[PATCH 4/7] omap iommu: simple virtual address space management

Hiroshi DOYU
2009-05-20T06:43:22Z

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/mach/map.h | 8
arch/arm/mm/ioremap.c | 6
arch/arm/mm/mmu.c | 1
arch/arm/plat-omap/include/mach/iovmm.h | 94 +++
arch/arm/plat-omap/iovmm.c | 896 +++++++++++++++++++++++++++++++
5 files changed, 1005 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/mach/map.h b/arch/arm/include/asm/mach/map.h
index 58cf91f..742c2aa 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/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
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 9f88dd3..0ab75c6 100644
--- a/arch/arm/mm/ioremap.c
+++ b/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)
{
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e6344ec..70974d7 100644
--- a/arch/arm/mm/mmu.c
+++ b/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.
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..2fce2c1
--- /dev/null
+++ b/arch/arm/plat-omap/iovmm.c
@@ -0,0 +1,896 @@
+/*
+ * 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");