#define pr_fmt(fmt) "cma_heap: " fmt
#include <linux/cma.h>
#include <linux/dma-buf.h>
#include <linux/dma-buf/heaps/cma.h>
#include <linux/dma-heap.h>
#include <linux/dma-map-ops.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_reserved_mem.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#define DEFAULT_CMA_NAME "default_cma_region"
static struct cma *dma_areas[MAX_CMA_AREAS] __initdata;
static unsigned int dma_areas_num __initdata;
int __init dma_heap_cma_register_heap(struct cma *cma)
{
if (dma_areas_num >= ARRAY_SIZE(dma_areas))
return -EINVAL;
dma_areas[dma_areas_num++] = cma;
return 0;
}
struct cma_heap {
struct dma_heap *heap;
struct cma *cma;
};
struct cma_heap_buffer {
struct cma_heap *heap;
struct list_head attachments;
struct mutex lock;
unsigned long len;
struct page *cma_pages;
struct page **pages;
pgoff_t pagecount;
int vmap_cnt;
void *vaddr;
};
struct dma_heap_attachment {
struct device *dev;
struct sg_table table;
struct list_head list;
bool mapped;
};
static int cma_heap_attach(struct dma_buf *dmabuf,
struct dma_buf_attachment *attachment)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
struct dma_heap_attachment *a;
int ret;
a = kzalloc_obj(*a);
if (!a)
return -ENOMEM;
ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
buffer->pagecount, 0,
buffer->pagecount << PAGE_SHIFT,
GFP_KERNEL);
if (ret) {
kfree(a);
return ret;
}
a->dev = attachment->dev;
INIT_LIST_HEAD(&a->list);
a->mapped = false;
attachment->priv = a;
mutex_lock(&buffer->lock);
list_add(&a->list, &buffer->attachments);
mutex_unlock(&buffer->lock);
return 0;
}
static void cma_heap_detach(struct dma_buf *dmabuf,
struct dma_buf_attachment *attachment)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
struct dma_heap_attachment *a = attachment->priv;
mutex_lock(&buffer->lock);
list_del(&a->list);
mutex_unlock(&buffer->lock);
sg_free_table(&a->table);
kfree(a);
}
static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachment,
enum dma_data_direction direction)
{
struct dma_heap_attachment *a = attachment->priv;
struct sg_table *table = &a->table;
int ret;
ret = dma_map_sgtable(attachment->dev, table, direction, 0);
if (ret)
return ERR_PTR(-ENOMEM);
a->mapped = true;
return table;
}
static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
struct sg_table *table,
enum dma_data_direction direction)
{
struct dma_heap_attachment *a = attachment->priv;
a->mapped = false;
dma_unmap_sgtable(attachment->dev, table, direction, 0);
}
static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
enum dma_data_direction direction)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
struct dma_heap_attachment *a;
mutex_lock(&buffer->lock);
if (buffer->vmap_cnt)
invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);
list_for_each_entry(a, &buffer->attachments, list) {
if (!a->mapped)
continue;
dma_sync_sgtable_for_cpu(a->dev, &a->table, direction);
}
mutex_unlock(&buffer->lock);
return 0;
}
static int cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
enum dma_data_direction direction)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
struct dma_heap_attachment *a;
mutex_lock(&buffer->lock);
if (buffer->vmap_cnt)
flush_kernel_vmap_range(buffer->vaddr, buffer->len);
list_for_each_entry(a, &buffer->attachments, list) {
if (!a->mapped)
continue;
dma_sync_sgtable_for_device(a->dev, &a->table, direction);
}
mutex_unlock(&buffer->lock);
return 0;
}
static vm_fault_t cma_heap_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct cma_heap_buffer *buffer = vma->vm_private_data;
if (vmf->pgoff >= buffer->pagecount)
return VM_FAULT_SIGBUS;
return vmf_insert_pfn(vma, vmf->address, page_to_pfn(buffer->pages[vmf->pgoff]));
}
static const struct vm_operations_struct dma_heap_vm_ops = {
.fault = cma_heap_vm_fault,
};
static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
return -EINVAL;
vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
vma->vm_ops = &dma_heap_vm_ops;
vma->vm_private_data = buffer;
return 0;
}
static void *cma_heap_do_vmap(struct cma_heap_buffer *buffer)
{
void *vaddr;
vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
if (!vaddr)
return ERR_PTR(-ENOMEM);
return vaddr;
}
static int cma_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
void *vaddr;
int ret = 0;
mutex_lock(&buffer->lock);
if (buffer->vmap_cnt) {
buffer->vmap_cnt++;
iosys_map_set_vaddr(map, buffer->vaddr);
goto out;
}
vaddr = cma_heap_do_vmap(buffer);
if (IS_ERR(vaddr)) {
ret = PTR_ERR(vaddr);
goto out;
}
buffer->vaddr = vaddr;
buffer->vmap_cnt++;
iosys_map_set_vaddr(map, buffer->vaddr);
out:
mutex_unlock(&buffer->lock);
return ret;
}
static void cma_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
mutex_lock(&buffer->lock);
if (!--buffer->vmap_cnt) {
vunmap(buffer->vaddr);
buffer->vaddr = NULL;
}
mutex_unlock(&buffer->lock);
iosys_map_clear(map);
}
static void cma_heap_dma_buf_release(struct dma_buf *dmabuf)
{
struct cma_heap_buffer *buffer = dmabuf->priv;
struct cma_heap *cma_heap = buffer->heap;
if (buffer->vmap_cnt > 0) {
WARN(1, "%s: buffer still mapped in the kernel\n", __func__);
vunmap(buffer->vaddr);
buffer->vaddr = NULL;
}
kfree(buffer->pages);
cma_release(cma_heap->cma, buffer->cma_pages, buffer->pagecount);
kfree(buffer);
}
static const struct dma_buf_ops cma_heap_buf_ops = {
.attach = cma_heap_attach,
.detach = cma_heap_detach,
.map_dma_buf = cma_heap_map_dma_buf,
.unmap_dma_buf = cma_heap_unmap_dma_buf,
.begin_cpu_access = cma_heap_dma_buf_begin_cpu_access,
.end_cpu_access = cma_heap_dma_buf_end_cpu_access,
.mmap = cma_heap_mmap,
.vmap = cma_heap_vmap,
.vunmap = cma_heap_vunmap,
.release = cma_heap_dma_buf_release,
};
static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
unsigned long len,
u32 fd_flags,
u64 heap_flags)
{
struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
struct cma_heap_buffer *buffer;
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
size_t size = PAGE_ALIGN(len);
pgoff_t pagecount = size >> PAGE_SHIFT;
unsigned long align = get_order(size);
struct page *cma_pages;
struct dma_buf *dmabuf;
int ret = -ENOMEM;
pgoff_t pg;
buffer = kzalloc_obj(*buffer);
if (!buffer)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&buffer->attachments);
mutex_init(&buffer->lock);
buffer->len = size;
if (align > CONFIG_CMA_ALIGNMENT)
align = CONFIG_CMA_ALIGNMENT;
cma_pages = cma_alloc(cma_heap->cma, pagecount, align, false);
if (!cma_pages)
goto free_buffer;
if (PageHighMem(cma_pages)) {
unsigned long nr_clear_pages = pagecount;
struct page *page = cma_pages;
while (nr_clear_pages > 0) {
void *vaddr = kmap_local_page(page);
clear_page(vaddr);
kunmap_local(vaddr);
if (fatal_signal_pending(current))
goto free_cma;
page++;
nr_clear_pages--;
}
} else {
memset(page_address(cma_pages), 0, size);
}
buffer->pages = kmalloc_objs(*buffer->pages, pagecount);
if (!buffer->pages) {
ret = -ENOMEM;
goto free_cma;
}
for (pg = 0; pg < pagecount; pg++)
buffer->pages[pg] = &cma_pages[pg];
buffer->cma_pages = cma_pages;
buffer->heap = cma_heap;
buffer->pagecount = pagecount;
exp_info.exp_name = dma_heap_get_name(heap);
exp_info.ops = &cma_heap_buf_ops;
exp_info.size = buffer->len;
exp_info.flags = fd_flags;
exp_info.priv = buffer;
dmabuf = dma_buf_export(&exp_info);
if (IS_ERR(dmabuf)) {
ret = PTR_ERR(dmabuf);
goto free_pages;
}
return dmabuf;
free_pages:
kfree(buffer->pages);
free_cma:
cma_release(cma_heap->cma, cma_pages, pagecount);
free_buffer:
kfree(buffer);
return ERR_PTR(ret);
}
static const struct dma_heap_ops cma_heap_ops = {
.allocate = cma_heap_allocate,
};
static int __init __add_cma_heap(struct cma *cma, const char *name)
{
struct dma_heap_export_info exp_info;
struct cma_heap *cma_heap;
cma_heap = kzalloc_obj(*cma_heap);
if (!cma_heap)
return -ENOMEM;
cma_heap->cma = cma;
exp_info.name = name;
exp_info.ops = &cma_heap_ops;
exp_info.priv = cma_heap;
cma_heap->heap = dma_heap_add(&exp_info);
if (IS_ERR(cma_heap->heap)) {
int ret = PTR_ERR(cma_heap->heap);
kfree(cma_heap);
return ret;
}
return 0;
}
static int __init add_cma_heaps(void)
{
struct cma *default_cma = dev_get_cma_area(NULL);
unsigned int i;
int ret;
if (default_cma) {
ret = __add_cma_heap(default_cma, DEFAULT_CMA_NAME);
if (ret)
return ret;
}
for (i = 0; i < dma_areas_num; i++) {
struct cma *cma = dma_areas[i];
ret = __add_cma_heap(cma, cma_get_name(cma));
if (ret) {
pr_warn("Failed to add CMA heap %s", cma_get_name(cma));
continue;
}
}
return 0;
}
module_init(add_cma_heaps);
MODULE_DESCRIPTION("DMA-BUF CMA Heap");
