Logo Search packages:      
Sourcecode: linux version File versions  Download package

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':  discontiguous 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((unsigned long)new->addr,
                        (unsigned long)(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;
out:
      mutex_unlock(&obj->mmap_lock);

      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((unsigned long)_va, (unsigned long)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 readability.
       */
      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 readability
       */
      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");

Generated by  Doxygen 1.6.0   Back to index