Merge branch 'next/devel-samsung-iommu' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into next/drivers

* 'next/devel-samsung-iommu' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  iommu/exynos: Add iommu driver for EXYNOS Platforms

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 1098 insertions, 0 deletions

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 3bd9fff..23db792 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -162,4 +162,25 @@ config TEGRA_IOMMU_SMMU
 	  space through the SMMU (System Memory Management Unit)
 	  hardware included on Tegra SoCs.
 
+config EXYNOS_IOMMU
+	bool "Exynos IOMMU Support"
+	depends on ARCH_EXYNOS && EXYNOS_DEV_SYSMMU
+	select IOMMU_API
+	help
+	  Support for the IOMMU(System MMU) of Samsung Exynos application
+	  processor family. This enables H/W multimedia accellerators to see
+	  non-linear physical memory chunks as a linear memory in their
+	  address spaces
+
+	  If unsure, say N here.
+
+config EXYNOS_IOMMU_DEBUG
+	bool "Debugging log for Exynos IOMMU"
+	depends on EXYNOS_IOMMU
+	help
+	  Select this to see the detailed log message that shows what
+	  happens in the IOMMU driver
+
+	  Say N unless you need kernel log message for IOMMU debugging
+
 endif # IOMMU_SUPPORT
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 7ad7a3b..d06dec6 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_OMAP_IOVMM) += omap-iovmm.o
 obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
 obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
 obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
+obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
new file mode 100644
index 0000000..9a114b9
--- /dev/null
+++ b/drivers/iommu/exynos-iommu.c
@@ -0,0 +1,1076 @@
+/* linux/drivers/iommu/exynos_iommu.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * 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.
+ */
+
+#ifdef CONFIG_EXYNOS_IOMMU_DEBUG
+#define DEBUG
+#endif
+
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/iommu.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
+#include <linux/export.h>
+
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+
+#include <mach/sysmmu.h>
+
+/* We does not consider super section mapping (16MB) */
+#define SECT_ORDER 20
+#define LPAGE_ORDER 16
+#define SPAGE_ORDER 12
+
+#define SECT_SIZE (1 << SECT_ORDER)
+#define LPAGE_SIZE (1 << LPAGE_ORDER)
+#define SPAGE_SIZE (1 << SPAGE_ORDER)
+
+#define SECT_MASK (~(SECT_SIZE - 1))
+#define LPAGE_MASK (~(LPAGE_SIZE - 1))
+#define SPAGE_MASK (~(SPAGE_SIZE - 1))
+
+#define lv1ent_fault(sent) (((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
+#define lv1ent_page(sent) ((*(sent) & 3) == 1)
+#define lv1ent_section(sent) ((*(sent) & 3) == 2)
+
+#define lv2ent_fault(pent) ((*(pent) & 3) == 0)
+#define lv2ent_small(pent) ((*(pent) & 2) == 2)
+#define lv2ent_large(pent) ((*(pent) & 3) == 1)
+
+#define section_phys(sent) (*(sent) & SECT_MASK)
+#define section_offs(iova) ((iova) & 0xFFFFF)
+#define lpage_phys(pent) (*(pent) & LPAGE_MASK)
+#define lpage_offs(iova) ((iova) & 0xFFFF)
+#define spage_phys(pent) (*(pent) & SPAGE_MASK)
+#define spage_offs(iova) ((iova) & 0xFFF)
+
+#define lv1ent_offset(iova) ((iova) >> SECT_ORDER)
+#define lv2ent_offset(iova) (((iova) & 0xFF000) >> SPAGE_ORDER)
+
+#define NUM_LV1ENTRIES 4096
+#define NUM_LV2ENTRIES 256
+
+#define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(long))
+
+#define SPAGES_PER_LPAGE (LPAGE_SIZE / SPAGE_SIZE)
+
+#define lv2table_base(sent) (*(sent) & 0xFFFFFC00)
+
+#define mk_lv1ent_sect(pa) ((pa) | 2)
+#define mk_lv1ent_page(pa) ((pa) | 1)
+#define mk_lv2ent_lpage(pa) ((pa) | 1)
+#define mk_lv2ent_spage(pa) ((pa) | 2)
+
+#define CTRL_ENABLE	0x5
+#define CTRL_BLOCK	0x7
+#define CTRL_DISABLE	0x0
+
+#define REG_MMU_CTRL		0x000
+#define REG_MMU_CFG		0x004
+#define REG_MMU_STATUS		0x008
+#define REG_MMU_FLUSH		0x00C
+#define REG_MMU_FLUSH_ENTRY	0x010
+#define REG_PT_BASE_ADDR	0x014
+#define REG_INT_STATUS		0x018
+#define REG_INT_CLEAR		0x01C
+
+#define REG_PAGE_FAULT_ADDR	0x024
+#define REG_AW_FAULT_ADDR	0x028
+#define REG_AR_FAULT_ADDR	0x02C
+#define REG_DEFAULT_SLAVE_ADDR	0x030
+
+#define REG_MMU_VERSION		0x034
+
+#define REG_PB0_SADDR		0x04C
+#define REG_PB0_EADDR		0x050
+#define REG_PB1_SADDR		0x054
+#define REG_PB1_EADDR		0x058
+
+static unsigned long *section_entry(unsigned long *pgtable, unsigned long iova)
+{
+	return pgtable + lv1ent_offset(iova);
+}
+
+static unsigned long *page_entry(unsigned long *sent, unsigned long iova)
+{
+	return (unsigned long *)__va(lv2table_base(sent)) + lv2ent_offset(iova);
+}
+
+enum exynos_sysmmu_inttype {
+	SYSMMU_PAGEFAULT,
+	SYSMMU_AR_MULTIHIT,
+	SYSMMU_AW_MULTIHIT,
+	SYSMMU_BUSERROR,
+	SYSMMU_AR_SECURITY,
+	SYSMMU_AR_ACCESS,
+	SYSMMU_AW_SECURITY,
+	SYSMMU_AW_PROTECTION, /* 7 */
+	SYSMMU_FAULT_UNKNOWN,
+	SYSMMU_FAULTS_NUM
+};
+
+/*
+ * @itype: type of fault.
+ * @pgtable_base: the physical address of page table base. This is 0 if @itype
+ *                is SYSMMU_BUSERROR.
+ * @fault_addr: the device (virtual) address that the System MMU tried to
+ *             translated. This is 0 if @itype is SYSMMU_BUSERROR.
+ */
+typedef int (*sysmmu_fault_handler_t)(enum exynos_sysmmu_inttype itype,
+			unsigned long pgtable_base, unsigned long fault_addr);
+
+static unsigned short fault_reg_offset[SYSMMU_FAULTS_NUM] = {
+	REG_PAGE_FAULT_ADDR,
+	REG_AR_FAULT_ADDR,
+	REG_AW_FAULT_ADDR,
+	REG_DEFAULT_SLAVE_ADDR,
+	REG_AR_FAULT_ADDR,
+	REG_AR_FAULT_ADDR,
+	REG_AW_FAULT_ADDR,
+	REG_AW_FAULT_ADDR
+};
+
+static char *sysmmu_fault_name[SYSMMU_FAULTS_NUM] = {
+	"PAGE FAULT",
+	"AR MULTI-HIT FAULT",
+	"AW MULTI-HIT FAULT",
+	"BUS ERROR",
+	"AR SECURITY PROTECTION FAULT",
+	"AR ACCESS PROTECTION FAULT",
+	"AW SECURITY PROTECTION FAULT",
+	"AW ACCESS PROTECTION FAULT",
+	"UNKNOWN FAULT"
+};
+
+struct exynos_iommu_domain {
+	struct list_head clients; /* list of sysmmu_drvdata.node */
+	unsigned long *pgtable; /* lv1 page table, 16KB */
+	short *lv2entcnt; /* free lv2 entry counter for each section */
+	spinlock_t lock; /* lock for this structure */
+	spinlock_t pgtablelock; /* lock for modifying page table @ pgtable */
+};
+
+struct sysmmu_drvdata {
+	struct list_head node; /* entry of exynos_iommu_domain.clients */
+	struct device *sysmmu;	/* System MMU's device descriptor */
+	struct device *dev;	/* Owner of system MMU */
+	char *dbgname;
+	int nsfrs;
+	void __iomem **sfrbases;
+	struct clk *clk[2];
+	int activations;
+	rwlock_t lock;
+	struct iommu_domain *domain;
+	sysmmu_fault_handler_t fault_handler;
+	unsigned long pgtable;
+};
+
+static bool set_sysmmu_active(struct sysmmu_drvdata *data)
+{
+	/* return true if the System MMU was not active previously
+	   and it needs to be initialized */
+	return ++data->activations == 1;
+}
+
+static bool set_sysmmu_inactive(struct sysmmu_drvdata *data)
+{
+	/* return true if the System MMU is needed to be disabled */
+	BUG_ON(data->activations < 1);
+	return --data->activations == 0;
+}
+
+static bool is_sysmmu_active(struct sysmmu_drvdata *data)
+{
+	return data->activations > 0;
+}
+
+static void sysmmu_unblock(void __iomem *sfrbase)
+{
+	__raw_writel(CTRL_ENABLE, sfrbase + REG_MMU_CTRL);
+}
+
+static bool sysmmu_block(void __iomem *sfrbase)
+{
+	int i = 120;
+
+	__raw_writel(CTRL_BLOCK, sfrbase + REG_MMU_CTRL);
+	while ((i > 0) && !(__raw_readl(sfrbase + REG_MMU_STATUS) & 1))
+		--i;
+
+	if (!(__raw_readl(sfrbase + REG_MMU_STATUS) & 1)) {
+		sysmmu_unblock(sfrbase);
+		return false;
+	}
+
+	return true;
+}
+
+static void __sysmmu_tlb_invalidate(void __iomem *sfrbase)
+{
+	__raw_writel(0x1, sfrbase + REG_MMU_FLUSH);
+}
+
+static void __sysmmu_tlb_invalidate_entry(void __iomem *sfrbase,
+						unsigned long iova)
+{
+	__raw_writel((iova & SPAGE_MASK) | 1, sfrbase + REG_MMU_FLUSH_ENTRY);
+}
+
+static void __sysmmu_set_ptbase(void __iomem *sfrbase,
+				       unsigned long pgd)
+{
+	__raw_writel(0x1, sfrbase + REG_MMU_CFG); /* 16KB LV1, LRU */
+	__raw_writel(pgd, sfrbase + REG_PT_BASE_ADDR);
+
+	__sysmmu_tlb_invalidate(sfrbase);
+}
+
+static void __sysmmu_set_prefbuf(void __iomem *sfrbase, unsigned long base,
+						unsigned long size, int idx)
+{
+	__raw_writel(base, sfrbase + REG_PB0_SADDR + idx * 8);
+	__raw_writel(size - 1 + base,  sfrbase + REG_PB0_EADDR + idx * 8);
+}
+
+void exynos_sysmmu_set_prefbuf(struct device *dev,
+				unsigned long base0, unsigned long size0,
+				unsigned long base1, unsigned long size1)
+{
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+	unsigned long flags;
+	int i;
+
+	BUG_ON((base0 + size0) <= base0);
+	BUG_ON((size1 > 0) && ((base1 + size1) <= base1));
+
+	read_lock_irqsave(&data->lock, flags);
+	if (!is_sysmmu_active(data))
+		goto finish;
+
+	for (i = 0; i < data->nsfrs; i++) {
+		if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
+			if (!sysmmu_block(data->sfrbases[i]))
+				continue;
+
+			if (size1 == 0) {
+				if (size0 <= SZ_128K) {
+					base1 = base0;
+					size1 = size0;
+				} else {
+					size1 = size0 -
+						ALIGN(size0 / 2, SZ_64K);
+					size0 = size0 - size1;
+					base1 = base0 + size0;
+				}
+			}
+
+			__sysmmu_set_prefbuf(
+					data->sfrbases[i], base0, size0, 0);
+			__sysmmu_set_prefbuf(
+					data->sfrbases[i], base1, size1, 1);
+
+			sysmmu_unblock(data->sfrbases[i]);
+		}
+	}
+finish:
+	read_unlock_irqrestore(&data->lock, flags);
+}
+
+static void __set_fault_handler(struct sysmmu_drvdata *data,
+					sysmmu_fault_handler_t handler)
+{
+	unsigned long flags;
+
+	write_lock_irqsave(&data->lock, flags);
+	data->fault_handler = handler;
+	write_unlock_irqrestore(&data->lock, flags);
+}
+
+void exynos_sysmmu_set_fault_handler(struct device *dev,
+					sysmmu_fault_handler_t handler)
+{
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+
+	__set_fault_handler(data, handler);
+}
+
+static int default_fault_handler(enum exynos_sysmmu_inttype itype,
+		     unsigned long pgtable_base, unsigned long fault_addr)
+{
+	unsigned long *ent;
+
+	if ((itype >= SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
+		itype = SYSMMU_FAULT_UNKNOWN;
+
+	pr_err("%s occured at 0x%lx(Page table base: 0x%lx)\n",
+			sysmmu_fault_name[itype], fault_addr, pgtable_base);
+
+	ent = section_entry(__va(pgtable_base), fault_addr);
+	pr_err("\tLv1 entry: 0x%lx\n", *ent);
+
+	if (lv1ent_page(ent)) {
+		ent = page_entry(ent, fault_addr);
+		pr_err("\t Lv2 entry: 0x%lx\n", *ent);
+	}
+
+	pr_err("Generating Kernel OOPS... because it is unrecoverable.\n");
+
+	BUG();
+
+	return 0;
+}
+
+static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
+{
+	/* SYSMMU is in blocked when interrupt occurred. */
+	struct sysmmu_drvdata *data = dev_id;
+	struct resource *irqres;
+	struct platform_device *pdev;
+	enum exynos_sysmmu_inttype itype;
+	unsigned long addr = -1;
+
+	int i, ret = -ENOSYS;
+
+	read_lock(&data->lock);
+
+	WARN_ON(!is_sysmmu_active(data));
+
+	pdev = to_platform_device(data->sysmmu);
+	for (i = 0; i < (pdev->num_resources / 2); i++) {
+		irqres = platform_get_resource(pdev, IORESOURCE_IRQ, i);
+		if (irqres && ((int)irqres->start == irq))
+			break;
+	}
+
+	if (i == pdev->num_resources) {
+		itype = SYSMMU_FAULT_UNKNOWN;
+	} else {
+		itype = (enum exynos_sysmmu_inttype)
+			__ffs(__raw_readl(data->sfrbases[i] + REG_INT_STATUS));
+		if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
+			itype = SYSMMU_FAULT_UNKNOWN;
+		else
+			addr = __raw_readl(
+				data->sfrbases[i] + fault_reg_offset[itype]);
+	}
+
+	if (data->domain)
+		ret = report_iommu_fault(data->domain, data->dev,
+				addr, itype);
+
+	if ((ret == -ENOSYS) && data->fault_handler) {
+		unsigned long base = data->pgtable;
+		if (itype != SYSMMU_FAULT_UNKNOWN)
+			base = __raw_readl(
+					data->sfrbases[i] + REG_PT_BASE_ADDR);
+		ret = data->fault_handler(itype, base, addr);
+	}
+
+	if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
+		__raw_writel(1 << itype, data->sfrbases[i] + REG_INT_CLEAR);
+	else
+		dev_dbg(data->sysmmu, "(%s) %s is not handled.\n",
+				data->dbgname, sysmmu_fault_name[itype]);
+
+	if (itype != SYSMMU_FAULT_UNKNOWN)
+		sysmmu_unblock(data->sfrbases[i]);
+
+	read_unlock(&data->lock);
+
+	return IRQ_HANDLED;
+}
+
+static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
+{
+	unsigned long flags;
+	bool disabled = false;
+	int i;
+
+	write_lock_irqsave(&data->lock, flags);
+
+	if (!set_sysmmu_inactive(data))
+		goto finish;
+
+	for (i = 0; i < data->nsfrs; i++)
+		__raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
+
+	if (data->clk[1])
+		clk_disable(data->clk[1]);
+	if (data->clk[0])
+		clk_disable(data->clk[0]);
+
+	disabled = true;
+	data->pgtable = 0;
+	data->domain = NULL;
+finish:
+	write_unlock_irqrestore(&data->lock, flags);
+
+	if (disabled)
+		dev_dbg(data->sysmmu, "(%s) Disabled\n", data->dbgname);
+	else
+		dev_dbg(data->sysmmu, "(%s) %d times left to be disabled\n",
+					data->dbgname, data->activations);
+
+	return disabled;
+}
+
+/* __exynos_sysmmu_enable: Enables System MMU
+ *
+ * returns -error if an error occurred and System MMU is not enabled,
+ * 0 if the System MMU has been just enabled and 1 if System MMU was already
+ * enabled before.
+ */
+static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
+			unsigned long pgtable, struct iommu_domain *domain)
+{
+	int i, ret = 0;
+	unsigned long flags;
+
+	write_lock_irqsave(&data->lock, flags);
+
+	if (!set_sysmmu_active(data)) {
+		if (WARN_ON(pgtable != data->pgtable)) {
+			ret = -EBUSY;
+			set_sysmmu_inactive(data);
+		} else {
+			ret = 1;
+		}
+
+		dev_dbg(data->sysmmu, "(%s) Already enabled\n", data->dbgname);
+		goto finish;
+	}
+
+	if (data->clk[0])
+		clk_enable(data->clk[0]);
+	if (data->clk[1])
+		clk_enable(data->clk[1]);
+
+	data->pgtable = pgtable;
+
+	for (i = 0; i < data->nsfrs; i++) {
+		__sysmmu_set_ptbase(data->sfrbases[i], pgtable);
+
+		if ((readl(data->sfrbases[i] + REG_MMU_VERSION) >> 28) == 3) {
+			/* System MMU version is 3.x */
+			__raw_writel((1 << 12) | (2 << 28),
+					data->sfrbases[i] + REG_MMU_CFG);
+			__sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 0);
+			__sysmmu_set_prefbuf(data->sfrbases[i], 0, -1, 1);
+		}
+
+		__raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
+	}
+
+	data->domain = domain;
+
+	dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
+finish:
+	write_unlock_irqrestore(&data->lock, flags);
+
+	return ret;
+}
+
+int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
+{
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+	int ret;
+
+	BUG_ON(!memblock_is_memory(pgtable));
+
+	ret = pm_runtime_get_sync(data->sysmmu);
+	if (ret < 0) {
+		dev_dbg(data->sysmmu, "(%s) Failed to enable\n", data->dbgname);
+		return ret;
+	}
+
+	ret = __exynos_sysmmu_enable(data, pgtable, NULL);
+	if (WARN_ON(ret < 0)) {
+		pm_runtime_put(data->sysmmu);
+		dev_err(data->sysmmu,
+			"(%s) Already enabled with page table %#lx\n",
+			data->dbgname, data->pgtable);
+	} else {
+		data->dev = dev;
+	}
+
+	return ret;
+}
+
+bool exynos_sysmmu_disable(struct device *dev)
+{
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+	bool disabled;
+
+	disabled = __exynos_sysmmu_disable(data);
+	pm_runtime_put(data->sysmmu);
+
+	return disabled;
+}
+
+static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
+{
+	unsigned long flags;
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+
+	read_lock_irqsave(&data->lock, flags);
+
+	if (is_sysmmu_active(data)) {
+		int i;
+		for (i = 0; i < data->nsfrs; i++) {
+			if (sysmmu_block(data->sfrbases[i])) {
+				__sysmmu_tlb_invalidate_entry(
+						data->sfrbases[i], iova);
+				sysmmu_unblock(data->sfrbases[i]);
+			}
+		}
+	} else {
+		dev_dbg(data->sysmmu,
+			"(%s) Disabled. Skipping invalidating TLB.\n",
+			data->dbgname);
+	}
+
+	read_unlock_irqrestore(&data->lock, flags);
+}
+
+void exynos_sysmmu_tlb_invalidate(struct device *dev)
+{
+	unsigned long flags;
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+
+	read_lock_irqsave(&data->lock, flags);
+
+	if (is_sysmmu_active(data)) {
+		int i;
+		for (i = 0; i < data->nsfrs; i++) {
+			if (sysmmu_block(data->sfrbases[i])) {
+				__sysmmu_tlb_invalidate(data->sfrbases[i]);
+				sysmmu_unblock(data->sfrbases[i]);
+			}
+		}
+	} else {
+		dev_dbg(data->sysmmu,
+			"(%s) Disabled. Skipping invalidating TLB.\n",
+			data->dbgname);
+	}
+
+	read_unlock_irqrestore(&data->lock, flags);
+}
+
+static int exynos_sysmmu_probe(struct platform_device *pdev)
+{
+	int i, ret;
+	struct device *dev;
+	struct sysmmu_drvdata *data;
+
+	dev = &pdev->dev;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		dev_dbg(dev, "Not enough memory\n");
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	ret = dev_set_drvdata(dev, data);
+	if (ret) {
+		dev_dbg(dev, "Unabled to initialize driver data\n");
+		goto err_init;
+	}
+
+	data->nsfrs = pdev->num_resources / 2;
+	data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
+								GFP_KERNEL);
+	if (data->sfrbases == NULL) {
+		dev_dbg(dev, "Not enough memory\n");
+		ret = -ENOMEM;
+		goto err_init;
+	}
+
+	for (i = 0; i < data->nsfrs; i++) {
+		struct resource *res;
+		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+		if (!res) {
+			dev_dbg(dev, "Unable to find IOMEM region\n");
+			ret = -ENOENT;
+			goto err_res;
+		}
+
+		data->sfrbases[i] = ioremap(res->start, resource_size(res));
+		if (!data->sfrbases[i]) {
+			dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
+							res->start);
+			ret = -ENOENT;
+			goto err_res;
+		}
+	}
+
+	for (i = 0; i < data->nsfrs; i++) {
+		ret = platform_get_irq(pdev, i);
+		if (ret <= 0) {
+			dev_dbg(dev, "Unable to find IRQ resource\n");
+			goto err_irq;
+		}
+
+		ret = request_irq(ret, exynos_sysmmu_irq, 0,
+					dev_name(dev), data);
+		if (ret) {
+			dev_dbg(dev, "Unabled to register interrupt handler\n");
+			goto err_irq;
+		}
+	}
+
+	if (dev_get_platdata(dev)) {
+		char *deli, *beg;
+		struct sysmmu_platform_data *platdata = dev_get_platdata(dev);
+
+		beg = platdata->clockname;
+
+		for (deli = beg; (*deli != '\0') && (*deli != ','); deli++)
+			/* NOTHING */;
+
+		if (*deli == '\0')
+			deli = NULL;
+		else
+			*deli = '\0';
+
+		data->clk[0] = clk_get(dev, beg);
+		if (IS_ERR(data->clk[0])) {
+			data->clk[0] = NULL;
+			dev_dbg(dev, "No clock descriptor registered\n");
+		}
+
+		if (data->clk[0] && deli) {
+			*deli = ',';
+			data->clk[1] = clk_get(dev, deli + 1);
+			if (IS_ERR(data->clk[1]))
+				data->clk[1] = NULL;
+		}
+
+		data->dbgname = platdata->dbgname;
+	}
+
+	data->sysmmu = dev;
+	rwlock_init(&data->lock);
+	INIT_LIST_HEAD(&data->node);
+
+	__set_fault_handler(data, &default_fault_handler);
+
+	if (dev->parent)
+		pm_runtime_enable(dev);
+
+	dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
+	return 0;
+err_irq:
+	while (i-- > 0) {
+		int irq;
+
+		irq = platform_get_irq(pdev, i);
+		free_irq(irq, data);
+	}
+err_res:
+	while (data->nsfrs-- > 0)
+		iounmap(data->sfrbases[data->nsfrs]);
+	kfree(data->sfrbases);
+err_init:
+	kfree(data);
+err_alloc:
+	dev_err(dev, "Failed to initialize\n");
+	return ret;
+}
+
+static struct platform_driver exynos_sysmmu_driver = {
+	.probe		= exynos_sysmmu_probe,
+	.driver		= {
+		.owner		= THIS_MODULE,
+		.name		= "exynos-sysmmu",
+	}
+};
+
+static inline void pgtable_flush(void *vastart, void *vaend)
+{
+	dmac_flush_range(vastart, vaend);
+	outer_flush_range(virt_to_phys(vastart),
+				virt_to_phys(vaend));
+}
+
+static int exynos_iommu_domain_init(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->pgtable = (unsigned long *)__get_free_pages(
+						GFP_KERNEL | __GFP_ZERO, 2);
+	if (!priv->pgtable)
+		goto err_pgtable;
+
+	priv->lv2entcnt = (short *)__get_free_pages(
+						GFP_KERNEL | __GFP_ZERO, 1);
+	if (!priv->lv2entcnt)
+		goto err_counter;
+
+	pgtable_flush(priv->pgtable, priv->pgtable + NUM_LV1ENTRIES);
+
+	spin_lock_init(&priv->lock);
+	spin_lock_init(&priv->pgtablelock);
+	INIT_LIST_HEAD(&priv->clients);
+
+	domain->priv = priv;
+	return 0;
+
+err_counter:
+	free_pages((unsigned long)priv->pgtable, 2);
+err_pgtable:
+	kfree(priv);
+	return -ENOMEM;
+}
+
+static void exynos_iommu_domain_destroy(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	struct sysmmu_drvdata *data;
+	unsigned long flags;
+	int i;
+
+	WARN_ON(!list_empty(&priv->clients));
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	list_for_each_entry(data, &priv->clients, node) {
+		while (!exynos_sysmmu_disable(data->dev))
+			; /* until System MMU is actually disabled */
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	for (i = 0; i < NUM_LV1ENTRIES; i++)
+		if (lv1ent_page(priv->pgtable + i))
+			kfree(__va(lv2table_base(priv->pgtable + i)));
+
+	free_pages((unsigned long)priv->pgtable, 2);
+	free_pages((unsigned long)priv->lv2entcnt, 1);
+	kfree(domain->priv);
+	domain->priv = NULL;
+}
+
+static int exynos_iommu_attach_device(struct iommu_domain *domain,
+				   struct device *dev)
+{
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+	struct exynos_iommu_domain *priv = domain->priv;
+	unsigned long flags;
+	int ret;
+
+	ret = pm_runtime_get_sync(data->sysmmu);
+	if (ret < 0)
+		return ret;
+
+	ret = 0;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	ret = __exynos_sysmmu_enable(data, __pa(priv->pgtable), domain);
+
+	if (ret == 0) {
+		/* 'data->node' must not be appeared in priv->clients */
+		BUG_ON(!list_empty(&data->node));
+		data->dev = dev;
+		list_add_tail(&data->node, &priv->clients);
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (ret < 0) {
+		dev_err(dev, "%s: Failed to attach IOMMU with pgtable %#lx\n",
+				__func__, __pa(priv->pgtable));
+		pm_runtime_put(data->sysmmu);
+	} else if (ret > 0) {
+		dev_dbg(dev, "%s: IOMMU with pgtable 0x%lx already attached\n",
+					__func__, __pa(priv->pgtable));
+	} else {
+		dev_dbg(dev, "%s: Attached new IOMMU with pgtable 0x%lx\n",
+					__func__, __pa(priv->pgtable));
+	}
+
+	return ret;
+}
+
+static void exynos_iommu_detach_device(struct iommu_domain *domain,
+				    struct device *dev)
+{
+	struct sysmmu_drvdata *data = dev_get_drvdata(dev->archdata.iommu);
+	struct exynos_iommu_domain *priv = domain->priv;
+	struct list_head *pos;
+	unsigned long flags;
+	bool found = false;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	list_for_each(pos, &priv->clients) {
+		if (list_entry(pos, struct sysmmu_drvdata, node) == data) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		goto finish;
+
+	if (__exynos_sysmmu_disable(data)) {
+		dev_dbg(dev, "%s: Detached IOMMU with pgtable %#lx\n",
+					__func__, __pa(priv->pgtable));
+		list_del(&data->node);
+		INIT_LIST_HEAD(&data->node);
+
+	} else {
+		dev_dbg(dev, "%s: Detaching IOMMU with pgtable %#lx delayed",
+					__func__, __pa(priv->pgtable));
+	}
+
+finish:
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (found)
+		pm_runtime_put(data->sysmmu);
+}
+
+static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
+					short *pgcounter)
+{
+	if (lv1ent_fault(sent)) {
+		unsigned long *pent;
+
+		pent = kzalloc(LV2TABLE_SIZE, GFP_ATOMIC);
+		BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1));
+		if (!pent)
+			return NULL;
+
+		*sent = mk_lv1ent_page(__pa(pent));
+		*pgcounter = NUM_LV2ENTRIES;
+		pgtable_flush(pent, pent + NUM_LV2ENTRIES);
+		pgtable_flush(sent, sent + 1);
+	}
+
+	return page_entry(sent, iova);
+}
+
+static int lv1set_section(unsigned long *sent, phys_addr_t paddr, short *pgcnt)
+{
+	if (lv1ent_section(sent))
+		return -EADDRINUSE;
+
+	if (lv1ent_page(sent)) {
+		if (*pgcnt != NUM_LV2ENTRIES)
+			return -EADDRINUSE;
+
+		kfree(page_entry(sent, 0));
+
+		*pgcnt = 0;
+	}
+
+	*sent = mk_lv1ent_sect(paddr);
+
+	pgtable_flush(sent, sent + 1);
+
+	return 0;
+}
+
+static int lv2set_page(unsigned long *pent, phys_addr_t paddr, size_t size,
+								short *pgcnt)
+{
+	if (size == SPAGE_SIZE) {
+		if (!lv2ent_fault(pent))
+			return -EADDRINUSE;
+
+		*pent = mk_lv2ent_spage(paddr);
+		pgtable_flush(pent, pent + 1);
+		*pgcnt -= 1;
+	} else { /* size == LPAGE_SIZE */
+		int i;
+		for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
+			if (!lv2ent_fault(pent)) {
+				memset(pent, 0, sizeof(*pent) * i);
+				return -EADDRINUSE;
+			}
+
+			*pent = mk_lv2ent_lpage(paddr);
+		}
+		pgtable_flush(pent - SPAGES_PER_LPAGE, pent);
+		*pgcnt -= SPAGES_PER_LPAGE;
+	}
+
+	return 0;
+}
+
+static int exynos_iommu_map(struct iommu_domain *domain, unsigned long iova,
+			 phys_addr_t paddr, size_t size, int prot)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	unsigned long *entry;
+	unsigned long flags;
+	int ret = -ENOMEM;
+
+	BUG_ON(priv->pgtable == NULL);
+
+	spin_lock_irqsave(&priv->pgtablelock, flags);
+
+	entry = section_entry(priv->pgtable, iova);
+
+	if (size == SECT_SIZE) {
+		ret = lv1set_section(entry, paddr,
+					&priv->lv2entcnt[lv1ent_offset(iova)]);
+	} else {
+		unsigned long *pent;
+
+		pent = alloc_lv2entry(entry, iova,
+					&priv->lv2entcnt[lv1ent_offset(iova)]);
+
+		if (!pent)
+			ret = -ENOMEM;
+		else
+			ret = lv2set_page(pent, paddr, size,
+					&priv->lv2entcnt[lv1ent_offset(iova)]);
+	}
+
+	if (ret) {
+		pr_debug("%s: Failed to map iova 0x%lx/0x%x bytes\n",
+							__func__, iova, size);
+	}
+
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	return ret;
+}
+
+static size_t exynos_iommu_unmap(struct iommu_domain *domain,
+					       unsigned long iova, size_t size)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	struct sysmmu_drvdata *data;
+	unsigned long flags;
+	unsigned long *ent;
+
+	BUG_ON(priv->pgtable == NULL);
+
+	spin_lock_irqsave(&priv->pgtablelock, flags);
+
+	ent = section_entry(priv->pgtable, iova);
+
+	if (lv1ent_section(ent)) {
+		BUG_ON(size < SECT_SIZE);
+
+		*ent = 0;
+		pgtable_flush(ent, ent + 1);
+		size = SECT_SIZE;
+		goto done;
+	}
+
+	if (unlikely(lv1ent_fault(ent))) {
+		if (size > SECT_SIZE)
+			size = SECT_SIZE;
+		goto done;
+	}
+
+	/* lv1ent_page(sent) == true here */
+
+	ent = page_entry(ent, iova);
+
+	if (unlikely(lv2ent_fault(ent))) {
+		size = SPAGE_SIZE;
+		goto done;
+	}
+
+	if (lv2ent_small(ent)) {
+		*ent = 0;
+		size = SPAGE_SIZE;
+		priv->lv2entcnt[lv1ent_offset(iova)] += 1;
+		goto done;
+	}
+
+	/* lv1ent_large(ent) == true here */
+	BUG_ON(size < LPAGE_SIZE);
+
+	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
+
+	size = LPAGE_SIZE;
+	priv->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
+done:
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	list_for_each_entry(data, &priv->clients, node)
+		sysmmu_tlb_invalidate_entry(data->dev, iova);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+
+	return size;
+}
+
+static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain,
+					  unsigned long iova)
+{
+	struct exynos_iommu_domain *priv = domain->priv;
+	unsigned long *entry;
+	unsigned long flags;
+	phys_addr_t phys = 0;
+
+	spin_lock_irqsave(&priv->pgtablelock, flags);
+
+	entry = section_entry(priv->pgtable, iova);
+
+	if (lv1ent_section(entry)) {
+		phys = section_phys(entry) + section_offs(iova);
+	} else if (lv1ent_page(entry)) {
+		entry = page_entry(entry, iova);
+
+		if (lv2ent_large(entry))
+			phys = lpage_phys(entry) + lpage_offs(iova);
+		else if (lv2ent_small(entry))
+			phys = spage_phys(entry) + spage_offs(iova);
+	}
+
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	return phys;
+}
+
+static struct iommu_ops exynos_iommu_ops = {
+	.domain_init = &exynos_iommu_domain_init,
+	.domain_destroy = &exynos_iommu_domain_destroy,
+	.attach_dev = &exynos_iommu_attach_device,
+	.detach_dev = &exynos_iommu_detach_device,
+	.map = &exynos_iommu_map,
+	.unmap = &exynos_iommu_unmap,
+	.iova_to_phys = &exynos_iommu_iova_to_phys,
+	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
+};
+
+static int __init exynos_iommu_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&exynos_sysmmu_driver);
+
+	if (ret == 0)
+		bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
+
+	return ret;
+}
+subsys_initcall(exynos_iommu_init);