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// SPDX-License-Identifier: GPL-2.0
/*
* ION Memory Allocator generic heap helpers
*
* Copyright (C) 2011 Google, Inc.
*/
#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(array_size(npages,
sizeof(struct page *)));
struct page **tmp = pages;
if (!pages)
return ERR_PTR(-ENOMEM);
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);
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