Merge branch 'iommu' of...

Merge branch 'iommu' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6.git into devel

arch/arm/include/asm/mach/map.h

@@ -30,6 +30,14 @@ struct map_desc {
 
 #ifdef CONFIG_MMU
 extern void iotable_init(struct map_desc *, int);
+
+struct mem_type;
+extern const struct mem_type *get_mem_type(unsigned int type);
+/*
+ * external interface to remap single page with appropriate type
+ */
+extern int ioremap_page(unsigned long virt, unsigned long phys,
+			const struct mem_type *mtype);
 #else
 #define iotable_init(map,num)	do { } while (0)
 #endif

arch/arm/mach-omap2/Makefile

@@ -28,6 +28,11 @@ endif
 obj-$(CONFIG_ARCH_OMAP2)		+= clock24xx.o
 obj-$(CONFIG_ARCH_OMAP3)		+= clock34xx.o
 
+iommu-y					+= iommu2.o
+iommu-$(CONFIG_ARCH_OMAP3)		+= omap3-iommu.o
+
+obj-$(CONFIG_OMAP_IOMMU)		+= $(iommu-y)
+
 # Specific board support
 obj-$(CONFIG_MACH_OMAP_GENERIC)		+= board-generic.o
 obj-$(CONFIG_MACH_OMAP_H4)		+= board-h4.o

arch/arm/mach-omap2/iommu2.c

+/*
+ * omap iommu: omap2/3 architecture specific functions
+ *
+ * Copyright (C) 2008-2009 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/device.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/stringify.h>
+
+#include <mach/iommu.h>
+
+/*
+ * omap2 architecture specific register bit definitions
+ */
+#define IOMMU_ARCH_VERSION	0x00000011
+
+/* SYSCONF */
+#define MMU_SYS_IDLE_SHIFT	3
+#define MMU_SYS_IDLE_FORCE	(0 << MMU_SYS_IDLE_SHIFT)
+#define MMU_SYS_IDLE_NONE	(1 << MMU_SYS_IDLE_SHIFT)
+#define MMU_SYS_IDLE_SMART	(2 << MMU_SYS_IDLE_SHIFT)
+#define MMU_SYS_IDLE_MASK	(3 << MMU_SYS_IDLE_SHIFT)
+
+#define MMU_SYS_SOFTRESET	(1 << 1)
+#define MMU_SYS_AUTOIDLE	1
+
+/* SYSSTATUS */
+#define MMU_SYS_RESETDONE	1
+
+/* IRQSTATUS & IRQENABLE */
+#define MMU_IRQ_MULTIHITFAULT	(1 << 4)
+#define MMU_IRQ_TABLEWALKFAULT	(1 << 3)
+#define MMU_IRQ_EMUMISS		(1 << 2)
+#define MMU_IRQ_TRANSLATIONFAULT	(1 << 1)
+#define MMU_IRQ_TLBMISS		(1 << 0)
+#define MMU_IRQ_MASK	\
+	(MMU_IRQ_MULTIHITFAULT | MMU_IRQ_TABLEWALKFAULT | MMU_IRQ_EMUMISS | \
+	 MMU_IRQ_TRANSLATIONFAULT)
+
+/* MMU_CNTL */
+#define MMU_CNTL_SHIFT		1
+#define MMU_CNTL_MASK		(7 << MMU_CNTL_SHIFT)
+#define MMU_CNTL_EML_TLB	(1 << 3)
+#define MMU_CNTL_TWL_EN		(1 << 2)
+#define MMU_CNTL_MMU_EN		(1 << 1)
+
+#define get_cam_va_mask(pgsz)				\
+	(((pgsz) == MMU_CAM_PGSZ_16M) ? 0xff000000 :	\
+	 ((pgsz) == MMU_CAM_PGSZ_1M)  ? 0xfff00000 :	\
+	 ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 :	\
+	 ((pgsz) == MMU_CAM_PGSZ_4K)  ? 0xfffff000 : 0)
+
+static int omap2_iommu_enable(struct iommu *obj)
+{
+	u32 l, pa;
+	unsigned long timeout;
+
+	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;
+
+	iommu_write_reg(obj, MMU_SYS_SOFTRESET, MMU_SYSCONFIG);
+
+	timeout = jiffies + msecs_to_jiffies(20);
+	do {
+		l = iommu_read_reg(obj, MMU_SYSSTATUS);
+		if (l & MMU_SYS_RESETDONE)
+			break;
+	} while (time_after(jiffies, timeout));
+
+	if (!(l & MMU_SYS_RESETDONE)) {
+		dev_err(obj->dev, "can't take mmu out of reset\n");
+		return -ENODEV;
+	}
+
+	l = iommu_read_reg(obj, MMU_REVISION);
+	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
+		 (l >> 4) & 0xf, l & 0xf);
+
+	l = iommu_read_reg(obj, MMU_SYSCONFIG);
+	l &= ~MMU_SYS_IDLE_MASK;
+	l |= (MMU_SYS_IDLE_SMART | MMU_SYS_AUTOIDLE);
+	iommu_write_reg(obj, l, MMU_SYSCONFIG);
+
+	iommu_write_reg(obj, MMU_IRQ_MASK, MMU_IRQENABLE);
+	iommu_write_reg(obj, pa, MMU_TTB);
+
+	l = iommu_read_reg(obj, MMU_CNTL);
+	l &= ~MMU_CNTL_MASK;
+	l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
+	iommu_write_reg(obj, l, MMU_CNTL);
+
+	return 0;
+}
+
+static void omap2_iommu_disable(struct iommu *obj)
+{
+	u32 l = iommu_read_reg(obj, MMU_CNTL);
+
+	l &= ~MMU_CNTL_MASK;
+	iommu_write_reg(obj, l, MMU_CNTL);
+	iommu_write_reg(obj, MMU_SYS_IDLE_FORCE, MMU_SYSCONFIG);
+
+	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
+}
+
+static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
+{
+	int i;
+	u32 stat, da;
+	const char *err_msg[] =	{
+		"tlb miss",
+		"translation fault",
+		"emulation miss",
+		"table walk fault",
+		"multi hit fault",
+	};
+
+	stat = iommu_read_reg(obj, MMU_IRQSTATUS);
+	stat &= MMU_IRQ_MASK;
+	if (!stat)
+		return 0;
+
+	da = iommu_read_reg(obj, MMU_FAULT_AD);
+	*ra = da;
+
+	dev_err(obj->dev, "%s:\tda:%08x ", __func__, da);
+
+	for (i = 0; i < ARRAY_SIZE(err_msg); i++) {
+		if (stat & (1 << i))
+			printk("%s ", err_msg[i]);
+	}
+	printk("\n");
+
+	iommu_write_reg(obj, stat, MMU_IRQSTATUS);
+	return stat;
+}
+
+static void omap2_tlb_read_cr(struct 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 omap2_tlb_load_cr(struct 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);
+}
+
+static u32 omap2_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 struct cr_regs *omap2_alloc_cr(struct iommu *obj, struct iotlb_entry *e)
+{
+	struct cr_regs *cr;
+
+	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;
+	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
+
+	return cr;
+}
+
+static inline int omap2_cr_valid(struct cr_regs *cr)
+{
+	return cr->cam & MMU_CAM_V;
+}
+
+static u32 omap2_get_pte_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) ? 0 : 6);
+
+	return attr;
+}
+
+static ssize_t omap2_dump_cr(struct iommu *obj, struct cr_regs *cr, char *buf)
+{
+	char *p = buf;
+
+	/* FIXME: Need more detail analysis of cam/ram */
+	p += sprintf(p, "%08x %08x\n", cr->cam, cr->ram);
+
+	return p - buf;
+}
+
+#define pr_reg(name)							\
+	p += sprintf(p, "%20s: %08x\n",					\
+		     __stringify(name), iommu_read_reg(obj, MMU_##name));
+
+static ssize_t omap2_iommu_dump_ctx(struct iommu *obj, char *buf)
+{
+	char *p = buf;
+
+	pr_reg(REVISION);
+	pr_reg(SYSCONFIG);
+	pr_reg(SYSSTATUS);
+	pr_reg(IRQSTATUS);
+	pr_reg(IRQENABLE);
+	pr_reg(WALKING_ST);
+	pr_reg(CNTL);
+	pr_reg(FAULT_AD);
+	pr_reg(TTB);
+	pr_reg(LOCK);
+	pr_reg(LD_TLB);
+	pr_reg(CAM);
+	pr_reg(RAM);
+	pr_reg(GFLUSH);
+	pr_reg(FLUSH_ENTRY);
+	pr_reg(READ_CAM);
+	pr_reg(READ_RAM);
+	pr_reg(EMU_FAULT_AD);
+
+	return p - buf;
+}
+
+static void omap2_iommu_save_ctx(struct iommu *obj)
+{
+	int i;
+	u32 *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]);
+	}
+
+	BUG_ON(p[0] != IOMMU_ARCH_VERSION);
+}
+
+static void omap2_iommu_restore_ctx(struct iommu *obj)
+{
+	int i;
+	u32 *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]);
+	}
+
+	BUG_ON(p[0] != IOMMU_ARCH_VERSION);
+}
+
+static void omap2_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
+{
+	e->da		= cr->cam & MMU_CAM_VATAG_MASK;
+	e->pa		= cr->ram & MMU_RAM_PADDR_MASK;
+	e->valid	= cr->cam & MMU_CAM_V;
+	e->pgsz		= cr->cam & MMU_CAM_PGSZ_MASK;
+	e->endian	= cr->ram & MMU_RAM_ENDIAN_MASK;
+	e->elsz		= cr->ram & MMU_RAM_ELSZ_MASK;
+	e->mixed	= cr->ram & MMU_RAM_MIXED;
+}
+
+static const struct iommu_functions omap2_iommu_ops = {
+	.version	= IOMMU_ARCH_VERSION,
+
+	.enable		= omap2_iommu_enable,
+	.disable	= omap2_iommu_disable,
+	.fault_isr	= omap2_iommu_fault_isr,
+
+	.tlb_read_cr	= omap2_tlb_read_cr,
+	.tlb_load_cr	= omap2_tlb_load_cr,
+
+	.cr_to_e	= omap2_cr_to_e,
+	.cr_to_virt	= omap2_cr_to_virt,
+	.alloc_cr	= omap2_alloc_cr,
+	.cr_valid	= omap2_cr_valid,
+	.dump_cr	= omap2_dump_cr,
+
+	.get_pte_attr	= omap2_get_pte_attr,
+
+	.save_ctx	= omap2_iommu_save_ctx,
+	.restore_ctx	= omap2_iommu_restore_ctx,
+	.dump_ctx	= omap2_iommu_dump_ctx,
+};
+
+static int __init omap2_iommu_init(void)
+{
+	return install_iommu_arch(&omap2_iommu_ops);
+}
+module_init(omap2_iommu_init);
+
+static void __exit omap2_iommu_exit(void)
+{
+	uninstall_iommu_arch(&omap2_iommu_ops);
+}
+module_exit(omap2_iommu_exit);
+
+MODULE_AUTHOR("Hiroshi DOYU, Paul Mundt and Toshihiro Kobayashi");
+MODULE_DESCRIPTION("omap iommu: omap2/3 architecture specific functions");
+MODULE_LICENSE("GPL v2");

arch/arm/mach-omap2/omap3-iommu.c

+/*
+ * omap iommu: omap3 device registration
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.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.
+ */
+
+#include <linux/platform_device.h>
+
+#include <mach/iommu.h>
+
+#define OMAP3_MMU1_BASE	0x480bd400
+#define OMAP3_MMU2_BASE	0x5d000000
+#define OMAP3_MMU1_IRQ	24
+#define OMAP3_MMU2_IRQ	28
+
+
+static unsigned long iommu_base[] __initdata = {
+	OMAP3_MMU1_BASE,
+	OMAP3_MMU2_BASE,
+};
+
+static int iommu_irq[] __initdata = {
+	OMAP3_MMU1_IRQ,
+	OMAP3_MMU2_IRQ,
+};
+
+static const struct iommu_platform_data omap3_iommu_pdata[] __initconst = {
+	{
+		.name = "isp",
+		.nr_tlb_entries = 8,
+		.clk_name = "cam_ick",
+	},
+#if defined(CONFIG_MPU_BRIDGE_IOMMU)
+	{
+		.name = "iva2",
+		.nr_tlb_entries = 32,
+		.clk_name = "iva2_ck",
+	},
+#endif
+};
+#define NR_IOMMU_DEVICES ARRAY_SIZE(omap3_iommu_pdata)
+
+static struct platform_device *omap3_iommu_pdev[NR_IOMMU_DEVICES];
+
+static int __init omap3_iommu_init(void)
+{
+	int i, err;
+
+	for (i = 0; i < NR_IOMMU_DEVICES; i++) {
+		struct platform_device *pdev;
+		struct resource res[2];
+
+		pdev = platform_device_alloc("omap-iommu", i);
+		if (!pdev) {
+			err = -ENOMEM;
+			goto err_out;
+		}
+
+		memset(res, 0,  sizeof(res));
+		res[0].start = iommu_base[i];
+		res[0].end = iommu_base[i] + MMU_REG_SIZE - 1;
+		res[0].flags = IORESOURCE_MEM;
+		res[1].start = res[1].end = iommu_irq[i];
+		res[1].flags = IORESOURCE_IRQ;
+
+		err = platform_device_add_resources(pdev, res,
+						    ARRAY_SIZE(res));
+		if (err)
+			goto err_out;
+		err = platform_device_add_data(pdev, &omap3_iommu_pdata[i],
+					       sizeof(omap3_iommu_pdata[0]));
+		if (err)
+			goto err_out;
+		err = platform_device_add(pdev);
+		if (err)
+			goto err_out;
+		omap3_iommu_pdev[i] = pdev;
+	}
+	return 0;
+
+err_out:
+	while (i--)
+		platform_device_put(omap3_iommu_pdev[i]);
+	return err;
+}
+module_init(omap3_iommu_init);
+
+static void __exit omap3_iommu_exit(void)
+{
+	int i;
+
+	for (i = 0; i < NR_IOMMU_DEVICES; i++)
+		platform_device_unregister(omap3_iommu_pdev[i]);
+}
+module_exit(omap3_iommu_exit);
+
+MODULE_AUTHOR("Hiroshi DOYU");
+MODULE_DESCRIPTION("omap iommu: omap3 device registration");
+MODULE_LICENSE("GPL v2");

arch/arm/mm/ioremap.c

@@ -110,6 +110,12 @@ static int remap_area_pages(unsigned long start, unsigned long pfn,
 	return err;
 }
 
+int ioremap_page(unsigned long virt, unsigned long phys,
+		 const struct mem_type *mtype)
+{
+	return remap_area_pages(virt, __phys_to_pfn(phys), PAGE_SIZE, mtype);
+}
+EXPORT_SYMBOL(ioremap_page);
 
 void __check_kvm_seq(struct mm_struct *mm)
 {

arch/arm/mm/mmu.c

@@ -255,6 +255,7 @@ const struct mem_type *get_mem_type(unsigned int type)
 {
 	return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
 }
+EXPORT_SYMBOL(get_mem_type);
 
 /*
  * Adjust the PMD section entries according to the CPU in use.

arch/arm/plat-omap/Kconfig

@@ -115,6 +115,9 @@ config OMAP_MBOX_FWK
 	  Say Y here if you want to use OMAP Mailbox framework support for
 	  DSP, IVA1.0 and IVA2 in OMAP1/2/3.
 
+config OMAP_IOMMU
+	tristate
+
 choice
         prompt "System timer"
 	default OMAP_MPU_TIMER

arch/arm/plat-omap/Makefile

@@ -13,6 +13,7 @@ obj-  :=
 obj-$(CONFIG_ARCH_OMAP16XX) += ocpi.o
 
 obj-$(CONFIG_OMAP_MCBSP) += mcbsp.o
+obj-$(CONFIG_OMAP_IOMMU) += iommu.o iovmm.o
 
 obj-$(CONFIG_CPU_FREQ) += cpu-omap.o
 obj-$(CONFIG_OMAP_DM_TIMER) += dmtimer.o

arch/arm/plat-omap/include/mach/iommu.h

+/*
+ * omap iommu: main structures
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.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.
+ */
+
+#ifndef __MACH_IOMMU_H
+#define __MACH_IOMMU_H
+
+struct iotlb_entry {
+	u32 da;
+	u32 pa;
+	u32 pgsz, prsvd, valid;
+	union {
+		u16 ap;
+		struct {
+			u32 endian, elsz, mixed;
+		};
+	};
+};
+
+struct iommu {
+	const char	*name;
+	struct module	*owner;
+	struct clk	*clk;
+	void __iomem	*regbase;
+	struct device	*dev;
+
+	unsigned int	refcount;
+	struct mutex	iommu_lock;	/* global for this whole object */
+
+	/*
+	 * We don't change iopgd for a situation like pgd for a task,
+	 * but share it globally for each iommu.
+	 */
+	u32		*iopgd;
+	spinlock_t	page_table_lock; /* protect iopgd */
+
+	int		nr_tlb_entries;
+
+	struct list_head	mmap;
+	struct mutex		mmap_lock; /* protect mmap */
+
+	int (*isr)(struct iommu *obj);
+
+	void *ctx; /* iommu context: registres saved area */
+};
+
+struct cr_regs {
+	union {
+		struct {
+			u16 cam_l;
+			u16 cam_h;
+		};
+		u32 cam;
+	};
+	union {
+		struct {
+			u16 ram_l;
+			u16 ram_h;
+		};
+		u32 ram;
+	};
+};
+
+struct iotlb_lock {
+	short base;
+	short vict;
+};
+
+/* architecture specific functions */
+struct iommu_functions {
+	unsigned long	version;
+
+	int (*enable)(struct iommu *obj);
+	void (*disable)(struct iommu *obj);
+	u32 (*fault_isr)(struct iommu *obj, u32 *ra);
+
+	void (*tlb_read_cr)(struct iommu *obj, struct cr_regs *cr);
+	void (*tlb_load_cr)(struct iommu *obj, struct cr_regs *cr);
+
+	struct cr_regs *(*alloc_cr)(struct iommu *obj, struct iotlb_entry *e);
+	int (*cr_valid)(struct cr_regs *cr);
+	u32 (*cr_to_virt)(struct cr_regs *cr);
+	void (*cr_to_e)(struct cr_regs *cr, struct iotlb_entry *e);
+	ssize_t (*dump_cr)(struct iommu *obj, struct cr_regs *cr, char *buf);
+
+	u32 (*get_pte_attr)(struct iotlb_entry *e);
+
+	void (*save_ctx)(struct iommu *obj);
+	void (*restore_ctx)(struct iommu *obj);
+	ssize_t (*dump_ctx)(struct iommu *obj, char *buf);
+};
+
+struct iommu_platform_data {
+	const char *name;
+	const char *clk_name;
+	const int nr_tlb_entries;
+};
+
+#if defined(CONFIG_ARCH_OMAP1)
+#error "iommu for this processor not implemented yet"
+#else
+#include <mach/iommu2.h>
+#endif
+
+/*
+ * utilities for super page(16MB, 1MB, 64KB and 4KB)
+ */
+
+#define iopgsz_max(bytes)			\
+	(((bytes) >= SZ_16M) ? SZ_16M :		\
+	 ((bytes) >= SZ_1M)  ? SZ_1M  :		\
+	 ((bytes) >= SZ_64K) ? SZ_64K :		\
+	 ((bytes) >= SZ_4K)  ? SZ_4K  :	0)
+
+#define bytes_to_iopgsz(bytes)				\
+	(((bytes) == SZ_16M) ? MMU_CAM_PGSZ_16M :	\
+	 ((bytes) == SZ_1M)  ? MMU_CAM_PGSZ_1M  :	\
+	 ((bytes) == SZ_64K) ? MMU_CAM_PGSZ_64K :	\
+	 ((bytes) == SZ_4K)  ? MMU_CAM_PGSZ_4K  : -1)
+
+#define iopgsz_to_bytes(iopgsz)				\
+	(((iopgsz) == MMU_CAM_PGSZ_16M)	? SZ_16M :	\
+	 ((iopgsz) == MMU_CAM_PGSZ_1M)	? SZ_1M  :	\
+	 ((iopgsz) == MMU_CAM_PGSZ_64K)	? SZ_64K :	\
+	 ((iopgsz) == MMU_CAM_PGSZ_4K)	? SZ_4K  : 0)
+
+#define iopgsz_ok(bytes) (bytes_to_iopgsz(bytes) >= 0)
+
+/*
+ * global functions
+ */
+extern u32 iommu_arch_version(void);
+
+extern void iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e);
+extern u32 iotlb_cr_to_virt(struct cr_regs *cr);
+
+extern int load_iotlb_entry(struct iommu *obj, struct iotlb_entry *e);
+extern void flush_iotlb_page(struct iommu *obj, u32 da);
+extern void flush_iotlb_range(struct iommu *obj, u32 start, u32 end);
+extern void flush_iotlb_all(struct iommu *obj);
+
+extern int iopgtable_store_entry(struct iommu *obj, struct iotlb_entry *e);
+extern size_t iopgtable_clear_entry(struct iommu *obj, u32 iova);
+
+extern struct iommu *iommu_get(const char *name);
+extern void iommu_put(struct iommu *obj);
+
+extern void iommu_save_ctx(struct iommu *obj);
+extern void iommu_restore_ctx(struct iommu *obj);
+
+extern int install_iommu_arch(const struct iommu_functions *ops);
+extern void uninstall_iommu_arch(const struct iommu_functions *ops);
+
+extern int foreach_iommu_device(void *data,
+				int (*fn)(struct device *, void *));
+
+extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf);
+extern size_t dump_tlb_entries(struct iommu *obj, char *buf);
+
+#endif /* __MACH_IOMMU_H */

arch/arm/plat-omap/include/mach/iommu2.h

+/*
+ * omap iommu: omap2 architecture specific definitions
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.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.
+ */
+
+#ifndef __MACH_IOMMU2_H
+#define __MACH_IOMMU2_H
+
+#include <linux/io.h>
+
+/*
+ * MMU Register offsets
+ */
+#define MMU_REVISION		0x00
+#define MMU_SYSCONFIG		0x10
+#define MMU_SYSSTATUS		0x14
+#define MMU_IRQSTATUS		0x18
+#define MMU_IRQENABLE		0x1c
+#define MMU_WALKING_ST		0x40
+#define MMU_CNTL		0x44
+#define MMU_FAULT_AD		0x48
+#define MMU_TTB			0x4c
+#define MMU_LOCK		0x50
+#define MMU_LD_TLB		0x54
+#define MMU_CAM			0x58
+#define MMU_RAM			0x5c
+#define MMU_GFLUSH		0x60
+#define MMU_FLUSH_ENTRY		0x64
+#define MMU_READ_CAM		0x68
+#define MMU_READ_RAM		0x6c
+#define MMU_EMU_FAULT_AD	0x70
+
+#define MMU_REG_SIZE		256
+
+/*
+ * MMU Register bit definitions
+ */
+#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)
+
+#define MMU_CAM_VATAG_SHIFT	12
+#define MMU_CAM_VATAG_MASK \
+	((~0UL >> MMU_CAM_VATAG_SHIFT) << MMU_CAM_VATAG_SHIFT)
+#define MMU_CAM_P		(1 << 3)
+#define MMU_CAM_V		(1 << 2)
+#define MMU_CAM_PGSZ_MASK	3
+#define MMU_CAM_PGSZ_1M		(0 << 0)
+#define MMU_CAM_PGSZ_64K	(1 << 0)
+#define MMU_CAM_PGSZ_4K		(2 << 0)
+#define MMU_CAM_PGSZ_16M	(3 << 0)
+
+#define MMU_RAM_PADDR_SHIFT	12
+#define MMU_RAM_PADDR_MASK \
+	((~0UL >> MMU_RAM_PADDR_SHIFT) << MMU_RAM_PADDR_SHIFT)
+#define MMU_RAM_ENDIAN_SHIFT	9
+#define MMU_RAM_ENDIAN_MASK	(1 << MMU_RAM_ENDIAN_SHIFT)
+#define MMU_RAM_ENDIAN_BIG	(1 << MMU_RAM_ENDIAN_SHIFT)
+#define MMU_RAM_ENDIAN_LITTLE	(0 << MMU_RAM_ENDIAN_SHIFT)
+#define MMU_RAM_ELSZ_SHIFT	7
+#define MMU_RAM_ELSZ_MASK	(3 << MMU_RAM_ELSZ_SHIFT)
+#define MMU_RAM_ELSZ_8		(0 << MMU_RAM_ELSZ_SHIFT)
+#define MMU_RAM_ELSZ_16		(1 << MMU_RAM_ELSZ_SHIFT)
+#define MMU_RAM_ELSZ_32		(2 << MMU_RAM_ELSZ_SHIFT)
+#define MMU_RAM_ELSZ_NONE	(3 << MMU_RAM_ELSZ_SHIFT)
+#define MMU_RAM_MIXED_SHIFT	6
+#define MMU_RAM_MIXED_MASK	(1 << MMU_RAM_MIXED_SHIFT)
+#define MMU_RAM_MIXED		MMU_RAM_MIXED_MASK
+
+/*
+ * register accessors
+ */
+static inline u32 iommu_read_reg(struct iommu *obj, size_t offs)
+{
+	return __raw_readl(obj->regbase + offs);
+}
+
+static inline void iommu_write_reg(struct iommu *obj, u32 val, size_t offs)
+{
+	__raw_writel(val, obj->regbase + offs);
+}
+
+#endif /* __MACH_IOMMU2_H */

arch/arm/plat-omap/include/mach/iovmm.h

+/*
+ * omap iommu: simple virtual address space management
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.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.
+ */
+
+#ifndef __IOMMU_MMAP_H
+#define __IOMMU_MMAP_H
+
+struct iovm_struct {
+	struct iommu		*iommu;	/* iommu object which this belongs to */
+	u32			da_start; /* area definition */
+	u32			da_end;
+	u32			flags; /* IOVMF_: see below */
+	struct list_head	list; /* linked in ascending order */
+	const struct sg_table	*sgt; /* keep 'page' <-> 'da' mapping */
+	void			*va; /* mpu side mapped address */
+};
+
+/*
+ * IOVMF_FLAGS: attribute for iommu virtual memory area(iovma)
+ *
+ * lower 16 bit is used for h/w and upper 16 bit is for s/w.
+ */
+#define IOVMF_SW_SHIFT		16
+#define IOVMF_HW_SIZE		(1 << IOVMF_SW_SHIFT)
+#define IOVMF_HW_MASK		(IOVMF_HW_SIZE - 1)
+#define IOVMF_SW_MASK		(~IOVMF_HW_MASK)UL
+
+/*
+ * iovma: h/w flags derived from cam and ram attribute
+ */
+#define IOVMF_CAM_MASK		(~((1 << 10) - 1))
+#define IOVMF_RAM_MASK		(~IOVMF_CAM_MASK)
+
+#define IOVMF_PGSZ_MASK		(3 << 0)
+#define IOVMF_PGSZ_1M		MMU_CAM_PGSZ_1M
+#define IOVMF_PGSZ_64K		MMU_CAM_PGSZ_64K
+#define IOVMF_PGSZ_4K		MMU_CAM_PGSZ_4K
+#define IOVMF_PGSZ_16M		MMU_CAM_PGSZ_16M
+
+#define IOVMF_ENDIAN_MASK	(1 << 9)
+#define IOVMF_ENDIAN_BIG	MMU_RAM_ENDIAN_BIG
+#define IOVMF_ENDIAN_LITTLE	MMU_RAM_ENDIAN_LITTLE
+
+#define IOVMF_ELSZ_MASK		(3 << 7)
+#define IOVMF_ELSZ_8		MMU_RAM_ELSZ_8
+#define IOVMF_ELSZ_16		MMU_RAM_ELSZ_16
+#define IOVMF_ELSZ_32		MMU_RAM_ELSZ_32
+#define IOVMF_ELSZ_NONE		MMU_RAM_ELSZ_NONE
+
+#define IOVMF_MIXED_MASK	(1 << 6)
+#define IOVMF_MIXED		MMU_RAM_MIXED
+
+/*
+ * iovma: s/w flags, used for mapping and umapping internally.
+ */
+#define IOVMF_MMIO		(1 << IOVMF_SW_SHIFT)
+#define IOVMF_ALLOC		(2 << IOVMF_SW_SHIFT)
+#define IOVMF_ALLOC_MASK	(3 << IOVMF_SW_SHIFT)
+
+/* "superpages" is supported just with physically linear pages */
+#define IOVMF_DISCONT		(1 << (2 + IOVMF_SW_SHIFT))
+#define IOVMF_LINEAR		(2 << (2 + IOVMF_SW_SHIFT))
+#define IOVMF_LINEAR_MASK	(3 << (2 + IOVMF_SW_SHIFT))
+
+#define IOVMF_DA_FIXED		(1 << (4 + IOVMF_SW_SHIFT))
+#define IOVMF_DA_ANON		(2 << (4 + IOVMF_SW_SHIFT))
+#define IOVMF_DA_MASK		(3 << (4 + IOVMF_SW_SHIFT))
+
+
+extern struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da);
+extern u32 iommu_vmap(struct iommu *obj, u32 da,
+			const struct sg_table *sgt, u32 flags);
+extern struct sg_table *iommu_vunmap(struct iommu *obj, u32 da);
+extern u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes,
+			   u32 flags);
+extern void iommu_vfree(struct iommu *obj, const u32 da);
+extern u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
+			u32 flags);
+extern void iommu_kunmap(struct iommu *obj, u32 da);
+extern u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes,
+			   u32 flags);
+extern void iommu_kfree(struct iommu *obj, u32 da);
+
+extern void *da_to_va(struct iommu *obj, u32 da);
+
+#endif /* __IOMMU_MMAP_H */

arch/arm/plat-omap/iommu.c

+/*
+ * omap iommu: tlb and pagetable primitives
+ *
+ * Copyright (C) 2008-2009 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/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+
+#include <asm/cacheflush.h>
+
+#include <mach/iommu.h>
+
+#include "iopgtable.h"
+
+/* 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;
+
+	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);
+
+	BUG_ON(l->base != 0); /* Currently no preservation is used */
+}
+
+static void iotlb_lock_set(struct iommu *obj, struct iotlb_lock *l)
+{
+	u32 val;
+
+	BUG_ON(l->base != 0); /* Currently no preservation is used */
+
+	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);
+}
+
+/**
+ * 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 i;
+	int err = 0;
+	struct iotlb_lock l;
+	struct cr_regs *cr;
+
+	if (!obj || !obj->nr_tlb_entries || !e)
+		return -EINVAL;
+
+	clk_enable(obj->clk);
+
+	for (i = 0; i < obj->nr_tlb_entries; i++) {
+		struct cr_regs tmp;
+
+		iotlb_lock_get(obj, &l);
+		l.vict = i;
+		iotlb_lock_set(obj, &l);
+		iotlb_read_cr(obj, &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;
+	}
+
+	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);
+
+	/* increment victim for next tlb load */
+	if (++l.vict == obj->nr_tlb_entries)
+		l.vict = 0;
+	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)
+{
+	struct iotlb_lock l;
+	int i;
+
+	clk_enable(obj->clk);
+
+	for (i = 0; i < obj->nr_tlb_entries; i++) {
+		struct cr_regs cr;
+		u32 start;
+		size_t bytes;
+
+		iotlb_lock_get(obj, &l);
+		l.vict = i;
+		iotlb_lock_set(obj, &l);
+		iotlb_read_cr(obj, &cr);
+		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);
+
+			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);
+
+#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);
+
+	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 i;
+	struct iotlb_lock saved, l;
+	struct cr_regs *p = crs;
+
+	clk_enable(obj->clk);
+
+	iotlb_lock_get(obj, &saved);
+	memcpy(&l, &saved, sizeof(saved));
+
+	for (i = 0; i < obj->nr_tlb_entries; i++) {
+		struct cr_regs tmp;
+
+		iotlb_lock_get(obj, &l);
+		l.vict = i;
+		iotlb_lock_set(obj, &l);
+		iotlb_read_cr(obj, &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)
+{
+	int i, n;
+	struct cr_regs *cr;
+	char *p = buf;
+
+	cr = kcalloc(obj->nr_tlb_entries, sizeof(*cr), GFP_KERNEL);
+	if (!cr)
+		return 0;
+
+	n = __dump_tlb_entries(obj, cr);
+	for (i = 0; i < n; 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);
+
+	*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;
+
+	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 (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 & IOPGD_TABLE)
+		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 & IOPGD_TABLE) {
+		int i;
+		u32 *iopte = iopte_offset(iopgd, da);
+
+		bytes = IOPTE_SIZE;
+		if (*iopte & IOPTE_LARGE) {
+			nent *= 16;
+			/* rewind to the 1st entry */
+			iopte = (u32 *)((u32)iopte & 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) {
+			nent *= 16;
+			/* rewind to the 1st entry */
+			iopgd = (u32 *)((u32)iopgd & 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 & IOPGD_TABLE)
+			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 stat, da;
+	u32 *iopgd, *iopte;
+	int err = -EIO;
+	struct iommu *obj = data;
+
+	if (!obj->refcount)
+		return IRQ_NONE;
+
+	/* Dynamic loading TLB or PTE */
+	if (obj->isr)
+		err = obj->isr(obj);
+
+	if (!err)
+		return IRQ_HANDLED;
+
+	clk_enable(obj->clk);
+	stat = iommu_report_fault(obj, &da);
+	clk_disable(obj->clk);
+	if (!stat)
+		return IRQ_HANDLED;
+
+	iopgd = iopgd_offset(obj, da);
+
+	if (!(*iopgd & IOPGD_TABLE)) {
+		dev_err(obj->dev, "%s: da:%08x pgd:%p *pgd:%08x\n", __func__,
+			da, iopgd, *iopgd);
+		return IRQ_NONE;
+	}
+
+	iopte = iopte_offset(iopgd, da);
+
+	dev_err(obj->dev, "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
+		__func__, 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_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);
+
+/*
+ *	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);
+
+	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;
+	}
+	obj->regbase = ioremap(res->start, resource_size(res));
+	if (!obj->regbase) {
+		err = -ENOMEM;
+		goto err_mem;
+	}
+
+	res = request_mem_region(res->start, resource_size(res),
+				 dev_name(&pdev->dev));
+	if (!res) {
+		err = -EIO;
+		goto err_mem;
+	}
+
+	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:
+	release_mem_region(res->start, resource_size(res));
+	iounmap(obj->regbase);
+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");

arch/arm/plat-omap/iopgtable.h

+/*
+ * omap iommu: pagetable definitions
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.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.
+ */
+
+#ifndef __PLAT_OMAP_IOMMU_H
+#define __PLAT_OMAP_IOMMU_H
+
+#define IOPGD_SHIFT		20
+#define IOPGD_SIZE		(1 << IOPGD_SHIFT)
+#define IOPGD_MASK		(~(IOPGD_SIZE - 1))
+#define IOSECTION_MASK		IOPGD_MASK
+#define PTRS_PER_IOPGD		(1 << (32 - IOPGD_SHIFT))
+#define IOPGD_TABLE_SIZE	(PTRS_PER_IOPGD * sizeof(u32))
+
+#define IOSUPER_SIZE		(IOPGD_SIZE << 4)
+#define IOSUPER_MASK		(~(IOSUPER_SIZE - 1))
+
+#define IOPTE_SHIFT		12
+#define IOPTE_SIZE		(1 << IOPTE_SHIFT)
+#define IOPTE_MASK		(~(IOPTE_SIZE - 1))
+#define IOPAGE_MASK		IOPTE_MASK
+#define PTRS_PER_IOPTE		(1 << (IOPGD_SHIFT - IOPTE_SHIFT))
+#define IOPTE_TABLE_SIZE	(PTRS_PER_IOPTE * sizeof(u32))
+
+#define IOLARGE_SIZE		(IOPTE_SIZE << 4)
+#define IOLARGE_MASK		(~(IOLARGE_SIZE - 1))
+
+#define IOPGD_TABLE		(1 << 0)
+#define IOPGD_SECTION		(2 << 0)
+#define IOPGD_SUPER		(1 << 18 | 2 << 0)
+
+#define IOPTE_SMALL		(2 << 0)
+#define IOPTE_LARGE		(1 << 0)
+
+#define iopgd_index(da)		(((da) >> IOPGD_SHIFT) & (PTRS_PER_IOPGD - 1))
+#define iopgd_offset(obj, da)	((obj)->iopgd + iopgd_index(da))
+
+#define iopte_paddr(iopgd)	(*iopgd & ~((1 << 10) - 1))
+#define iopte_vaddr(iopgd)	((u32 *)phys_to_virt(iopte_paddr(iopgd)))
+
+#define iopte_index(da)		(((da) >> IOPTE_SHIFT) & (PTRS_PER_IOPTE - 1))
+#define iopte_offset(iopgd, da)	(iopte_vaddr(iopgd) + iopte_index(da))
+
+static inline u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa,
+				   u32 flags)
+{
+	memset(e, 0, sizeof(*e));
+
+	e->da		= da;
+	e->pa		= pa;
+	e->valid	= 1;
+	/* FIXME: add OMAP1 support */
+	e->pgsz		= flags & MMU_CAM_PGSZ_MASK;
+	e->endian	= flags & MMU_RAM_ENDIAN_MASK;
+	e->elsz		= flags & MMU_RAM_ELSZ_MASK;
+	e->mixed	= flags & MMU_RAM_MIXED_MASK;
+
+	return iopgsz_to_bytes(e->pgsz);
+}
+
+#define to_iommu(dev)							\
+	(struct iommu *)platform_get_drvdata(to_platform_device(dev))
+
+#endif /* __PLAT_OMAP_IOMMU_H */

arch/arm/plat-omap/iovmm.c

+/*
+ * omap iommu: simple virtual address space management
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.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.
+ */
+
+#include <linux/err.h>
+#include <linux/vmalloc.h>
+#include <linux/device.h>
+#include <linux/scatterlist.h>
+
+#include <asm/cacheflush.h>
+#include <asm/mach/map.h>
+
+#include <mach/iommu.h>
+#include <mach/iovmm.h>
+
+#include "iopgtable.h"
+
+/*
+ * A device driver needs to create address mappings between:
+ *
+ * - iommu/device address
+ * - physical address
+ * - mpu virtual address
+ *
+ * There are 4 possible patterns for them:
+ *
+ *    |iova/			  mapping		iommu_		page
+ *    | da	pa	va	(d)-(p)-(v)		function	type
+ *  ---------------------------------------------------------------------------
+ *  1 | c	c	c	 1 - 1 - 1	  _kmap() / _kunmap()	s
+ *  2 | c	c,a	c	 1 - 1 - 1	_kmalloc()/ _kfree()	s
+ *  3 | c	d	c	 1 - n - 1	  _vmap() / _vunmap()	s
+ *  4 | c	d,a	c	 1 - n - 1	_vmalloc()/ _vfree()	n*
+ *
+ *
+ *	'iova':	device iommu virtual address
+ *	'da':	alias of 'iova'
+ *	'pa':	physical address
+ *	'va':	mpu virtual address
+ *
+ *	'c':	contiguous memory area
+ *	'd':	dicontiguous memory area
+ *	'a':	anonymous memory allocation
+ *	'()':	optional feature
+ *
+ *	'n':	a normal page(4KB) size is used.
+ *	's':	multiple iommu superpage(16MB, 1MB, 64KB, 4KB) size is used.
+ *
+ *	'*':	not yet, but feasible.
+ */
+
+static struct kmem_cache *iovm_area_cachep;
+
+/* return total bytes of sg buffers */
+static size_t sgtable_len(const struct sg_table *sgt)
+{
+	unsigned int i, total = 0;
+	struct scatterlist *sg;
+
+	if (!sgt)
+		return 0;
+
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		size_t bytes;
+
+		bytes = sg_dma_len(sg);
+
+		if (!iopgsz_ok(bytes)) {
+			pr_err("%s: sg[%d] not iommu pagesize(%x)\n",
+			       __func__, i, bytes);
+			return 0;
+		}
+
+		total += bytes;
+	}
+
+	return total;
+}
+#define sgtable_ok(x)	(!!sgtable_len(x))
+
+/*
+ * calculate the optimal number sg elements from total bytes based on
+ * iommu superpages
+ */
+static unsigned int sgtable_nents(size_t bytes)
+{
+	int i;
+	unsigned int nr_entries;
+	const unsigned long pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
+
+	if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
+		pr_err("%s: wrong size %08x\n", __func__, bytes);
+		return 0;
+	}
+
+	nr_entries = 0;
+	for (i = 0; i < ARRAY_SIZE(pagesize); i++) {
+		if (bytes >= pagesize[i]) {
+			nr_entries += (bytes / pagesize[i]);
+			bytes %= pagesize[i];
+		}
+	}
+	BUG_ON(bytes);
+
+	return nr_entries;
+}
+
+/* allocate and initialize sg_table header(a kind of 'superblock') */
+static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags)
+{
+	unsigned int nr_entries;
+	int err;
+	struct sg_table *sgt;
+
+	if (!bytes)
+		return ERR_PTR(-EINVAL);
+
+	if (!IS_ALIGNED(bytes, PAGE_SIZE))
+		return ERR_PTR(-EINVAL);
+
+	/* FIXME: IOVMF_DA_FIXED should support 'superpages' */
+	if ((flags & IOVMF_LINEAR) && (flags & IOVMF_DA_ANON)) {
+		nr_entries = sgtable_nents(bytes);
+		if (!nr_entries)
+			return ERR_PTR(-EINVAL);
+	} else
+		nr_entries =  bytes / PAGE_SIZE;
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
+
+	err = sg_alloc_table(sgt, nr_entries, GFP_KERNEL);
+	if (err)
+		return ERR_PTR(err);
+
+	pr_debug("%s: sgt:%p(%d entries)\n", __func__, sgt, nr_entries);
+
+	return sgt;
+}
+
+/* free sg_table header(a kind of superblock) */
+static void sgtable_free(struct sg_table *sgt)
+{
+	if (!sgt)
+		return;
+
+	sg_free_table(sgt);
+	kfree(sgt);
+
+	pr_debug("%s: sgt:%p\n", __func__, sgt);
+}
+
+/* map 'sglist' to a contiguous mpu virtual area and return 'va' */
+static void *vmap_sg(const struct sg_table *sgt)
+{
+	u32 va;
+	size_t total;
+	unsigned int i;
+	struct scatterlist *sg;
+	struct vm_struct *new;
+	const struct mem_type *mtype;
+
+	mtype = get_mem_type(MT_DEVICE);
+	if (!mtype)
+		return ERR_PTR(-EINVAL);
+
+	total = sgtable_len(sgt);
+	if (!total)
+		return ERR_PTR(-EINVAL);
+
+	new = __get_vm_area(total, VM_IOREMAP, VMALLOC_START, VMALLOC_END);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+	va = (u32)new->addr;
+
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		size_t bytes;
+		u32 pa;
+		int err;
+
+		pa = sg_phys(sg);
+		bytes = sg_dma_len(sg);
+
+		BUG_ON(bytes != PAGE_SIZE);
+
+		err = ioremap_page(va,  pa, mtype);
+		if (err)
+			goto err_out;
+
+		va += bytes;
+	}
+
+	flush_cache_vmap(new->addr, total);
+	return new->addr;
+
+err_out:
+	WARN_ON(1); /* FIXME: cleanup some mpu mappings */
+	vunmap(new->addr);
+	return ERR_PTR(-EAGAIN);
+}
+
+static inline void vunmap_sg(const void *va)
+{
+	vunmap(va);
+}
+
+static struct iovm_struct *__find_iovm_area(struct iommu *obj, const u32 da)
+{
+	struct iovm_struct *tmp;
+
+	list_for_each_entry(tmp, &obj->mmap, list) {
+		if ((da >= tmp->da_start) && (da < tmp->da_end)) {
+			size_t len;
+
+			len = tmp->da_end - tmp->da_start;
+
+			dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n",
+				__func__, tmp->da_start, da, tmp->da_end, len,
+				tmp->flags);
+
+			return tmp;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * find_iovm_area  -  find iovma which includes @da
+ * @da:		iommu device virtual address
+ *
+ * Find the existing iovma starting at @da
+ */
+struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da)
+{
+	struct iovm_struct *area;
+
+	mutex_lock(&obj->mmap_lock);
+	area = __find_iovm_area(obj, da);
+	mutex_unlock(&obj->mmap_lock);
+
+	return area;
+}
+EXPORT_SYMBOL_GPL(find_iovm_area);
+
+/*
+ * This finds the hole(area) which fits the requested address and len
+ * in iovmas mmap, and returns the new allocated iovma.
+ */
+static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
+					   size_t bytes, u32 flags)
+{
+	struct iovm_struct *new, *tmp;
+	u32 start, prev_end, alignement;
+
+	if (!obj || !bytes)
+		return ERR_PTR(-EINVAL);
+
+	start = da;
+	alignement = PAGE_SIZE;
+
+	if (flags & IOVMF_DA_ANON) {
+		/*
+		 * Reserve the first page for NULL
+		 */
+		start = PAGE_SIZE;
+		if (flags & IOVMF_LINEAR)
+			alignement = iopgsz_max(bytes);
+		start = roundup(start, alignement);
+	}
+
+	tmp = NULL;
+	if (list_empty(&obj->mmap))
+		goto found;
+
+	prev_end = 0;
+	list_for_each_entry(tmp, &obj->mmap, list) {
+
+		if ((prev_end <= start) && (start + bytes < tmp->da_start))
+			goto found;
+
+		if (flags & IOVMF_DA_ANON)
+			start = roundup(tmp->da_end, alignement);
+
+		prev_end = tmp->da_end;
+	}
+
+	if ((start >= prev_end) && (ULONG_MAX - start >= bytes))
+		goto found;
+
+	dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
+		__func__, da, bytes, flags);
+
+	return ERR_PTR(-EINVAL);
+
+found:
+	new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+
+	new->iommu = obj;
+	new->da_start = start;
+	new->da_end = start + bytes;
+	new->flags = flags;
+
+	/*
+	 * keep ascending order of iovmas
+	 */
+	if (tmp)
+		list_add_tail(&new->list, &tmp->list);
+	else
+		list_add(&new->list, &obj->mmap);
+
+	dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
+		__func__, new->da_start, start, new->da_end, bytes, flags);
+
+	return new;
+}
+
+static void free_iovm_area(struct iommu *obj, struct iovm_struct *area)
+{
+	size_t bytes;
+
+	BUG_ON(!obj || !area);
+
+	bytes = area->da_end - area->da_start;
+
+	dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
+		__func__, area->da_start, area->da_end, bytes, area->flags);
+
+	list_del(&area->list);
+	kmem_cache_free(iovm_area_cachep, area);
+}
+
+/**
+ * da_to_va - convert (d) to (v)
+ * @obj:	objective iommu
+ * @da:		iommu device virtual address
+ * @va:		mpu virtual address
+ *
+ * Returns mpu virtual addr which corresponds to a given device virtual addr
+ */
+void *da_to_va(struct iommu *obj, u32 da)
+{
+	void *va = NULL;
+	struct iovm_struct *area;
+
+	mutex_lock(&obj->mmap_lock);
+
+	area = __find_iovm_area(obj, da);
+	if (!area) {
+		dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
+		goto out;
+	}
+	va = area->va;
+	mutex_unlock(&obj->mmap_lock);
+out:
+	return va;
+}
+EXPORT_SYMBOL_GPL(da_to_va);
+
+static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va)
+{
+	unsigned int i;
+	struct scatterlist *sg;
+	void *va = _va;
+	void *va_end;
+
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		struct page *pg;
+		const size_t bytes = PAGE_SIZE;
+
+		/*
+		 * iommu 'superpage' isn't supported with 'iommu_vmalloc()'
+		 */
+		pg = vmalloc_to_page(va);
+		BUG_ON(!pg);
+		sg_set_page(sg, pg, bytes, 0);
+
+		va += bytes;
+	}
+
+	va_end = _va + PAGE_SIZE * i;
+	flush_cache_vmap(_va, va_end);
+}
+
+static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
+{
+	/*
+	 * Actually this is not necessary at all, just exists for
+	 * consistency of the code readibility.
+	 */
+	BUG_ON(!sgt);
+}
+
+static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
+{
+	unsigned int i;
+	struct scatterlist *sg;
+	void *va;
+
+	va = phys_to_virt(pa);
+
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		size_t bytes;
+
+		bytes = iopgsz_max(len);
+
+		BUG_ON(!iopgsz_ok(bytes));
+
+		sg_set_buf(sg, phys_to_virt(pa), bytes);
+		/*
+		 * 'pa' is cotinuous(linear).
+		 */
+		pa += bytes;
+		len -= bytes;
+	}
+	BUG_ON(len);
+
+	clean_dcache_area(va, len);
+}
+
+static inline void sgtable_drain_kmalloc(struct sg_table *sgt)
+{
+	/*
+	 * Actually this is not necessary at all, just exists for
+	 * consistency of the code readibility
+	 */
+	BUG_ON(!sgt);
+}
+
+/* create 'da' <-> 'pa' mapping from 'sgt' */
+static int map_iovm_area(struct iommu *obj, struct iovm_struct *new,
+			 const struct sg_table *sgt, u32 flags)
+{
+	int err;
+	unsigned int i, j;
+	struct scatterlist *sg;
+	u32 da = new->da_start;
+
+	if (!obj || !new || !sgt)
+		return -EINVAL;
+
+	BUG_ON(!sgtable_ok(sgt));
+
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		u32 pa;
+		int pgsz;
+		size_t bytes;
+		struct iotlb_entry e;
+
+		pa = sg_phys(sg);
+		bytes = sg_dma_len(sg);
+
+		flags &= ~IOVMF_PGSZ_MASK;
+		pgsz = bytes_to_iopgsz(bytes);
+		if (pgsz < 0)
+			goto err_out;
+		flags |= pgsz;
+
+		pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
+			 i, da, pa, bytes);
+
+		iotlb_init_entry(&e, da, pa, flags);
+		err = iopgtable_store_entry(obj, &e);
+		if (err)
+			goto err_out;
+
+		da += bytes;
+	}
+	return 0;
+
+err_out:
+	da = new->da_start;
+
+	for_each_sg(sgt->sgl, sg, i, j) {
+		size_t bytes;
+
+		bytes = iopgtable_clear_entry(obj, da);
+
+		BUG_ON(!iopgsz_ok(bytes));
+
+		da += bytes;
+	}
+	return err;
+}
+
+/* release 'da' <-> 'pa' mapping */
+static void unmap_iovm_area(struct iommu *obj, struct iovm_struct *area)
+{
+	u32 start;
+	size_t total = area->da_end - area->da_start;
+
+	BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
+
+	start = area->da_start;
+	while (total > 0) {
+		size_t bytes;
+
+		bytes = iopgtable_clear_entry(obj, start);
+		if (bytes == 0)
+			bytes = PAGE_SIZE;
+		else
+			dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
+				__func__, start, bytes, area->flags);
+
+		BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
+
+		total -= bytes;
+		start += bytes;
+	}
+	BUG_ON(total);
+}
+
+/* template function for all unmapping */
+static struct sg_table *unmap_vm_area(struct iommu *obj, const u32 da,
+				      void (*fn)(const void *), u32 flags)
+{
+	struct sg_table *sgt = NULL;
+	struct iovm_struct *area;
+
+	if (!IS_ALIGNED(da, PAGE_SIZE)) {
+		dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
+		return NULL;
+	}
+
+	mutex_lock(&obj->mmap_lock);
+
+	area = __find_iovm_area(obj, da);
+	if (!area) {
+		dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
+		goto out;
+	}
+
+	if ((area->flags & flags) != flags) {
+		dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
+			area->flags);
+		goto out;
+	}
+	sgt = (struct sg_table *)area->sgt;
+
+	unmap_iovm_area(obj, area);
+
+	fn(area->va);
+
+	dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
+		area->da_start, da, area->da_end,
+		area->da_end - area->da_start, area->flags);
+
+	free_iovm_area(obj, area);
+out:
+	mutex_unlock(&obj->mmap_lock);
+
+	return sgt;
+}
+
+static u32 map_iommu_region(struct iommu *obj, u32 da,
+	      const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
+{
+	int err = -ENOMEM;
+	struct iovm_struct *new;
+
+	mutex_lock(&obj->mmap_lock);
+
+	new = alloc_iovm_area(obj, da, bytes, flags);
+	if (IS_ERR(new)) {
+		err = PTR_ERR(new);
+		goto err_alloc_iovma;
+	}
+	new->va = va;
+	new->sgt = sgt;
+
+	if (map_iovm_area(obj, new, sgt, new->flags))
+		goto err_map;
+
+	mutex_unlock(&obj->mmap_lock);
+
+	dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
+		__func__, new->da_start, bytes, new->flags, va);
+
+	return new->da_start;
+
+err_map:
+	free_iovm_area(obj, new);
+err_alloc_iovma:
+	mutex_unlock(&obj->mmap_lock);
+	return err;
+}
+
+static inline u32 __iommu_vmap(struct iommu *obj, u32 da,
+		 const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
+{
+	return map_iommu_region(obj, da, sgt, va, bytes, flags);
+}
+
+/**
+ * iommu_vmap  -  (d)-(p)-(v) address mapper
+ * @obj:	objective iommu
+ * @sgt:	address of scatter gather table
+ * @flags:	iovma and page property
+ *
+ * Creates 1-n-1 mapping with given @sgt and returns @da.
+ * All @sgt element must be io page size aligned.
+ */
+u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
+		 u32 flags)
+{
+	size_t bytes;
+	void *va;
+
+	if (!obj || !obj->dev || !sgt)
+		return -EINVAL;
+
+	bytes = sgtable_len(sgt);
+	if (!bytes)
+		return -EINVAL;
+	bytes = PAGE_ALIGN(bytes);
+
+	va = vmap_sg(sgt);
+	if (IS_ERR(va))
+		return PTR_ERR(va);
+
+	flags &= IOVMF_HW_MASK;
+	flags |= IOVMF_DISCONT;
+	flags |= IOVMF_MMIO;
+	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
+
+	da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
+	if (IS_ERR_VALUE(da))
+		vunmap_sg(va);
+
+	return da;
+}
+EXPORT_SYMBOL_GPL(iommu_vmap);
+
+/**
+ * iommu_vunmap  -  release virtual mapping obtained by 'iommu_vmap()'
+ * @obj:	objective iommu
+ * @da:		iommu device virtual address
+ *
+ * Free the iommu virtually contiguous memory area starting at
+ * @da, which was returned by 'iommu_vmap()'.
+ */
+struct sg_table *iommu_vunmap(struct iommu *obj, u32 da)
+{
+	struct sg_table *sgt;
+	/*
+	 * 'sgt' is allocated before 'iommu_vmalloc()' is called.
+	 * Just returns 'sgt' to the caller to free
+	 */
+	sgt = unmap_vm_area(obj, da, vunmap_sg, IOVMF_DISCONT | IOVMF_MMIO);
+	if (!sgt)
+		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
+	return sgt;
+}
+EXPORT_SYMBOL_GPL(iommu_vunmap);
+
+/**
+ * iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
+ * @obj:	objective iommu
+ * @da:		contiguous iommu virtual memory
+ * @bytes:	allocation size
+ * @flags:	iovma and page property
+ *
+ * Allocate @bytes linearly and creates 1-n-1 mapping and returns
+ * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
+ */
+u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
+{
+	void *va;
+	struct sg_table *sgt;
+
+	if (!obj || !obj->dev || !bytes)
+		return -EINVAL;
+
+	bytes = PAGE_ALIGN(bytes);
+
+	va = vmalloc(bytes);
+	if (!va)
+		return -ENOMEM;
+
+	sgt = sgtable_alloc(bytes, flags);
+	if (IS_ERR(sgt)) {
+		da = PTR_ERR(sgt);
+		goto err_sgt_alloc;
+	}
+	sgtable_fill_vmalloc(sgt, va);
+
+	flags &= IOVMF_HW_MASK;
+	flags |= IOVMF_DISCONT;
+	flags |= IOVMF_ALLOC;
+	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
+
+	da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
+	if (IS_ERR_VALUE(da))
+		goto err_iommu_vmap;
+
+	return da;
+
+err_iommu_vmap:
+	sgtable_drain_vmalloc(sgt);
+	sgtable_free(sgt);
+err_sgt_alloc:
+	vfree(va);
+	return da;
+}
+EXPORT_SYMBOL_GPL(iommu_vmalloc);
+
+/**
+ * iommu_vfree  -  release memory allocated by 'iommu_vmalloc()'
+ * @obj:	objective iommu
+ * @da:		iommu device virtual address
+ *
+ * Frees the iommu virtually continuous memory area starting at
+ * @da, as obtained from 'iommu_vmalloc()'.
+ */
+void iommu_vfree(struct iommu *obj, const u32 da)
+{
+	struct sg_table *sgt;
+
+	sgt = unmap_vm_area(obj, da, vfree, IOVMF_DISCONT | IOVMF_ALLOC);
+	if (!sgt)
+		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
+	sgtable_free(sgt);
+}
+EXPORT_SYMBOL_GPL(iommu_vfree);
+
+static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
+			  size_t bytes, u32 flags)
+{
+	struct sg_table *sgt;
+
+	sgt = sgtable_alloc(bytes, flags);
+	if (IS_ERR(sgt))
+		return PTR_ERR(sgt);
+
+	sgtable_fill_kmalloc(sgt, pa, bytes);
+
+	da = map_iommu_region(obj, da, sgt, va, bytes, flags);
+	if (IS_ERR_VALUE(da)) {
+		sgtable_drain_kmalloc(sgt);
+		sgtable_free(sgt);
+	}
+
+	return da;
+}
+
+/**
+ * iommu_kmap  -  (d)-(p)-(v) address mapper
+ * @obj:	objective iommu
+ * @da:		contiguous iommu virtual memory
+ * @pa:		contiguous physical memory
+ * @flags:	iovma and page property
+ *
+ * Creates 1-1-1 mapping and returns @da again, which can be
+ * adjusted if 'IOVMF_DA_ANON' is set.
+ */
+u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
+		 u32 flags)
+{
+	void *va;
+
+	if (!obj || !obj->dev || !bytes)
+		return -EINVAL;
+
+	bytes = PAGE_ALIGN(bytes);
+
+	va = ioremap(pa, bytes);
+	if (!va)
+		return -ENOMEM;
+
+	flags &= IOVMF_HW_MASK;
+	flags |= IOVMF_LINEAR;
+	flags |= IOVMF_MMIO;
+	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
+
+	da = __iommu_kmap(obj, da, pa, va, bytes, flags);
+	if (IS_ERR_VALUE(da))
+		iounmap(va);
+
+	return da;
+}
+EXPORT_SYMBOL_GPL(iommu_kmap);
+
+/**
+ * iommu_kunmap  -  release virtual mapping obtained by 'iommu_kmap()'
+ * @obj:	objective iommu
+ * @da:		iommu device virtual address
+ *
+ * Frees the iommu virtually contiguous memory area starting at
+ * @da, which was passed to and was returned by'iommu_kmap()'.
+ */
+void iommu_kunmap(struct iommu *obj, u32 da)
+{
+	struct sg_table *sgt;
+	typedef void (*func_t)(const void *);
+
+	sgt = unmap_vm_area(obj, da, (func_t)__iounmap,
+			    IOVMF_LINEAR | IOVMF_MMIO);
+	if (!sgt)
+		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
+	sgtable_free(sgt);
+}
+EXPORT_SYMBOL_GPL(iommu_kunmap);
+
+/**
+ * iommu_kmalloc  -  (d)-(p)-(v) address allocator and mapper
+ * @obj:	objective iommu
+ * @da:		contiguous iommu virtual memory
+ * @bytes:	bytes for allocation
+ * @flags:	iovma and page property
+ *
+ * Allocate @bytes linearly and creates 1-1-1 mapping and returns
+ * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
+ */
+u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
+{
+	void *va;
+	u32 pa;
+
+	if (!obj || !obj->dev || !bytes)
+		return -EINVAL;
+
+	bytes = PAGE_ALIGN(bytes);
+
+	va = kmalloc(bytes, GFP_KERNEL | GFP_DMA);
+	if (!va)
+		return -ENOMEM;
+	pa = virt_to_phys(va);
+
+	flags &= IOVMF_HW_MASK;
+	flags |= IOVMF_LINEAR;
+	flags |= IOVMF_ALLOC;
+	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
+
+	da = __iommu_kmap(obj, da, pa, va, bytes, flags);
+	if (IS_ERR_VALUE(da))
+		kfree(va);
+
+	return da;
+}
+EXPORT_SYMBOL_GPL(iommu_kmalloc);
+
+/**
+ * iommu_kfree  -  release virtual mapping obtained by 'iommu_kmalloc()'
+ * @obj:	objective iommu
+ * @da:		iommu device virtual address
+ *
+ * Frees the iommu virtually contiguous memory area starting at
+ * @da, which was passed to and was returned by'iommu_kmalloc()'.
+ */
+void iommu_kfree(struct iommu *obj, u32 da)
+{
+	struct sg_table *sgt;
+
+	sgt = unmap_vm_area(obj, da, kfree, IOVMF_LINEAR | IOVMF_ALLOC);
+	if (!sgt)
+		dev_dbg(obj->dev, "%s: No sgt\n", __func__);
+	sgtable_free(sgt);
+}
+EXPORT_SYMBOL_GPL(iommu_kfree);
+
+
+static int __init iovmm_init(void)
+{
+	const unsigned long flags = SLAB_HWCACHE_ALIGN;
+	struct kmem_cache *p;
+
+	p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
+			      flags, NULL);
+	if (!p)
+		return -ENOMEM;
+	iovm_area_cachep = p;
+
+	return 0;
+}
+module_init(iovmm_init);
+
+static void __exit iovmm_exit(void)
+{
+	kmem_cache_destroy(iovm_area_cachep);
+}
+module_exit(iovmm_exit);
+
+MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
+MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
+MODULE_LICENSE("GPL v2");