[thirdparty/openembedded/openembedded-core-contrib.git] /

From 07365182b998af3dc2b79e822b8e21a3f50262c4 Mon Sep 17 00:00:00 2001
From: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Date: Wed, 28 Jan 2009 21:32:08 +0200
Subject: [PATCH] omap iommu: simple virtual address space management

This patch provides a device drivers, which has a omap iommu, with
address mapping APIs between device virtual address(iommu), physical
address and MPU virtual address.

There are 4 possible patterns for iommu virtual address(iova/da) mapping.

    |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.

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
---
 arch/arm/include/asm/io.h               |    6 +
 arch/arm/mm/ioremap.c                   |   11 +
 arch/arm/plat-omap/include/mach/iovmm.h |   94 ++++
 arch/arm/plat-omap/iovmm.c              |  891 +++++++++++++++++++++++++++++++
 4 files changed, 1002 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/plat-omap/include/mach/iovmm.h
 create mode 100644 arch/arm/plat-omap/iovmm.c

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index d2a59cf..cbdadfe 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -75,6 +75,12 @@ extern void __iomem * __arm_ioremap(unsigned long, size_t, unsigned int);
 extern void __iounmap(volatile void __iomem *addr);
 
 /*
+ * external interface to remap single page with appropriate type
+ */
+extern int ioremap_page(unsigned long virt, unsigned long phys,
+                       unsigned int mtype);
+
+/*
  * Bad read/write accesses...
  */
 extern void __readwrite_bug(const char *fn);
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 9f88dd3..8441351 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -110,6 +110,17 @@ static int remap_area_pages(unsigned long start, unsigned long pfn,
        return err;
 }
 
+int ioremap_page(unsigned long virt, unsigned long phys, unsigned int mtype)
+{
+       const struct mem_type *type;
+
+       type = get_mem_type(mtype);
+       if (!type)
+               return -EINVAL;
+
+       return remap_area_pages(virt, __phys_to_pfn(phys), PAGE_SIZE, type);
+}
+EXPORT_SYMBOL(ioremap_page);
 
 void __check_kvm_seq(struct mm_struct *mm)
 {
diff --git a/arch/arm/plat-omap/include/mach/iovmm.h b/arch/arm/plat-omap/include/mach/iovmm.h
new file mode 100644
index 0000000..bdc7ce5
--- /dev/null
+++ b/arch/arm/plat-omap/include/mach/iovmm.h
@@ -0,0 +1,94 @@
+/*
+ * 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 */
diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
new file mode 100644
index 0000000..6726d10
--- /dev/null
+++ b/arch/arm/plat-omap/iovmm.c
@@ -0,0 +1,891 @@
+/*
+ * 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/io.h>
+#include <asm/cacheflush.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;
+
+       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, MT_DEVICE);
+               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_warn(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;
+
+       BUG_ON(in_interrupt());
+
+       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_err(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_err(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_err(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;
+
+       sgt = unmap_vm_area(obj, da, __iounmap, IOVMF_LINEAR | IOVMF_MMIO);
+       if (!sgt)
+               dev_err(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_err(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");
-- 
1.5.6.5