omap iommu: simple virtual address space management (69d3a84a) · Commits · 戴 / test

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

+8 −0

Original line number	Diff line number	Diff line
		@@ -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/mm/ioremap.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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

+1 −0

Original line number	Diff line number	Diff line
		@@ -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/include/mach/iovmm.h

0 → 100644

+94 −0

Original line number	Diff line number	Diff line
		/*
		* 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/iovmm.c

0 → 100644

+896 −0

Original line number	Diff line number	Diff line
		/*
		* 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");

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