/**
* _vb2_ion_get_vma() - lock userspace mapped memory
* @vaddr: starting virtual address of the area to be verified
* @size: size of the area
* @res_vma: will return locked copy of struct vm_area for the given area
*
* This function will go through memory area of size @size mapped at @vaddr
* If they are contiguous the virtual memory area is locked and a @res_vma is
* filled with the copy and @res_pa set to the physical address of the buffer.
*
* Returns 0 on success.
*/
static int _vb2_ion_get_vma(unsigned long vaddr, unsigned long size,
struct vm_area_struct **res_vma)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long start, end;
int ret = -EFAULT;
start = vaddr;
end = start + size;
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
if (vma == NULL || vma->vm_end < end)
goto done;
/* Lock vma and return to the caller */
*res_vma = vb2_get_vma(vma);
if (*res_vma == NULL) {
ret = -ENOMEM;
goto done;
}
ret = 0;
done:
up_read(&mm->mmap_sem);
return ret;
}
/**
* vb2_get_contig_userptr() - lock physically contiguous userspace mapped memory
* @vaddr: starting virtual address of the area to be verified
* @size: size of the area
* @res_paddr: will return physical address for the given vaddr
* @res_vma: will return locked copy of struct vm_area for the given area
*
* This function will go through memory area of size @size mapped at @vaddr and
* verify that the underlying physical pages are contiguous. If they are
* contiguous the virtual memory area is locked and a @res_vma is filled with
* the copy and @res_pa set to the physical address of the buffer.
*
* Returns 0 on success.
*/
int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
struct vm_area_struct **res_vma, dma_addr_t *res_pa)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long offset, start, end;
unsigned long this_pfn, prev_pfn;
dma_addr_t pa = 0;
int ret = -EFAULT;
start = vaddr;
offset = start & ~PAGE_MASK;
end = start + size;
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
if (vma == NULL || vma->vm_end < end)
goto done;
for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
ret = follow_pfn(vma, start, &this_pfn);
if (ret)
goto done;
if (prev_pfn == 0)
pa = this_pfn << PAGE_SHIFT;
else if (this_pfn != prev_pfn + 1) {
ret = -EFAULT;
goto done;
}
prev_pfn = this_pfn;
}
/*
* Memory is contigous, lock vma and return to the caller
*/
*res_vma = vb2_get_vma(vma);
if (*res_vma == NULL) {
ret = -ENOMEM;
goto done;
}
*res_pa = pa + offset;
ret = 0;
done:
up_read(&mm->mmap_sem);
return ret;
}
int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
struct vm_area_struct **res_vma, dma_addr_t *res_pa)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long offset, start, end;
unsigned long this_pfn, prev_pfn;
dma_addr_t pa = 0;
start = vaddr;
offset = start & ~PAGE_MASK;
end = start + size;
vma = find_vma(mm, start);
if (vma == NULL || vma->vm_end < end)
return -EFAULT;
for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
int ret = follow_pfn(vma, start, &this_pfn);
if (ret)
return ret;
if (prev_pfn == 0)
pa = this_pfn << PAGE_SHIFT;
else if (this_pfn != prev_pfn + 1)
return -EFAULT;
prev_pfn = this_pfn;
}
*res_vma = vb2_get_vma(vma);
if (*res_vma == NULL)
return -ENOMEM;
*res_pa = pa + offset;
return 0;
}
static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
unsigned long size,
enum dma_data_direction dma_dir)
{
struct vb2_dma_sg_conf *conf = alloc_ctx;
struct vb2_dma_sg_buf *buf;
unsigned long first, last;
int num_pages_from_user;
struct vm_area_struct *vma;
struct sg_table *sgt;
DEFINE_DMA_ATTRS(attrs);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,6,0)
dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs);
#endif
buf = kzalloc(sizeof *buf, GFP_KERNEL);
if (!buf)
return NULL;
buf->vaddr = NULL;
buf->dev = conf->dev;
buf->dma_dir = dma_dir;
buf->offset = vaddr & ~PAGE_MASK;
buf->size = size;
buf->dma_sgt = &buf->sg_table;
first = (vaddr & PAGE_MASK) >> PAGE_SHIFT;
last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
buf->num_pages = last - first + 1;
buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
GFP_KERNEL);
if (!buf->pages)
goto userptr_fail_alloc_pages;
vma = find_vma(current->mm, vaddr);
if (!vma) {
dprintk(1, "no vma for address %lu\n", vaddr);
goto userptr_fail_find_vma;
}
if (vma->vm_end < vaddr + size) {
dprintk(1, "vma at %lu is too small for %lu bytes\n",
vaddr, size);
goto userptr_fail_find_vma;
}
buf->vma = vb2_get_vma(vma);
if (!buf->vma) {
dprintk(1, "failed to copy vma\n");
goto userptr_fail_find_vma;
}
if (vma_is_io(buf->vma)) {
for (num_pages_from_user = 0;
num_pages_from_user < buf->num_pages;
++num_pages_from_user, vaddr += PAGE_SIZE) {
unsigned long pfn;
if (follow_pfn(vma, vaddr, &pfn)) {
dprintk(1, "no page for address %lu\n", vaddr);
break;
}
buf->pages[num_pages_from_user] = pfn_to_page(pfn);
}
} else
num_pages_from_user = get_user_pages(current, current->mm,
vaddr & PAGE_MASK,
buf->num_pages,
buf->dma_dir == DMA_FROM_DEVICE,
1, /* force */
buf->pages,
NULL);
if (num_pages_from_user != buf->num_pages)
goto userptr_fail_get_user_pages;
if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
buf->num_pages, buf->offset, size, 0))
goto userptr_fail_alloc_table_from_pages;
sgt = &buf->sg_table;
/*
* No need to sync to the device, this will happen later when the
* prepare() memop is called.
*/
sgt->nents = dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->orig_nents,
buf->dma_dir, &attrs);
if (!sgt->nents)
goto userptr_fail_map;
return buf;
userptr_fail_map:
sg_free_table(&buf->sg_table);
userptr_fail_alloc_table_from_pages:
userptr_fail_get_user_pages:
dprintk(1, "get_user_pages requested/got: %d/%d]\n",
buf->num_pages, num_pages_from_user);
if (!vma_is_io(buf->vma))
while (--num_pages_from_user >= 0)
put_page(buf->pages[num_pages_from_user]);
vb2_put_vma(buf->vma);
userptr_fail_find_vma:
kfree(buf->pages);
userptr_fail_alloc_pages:
kfree(buf);
return NULL;
}
static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
unsigned long size, int write)
{
struct vb2_dma_sg_buf *buf;
unsigned long first, last;
int num_pages_from_user;
struct vm_area_struct *vma;
buf = kzalloc(sizeof *buf, GFP_KERNEL);
if (!buf)
return NULL;
buf->vaddr = NULL;
buf->write = write;
buf->offset = vaddr & ~PAGE_MASK;
buf->size = size;
first = (vaddr & PAGE_MASK) >> PAGE_SHIFT;
last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
buf->num_pages = last - first + 1;
buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
GFP_KERNEL);
if (!buf->pages)
goto userptr_fail_alloc_pages;
vma = find_vma(current->mm, vaddr);
if (!vma) {
dprintk(1, "no vma for address %lu\n", vaddr);
goto userptr_fail_find_vma;
}
if (vma->vm_end < vaddr + size) {
dprintk(1, "vma at %lu is too small for %lu bytes\n",
vaddr, size);
goto userptr_fail_find_vma;
}
buf->vma = vb2_get_vma(vma);
if (!buf->vma) {
dprintk(1, "failed to copy vma\n");
goto userptr_fail_find_vma;
}
if (vma_is_io(buf->vma)) {
for (num_pages_from_user = 0;
num_pages_from_user < buf->num_pages;
++num_pages_from_user, vaddr += PAGE_SIZE) {
unsigned long pfn;
if (follow_pfn(buf->vma, vaddr, &pfn)) {
dprintk(1, "no page for address %lu\n", vaddr);
break;
}
buf->pages[num_pages_from_user] = pfn_to_page(pfn);
}
} else
num_pages_from_user = get_user_pages(current, current->mm,
vaddr & PAGE_MASK,
buf->num_pages,
write,
1, /* force */
buf->pages,
NULL);
if (num_pages_from_user != buf->num_pages)
goto userptr_fail_get_user_pages;
if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
buf->num_pages, buf->offset, size, 0))
goto userptr_fail_alloc_table_from_pages;
return buf;
userptr_fail_alloc_table_from_pages:
userptr_fail_get_user_pages:
dprintk(1, "get_user_pages requested/got: %d/%d]\n",
buf->num_pages, num_pages_from_user);
if (!vma_is_io(buf->vma))
while (--num_pages_from_user >= 0)
put_page(buf->pages[num_pages_from_user]);
vb2_put_vma(buf->vma);
userptr_fail_find_vma:
kfree(buf->pages);
userptr_fail_alloc_pages:
kfree(buf);
return NULL;
}
