[module] implement mmap on PCI kvmfr devices

This allows PCI kvmfr devices to be directly mmap'd just like in-memory
ones. Also, the more efficient mmap implementation is used for mapping
the dmabuf, avoiding the faulting code entirely.
This commit is contained in:
Quantum 2021-02-05 23:11:29 -05:00 committed by Geoffrey McRae
parent 2c909f0af7
commit 5774e21965

View File

@ -79,21 +79,6 @@ struct kvmfrbuf
struct page ** pages;
};
static vm_fault_t kvmfr_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct kvmfrbuf *kbuf = (struct kvmfrbuf *)vma->vm_private_data;
vmf->page = kbuf->pages[vmf->pgoff];
get_page(vmf->page);
return 0;
}
static const struct vm_operations_struct kvmfr_vm_ops =
{
.fault = kvmfr_vm_fault
};
static struct sg_table * map_kvmfrbuf(struct dma_buf_attachment *at,
enum dma_data_direction direction)
{
@ -153,9 +138,10 @@ static int mmap_kvmfrbuf(struct dma_buf * buf, struct vm_area_struct * vma)
switch (kbuf->kdev->type)
{
case KVMFR_TYPE_PCI:
vma->vm_ops = &kvmfr_vm_ops;
vma->vm_private_data = buf->priv;
return 0;
{
unsigned long pfn = virt_to_phys(kbuf->kdev->addr + kbuf->offset + offset) >> PAGE_SHIFT;
return remap_pfn_range(vma, vma->vm_start, pfn, size, vma->vm_page_prot);
}
case KVMFR_TYPE_STATIC:
return remap_vmalloc_range(vma, kbuf->kdev->addr + kbuf->offset, vma->vm_pgoff);
@ -297,6 +283,12 @@ static int device_mmap(struct file * filp, struct vm_area_struct * vma)
switch (kdev->type)
{
case KVMFR_TYPE_PCI:
{
unsigned long pfn = virt_to_phys(kdev->addr + offset) >> PAGE_SHIFT;
return remap_pfn_range(vma, vma->vm_start, pfn, size, vma->vm_page_prot);
}
case KVMFR_TYPE_STATIC:
return remap_vmalloc_range(vma, kdev->addr, vma->vm_pgoff);