omap: iommu/iovmm: move to dedicated iommu folder

Move OMAP's iommu drivers to the dedicated iommu drivers folder.

While OMAP's iovmm (virtual memory manager) driver does not strictly
belong to the iommu drivers folder, move it there as well, because
it's by no means OMAP-specific (in concept. technically it is still
coupled with OMAP's iommu).

Eventually, iovmm will be completely replaced with the generic,
iommu-based, dma-mapping API.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Conflicts:

	arch/arm/plat-omap/Kconfig
	drivers/iommu/Kconfig
	drivers/iommu/Makefile

Change-Id: Ie437869b8cbb92ea8fafc3d18333331a3b51ec06

1 files changed, 1102 insertions, 0 deletions

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
new file mode 100644
index 000000000000..129b3288397e
--- /dev/null
+++ b/drivers/iommu/omap-iommu.c
@@ -0,0 +1,1102 @@
+/*
+ * omap iommu: tlb and pagetable primitives
+ *
+ * Copyright (C) 2008-2010 Nokia Corporation
+ *
+ * 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/err.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+
+#include <asm/cacheflush.h>
+
+#include <plat/iommu.h>
+
+#include <plat/iopgtable.h>
+
+#define for_each_iotlb_cr(obj, n, __i, cr)				\
+	for (__i = 0;							\
+	     (__i < (n)) && (cr = __iotlb_read_cr((obj), __i), true);	\
+	     __i++)
+
+/* accommodate the difference between omap1 and omap2/3 */
+static const struct iommu_functions *arch_iommu;
+
+static struct platform_driver omap_iommu_driver;
+static struct kmem_cache *iopte_cachep;
+
+/**
+ * install_iommu_arch - Install archtecure specific iommu functions
+ * @ops:	a pointer to architecture specific iommu functions
+ *
+ * There are several kind of iommu algorithm(tlb, pagetable) among
+ * omap series. This interface installs such an iommu algorighm.
+ **/
+int install_iommu_arch(const struct iommu_functions *ops)
+{
+	if (arch_iommu)
+		return -EBUSY;
+
+	arch_iommu = ops;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(install_iommu_arch);
+
+/**
+ * uninstall_iommu_arch - Uninstall archtecure specific iommu functions
+ * @ops:	a pointer to architecture specific iommu functions
+ *
+ * This interface uninstalls the iommu algorighm installed previously.
+ **/
+void uninstall_iommu_arch(const struct iommu_functions *ops)
+{
+	if (arch_iommu != ops)
+		pr_err("%s: not your arch\n", __func__);
+
+	arch_iommu = NULL;
+}
+EXPORT_SYMBOL_GPL(uninstall_iommu_arch);
+
+/**
+ * iommu_save_ctx - Save registers for pm off-mode support
+ * @obj:	target iommu
+ **/
+void iommu_save_ctx(struct iommu *obj)
+{
+	arch_iommu->save_ctx(obj);
+}
+EXPORT_SYMBOL_GPL(iommu_save_ctx);
+
+/**
+ * iommu_restore_ctx - Restore registers for pm off-mode support
+ * @obj:	target iommu
+ **/
+void iommu_restore_ctx(struct iommu *obj)
+{
+	arch_iommu->restore_ctx(obj);
+}
+EXPORT_SYMBOL_GPL(iommu_restore_ctx);
+
+/**
+ * iommu_arch_version - Return running iommu arch version
+ **/
+u32 iommu_arch_version(void)
+{
+	return arch_iommu->version;
+}
+EXPORT_SYMBOL_GPL(iommu_arch_version);
+
+static int iommu_enable(struct iommu *obj)
+{
+	int err;
+
+	if (!obj)
+		return -EINVAL;
+
+	if (!arch_iommu)
+		return -ENODEV;
+
+	clk_enable(obj->clk);
+
+	err = arch_iommu->enable(obj);
+
+	clk_disable(obj->clk);
+	return err;
+}
+
+static void iommu_disable(struct iommu *obj)
+{
+	if (!obj)
+		return;
+
+	clk_enable(obj->clk);
+
+	arch_iommu->disable(obj);
+
+	clk_disable(obj->clk);
+}
+
+/*
+ *	TLB operations
+ */
+void iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
+{
+	BUG_ON(!cr || !e);
+
+	arch_iommu->cr_to_e(cr, e);
+}
+EXPORT_SYMBOL_GPL(iotlb_cr_to_e);
+
+static inline int iotlb_cr_valid(struct cr_regs *cr)
+{
+	if (!cr)
+		return -EINVAL;
+
+	return arch_iommu->cr_valid(cr);
+}
+
+static inline struct cr_regs *iotlb_alloc_cr(struct iommu *obj,
+					     struct iotlb_entry *e)
+{
+	if (!e)
+		return NULL;
+
+	return arch_iommu->alloc_cr(obj, e);
+}
+
+u32 iotlb_cr_to_virt(struct cr_regs *cr)
+{
+	return arch_iommu->cr_to_virt(cr);
+}
+EXPORT_SYMBOL_GPL(iotlb_cr_to_virt);
+
+static u32 get_iopte_attr(struct iotlb_entry *e)
+{
+	return arch_iommu->get_pte_attr(e);
+}
+
+static u32 iommu_report_fault(struct iommu *obj, u32 *da)
+{
+	return arch_iommu->fault_isr(obj, da);
+}
+
+static void iotlb_lock_get(struct 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);
+
+}
+
+static void iotlb_lock_set(struct 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 iommu *obj, struct cr_regs *cr)
+{
+	arch_iommu->tlb_read_cr(obj, cr);
+}
+
+static void iotlb_load_cr(struct iommu *obj, struct cr_regs *cr)
+{
+	arch_iommu->tlb_load_cr(obj, cr);
+
+	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
+	iommu_write_reg(obj, 1, MMU_LD_TLB);
+}
+
+/**
+ * iotlb_dump_cr - Dump an iommu tlb entry into buf
+ * @obj:	target iommu
+ * @cr:		contents of cam and ram register
+ * @buf:	output buffer
+ **/
+static inline ssize_t iotlb_dump_cr(struct iommu *obj, struct cr_regs *cr,
+				    char *buf)
+{
+	BUG_ON(!cr || !buf);
+
+	return arch_iommu->dump_cr(obj, cr, buf);
+}
+
+/* only used in iotlb iteration for-loop */
+static struct cr_regs __iotlb_read_cr(struct 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;
+}
+
+/**
+ * load_iotlb_entry - Set an iommu tlb entry
+ * @obj:	target iommu
+ * @e:		an iommu tlb entry info
+ **/
+int load_iotlb_entry(struct 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;
+
+	clk_enable(obj->clk);
+
+	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)) {
+		clk_disable(obj->clk);
+		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:
+	clk_disable(obj->clk);
+	return err;
+}
+EXPORT_SYMBOL_GPL(load_iotlb_entry);
+
+/**
+ * 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.
+ **/
+void flush_iotlb_page(struct iommu *obj, u32 da)
+{
+	int i;
+	struct cr_regs cr;
+
+	clk_enable(obj->clk);
+
+	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);
+		}
+	}
+	clk_disable(obj->clk);
+
+	if (i == obj->nr_tlb_entries)
+		dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
+}
+EXPORT_SYMBOL_GPL(flush_iotlb_page);
+
+/**
+ * flush_iotlb_range - Clear an iommu tlb entries
+ * @obj:	target iommu
+ * @start:	iommu device virtual address(start)
+ * @end:	iommu device virtual address(end)
+ *
+ * Clear an iommu tlb entry which includes 'da' address.
+ **/
+void flush_iotlb_range(struct iommu *obj, u32 start, u32 end)
+{
+	u32 da = start;
+
+	while (da < end) {
+		flush_iotlb_page(obj, da);
+		/* FIXME: Optimize for multiple page size */
+		da += IOPTE_SIZE;
+	}
+}
+EXPORT_SYMBOL_GPL(flush_iotlb_range);
+
+/**
+ * flush_iotlb_all - Clear all iommu tlb entries
+ * @obj:	target iommu
+ **/
+void flush_iotlb_all(struct iommu *obj)
+{
+	struct iotlb_lock l;
+
+	clk_enable(obj->clk);
+
+	l.base = 0;
+	l.vict = 0;
+	iotlb_lock_set(obj, &l);
+
+	iommu_write_reg(obj, 1, MMU_GFLUSH);
+
+	clk_disable(obj->clk);
+}
+EXPORT_SYMBOL_GPL(flush_iotlb_all);
+
+/**
+ * iommu_set_twl - enable/disable table walking logic
+ * @obj:	target iommu
+ * @on:		enable/disable
+ *
+ * Function used to enable/disable TWL. If one wants to work
+ * exclusively with locked TLB entries and receive notifications
+ * for TLB miss then call this function to disable TWL.
+ */
+void iommu_set_twl(struct iommu *obj, bool on)
+{
+	clk_enable(obj->clk);
+	arch_iommu->set_twl(obj, on);
+	clk_disable(obj->clk);
+}
+EXPORT_SYMBOL_GPL(iommu_set_twl);
+
+#if defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
+
+ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t bytes)
+{
+	if (!obj || !buf)
+		return -EINVAL;
+
+	clk_enable(obj->clk);
+
+	bytes = arch_iommu->dump_ctx(obj, buf, bytes);
+
+	clk_disable(obj->clk);
+
+	return bytes;
+}
+EXPORT_SYMBOL_GPL(iommu_dump_ctx);
+
+static int __dump_tlb_entries(struct iommu *obj, struct cr_regs *crs, int num)
+{
+	int i;
+	struct iotlb_lock saved;
+	struct cr_regs tmp;
+	struct cr_regs *p = crs;
+
+	clk_enable(obj->clk);
+	iotlb_lock_get(obj, &saved);
+
+	for_each_iotlb_cr(obj, num, i, tmp) {
+		if (!iotlb_cr_valid(&tmp))
+			continue;
+		*p++ = tmp;
+	}
+
+	iotlb_lock_set(obj, &saved);
+	clk_disable(obj->clk);
+
+	return  p - crs;
+}
+
+/**
+ * dump_tlb_entries - dump cr arrays to given buffer
+ * @obj:	target iommu
+ * @buf:	output buffer
+ **/
+size_t dump_tlb_entries(struct iommu *obj, char *buf, ssize_t bytes)
+{
+	int i, num;
+	struct cr_regs *cr;
+	char *p = buf;
+
+	num = bytes / sizeof(*cr);
+	num = min(obj->nr_tlb_entries, num);
+
+	cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
+	if (!cr)
+		return 0;
+
+	num = __dump_tlb_entries(obj, cr, num);
+	for (i = 0; i < num; i++)
+		p += iotlb_dump_cr(obj, cr + i, p);
+	kfree(cr);
+
+	return p - buf;
+}
+EXPORT_SYMBOL_GPL(dump_tlb_entries);
+
+int foreach_iommu_device(void *data, int (*fn)(struct device *, void *))
+{
+	return driver_for_each_device(&omap_iommu_driver.driver,
+				      NULL, data, fn);
+}
+EXPORT_SYMBOL_GPL(foreach_iommu_device);
+
+#endif /* CONFIG_OMAP_IOMMU_DEBUG_MODULE */
+
+/*
+ *	H/W pagetable operations
+ */
+static void flush_iopgd_range(u32 *first, u32 *last)
+{
+	/* FIXME: L2 cache should be taken care of if it exists */
+	do {
+		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pgd"
+		    : : "r" (first));
+		first += L1_CACHE_BYTES / sizeof(*first);
+	} while (first <= last);
+}
+
+static void flush_iopte_range(u32 *first, u32 *last)
+{
+	/* FIXME: L2 cache should be taken care of if it exists */
+	do {
+		asm("mcr	p15, 0, %0, c7, c10, 1 @ flush_pte"
+		    : : "r" (first));
+		first += L1_CACHE_BYTES / sizeof(*first);
+	} while (first <= last);
+}
+
+static void iopte_free(u32 *iopte)
+{
+	/* Note: freed iopte's must be clean ready for re-use */
+	kmem_cache_free(iopte_cachep, iopte);
+}
+
+static u32 *iopte_alloc(struct iommu *obj, u32 *iopgd, u32 da)
+{
+	u32 *iopte;
+
+	/* 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);
+
+		*iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
+		flush_iopgd_range(iopgd, iopgd);
+
+		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
+	} else {
+		/* We raced, free the reduniovant table */
+		iopte_free(iopte);
+	}
+
+pte_ready:
+	iopte = iopte_offset(iopgd, da);
+
+	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 iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, 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_iopgd_range(iopgd, iopgd);
+	return 0;
+}
+
+static int iopgd_alloc_super(struct iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, 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_iopgd_range(iopgd, iopgd + 15);
+	return 0;
+}
+
+static int iopte_alloc_page(struct iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, da);
+	u32 *iopte = iopte_alloc(obj, iopgd, da);
+
+	if (IS_ERR(iopte))
+		return PTR_ERR(iopte);
+
+	*iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
+	flush_iopte_range(iopte, iopte);
+
+	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 iommu *obj, u32 da, u32 pa, u32 prot)
+{
+	u32 *iopgd = iopgd_offset(obj, da);
+	u32 *iopte = iopte_alloc(obj, iopgd, 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(iopte, iopte + 15);
+	return 0;
+}
+
+static int iopgtable_store_entry_core(struct iommu *obj, struct iotlb_entry *e)
+{
+	int (*fn)(struct 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;
+		BUG();
+		break;
+	}
+
+	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;
+}
+
+/**
+ * iopgtable_store_entry - Make an iommu pte entry
+ * @obj:	target iommu
+ * @e:		an iommu tlb entry info
+ **/
+int iopgtable_store_entry(struct iommu *obj, struct iotlb_entry *e)
+{
+	int err;
+
+	flush_iotlb_page(obj, e->da);
+	err = iopgtable_store_entry_core(obj, e);
+#ifdef PREFETCH_IOTLB
+	if (!err)
+		load_iotlb_entry(obj, e);
+#endif
+	return err;
+}
+EXPORT_SYMBOL_GPL(iopgtable_store_entry);
+
+/**
+ * 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
+ **/
+void iopgtable_lookup_entry(struct 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;
+}
+EXPORT_SYMBOL_GPL(iopgtable_lookup_entry);
+
+static size_t iopgtable_clear_entry_core(struct iommu *obj, u32 da)
+{
+	size_t bytes;
+	u32 *iopgd = iopgd_offset(obj, da);
+	int nent = 1;
+
+	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));
+		flush_iopte_range(iopte, iopte + (nent - 1) * sizeof(*iopte));
+
+		/*
+		 * 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(iopte);
+		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_iopgd_range(iopgd, iopgd + (nent - 1) * sizeof(*iopgd));
+out:
+	return bytes;
+}
+
+/**
+ * iopgtable_clear_entry - Remove an iommu pte entry
+ * @obj:	target iommu
+ * @da:		iommu device virtual address
+ **/
+size_t iopgtable_clear_entry(struct 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;
+}
+EXPORT_SYMBOL_GPL(iopgtable_clear_entry);
+
+static void iopgtable_clear_entry_all(struct iommu *obj)
+{
+	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);
+
+		if (!*iopgd)
+			continue;
+
+		if (iopgd_is_table(*iopgd))
+			iopte_free(iopte_offset(iopgd, 0));
+
+		*iopgd = 0;
+		flush_iopgd_range(iopgd, iopgd);
+	}
+
+	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 iommu *obj = data;
+
+	if (!obj->refcount)
+		return IRQ_NONE;
+
+	clk_enable(obj->clk);
+	errs = iommu_report_fault(obj, &da);
+	clk_disable(obj->clk);
+	if (errs == 0)
+		return IRQ_HANDLED;
+
+	/* Fault callback or TLB/PTE Dynamic loading */
+	if (obj->isr && !obj->isr(obj, da, errs, obj->isr_priv))
+		return IRQ_HANDLED;
+
+	iommu_disable(obj);
+
+	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;
+}
+
+static int device_match_by_alias(struct device *dev, void *data)
+{
+	struct iommu *obj = to_iommu(dev);
+	const char *name = data;
+
+	pr_debug("%s: %s %s\n", __func__, obj->name, name);
+
+	return strcmp(obj->name, name) == 0;
+}
+
+/**
+ * iommu_set_da_range - Set a valid device address range
+ * @obj:		target iommu
+ * @start		Start of valid range
+ * @end			End of valid range
+ **/
+int iommu_set_da_range(struct iommu *obj, u32 start, u32 end)
+{
+
+	if (!obj)
+		return -EFAULT;
+
+	if (end < start || !PAGE_ALIGN(start | end))
+		return -EINVAL;
+
+	obj->da_start = start;
+	obj->da_end = end;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(iommu_set_da_range);
+
+/**
+ * iommu_get - Get iommu handler
+ * @name:	target iommu name
+ **/
+struct iommu *iommu_get(const char *name)
+{
+	int err = -ENOMEM;
+	struct device *dev;
+	struct iommu *obj;
+
+	dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,
+				 device_match_by_alias);
+	if (!dev)
+		return ERR_PTR(-ENODEV);
+
+	obj = to_iommu(dev);
+
+	mutex_lock(&obj->iommu_lock);
+
+	if (obj->refcount++ == 0) {
+		err = iommu_enable(obj);
+		if (err)
+			goto err_enable;
+		flush_iotlb_all(obj);
+	}
+
+	if (!try_module_get(obj->owner))
+		goto err_module;
+
+	mutex_unlock(&obj->iommu_lock);
+
+	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
+	return obj;
+
+err_module:
+	if (obj->refcount == 1)
+		iommu_disable(obj);
+err_enable:
+	obj->refcount--;
+	mutex_unlock(&obj->iommu_lock);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(iommu_get);
+
+/**
+ * iommu_put - Put back iommu handler
+ * @obj:	target iommu
+ **/
+void iommu_put(struct iommu *obj)
+{
+	if (!obj || IS_ERR(obj))
+		return;
+
+	mutex_lock(&obj->iommu_lock);
+
+	if (--obj->refcount == 0)
+		iommu_disable(obj);
+
+	module_put(obj->owner);
+
+	mutex_unlock(&obj->iommu_lock);
+
+	dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
+}
+EXPORT_SYMBOL_GPL(iommu_put);
+
+int iommu_set_isr(const char *name,
+		  int (*isr)(struct iommu *obj, u32 da, u32 iommu_errs,
+			     void *priv),
+		  void *isr_priv)
+{
+	struct device *dev;
+	struct iommu *obj;
+
+	dev = driver_find_device(&omap_iommu_driver.driver, NULL, (void *)name,
+				 device_match_by_alias);
+	if (!dev)
+		return -ENODEV;
+
+	obj = to_iommu(dev);
+	mutex_lock(&obj->iommu_lock);
+	if (obj->refcount != 0) {
+		mutex_unlock(&obj->iommu_lock);
+		return -EBUSY;
+	}
+	obj->isr = isr;
+	obj->isr_priv = isr_priv;
+	mutex_unlock(&obj->iommu_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(iommu_set_isr);
+
+/*
+ *	OMAP Device MMU(IOMMU) detection
+ */
+static int __devinit omap_iommu_probe(struct platform_device *pdev)
+{
+	int err = -ENODEV;
+	void *p;
+	int irq;
+	struct iommu *obj;
+	struct resource *res;
+	struct iommu_platform_data *pdata = pdev->dev.platform_data;
+
+	if (pdev->num_resources != 2)
+		return -EINVAL;
+
+	obj = kzalloc(sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
+	if (!obj)
+		return -ENOMEM;
+
+	obj->clk = clk_get(&pdev->dev, pdata->clk_name);
+	if (IS_ERR(obj->clk))
+		goto err_clk;
+
+	obj->nr_tlb_entries = pdata->nr_tlb_entries;
+	obj->name = pdata->name;
+	obj->dev = &pdev->dev;
+	obj->ctx = (void *)obj + sizeof(*obj);
+	obj->da_start = pdata->da_start;
+	obj->da_end = pdata->da_end;
+
+	mutex_init(&obj->iommu_lock);
+	mutex_init(&obj->mmap_lock);
+	spin_lock_init(&obj->page_table_lock);
+	INIT_LIST_HEAD(&obj->mmap);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		err = -ENODEV;
+		goto err_mem;
+	}
+
+	res = request_mem_region(res->start, resource_size(res),
+				 dev_name(&pdev->dev));
+	if (!res) {
+		err = -EIO;
+		goto err_mem;
+	}
+
+	obj->regbase = ioremap(res->start, resource_size(res));
+	if (!obj->regbase) {
+		err = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		err = -ENODEV;
+		goto err_irq;
+	}
+	err = request_irq(irq, iommu_fault_handler, IRQF_SHARED,
+			  dev_name(&pdev->dev), obj);
+	if (err < 0)
+		goto err_irq;
+	platform_set_drvdata(pdev, obj);
+
+	p = (void *)__get_free_pages(GFP_KERNEL, get_order(IOPGD_TABLE_SIZE));
+	if (!p) {
+		err = -ENOMEM;
+		goto err_pgd;
+	}
+	memset(p, 0, IOPGD_TABLE_SIZE);
+	clean_dcache_area(p, IOPGD_TABLE_SIZE);
+	obj->iopgd = p;
+
+	BUG_ON(!IS_ALIGNED((unsigned long)obj->iopgd, IOPGD_TABLE_SIZE));
+
+	dev_info(&pdev->dev, "%s registered\n", obj->name);
+	return 0;
+
+err_pgd:
+	free_irq(irq, obj);
+err_irq:
+	iounmap(obj->regbase);
+err_ioremap:
+	release_mem_region(res->start, resource_size(res));
+err_mem:
+	clk_put(obj->clk);
+err_clk:
+	kfree(obj);
+	return err;
+}
+
+static int __devexit omap_iommu_remove(struct platform_device *pdev)
+{
+	int irq;
+	struct resource *res;
+	struct iommu *obj = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	iopgtable_clear_entry_all(obj);
+	free_pages((unsigned long)obj->iopgd, get_order(IOPGD_TABLE_SIZE));
+
+	irq = platform_get_irq(pdev, 0);
+	free_irq(irq, obj);
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(res->start, resource_size(res));
+	iounmap(obj->regbase);
+
+	clk_put(obj->clk);
+	dev_info(&pdev->dev, "%s removed\n", obj->name);
+	kfree(obj);
+	return 0;
+}
+
+static struct platform_driver omap_iommu_driver = {
+	.probe	= omap_iommu_probe,
+	.remove	= __devexit_p(omap_iommu_remove),
+	.driver	= {
+		.name	= "omap-iommu",
+	},
+};
+
+static void iopte_cachep_ctor(void *iopte)
+{
+	clean_dcache_area(iopte, IOPTE_TABLE_SIZE);
+}
+
+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 */
+
+	p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
+			      iopte_cachep_ctor);
+	if (!p)
+		return -ENOMEM;
+	iopte_cachep = p;
+
+	return platform_driver_register(&omap_iommu_driver);
+}
+module_init(omap_iommu_init);
+
+static void __exit omap_iommu_exit(void)
+{
+	kmem_cache_destroy(iopte_cachep);
+
+	platform_driver_unregister(&omap_iommu_driver);
+}
+module_exit(omap_iommu_exit);
+
+MODULE_DESCRIPTION("omap iommu: tlb and pagetable primitives");
+MODULE_ALIAS("platform:omap-iommu");
+MODULE_AUTHOR("Hiroshi DOYU, Paul Mundt and Toshihiro Kobayashi");
+MODULE_LICENSE("GPL v2");