gpu: ion: Add ION Memory Manager

Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
[jstultz: Squished in Colin Cross' move to staging change,
also disables ION from the build, as it won't compile till
the end of the patchset]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/Kconfig

@@ -100,6 +100,8 @@ config SW_SYNC_USER
 	  *WARNING* improper use of this can result in deadlocking kernel
 	  drivers from userspace.
 
+source "drivers/staging/android/ion/Kconfig"
+
 endif # if ANDROID
 
 endmenu

drivers/staging/android/Makefile

 ccflags-y += -I$(src)			# needed for trace events
 
+# ION doesn't build just yet, so disable it from the build
+#obj-y					+= ion/
+
 obj-$(CONFIG_ANDROID_BINDER_IPC)	+= binder.o
 obj-$(CONFIG_ASHMEM)			+= ashmem.o
 obj-$(CONFIG_ANDROID_LOGGER)		+= logger.o

drivers/staging/android/ion/Kconfig

+menuconfig ION
+	tristate "Ion Memory Manager"
+	select GENERIC_ALLOCATOR
+	help
+	  Chose this option to enable the ION Memory Manager.
+
+config ION_TEGRA
+	tristate "Ion for Tegra"
+	depends on ARCH_TEGRA && ION
+	help
+	  Choose this option if you wish to use ion on an nVidia Tegra.
+

drivers/staging/android/ion/Makefile

+obj-$(CONFIG_ION) +=	ion.o ion_heap.o ion_system_heap.o ion_carveout_heap.o
+obj-$(CONFIG_ION_TEGRA) += tegra/

drivers/staging/android/ion/ion_carveout_heap.c

+/*
+ * drivers/staging/android/ion/ion_carveout_heap.c
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/spinlock.h>
+
+#include <linux/err.h>
+#include <linux/genalloc.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "ion.h"
+#include "ion_priv.h"
+
+#include <asm/mach/map.h>
+
+struct ion_carveout_heap {
+	struct ion_heap heap;
+	struct gen_pool *pool;
+	ion_phys_addr_t base;
+};
+
+ion_phys_addr_t ion_carveout_allocate(struct ion_heap *heap,
+				      unsigned long size,
+				      unsigned long align)
+{
+	struct ion_carveout_heap *carveout_heap =
+		container_of(heap, struct ion_carveout_heap, heap);
+	unsigned long offset = gen_pool_alloc(carveout_heap->pool, size);
+
+	if (!offset)
+		return ION_CARVEOUT_ALLOCATE_FAIL;
+
+	return offset;
+}
+
+void ion_carveout_free(struct ion_heap *heap, ion_phys_addr_t addr,
+		       unsigned long size)
+{
+	struct ion_carveout_heap *carveout_heap =
+		container_of(heap, struct ion_carveout_heap, heap);
+
+	if (addr == ION_CARVEOUT_ALLOCATE_FAIL)
+		return;
+	gen_pool_free(carveout_heap->pool, addr, size);
+}
+
+static int ion_carveout_heap_phys(struct ion_heap *heap,
+				  struct ion_buffer *buffer,
+				  ion_phys_addr_t *addr, size_t *len)
+{
+	*addr = buffer->priv_phys;
+	*len = buffer->size;
+	return 0;
+}
+
+static int ion_carveout_heap_allocate(struct ion_heap *heap,
+				      struct ion_buffer *buffer,
+				      unsigned long size, unsigned long align,
+				      unsigned long flags)
+{
+	buffer->priv_phys = ion_carveout_allocate(heap, size, align);
+	return buffer->priv_phys == ION_CARVEOUT_ALLOCATE_FAIL ? -ENOMEM : 0;
+}
+
+static void ion_carveout_heap_free(struct ion_buffer *buffer)
+{
+	struct ion_heap *heap = buffer->heap;
+
+	ion_carveout_free(heap, buffer->priv_phys, buffer->size);
+	buffer->priv_phys = ION_CARVEOUT_ALLOCATE_FAIL;
+}
+
+struct scatterlist *ion_carveout_heap_map_dma(struct ion_heap *heap,
+					      struct ion_buffer *buffer)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+void ion_carveout_heap_unmap_dma(struct ion_heap *heap,
+				 struct ion_buffer *buffer)
+{
+	return;
+}
+
+void *ion_carveout_heap_map_kernel(struct ion_heap *heap,
+				   struct ion_buffer *buffer)
+{
+	return __arch_ioremap(buffer->priv_phys, buffer->size,
+			      MT_MEMORY_NONCACHED);
+}
+
+void ion_carveout_heap_unmap_kernel(struct ion_heap *heap,
+				    struct ion_buffer *buffer)
+{
+	__arch_iounmap(buffer->vaddr);
+	buffer->vaddr = NULL;
+	return;
+}
+
+int ion_carveout_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
+			       struct vm_area_struct *vma)
+{
+	return remap_pfn_range(vma, vma->vm_start,
+			       __phys_to_pfn(buffer->priv_phys) + vma->vm_pgoff,
+			       buffer->size,
+			       pgprot_noncached(vma->vm_page_prot));
+}
+
+static struct ion_heap_ops carveout_heap_ops = {
+	.allocate = ion_carveout_heap_allocate,
+	.free = ion_carveout_heap_free,
+	.phys = ion_carveout_heap_phys,
+	.map_user = ion_carveout_heap_map_user,
+	.map_kernel = ion_carveout_heap_map_kernel,
+	.unmap_kernel = ion_carveout_heap_unmap_kernel,
+};
+
+struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *heap_data)
+{
+	struct ion_carveout_heap *carveout_heap;
+
+	carveout_heap = kzalloc(sizeof(struct ion_carveout_heap), GFP_KERNEL);
+	if (!carveout_heap)
+		return ERR_PTR(-ENOMEM);
+
+	carveout_heap->pool = gen_pool_create(12, -1);
+	if (!carveout_heap->pool) {
+		kfree(carveout_heap);
+		return ERR_PTR(-ENOMEM);
+	}
+	carveout_heap->base = heap_data->base;
+	gen_pool_add(carveout_heap->pool, carveout_heap->base, heap_data->size,
+		     -1);
+	carveout_heap->heap.ops = &carveout_heap_ops;
+	carveout_heap->heap.type = ION_HEAP_TYPE_CARVEOUT;
+
+	return &carveout_heap->heap;
+}
+
+void ion_carveout_heap_destroy(struct ion_heap *heap)
+{
+	struct ion_carveout_heap *carveout_heap =
+	     container_of(heap, struct  ion_carveout_heap, heap);
+
+	gen_pool_destroy(carveout_heap->pool);
+	kfree(carveout_heap);
+	carveout_heap = NULL;
+}

drivers/staging/android/ion/ion_heap.c

+/*
+ * drivers/staging/android/ion/ion_heap.c
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include "ion.h"
+#include "ion_priv.h"
+
+struct ion_heap *ion_heap_create(struct ion_platform_heap *heap_data)
+{
+	struct ion_heap *heap = NULL;
+
+	switch (heap_data->type) {
+	case ION_HEAP_TYPE_SYSTEM_CONTIG:
+		heap = ion_system_contig_heap_create(heap_data);
+		break;
+	case ION_HEAP_TYPE_SYSTEM:
+		heap = ion_system_heap_create(heap_data);
+		break;
+	case ION_HEAP_TYPE_CARVEOUT:
+		heap = ion_carveout_heap_create(heap_data);
+		break;
+	default:
+		pr_err("%s: Invalid heap type %d\n", __func__,
+		       heap_data->type);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (IS_ERR_OR_NULL(heap)) {
+		pr_err("%s: error creating heap %s type %d base %lu size %u\n",
+		       __func__, heap_data->name, heap_data->type,
+		       heap_data->base, heap_data->size);
+		return ERR_PTR(-EINVAL);
+	}
+
+	heap->name = heap_data->name;
+	heap->id = heap_data->id;
+	return heap;
+}
+
+void ion_heap_destroy(struct ion_heap *heap)
+{
+	if (!heap)
+		return;
+
+	switch (heap->type) {
+	case ION_HEAP_TYPE_SYSTEM_CONTIG:
+		ion_system_contig_heap_destroy(heap);
+		break;
+	case ION_HEAP_TYPE_SYSTEM:
+		ion_system_heap_destroy(heap);
+		break;
+	case ION_HEAP_TYPE_CARVEOUT:
+		ion_carveout_heap_destroy(heap);
+		break;
+	default:
+		pr_err("%s: Invalid heap type %d\n", __func__,
+		       heap->type);
+	}
+}

drivers/staging/android/ion/ion_priv.h

+/*
+ * drivers/staging/android/ion/ion_priv.h
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _ION_PRIV_H
+#define _ION_PRIV_H
+
+#include <linux/kref.h>
+#include <linux/mm_types.h>
+#include <linux/mutex.h>
+#include <linux/rbtree.h>
+
+#include "ion.h"
+
+struct ion_mapping;
+
+struct ion_dma_mapping {
+	struct kref ref;
+	struct scatterlist *sglist;
+};
+
+struct ion_kernel_mapping {
+	struct kref ref;
+	void *vaddr;
+};
+
+struct ion_buffer *ion_handle_buffer(struct ion_handle *handle);
+
+/**
+ * struct ion_buffer - metadata for a particular buffer
+ * @ref:		refernce count
+ * @node:		node in the ion_device buffers tree
+ * @dev:		back pointer to the ion_device
+ * @heap:		back pointer to the heap the buffer came from
+ * @flags:		buffer specific flags
+ * @size:		size of the buffer
+ * @priv_virt:		private data to the buffer representable as
+ *			a void *
+ * @priv_phys:		private data to the buffer representable as
+ *			an ion_phys_addr_t (and someday a phys_addr_t)
+ * @lock:		protects the buffers cnt fields
+ * @kmap_cnt:		number of times the buffer is mapped to the kernel
+ * @vaddr:		the kenrel mapping if kmap_cnt is not zero
+ * @dmap_cnt:		number of times the buffer is mapped for dma
+ * @sglist:		the scatterlist for the buffer is dmap_cnt is not zero
+*/
+struct ion_buffer {
+	struct kref ref;
+	struct rb_node node;
+	struct ion_device *dev;
+	struct ion_heap *heap;
+	unsigned long flags;
+	size_t size;
+	union {
+		void *priv_virt;
+		ion_phys_addr_t priv_phys;
+	};
+	struct mutex lock;
+	int kmap_cnt;
+	void *vaddr;
+	int dmap_cnt;
+	struct scatterlist *sglist;
+};
+
+/**
+ * struct ion_heap_ops - ops to operate on a given heap
+ * @allocate:		allocate memory
+ * @free:		free memory
+ * @phys		get physical address of a buffer (only define on
+ *			physically contiguous heaps)
+ * @map_dma		map the memory for dma to a scatterlist
+ * @unmap_dma		unmap the memory for dma
+ * @map_kernel		map memory to the kernel
+ * @unmap_kernel	unmap memory to the kernel
+ * @map_user		map memory to userspace
+ */
+struct ion_heap_ops {
+	int (*allocate) (struct ion_heap *heap,
+			 struct ion_buffer *buffer, unsigned long len,
+			 unsigned long align, unsigned long flags);
+	void (*free) (struct ion_buffer *buffer);
+	int (*phys) (struct ion_heap *heap, struct ion_buffer *buffer,
+		     ion_phys_addr_t *addr, size_t *len);
+	struct scatterlist *(*map_dma) (struct ion_heap *heap,
+					struct ion_buffer *buffer);
+	void (*unmap_dma) (struct ion_heap *heap, struct ion_buffer *buffer);
+	void * (*map_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
+	void (*unmap_kernel) (struct ion_heap *heap, struct ion_buffer *buffer);
+	int (*map_user) (struct ion_heap *mapper, struct ion_buffer *buffer,
+			 struct vm_area_struct *vma);
+};
+
+/**
+ * struct ion_heap - represents a heap in the system
+ * @node:		rb node to put the heap on the device's tree of heaps
+ * @dev:		back pointer to the ion_device
+ * @type:		type of heap
+ * @ops:		ops struct as above
+ * @id:			id of heap, also indicates priority of this heap when
+ *			allocating.  These are specified by platform data and
+ *			MUST be unique
+ * @name:		used for debugging
+ *
+ * Represents a pool of memory from which buffers can be made.  In some
+ * systems the only heap is regular system memory allocated via vmalloc.
+ * On others, some blocks might require large physically contiguous buffers
+ * that are allocated from a specially reserved heap.
+ */
+struct ion_heap {
+	struct rb_node node;
+	struct ion_device *dev;
+	enum ion_heap_type type;
+	struct ion_heap_ops *ops;
+	int id;
+	const char *name;
+};
+
+/**
+ * ion_device_create - allocates and returns an ion device
+ * @custom_ioctl:	arch specific ioctl function if applicable
+ *
+ * returns a valid device or -PTR_ERR
+ */
+struct ion_device *ion_device_create(long (*custom_ioctl)
+				     (struct ion_client *client,
+				      unsigned int cmd,
+				      unsigned long arg));
+
+/**
+ * ion_device_destroy - free and device and it's resource
+ * @dev:		the device
+ */
+void ion_device_destroy(struct ion_device *dev);
+
+/**
+ * ion_device_add_heap - adds a heap to the ion device
+ * @dev:		the device
+ * @heap:		the heap to add
+ */
+void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap);
+
+/**
+ * functions for creating and destroying the built in ion heaps.
+ * architectures can add their own custom architecture specific
+ * heaps as appropriate.
+ */
+
+struct ion_heap *ion_heap_create(struct ion_platform_heap *);
+void ion_heap_destroy(struct ion_heap *);
+
+struct ion_heap *ion_system_heap_create(struct ion_platform_heap *);
+void ion_system_heap_destroy(struct ion_heap *);
+
+struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *);
+void ion_system_contig_heap_destroy(struct ion_heap *);
+
+struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *);
+void ion_carveout_heap_destroy(struct ion_heap *);
+/**
+ * kernel api to allocate/free from carveout -- used when carveout is
+ * used to back an architecture specific custom heap
+ */
+ion_phys_addr_t ion_carveout_allocate(struct ion_heap *heap, unsigned long size,
+				      unsigned long align);
+void ion_carveout_free(struct ion_heap *heap, ion_phys_addr_t addr,
+		       unsigned long size);
+/**
+ * The carveout heap returns physical addresses, since 0 may be a valid
+ * physical address, this is used to indicate allocation failed
+ */
+#define ION_CARVEOUT_ALLOCATE_FAIL -1
+
+#endif /* _ION_PRIV_H */

drivers/staging/android/ion/ion_system_heap.c

+/*
+ * drivers/staging/android/ion/ion_system_heap.c
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "ion.h"
+#include "ion_priv.h"
+
+static int ion_system_heap_allocate(struct ion_heap *heap,
+				     struct ion_buffer *buffer,
+				     unsigned long size, unsigned long align,
+				     unsigned long flags)
+{
+	buffer->priv_virt = vmalloc_user(size);
+	if (!buffer->priv_virt)
+		return -ENOMEM;
+	return 0;
+}
+
+void ion_system_heap_free(struct ion_buffer *buffer)
+{
+	vfree(buffer->priv_virt);
+}
+
+struct scatterlist *ion_system_heap_map_dma(struct ion_heap *heap,
+					    struct ion_buffer *buffer)
+{
+	struct scatterlist *sglist;
+	struct page *page;
+	int i;
+	int npages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
+	void *vaddr = buffer->priv_virt;
+
+	sglist = vmalloc(npages * sizeof(struct scatterlist));
+	if (!sglist)
+		return ERR_PTR(-ENOMEM);
+	memset(sglist, 0, npages * sizeof(struct scatterlist));
+	sg_init_table(sglist, npages);
+	for (i = 0; i < npages; i++) {
+		page = vmalloc_to_page(vaddr);
+		if (!page)
+			goto end;
+		sg_set_page(&sglist[i], page, PAGE_SIZE, 0);
+		vaddr += PAGE_SIZE;
+	}
+	/* XXX do cache maintenance for dma? */
+	return sglist;
+end:
+	vfree(sglist);
+	return NULL;
+}
+
+void ion_system_heap_unmap_dma(struct ion_heap *heap,
+			       struct ion_buffer *buffer)
+{
+	/* XXX undo cache maintenance for dma? */
+	if (buffer->sglist)
+		vfree(buffer->sglist);
+}
+
+void *ion_system_heap_map_kernel(struct ion_heap *heap,
+				 struct ion_buffer *buffer)
+{
+	return buffer->priv_virt;
+}
+
+void ion_system_heap_unmap_kernel(struct ion_heap *heap,
+				  struct ion_buffer *buffer)
+{
+}
+
+int ion_system_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
+			     struct vm_area_struct *vma)
+{
+	return remap_vmalloc_range(vma, buffer->priv_virt, vma->vm_pgoff);
+}
+
+static struct ion_heap_ops vmalloc_ops = {
+	.allocate = ion_system_heap_allocate,
+	.free = ion_system_heap_free,
+	.map_dma = ion_system_heap_map_dma,
+	.unmap_dma = ion_system_heap_unmap_dma,
+	.map_kernel = ion_system_heap_map_kernel,
+	.unmap_kernel = ion_system_heap_unmap_kernel,
+	.map_user = ion_system_heap_map_user,
+};
+
+struct ion_heap *ion_system_heap_create(struct ion_platform_heap *unused)
+{
+	struct ion_heap *heap;
+
+	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
+	if (!heap)
+		return ERR_PTR(-ENOMEM);
+	heap->ops = &vmalloc_ops;
+	heap->type = ION_HEAP_TYPE_SYSTEM;
+	return heap;
+}
+
+void ion_system_heap_destroy(struct ion_heap *heap)
+{
+	kfree(heap);
+}
+
+static int ion_system_contig_heap_allocate(struct ion_heap *heap,
+					   struct ion_buffer *buffer,
+					   unsigned long len,
+					   unsigned long align,
+					   unsigned long flags)
+{
+	buffer->priv_virt = kzalloc(len, GFP_KERNEL);
+	if (!buffer->priv_virt)
+		return -ENOMEM;
+	return 0;
+}
+
+void ion_system_contig_heap_free(struct ion_buffer *buffer)
+{
+	kfree(buffer->priv_virt);
+}
+
+static int ion_system_contig_heap_phys(struct ion_heap *heap,
+				       struct ion_buffer *buffer,
+				       ion_phys_addr_t *addr, size_t *len)
+{
+	*addr = virt_to_phys(buffer->priv_virt);
+	*len = buffer->size;
+	return 0;
+}
+
+struct scatterlist *ion_system_contig_heap_map_dma(struct ion_heap *heap,
+						   struct ion_buffer *buffer)
+{
+	struct scatterlist *sglist;
+
+	sglist = vmalloc(sizeof(struct scatterlist));
+	if (!sglist)
+		return ERR_PTR(-ENOMEM);
+	sg_init_table(sglist, 1);
+	sg_set_page(sglist, virt_to_page(buffer->priv_virt), buffer->size, 0);
+	return sglist;
+}
+
+int ion_system_contig_heap_map_user(struct ion_heap *heap,
+				    struct ion_buffer *buffer,
+				    struct vm_area_struct *vma)
+{
+	unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv_virt));
+	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+			       vma->vm_end - vma->vm_start,
+			       vma->vm_page_prot);
+
+}
+
+static struct ion_heap_ops kmalloc_ops = {
+	.allocate = ion_system_contig_heap_allocate,
+	.free = ion_system_contig_heap_free,
+	.phys = ion_system_contig_heap_phys,
+	.map_dma = ion_system_contig_heap_map_dma,
+	.unmap_dma = ion_system_heap_unmap_dma,
+	.map_kernel = ion_system_heap_map_kernel,
+	.unmap_kernel = ion_system_heap_unmap_kernel,
+	.map_user = ion_system_contig_heap_map_user,
+};
+
+struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *unused)
+{
+	struct ion_heap *heap;
+
+	heap = kzalloc(sizeof(struct ion_heap), GFP_KERNEL);
+	if (!heap)
+		return ERR_PTR(-ENOMEM);
+	heap->ops = &kmalloc_ops;
+	heap->type = ION_HEAP_TYPE_SYSTEM_CONTIG;
+	return heap;
+}
+
+void ion_system_contig_heap_destroy(struct ion_heap *heap)
+{
+	kfree(heap);
+}
+

drivers/staging/android/ion/ion_system_mapper.c

+/*
+ * drivers/staging/android/ion/ion_system_mapper.c
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/memory.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "ion.h"
+#include "ion_priv.h"
+/*
+ * This mapper is valid for any heap that allocates memory that already has
+ * a kernel mapping, this includes vmalloc'd memory, kmalloc'd memory,
+ * pages obtained via io_remap, etc.
+ */
+static void *ion_kernel_mapper_map(struct ion_mapper *mapper,
+				   struct ion_buffer *buffer,
+				   struct ion_mapping **mapping)
+{
+	if (!((1 << buffer->heap->type) & mapper->heap_mask)) {
+		pr_err("%s: attempting to map an unsupported heap\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+	/* XXX REVISIT ME!!! */
+	*((unsigned long *)mapping) = (unsigned long)buffer->priv;
+	return buffer->priv;
+}
+
+static void ion_kernel_mapper_unmap(struct ion_mapper *mapper,
+				    struct ion_buffer *buffer,
+				    struct ion_mapping *mapping)
+{
+	if (!((1 << buffer->heap->type) & mapper->heap_mask))
+		pr_err("%s: attempting to unmap an unsupported heap\n",
+		       __func__);
+}
+
+static void *ion_kernel_mapper_map_kernel(struct ion_mapper *mapper,
+					struct ion_buffer *buffer,
+					struct ion_mapping *mapping)
+{
+	if (!((1 << buffer->heap->type) & mapper->heap_mask)) {
+		pr_err("%s: attempting to unmap an unsupported heap\n",
+		       __func__);
+		return ERR_PTR(-EINVAL);
+	}
+	return buffer->priv;
+}
+
+static int ion_kernel_mapper_map_user(struct ion_mapper *mapper,
+				      struct ion_buffer *buffer,
+				      struct vm_area_struct *vma,
+				      struct ion_mapping *mapping)
+{
+	int ret;
+
+	switch (buffer->heap->type) {
+	case ION_HEAP_KMALLOC:
+	{
+		unsigned long pfn = __phys_to_pfn(virt_to_phys(buffer->priv));
+		ret = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+				      vma->vm_end - vma->vm_start,
+				      vma->vm_page_prot);
+		break;
+	}
+	case ION_HEAP_VMALLOC:
+		ret = remap_vmalloc_range(vma, buffer->priv, vma->vm_pgoff);
+		break;
+	default:
+		pr_err("%s: attempting to map unsupported heap to userspace\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static struct ion_mapper_ops ops = {
+	.map = ion_kernel_mapper_map,
+	.map_kernel = ion_kernel_mapper_map_kernel,
+	.map_user = ion_kernel_mapper_map_user,
+	.unmap = ion_kernel_mapper_unmap,
+};
+
+struct ion_mapper *ion_system_mapper_create(void)
+{
+	struct ion_mapper *mapper;
+	mapper = kzalloc(sizeof(struct ion_mapper), GFP_KERNEL);
+	if (!mapper)
+		return ERR_PTR(-ENOMEM);
+	mapper->type = ION_SYSTEM_MAPPER;
+	mapper->ops = &ops;
+	mapper->heap_mask = (1 << ION_HEAP_VMALLOC) | (1 << ION_HEAP_KMALLOC);
+	return mapper;
+}
+
+void ion_system_mapper_destroy(struct ion_mapper *mapper)
+{
+	kfree(mapper);
+}
+

drivers/staging/android/ion/tegra/Makefile

+obj-y += tegra_ion.o

drivers/staging/android/ion/tegra/tegra_ion.c

+/*
+ * drivers/gpu/tegra/tegra_ion.c
+ *
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include "../ion.h"
+#include "../ion_priv.h"
+
+struct ion_device *idev;
+struct ion_mapper *tegra_user_mapper;
+int num_heaps;
+struct ion_heap **heaps;
+
+int tegra_ion_probe(struct platform_device *pdev)
+{
+	struct ion_platform_data *pdata = pdev->dev.platform_data;
+	int err;
+	int i;
+
+	num_heaps = pdata->nr;
+
+	heaps = kzalloc(sizeof(struct ion_heap *) * pdata->nr, GFP_KERNEL);
+
+	idev = ion_device_create(NULL);
+	if (IS_ERR_OR_NULL(idev)) {
+		kfree(heaps);
+		return PTR_ERR(idev);
+	}
+
+	/* create the heaps as specified in the board file */
+	for (i = 0; i < num_heaps; i++) {
+		struct ion_platform_heap *heap_data = &pdata->heaps[i];
+
+		heaps[i] = ion_heap_create(heap_data);
+		if (IS_ERR_OR_NULL(heaps[i])) {
+			err = PTR_ERR(heaps[i]);
+			goto err;
+		}
+		ion_device_add_heap(idev, heaps[i]);
+	}
+	platform_set_drvdata(pdev, idev);
+	return 0;
+err:
+	for (i = 0; i < num_heaps; i++) {
+		if (heaps[i])
+			ion_heap_destroy(heaps[i]);
+	}
+	kfree(heaps);
+	return err;
+}
+
+int tegra_ion_remove(struct platform_device *pdev)
+{
+	struct ion_device *idev = platform_get_drvdata(pdev);
+	int i;
+
+	ion_device_destroy(idev);
+	for (i = 0; i < num_heaps; i++)
+		ion_heap_destroy(heaps[i]);
+	kfree(heaps);
+	return 0;
+}
+
+static struct platform_driver ion_driver = {
+	.probe = tegra_ion_probe,
+	.remove = tegra_ion_remove,
+	.driver = { .name = "ion-tegra" }
+};
+
+static int __init ion_init(void)
+{
+	return platform_driver_register(&ion_driver);
+}
+
+static void __exit ion_exit(void)
+{
+	platform_driver_unregister(&ion_driver);
+}
+
+module_init(ion_init);
+module_exit(ion_exit);
+