drivers/staging/android/ion/ion_heap.c - arm/linux - Git at Google

 /*
  * 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 <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/mm.h>
 #include <linux/rtmutex.h>
 #include <linux/sched.h>
 #include <uapi/linux/sched/types.h>
 #include <linux/scatterlist.h>
 #include <linux/vmalloc.h>
 #include "ion.h"

 void *ion_heap_map_kernel(struct ion_heap *heap,
 			  struct ion_buffer *buffer)
 {
 	struct scatterlist *sg;
 	int i, j;
 	void *vaddr;
 	pgprot_t pgprot;
 	struct sg_table *table = buffer->sg_table;
 	int npages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
 	struct page **pages = vmalloc(sizeof(struct page *) * npages);
 	struct page **tmp = pages;

 	if (!pages)
 		return NULL;

 	if (buffer->flags & ION_FLAG_CACHED)
 		pgprot = PAGE_KERNEL;
 	else
 		pgprot = pgprot_writecombine(PAGE_KERNEL);

 	for_each_sg(table->sgl, sg, table->nents, i) {
 		int npages_this_entry = PAGE_ALIGN(sg->length) / PAGE_SIZE;
 		struct page *page = sg_page(sg);

 		BUG_ON(i >= npages);
 		for (j = 0; j < npages_this_entry; j++)
 			*(tmp++) = page++;
 	}
 	vaddr = vmap(pages, npages, VM_MAP, pgprot);
 	vfree(pages);

 	if (!vaddr)
 		return ERR_PTR(-ENOMEM);

 	return vaddr;
 }

 void ion_heap_unmap_kernel(struct ion_heap *heap,
 			   struct ion_buffer *buffer)
 {
 	vunmap(buffer->vaddr);
 }

 int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
 		      struct vm_area_struct *vma)
 {
 	struct sg_table *table = buffer->sg_table;
 	unsigned long addr = vma->vm_start;
 	unsigned long offset = vma->vm_pgoff * PAGE_SIZE;
 	struct scatterlist *sg;
 	int i;
 	int ret;

 	for_each_sg(table->sgl, sg, table->nents, i) {
 		struct page *page = sg_page(sg);
 		unsigned long remainder = vma->vm_end - addr;
 		unsigned long len = sg->length;

 		if (offset >= sg->length) {
 			offset -= sg->length;
 			continue;
 		} else if (offset) {
 			page += offset / PAGE_SIZE;
 			len = sg->length - offset;
 			offset = 0;
 		}
 		len = min(len, remainder);
 		ret = remap_pfn_range(vma, addr, page_to_pfn(page), len,
 				      vma->vm_page_prot);
 		if (ret)
 			return ret;
 		addr += len;
 		if (addr >= vma->vm_end)
 			return 0;
 	}
 	return 0;
 }

 static int ion_heap_clear_pages(struct page **pages, int num, pgprot_t pgprot)
 {
 	void *addr = vm_map_ram(pages, num, -1, pgprot);

 	if (!addr)
 		return -ENOMEM;
 	memset(addr, 0, PAGE_SIZE * num);
 	vm_unmap_ram(addr, num);

 	return 0;
 }

 static int ion_heap_sglist_zero(struct scatterlist *sgl, unsigned int nents,
 				pgprot_t pgprot)
 {
 	int p = 0;
 	int ret = 0;
 	struct sg_page_iter piter;
 	struct page *pages[32];

 	for_each_sg_page(sgl, &piter, nents, 0) {
 		pages[p++] = sg_page_iter_page(&piter);
 		if (p == ARRAY_SIZE(pages)) {
 			ret = ion_heap_clear_pages(pages, p, pgprot);
 			if (ret)
 				return ret;
 			p = 0;
 		}
 	}
 	if (p)
 		ret = ion_heap_clear_pages(pages, p, pgprot);

 	return ret;
 }

 int ion_heap_buffer_zero(struct ion_buffer *buffer)
 {
 	struct sg_table *table = buffer->sg_table;
 	pgprot_t pgprot;

 	if (buffer->flags & ION_FLAG_CACHED)
 		pgprot = PAGE_KERNEL;
 	else
 		pgprot = pgprot_writecombine(PAGE_KERNEL);

 	return ion_heap_sglist_zero(table->sgl, table->nents, pgprot);
 }

 int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot)
 {
 	struct scatterlist sg;

 	sg_init_table(&sg, 1);
 	sg_set_page(&sg, page, size, 0);
 	return ion_heap_sglist_zero(&sg, 1, pgprot);
 }

 void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer)
 {
 	spin_lock(&heap->free_lock);
 	list_add(&buffer->list, &heap->free_list);
 	heap->free_list_size += buffer->size;
 	spin_unlock(&heap->free_lock);
 	wake_up(&heap->waitqueue);
 }

 size_t ion_heap_freelist_size(struct ion_heap *heap)
 {
 	size_t size;

 	spin_lock(&heap->free_lock);
 	size = heap->free_list_size;
 	spin_unlock(&heap->free_lock);

 	return size;
 }

 static size_t _ion_heap_freelist_drain(struct ion_heap *heap, size_t size,
 				       bool skip_pools)
 {
 	struct ion_buffer *buffer;
 	size_t total_drained = 0;

 	if (ion_heap_freelist_size(heap) == 0)
 		return 0;

 	spin_lock(&heap->free_lock);
 	if (size == 0)
 		size = heap->free_list_size;

 	while (!list_empty(&heap->free_list)) {
 		if (total_drained >= size)
 			break;
 		buffer = list_first_entry(&heap->free_list, struct ion_buffer,
 					  list);
 		list_del(&buffer->list);
 		heap->free_list_size -= buffer->size;
 		if (skip_pools)
 			buffer->private_flags |= ION_PRIV_FLAG_SHRINKER_FREE;
 		total_drained += buffer->size;
 		spin_unlock(&heap->free_lock);
 		ion_buffer_destroy(buffer);
 		spin_lock(&heap->free_lock);
 	}
 	spin_unlock(&heap->free_lock);

 	return total_drained;
 }

 size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size)
 {
 	return _ion_heap_freelist_drain(heap, size, false);
 }

 size_t ion_heap_freelist_shrink(struct ion_heap *heap, size_t size)
 {
 	return _ion_heap_freelist_drain(heap, size, true);
 }

 static int ion_heap_deferred_free(void *data)
 {
 	struct ion_heap *heap = data;

 	while (true) {
 		struct ion_buffer *buffer;

 		wait_event_freezable(heap->waitqueue,
 				     ion_heap_freelist_size(heap) > 0);

 		spin_lock(&heap->free_lock);
 		if (list_empty(&heap->free_list)) {
 			spin_unlock(&heap->free_lock);
 			continue;
 		}
 		buffer = list_first_entry(&heap->free_list, struct ion_buffer,
 					  list);
 		list_del(&buffer->list);
 		heap->free_list_size -= buffer->size;
 		spin_unlock(&heap->free_lock);
 		ion_buffer_destroy(buffer);
 	}

 	return 0;
 }

 int ion_heap_init_deferred_free(struct ion_heap *heap)
 {
 	struct sched_param param = { .sched_priority = 0 };

 	INIT_LIST_HEAD(&heap->free_list);
 	init_waitqueue_head(&heap->waitqueue);
 	heap->task = kthread_run(ion_heap_deferred_free, heap,
 				 "%s", heap->name);
 	if (IS_ERR(heap->task)) {
 		pr_err("%s: creating thread for deferred free failed\n",
 		       __func__);
 		return PTR_ERR_OR_ZERO(heap->task);
 	}
 	sched_setscheduler(heap->task, SCHED_IDLE, &param);
 	return 0;
 }

 static unsigned long ion_heap_shrink_count(struct shrinker *shrinker,
 					   struct shrink_control *sc)
 {
 	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
 					     shrinker);
 	int total = 0;

 	total = ion_heap_freelist_size(heap) / PAGE_SIZE;
 	if (heap->ops->shrink)
 		total += heap->ops->shrink(heap, sc->gfp_mask, 0);
 	return total;
 }

 static unsigned long ion_heap_shrink_scan(struct shrinker *shrinker,
 					  struct shrink_control *sc)
 {
 	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
 					     shrinker);
 	int freed = 0;
 	int to_scan = sc->nr_to_scan;

 	if (to_scan == 0)
 		return 0;

 	/*
 	 * shrink the free list first, no point in zeroing the memory if we're
 	 * just going to reclaim it. Also, skip any possible page pooling.
 	 */
 	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
 		freed = ion_heap_freelist_shrink(heap, to_scan * PAGE_SIZE) /
 				PAGE_SIZE;

 	to_scan -= freed;
 	if (to_scan <= 0)
 		return freed;

 	if (heap->ops->shrink)
 		freed += heap->ops->shrink(heap, sc->gfp_mask, to_scan);
 	return freed;
 }

 void ion_heap_init_shrinker(struct ion_heap *heap)
 {
 	heap->shrinker.count_objects = ion_heap_shrink_count;
 	heap->shrinker.scan_objects = ion_heap_shrink_scan;
 	heap->shrinker.seeks = DEFAULT_SEEKS;
 	heap->shrinker.batch = 0;
 	register_shrinker(&heap->shrinker);
 }
	/*
	* 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 <linux/freezer.h>
	#include <linux/kthread.h>
	#include <linux/mm.h>
	#include <linux/rtmutex.h>
	#include <linux/sched.h>
	#include <uapi/linux/sched/types.h>
	#include <linux/scatterlist.h>
	#include <linux/vmalloc.h>
	#include "ion.h"

	void ion_heap_map_kernel(struct ion_heap heap,
	struct ion_buffer *buffer)
	{
	struct scatterlist *sg;
	int i, j;
	void *vaddr;
	pgprot_t pgprot;
	struct sg_table *table = buffer->sg_table;
	int npages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
	struct page *pages = vmalloc(sizeof(struct page ) * npages);
	struct page **tmp = pages;

	if (!pages)
	return NULL;

	if (buffer->flags & ION_FLAG_CACHED)
	pgprot = PAGE_KERNEL;
	else
	pgprot = pgprot_writecombine(PAGE_KERNEL);

	for_each_sg(table->sgl, sg, table->nents, i) {
	int npages_this_entry = PAGE_ALIGN(sg->length) / PAGE_SIZE;
	struct page *page = sg_page(sg);

	BUG_ON(i >= npages);
	for (j = 0; j < npages_this_entry; j++)
	*(tmp++) = page++;
	}
	vaddr = vmap(pages, npages, VM_MAP, pgprot);
	vfree(pages);

	if (!vaddr)
	return ERR_PTR(-ENOMEM);

	return vaddr;
	}

	void ion_heap_unmap_kernel(struct ion_heap *heap,
	struct ion_buffer *buffer)
	{
	vunmap(buffer->vaddr);
	}

	int ion_heap_map_user(struct ion_heap heap, struct ion_buffer buffer,
	struct vm_area_struct *vma)
	{
	struct sg_table *table = buffer->sg_table;
	unsigned long addr = vma->vm_start;
	unsigned long offset = vma->vm_pgoff * PAGE_SIZE;
	struct scatterlist *sg;
	int i;
	int ret;

	for_each_sg(table->sgl, sg, table->nents, i) {
	struct page *page = sg_page(sg);
	unsigned long remainder = vma->vm_end - addr;
	unsigned long len = sg->length;

	if (offset >= sg->length) {
	offset -= sg->length;
	continue;
	} else if (offset) {
	page += offset / PAGE_SIZE;
	len = sg->length - offset;
	offset = 0;
	}
	len = min(len, remainder);
	ret = remap_pfn_range(vma, addr, page_to_pfn(page), len,
	vma->vm_page_prot);
	if (ret)
	return ret;
	addr += len;
	if (addr >= vma->vm_end)
	return 0;
	}
	return 0;
	}

	static int ion_heap_clear_pages(struct page **pages, int num, pgprot_t pgprot)
	{
	void *addr = vm_map_ram(pages, num, -1, pgprot);

	if (!addr)
	return -ENOMEM;
	memset(addr, 0, PAGE_SIZE * num);
	vm_unmap_ram(addr, num);

	return 0;
	}

	static int ion_heap_sglist_zero(struct scatterlist *sgl, unsigned int nents,
	pgprot_t pgprot)
	{
	int p = 0;
	int ret = 0;
	struct sg_page_iter piter;
	struct page *pages[32];

	for_each_sg_page(sgl, &piter, nents, 0) {
	pages[p++] = sg_page_iter_page(&piter);
	if (p == ARRAY_SIZE(pages)) {
	ret = ion_heap_clear_pages(pages, p, pgprot);
	if (ret)
	return ret;
	p = 0;
	}
	}
	if (p)
	ret = ion_heap_clear_pages(pages, p, pgprot);

	return ret;
	}

	int ion_heap_buffer_zero(struct ion_buffer *buffer)
	{
	struct sg_table *table = buffer->sg_table;
	pgprot_t pgprot;

	if (buffer->flags & ION_FLAG_CACHED)
	pgprot = PAGE_KERNEL;
	else
	pgprot = pgprot_writecombine(PAGE_KERNEL);

	return ion_heap_sglist_zero(table->sgl, table->nents, pgprot);
	}

	int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot)
	{
	struct scatterlist sg;

	sg_init_table(&sg, 1);
	sg_set_page(&sg, page, size, 0);
	return ion_heap_sglist_zero(&sg, 1, pgprot);
	}

	void ion_heap_freelist_add(struct ion_heap heap, struct ion_buffer buffer)
	{
	spin_lock(&heap->free_lock);
	list_add(&buffer->list, &heap->free_list);
	heap->free_list_size += buffer->size;
	spin_unlock(&heap->free_lock);
	wake_up(&heap->waitqueue);
	}

	size_t ion_heap_freelist_size(struct ion_heap *heap)
	{
	size_t size;

	spin_lock(&heap->free_lock);
	size = heap->free_list_size;
	spin_unlock(&heap->free_lock);

	return size;
	}

	static size_t _ion_heap_freelist_drain(struct ion_heap *heap, size_t size,
	bool skip_pools)
	{
	struct ion_buffer *buffer;
	size_t total_drained = 0;

	if (ion_heap_freelist_size(heap) == 0)
	return 0;

	spin_lock(&heap->free_lock);
	if (size == 0)
	size = heap->free_list_size;

	while (!list_empty(&heap->free_list)) {
	if (total_drained >= size)
	break;
	buffer = list_first_entry(&heap->free_list, struct ion_buffer,
	list);
	list_del(&buffer->list);
	heap->free_list_size -= buffer->size;
	if (skip_pools)
	buffer->private_flags \|= ION_PRIV_FLAG_SHRINKER_FREE;
	total_drained += buffer->size;
	spin_unlock(&heap->free_lock);
	ion_buffer_destroy(buffer);
	spin_lock(&heap->free_lock);
	}
	spin_unlock(&heap->free_lock);

	return total_drained;
	}

	size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size)
	{
	return _ion_heap_freelist_drain(heap, size, false);
	}

	size_t ion_heap_freelist_shrink(struct ion_heap *heap, size_t size)
	{
	return _ion_heap_freelist_drain(heap, size, true);
	}

	static int ion_heap_deferred_free(void *data)
	{
	struct ion_heap *heap = data;

	while (true) {
	struct ion_buffer *buffer;

	wait_event_freezable(heap->waitqueue,
	ion_heap_freelist_size(heap) > 0);

	spin_lock(&heap->free_lock);
	if (list_empty(&heap->free_list)) {
	spin_unlock(&heap->free_lock);
	continue;
	}
	buffer = list_first_entry(&heap->free_list, struct ion_buffer,
	list);
	list_del(&buffer->list);
	heap->free_list_size -= buffer->size;
	spin_unlock(&heap->free_lock);
	ion_buffer_destroy(buffer);
	}

	return 0;
	}

	int ion_heap_init_deferred_free(struct ion_heap *heap)
	{
	struct sched_param param = { .sched_priority = 0 };

	INIT_LIST_HEAD(&heap->free_list);
	init_waitqueue_head(&heap->waitqueue);
	heap->task = kthread_run(ion_heap_deferred_free, heap,
	"%s", heap->name);
	if (IS_ERR(heap->task)) {
	pr_err("%s: creating thread for deferred free failed\n",
	__func__);
	return PTR_ERR_OR_ZERO(heap->task);
	}
	sched_setscheduler(heap->task, SCHED_IDLE, &param);
	return 0;
	}

	static unsigned long ion_heap_shrink_count(struct shrinker *shrinker,
	struct shrink_control *sc)
	{
	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
	shrinker);
	int total = 0;

	total = ion_heap_freelist_size(heap) / PAGE_SIZE;
	if (heap->ops->shrink)
	total += heap->ops->shrink(heap, sc->gfp_mask, 0);
	return total;
	}

	static unsigned long ion_heap_shrink_scan(struct shrinker *shrinker,
	struct shrink_control *sc)
	{
	struct ion_heap *heap = container_of(shrinker, struct ion_heap,
	shrinker);
	int freed = 0;
	int to_scan = sc->nr_to_scan;

	if (to_scan == 0)
	return 0;

	/*
	* shrink the free list first, no point in zeroing the memory if we're
	* just going to reclaim it. Also, skip any possible page pooling.
	*/
	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
	freed = ion_heap_freelist_shrink(heap, to_scan * PAGE_SIZE) /
	PAGE_SIZE;

	to_scan -= freed;
	if (to_scan <= 0)
	return freed;

	if (heap->ops->shrink)
	freed += heap->ops->shrink(heap, sc->gfp_mask, to_scan);
	return freed;
	}

	void ion_heap_init_shrinker(struct ion_heap *heap)
	{
	heap->shrinker.count_objects = ion_heap_shrink_count;
	heap->shrinker.scan_objects = ion_heap_shrink_scan;
	heap->shrinker.seeks = DEFAULT_SEEKS;
	heap->shrinker.batch = 0;
	register_shrinker(&heap->shrinker);
	}