linux/drivers/gpu/drm/udl/udl_gem.c
David Herrmann 0cdbe8ac69 drm/gem: remove misleading gfp parameter to get_pages()
drm_gem_get_pages() currently allows passing a 'gfp' parameter that is
passed to shmem combined with mapping_gfp_mask(). Given that the default
mapping_gfp_mask() is GFP_HIGHUSER, it is _very_ unlikely that anyone will
ever make use of that parameter. In fact, all drivers currently pass
redundant flags or 0.

This patch removes the 'gfp' parameter. The only reason to keep it is to
remove flags like __GFP_WAIT. But in its current form, it can only be used
to add flags. So to remove __GFP_WAIT, you'd have to drop it from the
mapping_gfp_mask, which again is stupid as this mask is used by shmem-core
for other allocations, too.

If any driver ever requires that parameter, we can introduce a new helper
that takes the raw 'gfp' parameter. The caller'd be responsible to combine
it with mapping_gfp_mask() in a suitable way. The current
drm_gem_get_pages() helper would then simply use mapping_gfp_mask() and
call the new helper. This is what shmem_read_mapping_pages{_gfp,} does
right now.

Moreover, the gfp-zone flag-usage is not obvious: If you pass a modified
zone, shmem core will WARN() or even BUG(). In other words, the following
must be true for 'gfp' passed to shmem_read_mapping_pages_gfp():
    gfp_zone(mapping_gfp_mask(mapping)) == gfp_zone(gfp)
Add a comment to drm_gem_read_pages() explaining that constraint.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
2014-07-08 00:29:53 +02:00

293 lines
5.8 KiB
C

/*
* Copyright (C) 2012 Red Hat
*
* This file is subject to the terms and conditions of the GNU General Public
* License v2. See the file COPYING in the main directory of this archive for
* more details.
*/
#include <drm/drmP.h>
#include "udl_drv.h"
#include <linux/shmem_fs.h>
#include <linux/dma-buf.h>
struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
size_t size)
{
struct udl_gem_object *obj;
obj = kzalloc(sizeof(*obj), GFP_KERNEL);
if (obj == NULL)
return NULL;
if (drm_gem_object_init(dev, &obj->base, size) != 0) {
kfree(obj);
return NULL;
}
return obj;
}
static int
udl_gem_create(struct drm_file *file,
struct drm_device *dev,
uint64_t size,
uint32_t *handle_p)
{
struct udl_gem_object *obj;
int ret;
u32 handle;
size = roundup(size, PAGE_SIZE);
obj = udl_gem_alloc_object(dev, size);
if (obj == NULL)
return -ENOMEM;
ret = drm_gem_handle_create(file, &obj->base, &handle);
if (ret) {
drm_gem_object_release(&obj->base);
kfree(obj);
return ret;
}
drm_gem_object_unreference(&obj->base);
*handle_p = handle;
return 0;
}
int udl_dumb_create(struct drm_file *file,
struct drm_device *dev,
struct drm_mode_create_dumb *args)
{
args->pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
args->size = args->pitch * args->height;
return udl_gem_create(file, dev,
args->size, &args->handle);
}
int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
{
int ret;
ret = drm_gem_mmap(filp, vma);
if (ret)
return ret;
vma->vm_flags &= ~VM_PFNMAP;
vma->vm_flags |= VM_MIXEDMAP;
return ret;
}
int udl_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct udl_gem_object *obj = to_udl_bo(vma->vm_private_data);
struct page *page;
unsigned int page_offset;
int ret = 0;
page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
PAGE_SHIFT;
if (!obj->pages)
return VM_FAULT_SIGBUS;
page = obj->pages[page_offset];
ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address, page);
switch (ret) {
case -EAGAIN:
case 0:
case -ERESTARTSYS:
return VM_FAULT_NOPAGE;
case -ENOMEM:
return VM_FAULT_OOM;
default:
return VM_FAULT_SIGBUS;
}
}
static int udl_gem_get_pages(struct udl_gem_object *obj)
{
struct page **pages;
if (obj->pages)
return 0;
pages = drm_gem_get_pages(&obj->base);
if (IS_ERR(pages))
return PTR_ERR(pages);
obj->pages = pages;
return 0;
}
static void udl_gem_put_pages(struct udl_gem_object *obj)
{
if (obj->base.import_attach) {
drm_free_large(obj->pages);
obj->pages = NULL;
return;
}
drm_gem_put_pages(&obj->base, obj->pages, false, false);
obj->pages = NULL;
}
int udl_gem_vmap(struct udl_gem_object *obj)
{
int page_count = obj->base.size / PAGE_SIZE;
int ret;
if (obj->base.import_attach) {
obj->vmapping = dma_buf_vmap(obj->base.import_attach->dmabuf);
if (!obj->vmapping)
return -ENOMEM;
return 0;
}
ret = udl_gem_get_pages(obj);
if (ret)
return ret;
obj->vmapping = vmap(obj->pages, page_count, 0, PAGE_KERNEL);
if (!obj->vmapping)
return -ENOMEM;
return 0;
}
void udl_gem_vunmap(struct udl_gem_object *obj)
{
if (obj->base.import_attach) {
dma_buf_vunmap(obj->base.import_attach->dmabuf, obj->vmapping);
return;
}
if (obj->vmapping)
vunmap(obj->vmapping);
udl_gem_put_pages(obj);
}
void udl_gem_free_object(struct drm_gem_object *gem_obj)
{
struct udl_gem_object *obj = to_udl_bo(gem_obj);
if (obj->vmapping)
udl_gem_vunmap(obj);
if (gem_obj->import_attach) {
drm_prime_gem_destroy(gem_obj, obj->sg);
put_device(gem_obj->dev->dev);
}
if (obj->pages)
udl_gem_put_pages(obj);
drm_gem_free_mmap_offset(gem_obj);
}
/* the dumb interface doesn't work with the GEM straight MMAP
interface, it expects to do MMAP on the drm fd, like normal */
int udl_gem_mmap(struct drm_file *file, struct drm_device *dev,
uint32_t handle, uint64_t *offset)
{
struct udl_gem_object *gobj;
struct drm_gem_object *obj;
int ret = 0;
mutex_lock(&dev->struct_mutex);
obj = drm_gem_object_lookup(dev, file, handle);
if (obj == NULL) {
ret = -ENOENT;
goto unlock;
}
gobj = to_udl_bo(obj);
ret = udl_gem_get_pages(gobj);
if (ret)
goto out;
ret = drm_gem_create_mmap_offset(obj);
if (ret)
goto out;
*offset = drm_vma_node_offset_addr(&gobj->base.vma_node);
out:
drm_gem_object_unreference(&gobj->base);
unlock:
mutex_unlock(&dev->struct_mutex);
return ret;
}
static int udl_prime_create(struct drm_device *dev,
size_t size,
struct sg_table *sg,
struct udl_gem_object **obj_p)
{
struct udl_gem_object *obj;
int npages;
npages = size / PAGE_SIZE;
*obj_p = NULL;
obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
if (!obj)
return -ENOMEM;
obj->sg = sg;
obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
if (obj->pages == NULL) {
DRM_ERROR("obj pages is NULL %d\n", npages);
return -ENOMEM;
}
drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
*obj_p = obj;
return 0;
}
struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
struct dma_buf *dma_buf)
{
struct dma_buf_attachment *attach;
struct sg_table *sg;
struct udl_gem_object *uobj;
int ret;
/* need to attach */
get_device(dev->dev);
attach = dma_buf_attach(dma_buf, dev->dev);
if (IS_ERR(attach)) {
put_device(dev->dev);
return ERR_CAST(attach);
}
get_dma_buf(dma_buf);
sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
if (IS_ERR(sg)) {
ret = PTR_ERR(sg);
goto fail_detach;
}
ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
if (ret) {
goto fail_unmap;
}
uobj->base.import_attach = attach;
return &uobj->base;
fail_unmap:
dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
fail_detach:
dma_buf_detach(dma_buf, attach);
dma_buf_put(dma_buf);
put_device(dev->dev);
return ERR_PTR(ret);
}