		oiommu = platform_get_drvdata(pdev);
+		if (!oiommu) {
+			of_node_put(np);
+			kfree(arch_data);
+			return -EINVAL;
+		}
+
+		tmp->iommu_dev = oiommu;
+
+		of_node_put(np);
+	}
+
+	/*
+	 * use the first IOMMU alone for the sysfs device linking.
+	 * TODO: Evaluate if a single iommu_group needs to be
+	 * maintained for both IOMMUs
+	 */
+	oiommu = arch_data->iommu_dev;
+	ret = iommu_device_link(&oiommu->iommu, dev);
+	if (ret) {
+		kfree(arch_data);
+		return ret;
+	}
+
+	dev->archdata.iommu = arch_data;
+
+	/*
+	 * IOMMU group initialization calls into omap_iommu_device_group, which
+	 * needs a valid dev->archdata.iommu pointer
+	 */
+	group = iommu_group_get_for_dev(dev);
+	if (IS_ERR(group)) {
+		iommu_device_unlink(&oiommu->iommu, dev);
+		dev->archdata.iommu = NULL;
+		kfree(arch_data);
+		return PTR_ERR(group);
+	}
+	iommu_group_put(group);
+
+	return 0;
+}
+
+static void omap_iommu_remove_device(struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+
+	if (!dev->of_node || !arch_data)
+		return;
+
+	iommu_device_unlink(&arch_data->iommu_dev->iommu, dev);
+	iommu_group_remove_device(dev);
+
+	dev->archdata.iommu = NULL;
+	kfree(arch_data);
+
+}
+
+static struct iommu_group *omap_iommu_device_group(struct device *dev)
+{
+	struct omap_iommu_arch_data *arch_data = dev->archdata.iommu;
+	struct iommu_group *group = ERR_PTR(-EINVAL);
+
+	if (arch_data->iommu_dev)
+		group = iommu_group_ref_get(arch_data->iommu_dev->group);
+
+	return group;
+}
+
+static const struct iommu_ops omap_iommu_ops = {
+	.domain_alloc	= omap_iommu_domain_alloc,
+	.domain_free	= omap_iommu_domain_free,
+	.attach_dev	= omap_iommu_attach_dev,
+	.detach_dev	= omap_iommu_detach_dev,
+	.map		= omap_iommu_map,
+	.unmap		= omap_iommu_unmap,
+	.iova_to_phys	= omap_iommu_iova_to_phys,
+	.add_device	= omap_iommu_add_device,
+	.remove_device	= omap_iommu_remove_device,
+	.device_group	= omap_iommu_device_group,
+	.pgsize_bitmap	= OMAP_IOMMU_PGSIZES,
+};
+
+static int __init omap_iommu_init(void)
+{
+	struct kmem_cache *p;
+	const unsigned long flags = SLAB_HWCACHE_ALIGN;
+	size_t align = 1 << 10; /* L2 pagetable alignement */
+	struct device_node *np;
+	int ret;
+
+	np = of_find_matching_node(NULL, omap_iommu_of_match);
+	if (!np)
+		return 0;
+
+	of_node_put(np);
+
+	p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
+			      NULL);
+	if (!p)
+		return -ENOMEM;
+	iopte_cachep = p;
+
+	omap_iommu_debugfs_init();
+
+	ret = platform_driver_register(&omap_iommu_driver);
+	if (ret) {
+		pr_err("%s: failed to register driver\n", __func__);
+		goto fail_driver;
+	}
+
+	ret = bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
+	if (ret)
+		goto fail_bus;
+
+	return 0;
+
+fail_bus:
+	platform_driver_unregister(&omap_iommu_driver);
+fail_driver:
+	kmem_cache_destroy(iopte_cachep);
+	return ret;
+}
+subsys_initcall(omap_iommu_init);
+/* must be ready before omap3isp is probed */