Initial import

1 files changed, 1242 insertions, 0 deletions

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
new file mode 100644
index 000000000..3e898504a
--- /dev/null
+++ b/drivers/iommu/exynos-iommu.c
@@ -0,0 +1,1242 @@
+/* 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>
+
+typedef u32 sysmmu_iova_t;
+typedef u32 sysmmu_pte_t;
+
+/* We do 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) == ZERO_LV2LINK) || \
+			   ((*(sent) & 3) == 0) || ((*(sent) & 3) == 3))
+#define lv1ent_zero(sent) (*(sent) == ZERO_LV2LINK)
+#define lv1ent_page_zero(sent) ((*(sent) & 3) == 1)
+#define lv1ent_page(sent) ((*(sent) != ZERO_LV2LINK) && \
+			  ((*(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)
+
+static u32 sysmmu_page_offset(sysmmu_iova_t iova, u32 size)
+{
+	return iova & (size - 1);
+}
+
+#define section_phys(sent) (*(sent) & SECT_MASK)
+#define section_offs(iova) sysmmu_page_offset((iova), SECT_SIZE)
+#define lpage_phys(pent) (*(pent) & LPAGE_MASK)
+#define lpage_offs(iova) sysmmu_page_offset((iova), LPAGE_SIZE)
+#define spage_phys(pent) (*(pent) & SPAGE_MASK)
+#define spage_offs(iova) sysmmu_page_offset((iova), SPAGE_SIZE)
+
+#define NUM_LV1ENTRIES 4096
+#define NUM_LV2ENTRIES (SECT_SIZE / SPAGE_SIZE)
+
+static u32 lv1ent_offset(sysmmu_iova_t iova)
+{
+	return iova >> SECT_ORDER;
+}
+
+static u32 lv2ent_offset(sysmmu_iova_t iova)
+{
+	return (iova >> SPAGE_ORDER) & (NUM_LV2ENTRIES - 1);
+}
+
+#define LV2TABLE_SIZE (NUM_LV2ENTRIES * sizeof(sysmmu_pte_t))
+
+#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 CFG_LRU		0x1
+#define CFG_QOS(n)	((n & 0xF) << 7)
+#define CFG_MASK	0x0150FFFF /* Selecting bit 0-15, 20, 22 and 24 */
+#define CFG_ACGEN	(1 << 24) /* System MMU 3.3 only */
+#define CFG_SYSSEL	(1 << 22) /* System MMU 3.2 only */
+#define CFG_FLPDCACHE	(1 << 20) /* System MMU 3.2+ only */
+
+#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 MMU_MAJ_VER(val)	((val) >> 7)
+#define MMU_MIN_VER(val)	((val) & 0x7F)
+#define MMU_RAW_VER(reg)	(((reg) >> 21) & ((1 << 11) - 1)) /* 11 bits */
+
+#define MAKE_MMU_VER(maj, min)	((((maj) & 0xF) << 7) | ((min) & 0x7F))
+
+#define REG_PB0_SADDR		0x04C
+#define REG_PB0_EADDR		0x050
+#define REG_PB1_SADDR		0x054
+#define REG_PB1_EADDR		0x058
+
+#define has_sysmmu(dev)		(dev->archdata.iommu != NULL)
+
+static struct kmem_cache *lv2table_kmem_cache;
+static sysmmu_pte_t *zero_lv2_table;
+#define ZERO_LV2LINK mk_lv1ent_page(virt_to_phys(zero_lv2_table))
+
+static sysmmu_pte_t *section_entry(sysmmu_pte_t *pgtable, sysmmu_iova_t iova)
+{
+	return pgtable + lv1ent_offset(iova);
+}
+
+static sysmmu_pte_t *page_entry(sysmmu_pte_t *sent, sysmmu_iova_t iova)
+{
+	return (sysmmu_pte_t *)phys_to_virt(
+				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
+};
+
+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"
+};
+
+/* attached to dev.archdata.iommu of the master device */
+struct exynos_iommu_owner {
+	struct list_head client; /* entry of exynos_iommu_domain.clients */
+	struct device *dev;
+	struct device *sysmmu;
+	struct iommu_domain *domain;
+	void *vmm_data;         /* IO virtual memory manager's data */
+	spinlock_t lock;        /* Lock to preserve consistency of System MMU */
+};
+
+struct exynos_iommu_domain {
+	struct list_head clients; /* list of sysmmu_drvdata.node */
+	sysmmu_pte_t *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 iommu_domain domain; /* generic domain data structure */
+};
+
+struct sysmmu_drvdata {
+	struct device *sysmmu;	/* System MMU's device descriptor */
+	struct device *master;	/* Owner of system MMU */
+	void __iomem *sfrbase;
+	struct clk *clk;
+	struct clk *clk_master;
+	int activations;
+	spinlock_t lock;
+	struct iommu_domain *domain;
+	phys_addr_t pgtable;
+};
+
+static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
+{
+	return container_of(dom, struct exynos_iommu_domain, domain);
+}
+
+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 unsigned int __raw_sysmmu_version(struct sysmmu_drvdata *data)
+{
+	return MMU_RAW_VER(__raw_readl(data->sfrbase + REG_MMU_VERSION));
+}
+
+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,
+				sysmmu_iova_t iova, unsigned int num_inv)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_inv; i++) {
+		__raw_writel((iova & SPAGE_MASK) | 1,
+				sfrbase + REG_MMU_FLUSH_ENTRY);
+		iova += SPAGE_SIZE;
+	}
+}
+
+static void __sysmmu_set_ptbase(void __iomem *sfrbase,
+				       phys_addr_t pgd)
+{
+	__raw_writel(pgd, sfrbase + REG_PT_BASE_ADDR);
+
+	__sysmmu_tlb_invalidate(sfrbase);
+}
+
+static void show_fault_information(const char *name,
+		enum exynos_sysmmu_inttype itype,
+		phys_addr_t pgtable_base, sysmmu_iova_t fault_addr)
+{
+	sysmmu_pte_t *ent;
+
+	if ((itype >= SYSMMU_FAULTS_NUM) || (itype < SYSMMU_PAGEFAULT))
+		itype = SYSMMU_FAULT_UNKNOWN;
+
+	pr_err("%s occurred at %#x by %s(Page table base: %pa)\n",
+		sysmmu_fault_name[itype], fault_addr, name, &pgtable_base);
+
+	ent = section_entry(phys_to_virt(pgtable_base), fault_addr);
+	pr_err("\tLv1 entry: %#x\n", *ent);
+
+	if (lv1ent_page(ent)) {
+		ent = page_entry(ent, fault_addr);
+		pr_err("\t Lv2 entry: %#x\n", *ent);
+	}
+}
+
+static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
+{
+	/* SYSMMU is in blocked state when interrupt occurred. */
+	struct sysmmu_drvdata *data = dev_id;
+	enum exynos_sysmmu_inttype itype;
+	sysmmu_iova_t addr = -1;
+	int ret = -ENOSYS;
+
+	WARN_ON(!is_sysmmu_active(data));
+
+	spin_lock(&data->lock);
+
+	if (!IS_ERR(data->clk_master))
+		clk_enable(data->clk_master);
+
+	itype = (enum exynos_sysmmu_inttype)
+		__ffs(__raw_readl(data->sfrbase + REG_INT_STATUS));
+	if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
+		itype = SYSMMU_FAULT_UNKNOWN;
+	else
+		addr = __raw_readl(data->sfrbase + fault_reg_offset[itype]);
+
+	if (itype == SYSMMU_FAULT_UNKNOWN) {
+		pr_err("%s: Fault is not occurred by System MMU '%s'!\n",
+			__func__, dev_name(data->sysmmu));
+		pr_err("%s: Please check if IRQ is correctly configured.\n",
+			__func__);
+		BUG();
+	} else {
+		unsigned int base =
+				__raw_readl(data->sfrbase + REG_PT_BASE_ADDR);
+		show_fault_information(dev_name(data->sysmmu),
+					itype, base, addr);
+		if (data->domain)
+			ret = report_iommu_fault(data->domain,
+					data->master, addr, itype);
+	}
+
+	/* fault is not recovered by fault handler */
+	BUG_ON(ret != 0);
+
+	__raw_writel(1 << itype, data->sfrbase + REG_INT_CLEAR);
+
+	sysmmu_unblock(data->sfrbase);
+
+	if (!IS_ERR(data->clk_master))
+		clk_disable(data->clk_master);
+
+	spin_unlock(&data->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void __sysmmu_disable_nocount(struct sysmmu_drvdata *data)
+{
+	if (!IS_ERR(data->clk_master))
+		clk_enable(data->clk_master);
+
+	__raw_writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);
+	__raw_writel(0, data->sfrbase + REG_MMU_CFG);
+
+	clk_disable(data->clk);
+	if (!IS_ERR(data->clk_master))
+		clk_disable(data->clk_master);
+}
+
+static bool __sysmmu_disable(struct sysmmu_drvdata *data)
+{
+	bool disabled;
+	unsigned long flags;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	disabled = set_sysmmu_inactive(data);
+
+	if (disabled) {
+		data->pgtable = 0;
+		data->domain = NULL;
+
+		__sysmmu_disable_nocount(data);
+
+		dev_dbg(data->sysmmu, "Disabled\n");
+	} else  {
+		dev_dbg(data->sysmmu, "%d times left to disable\n",
+					data->activations);
+	}
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return disabled;
+}
+
+static void __sysmmu_init_config(struct sysmmu_drvdata *data)
+{
+	unsigned int cfg = CFG_LRU | CFG_QOS(15);
+	unsigned int ver;
+
+	ver = __raw_sysmmu_version(data);
+	if (MMU_MAJ_VER(ver) == 3) {
+		if (MMU_MIN_VER(ver) >= 2) {
+			cfg |= CFG_FLPDCACHE;
+			if (MMU_MIN_VER(ver) == 3) {
+				cfg |= CFG_ACGEN;
+				cfg &= ~CFG_LRU;
+			} else {
+				cfg |= CFG_SYSSEL;
+			}
+		}
+	}
+
+	__raw_writel(cfg, data->sfrbase + REG_MMU_CFG);
+}
+
+static void __sysmmu_enable_nocount(struct sysmmu_drvdata *data)
+{
+	if (!IS_ERR(data->clk_master))
+		clk_enable(data->clk_master);
+	clk_enable(data->clk);
+
+	__raw_writel(CTRL_BLOCK, data->sfrbase + REG_MMU_CTRL);
+
+	__sysmmu_init_config(data);
+
+	__sysmmu_set_ptbase(data->sfrbase, data->pgtable);
+
+	__raw_writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);
+
+	if (!IS_ERR(data->clk_master))
+		clk_disable(data->clk_master);
+}
+
+static int __sysmmu_enable(struct sysmmu_drvdata *data,
+			phys_addr_t pgtable, struct iommu_domain *domain)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&data->lock, flags);
+	if (set_sysmmu_active(data)) {
+		data->pgtable = pgtable;
+		data->domain = domain;
+
+		__sysmmu_enable_nocount(data);
+
+		dev_dbg(data->sysmmu, "Enabled\n");
+	} else {
+		ret = (pgtable == data->pgtable) ? 1 : -EBUSY;
+
+		dev_dbg(data->sysmmu, "already enabled\n");
+	}
+
+	if (WARN_ON(ret < 0))
+		set_sysmmu_inactive(data); /* decrement count */
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return ret;
+}
+
+/* __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 device *dev, phys_addr_t pgtable,
+				  struct iommu_domain *domain)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	struct sysmmu_drvdata *data;
+
+	BUG_ON(!has_sysmmu(dev));
+
+	spin_lock_irqsave(&owner->lock, flags);
+
+	data = dev_get_drvdata(owner->sysmmu);
+
+	ret = __sysmmu_enable(data, pgtable, domain);
+	if (ret >= 0)
+		data->master = dev;
+
+	spin_unlock_irqrestore(&owner->lock, flags);
+
+	return ret;
+}
+
+int exynos_sysmmu_enable(struct device *dev, phys_addr_t pgtable)
+{
+	BUG_ON(!memblock_is_memory(pgtable));
+
+	return __exynos_sysmmu_enable(dev, pgtable, NULL);
+}
+
+static bool exynos_sysmmu_disable(struct device *dev)
+{
+	unsigned long flags;
+	bool disabled = true;
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	struct sysmmu_drvdata *data;
+
+	BUG_ON(!has_sysmmu(dev));
+
+	spin_lock_irqsave(&owner->lock, flags);
+
+	data = dev_get_drvdata(owner->sysmmu);
+
+	disabled = __sysmmu_disable(data);
+	if (disabled)
+		data->master = NULL;
+
+	spin_unlock_irqrestore(&owner->lock, flags);
+
+	return disabled;
+}
+
+static void __sysmmu_tlb_invalidate_flpdcache(struct sysmmu_drvdata *data,
+					      sysmmu_iova_t iova)
+{
+	if (__raw_sysmmu_version(data) == MAKE_MMU_VER(3, 3))
+		__raw_writel(iova | 0x1, data->sfrbase + REG_MMU_FLUSH_ENTRY);
+}
+
+static void sysmmu_tlb_invalidate_flpdcache(struct device *dev,
+					    sysmmu_iova_t iova)
+{
+	unsigned long flags;
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	struct sysmmu_drvdata *data = dev_get_drvdata(owner->sysmmu);
+
+	if (!IS_ERR(data->clk_master))
+		clk_enable(data->clk_master);
+
+	spin_lock_irqsave(&data->lock, flags);
+	if (is_sysmmu_active(data))
+		__sysmmu_tlb_invalidate_flpdcache(data, iova);
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	if (!IS_ERR(data->clk_master))
+		clk_disable(data->clk_master);
+}
+
+static void sysmmu_tlb_invalidate_entry(struct device *dev, sysmmu_iova_t iova,
+					size_t size)
+{
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	unsigned long flags;
+	struct sysmmu_drvdata *data;
+
+	data = dev_get_drvdata(owner->sysmmu);
+
+	spin_lock_irqsave(&data->lock, flags);
+	if (is_sysmmu_active(data)) {
+		unsigned int num_inv = 1;
+
+		if (!IS_ERR(data->clk_master))
+			clk_enable(data->clk_master);
+
+		/*
+		 * L2TLB invalidation required
+		 * 4KB page: 1 invalidation
+		 * 64KB page: 16 invalidations
+		 * 1MB page: 64 invalidations
+		 * because it is set-associative TLB
+		 * with 8-way and 64 sets.
+		 * 1MB page can be cached in one of all sets.
+		 * 64KB page can be one of 16 consecutive sets.
+		 */
+		if (MMU_MAJ_VER(__raw_sysmmu_version(data)) == 2)
+			num_inv = min_t(unsigned int, size / PAGE_SIZE, 64);
+
+		if (sysmmu_block(data->sfrbase)) {
+			__sysmmu_tlb_invalidate_entry(
+				data->sfrbase, iova, num_inv);
+			sysmmu_unblock(data->sfrbase);
+		}
+		if (!IS_ERR(data->clk_master))
+			clk_disable(data->clk_master);
+	} else {
+		dev_dbg(dev, "disabled. Skipping TLB invalidation @ %#x\n",
+			iova);
+	}
+	spin_unlock_irqrestore(&data->lock, flags);
+}
+
+void exynos_sysmmu_tlb_invalidate(struct device *dev)
+{
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	unsigned long flags;
+	struct sysmmu_drvdata *data;
+
+	data = dev_get_drvdata(owner->sysmmu);
+
+	spin_lock_irqsave(&data->lock, flags);
+	if (is_sysmmu_active(data)) {
+		if (!IS_ERR(data->clk_master))
+			clk_enable(data->clk_master);
+		if (sysmmu_block(data->sfrbase)) {
+			__sysmmu_tlb_invalidate(data->sfrbase);
+			sysmmu_unblock(data->sfrbase);
+		}
+		if (!IS_ERR(data->clk_master))
+			clk_disable(data->clk_master);
+	} else {
+		dev_dbg(dev, "disabled. Skipping TLB invalidation\n");
+	}
+	spin_unlock_irqrestore(&data->lock, flags);
+}
+
+static int __init exynos_sysmmu_probe(struct platform_device *pdev)
+{
+	int irq, ret;
+	struct device *dev = &pdev->dev;
+	struct sysmmu_drvdata *data;
+	struct resource *res;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->sfrbase = devm_ioremap_resource(dev, res);
+	if (IS_ERR(data->sfrbase))
+		return PTR_ERR(data->sfrbase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(dev, "Unable to find IRQ resource\n");
+		return irq;
+	}
+
+	ret = devm_request_irq(dev, irq, exynos_sysmmu_irq, 0,
+				dev_name(dev), data);
+	if (ret) {
+		dev_err(dev, "Unabled to register handler of irq %d\n", irq);
+		return ret;
+	}
+
+	data->clk = devm_clk_get(dev, "sysmmu");
+	if (IS_ERR(data->clk)) {
+		dev_err(dev, "Failed to get clock!\n");
+		return PTR_ERR(data->clk);
+	} else  {
+		ret = clk_prepare(data->clk);
+		if (ret) {
+			dev_err(dev, "Failed to prepare clk\n");
+			return ret;
+		}
+	}
+
+	data->clk_master = devm_clk_get(dev, "master");
+	if (!IS_ERR(data->clk_master)) {
+		ret = clk_prepare(data->clk_master);
+		if (ret) {
+			clk_unprepare(data->clk);
+			dev_err(dev, "Failed to prepare master's clk\n");
+			return ret;
+		}
+	}
+
+	data->sysmmu = dev;
+	spin_lock_init(&data->lock);
+
+	platform_set_drvdata(pdev, data);
+
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static const struct of_device_id sysmmu_of_match[] __initconst = {
+	{ .compatible	= "samsung,exynos-sysmmu", },
+	{ },
+};
+
+static struct platform_driver exynos_sysmmu_driver __refdata = {
+	.probe	= exynos_sysmmu_probe,
+	.driver	= {
+		.name		= "exynos-sysmmu",
+		.of_match_table	= sysmmu_of_match,
+	}
+};
+
+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 struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
+{
+	struct exynos_iommu_domain *exynos_domain;
+	int i;
+
+	if (type != IOMMU_DOMAIN_UNMANAGED)
+		return NULL;
+
+	exynos_domain = kzalloc(sizeof(*exynos_domain), GFP_KERNEL);
+	if (!exynos_domain)
+		return NULL;
+
+	exynos_domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
+	if (!exynos_domain->pgtable)
+		goto err_pgtable;
+
+	exynos_domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
+	if (!exynos_domain->lv2entcnt)
+		goto err_counter;
+
+	/* Workaround for System MMU v3.3 to prevent caching 1MiB mapping */
+	for (i = 0; i < NUM_LV1ENTRIES; i += 8) {
+		exynos_domain->pgtable[i + 0] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 1] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 2] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 3] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 4] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 5] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 6] = ZERO_LV2LINK;
+		exynos_domain->pgtable[i + 7] = ZERO_LV2LINK;
+	}
+
+	pgtable_flush(exynos_domain->pgtable, exynos_domain->pgtable + NUM_LV1ENTRIES);
+
+	spin_lock_init(&exynos_domain->lock);
+	spin_lock_init(&exynos_domain->pgtablelock);
+	INIT_LIST_HEAD(&exynos_domain->clients);
+
+	exynos_domain->domain.geometry.aperture_start = 0;
+	exynos_domain->domain.geometry.aperture_end   = ~0UL;
+	exynos_domain->domain.geometry.force_aperture = true;
+
+	return &exynos_domain->domain;
+
+err_counter:
+	free_pages((unsigned long)exynos_domain->pgtable, 2);
+err_pgtable:
+	kfree(exynos_domain);
+	return NULL;
+}
+
+static void exynos_iommu_domain_free(struct iommu_domain *domain)
+{
+	struct exynos_iommu_domain *priv = to_exynos_domain(domain);
+	struct exynos_iommu_owner *owner;
+	unsigned long flags;
+	int i;
+
+	WARN_ON(!list_empty(&priv->clients));
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	list_for_each_entry(owner, &priv->clients, client) {
+		while (!exynos_sysmmu_disable(owner->dev))
+			; /* until System MMU is actually disabled */
+	}
+
+	while (!list_empty(&priv->clients))
+		list_del_init(priv->clients.next);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	for (i = 0; i < NUM_LV1ENTRIES; i++)
+		if (lv1ent_page(priv->pgtable + i))
+			kmem_cache_free(lv2table_kmem_cache,
+				phys_to_virt(lv2table_base(priv->pgtable + i)));
+
+	free_pages((unsigned long)priv->pgtable, 2);
+	free_pages((unsigned long)priv->lv2entcnt, 1);
+	kfree(priv);
+}
+
+static int exynos_iommu_attach_device(struct iommu_domain *domain,
+				   struct device *dev)
+{
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	struct exynos_iommu_domain *priv = to_exynos_domain(domain);
+	phys_addr_t pagetable = virt_to_phys(priv->pgtable);
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	ret = __exynos_sysmmu_enable(dev, pagetable, domain);
+	if (ret == 0) {
+		list_add_tail(&owner->client, &priv->clients);
+		owner->domain = domain;
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (ret < 0) {
+		dev_err(dev, "%s: Failed to attach IOMMU with pgtable %pa\n",
+					__func__, &pagetable);
+		return ret;
+	}
+
+	dev_dbg(dev, "%s: Attached IOMMU with pgtable %pa %s\n",
+		__func__, &pagetable, (ret == 0) ? "" : ", again");
+
+	return ret;
+}
+
+static void exynos_iommu_detach_device(struct iommu_domain *domain,
+				    struct device *dev)
+{
+	struct exynos_iommu_owner *owner;
+	struct exynos_iommu_domain *priv = to_exynos_domain(domain);
+	phys_addr_t pagetable = virt_to_phys(priv->pgtable);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	list_for_each_entry(owner, &priv->clients, client) {
+		if (owner == dev->archdata.iommu) {
+			if (exynos_sysmmu_disable(dev)) {
+				list_del_init(&owner->client);
+				owner->domain = NULL;
+			}
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (owner == dev->archdata.iommu)
+		dev_dbg(dev, "%s: Detached IOMMU with pgtable %pa\n",
+					__func__, &pagetable);
+	else
+		dev_err(dev, "%s: No IOMMU is attached\n", __func__);
+}
+
+static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *priv,
+		sysmmu_pte_t *sent, sysmmu_iova_t iova, short *pgcounter)
+{
+	if (lv1ent_section(sent)) {
+		WARN(1, "Trying mapping on %#08x mapped with 1MiB page", iova);
+		return ERR_PTR(-EADDRINUSE);
+	}
+
+	if (lv1ent_fault(sent)) {
+		sysmmu_pte_t *pent;
+		bool need_flush_flpd_cache = lv1ent_zero(sent);
+
+		pent = kmem_cache_zalloc(lv2table_kmem_cache, GFP_ATOMIC);
+		BUG_ON((unsigned int)pent & (LV2TABLE_SIZE - 1));
+		if (!pent)
+			return ERR_PTR(-ENOMEM);
+
+		*sent = mk_lv1ent_page(virt_to_phys(pent));
+		*pgcounter = NUM_LV2ENTRIES;
+		pgtable_flush(pent, pent + NUM_LV2ENTRIES);
+		pgtable_flush(sent, sent + 1);
+
+		/*
+		 * If pre-fetched SLPD is a faulty SLPD in zero_l2_table,
+		 * FLPD cache may cache the address of zero_l2_table. This
+		 * function replaces the zero_l2_table with new L2 page table
+		 * to write valid mappings.
+		 * Accessing the valid area may cause page fault since FLPD
+		 * cache may still cache zero_l2_table for the valid area
+		 * instead of new L2 page table that has the mapping
+		 * information of the valid area.
+		 * Thus any replacement of zero_l2_table with other valid L2
+		 * page table must involve FLPD cache invalidation for System
+		 * MMU v3.3.
+		 * FLPD cache invalidation is performed with TLB invalidation
+		 * by VPN without blocking. It is safe to invalidate TLB without
+		 * blocking because the target address of TLB invalidation is
+		 * not currently mapped.
+		 */
+		if (need_flush_flpd_cache) {
+			struct exynos_iommu_owner *owner;
+
+			spin_lock(&priv->lock);
+			list_for_each_entry(owner, &priv->clients, client)
+				sysmmu_tlb_invalidate_flpdcache(
+							owner->dev, iova);
+			spin_unlock(&priv->lock);
+		}
+	}
+
+	return page_entry(sent, iova);
+}
+
+static int lv1set_section(struct exynos_iommu_domain *priv,
+			  sysmmu_pte_t *sent, sysmmu_iova_t iova,
+			  phys_addr_t paddr, short *pgcnt)
+{
+	if (lv1ent_section(sent)) {
+		WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
+			iova);
+		return -EADDRINUSE;
+	}
+
+	if (lv1ent_page(sent)) {
+		if (*pgcnt != NUM_LV2ENTRIES) {
+			WARN(1, "Trying mapping on 1MiB@%#08x that is mapped",
+				iova);
+			return -EADDRINUSE;
+		}
+
+		kmem_cache_free(lv2table_kmem_cache, page_entry(sent, 0));
+		*pgcnt = 0;
+	}
+
+	*sent = mk_lv1ent_sect(paddr);
+
+	pgtable_flush(sent, sent + 1);
+
+	spin_lock(&priv->lock);
+	if (lv1ent_page_zero(sent)) {
+		struct exynos_iommu_owner *owner;
+		/*
+		 * Flushing FLPD cache in System MMU v3.3 that may cache a FLPD
+		 * entry by speculative prefetch of SLPD which has no mapping.
+		 */
+		list_for_each_entry(owner, &priv->clients, client)
+			sysmmu_tlb_invalidate_flpdcache(owner->dev, iova);
+	}
+	spin_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int lv2set_page(sysmmu_pte_t *pent, phys_addr_t paddr, size_t size,
+								short *pgcnt)
+{
+	if (size == SPAGE_SIZE) {
+		if (WARN_ON(!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 (WARN_ON(!lv2ent_fault(pent))) {
+				if (i > 0)
+					memset(pent - i, 0, sizeof(*pent) * i);
+				return -EADDRINUSE;
+			}
+
+			*pent = mk_lv2ent_lpage(paddr);
+		}
+		pgtable_flush(pent - SPAGES_PER_LPAGE, pent);
+		*pgcnt -= SPAGES_PER_LPAGE;
+	}
+
+	return 0;
+}
+
+/*
+ * *CAUTION* to the I/O virtual memory managers that support exynos-iommu:
+ *
+ * System MMU v3.x has advanced logic to improve address translation
+ * performance with caching more page table entries by a page table walk.
+ * However, the logic has a bug that while caching faulty page table entries,
+ * System MMU reports page fault if the cached fault entry is hit even though
+ * the fault entry is updated to a valid entry after the entry is cached.
+ * To prevent caching faulty page table entries which may be updated to valid
+ * entries later, the virtual memory manager should care about the workaround
+ * for the problem. The following describes the workaround.
+ *
+ * Any two consecutive I/O virtual address regions must have a hole of 128KiB
+ * at maximum to prevent misbehavior of System MMU 3.x (workaround for h/w bug).
+ *
+ * Precisely, any start address of I/O virtual region must be aligned with
+ * the following sizes for System MMU v3.1 and v3.2.
+ * System MMU v3.1: 128KiB
+ * System MMU v3.2: 256KiB
+ *
+ * Because System MMU v3.3 caches page table entries more aggressively, it needs
+ * more workarounds.
+ * - Any two consecutive I/O virtual regions must have a hole of size larger
+ *   than or equal to 128KiB.
+ * - Start address of an I/O virtual region must be aligned by 128KiB.
+ */
+static int exynos_iommu_map(struct iommu_domain *domain, unsigned long l_iova,
+			 phys_addr_t paddr, size_t size, int prot)
+{
+	struct exynos_iommu_domain *priv = to_exynos_domain(domain);
+	sysmmu_pte_t *entry;
+	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
+	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(priv, entry, iova, paddr,
+					&priv->lv2entcnt[lv1ent_offset(iova)]);
+	} else {
+		sysmmu_pte_t *pent;
+
+		pent = alloc_lv2entry(priv, entry, iova,
+					&priv->lv2entcnt[lv1ent_offset(iova)]);
+
+		if (IS_ERR(pent))
+			ret = PTR_ERR(pent);
+		else
+			ret = lv2set_page(pent, paddr, size,
+					&priv->lv2entcnt[lv1ent_offset(iova)]);
+	}
+
+	if (ret)
+		pr_err("%s: Failed(%d) to map %#zx bytes @ %#x\n",
+			__func__, ret, size, iova);
+
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	return ret;
+}
+
+static void exynos_iommu_tlb_invalidate_entry(struct exynos_iommu_domain *priv,
+						sysmmu_iova_t iova, size_t size)
+{
+	struct exynos_iommu_owner *owner;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	list_for_each_entry(owner, &priv->clients, client)
+		sysmmu_tlb_invalidate_entry(owner->dev, iova, size);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static size_t exynos_iommu_unmap(struct iommu_domain *domain,
+					unsigned long l_iova, size_t size)
+{
+	struct exynos_iommu_domain *priv = to_exynos_domain(domain);
+	sysmmu_iova_t iova = (sysmmu_iova_t)l_iova;
+	sysmmu_pte_t *ent;
+	size_t err_pgsize;
+	unsigned long flags;
+
+	BUG_ON(priv->pgtable == NULL);
+
+	spin_lock_irqsave(&priv->pgtablelock, flags);
+
+	ent = section_entry(priv->pgtable, iova);
+
+	if (lv1ent_section(ent)) {
+		if (WARN_ON(size < SECT_SIZE)) {
+			err_pgsize = SECT_SIZE;
+			goto err;
+		}
+
+		/* workaround for h/w bug in System MMU v3.3 */
+		*ent = ZERO_LV2LINK;
+		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;
+		pgtable_flush(ent, ent + 1);
+		priv->lv2entcnt[lv1ent_offset(iova)] += 1;
+		goto done;
+	}
+
+	/* lv1ent_large(ent) == true here */
+	if (WARN_ON(size < LPAGE_SIZE)) {
+		err_pgsize = LPAGE_SIZE;
+		goto err;
+	}
+
+	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
+	pgtable_flush(ent, ent + SPAGES_PER_LPAGE);
+
+	size = LPAGE_SIZE;
+	priv->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
+done:
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	exynos_iommu_tlb_invalidate_entry(priv, iova, size);
+
+	return size;
+err:
+	spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+	pr_err("%s: Failed: size(%#zx) @ %#x is smaller than page size %#zx\n",
+		__func__, size, iova, err_pgsize);
+
+	return 0;
+}
+
+static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain,
+					  dma_addr_t iova)
+{
+	struct exynos_iommu_domain *priv = to_exynos_domain(domain);
+	sysmmu_pte_t *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 int exynos_iommu_add_device(struct device *dev)
+{
+	struct iommu_group *group;
+	int ret;
+
+	group = iommu_group_get(dev);
+
+	if (!group) {
+		group = iommu_group_alloc();
+		if (IS_ERR(group)) {
+			dev_err(dev, "Failed to allocate IOMMU group\n");
+			return PTR_ERR(group);
+		}
+	}
+
+	ret = iommu_group_add_device(group, dev);
+	iommu_group_put(group);
+
+	return ret;
+}
+
+static void exynos_iommu_remove_device(struct device *dev)
+{
+	iommu_group_remove_device(dev);
+}
+
+static const struct iommu_ops exynos_iommu_ops = {
+	.domain_alloc = exynos_iommu_domain_alloc,
+	.domain_free = exynos_iommu_domain_free,
+	.attach_dev = exynos_iommu_attach_device,
+	.detach_dev = exynos_iommu_detach_device,
+	.map = exynos_iommu_map,
+	.unmap = exynos_iommu_unmap,
+	.map_sg = default_iommu_map_sg,
+	.iova_to_phys = exynos_iommu_iova_to_phys,
+	.add_device = exynos_iommu_add_device,
+	.remove_device = exynos_iommu_remove_device,
+	.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
+};
+
+static int __init exynos_iommu_init(void)
+{
+	struct device_node *np;
+	int ret;
+
+	np = of_find_matching_node(NULL, sysmmu_of_match);
+	if (!np)
+		return 0;
+
+	of_node_put(np);
+
+	lv2table_kmem_cache = kmem_cache_create("exynos-iommu-lv2table",
+				LV2TABLE_SIZE, LV2TABLE_SIZE, 0, NULL);
+	if (!lv2table_kmem_cache) {
+		pr_err("%s: Failed to create kmem cache\n", __func__);
+		return -ENOMEM;
+	}
+
+	ret = platform_driver_register(&exynos_sysmmu_driver);
+	if (ret) {
+		pr_err("%s: Failed to register driver\n", __func__);
+		goto err_reg_driver;
+	}
+
+	zero_lv2_table = kmem_cache_zalloc(lv2table_kmem_cache, GFP_KERNEL);
+	if (zero_lv2_table == NULL) {
+		pr_err("%s: Failed to allocate zero level2 page table\n",
+			__func__);
+		ret = -ENOMEM;
+		goto err_zero_lv2;
+	}
+
+	ret = bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
+	if (ret) {
+		pr_err("%s: Failed to register exynos-iommu driver.\n",
+								__func__);
+		goto err_set_iommu;
+	}
+
+	return 0;
+err_set_iommu:
+	kmem_cache_free(lv2table_kmem_cache, zero_lv2_table);
+err_zero_lv2:
+	platform_driver_unregister(&exynos_sysmmu_driver);
+err_reg_driver:
+	kmem_cache_destroy(lv2table_kmem_cache);
+	return ret;
+}
+subsys_initcall(exynos_iommu_init);