linux/drivers/gpu/drm/msm/msm_gem_vma.c
Jordan Crouse ee546cd34a drm/msm: Reference count address spaces
There are reasons for a memory object to outlive the file descriptor
that created it and so the address space that a buffer object is
attached to must also outlive the file descriptor. Reference count
the address space so that it can remain viable until all the objects
have released their addresses.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
2017-04-08 06:59:36 -04:00

107 lines
2.5 KiB
C

/*
* Copyright (C) 2016 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "msm_drv.h"
#include "msm_gem.h"
#include "msm_mmu.h"
static void
msm_gem_address_space_destroy(struct kref *kref)
{
struct msm_gem_address_space *aspace = container_of(kref,
struct msm_gem_address_space, kref);
drm_mm_takedown(&aspace->mm);
if (aspace->mmu)
aspace->mmu->funcs->destroy(aspace->mmu);
kfree(aspace);
}
void msm_gem_address_space_put(struct msm_gem_address_space *aspace)
{
if (aspace)
kref_put(&aspace->kref, msm_gem_address_space_destroy);
}
void
msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma, struct sg_table *sgt)
{
if (!vma->iova)
return;
if (aspace->mmu) {
unsigned size = vma->node.size << PAGE_SHIFT;
aspace->mmu->funcs->unmap(aspace->mmu, vma->iova, sgt, size);
}
drm_mm_remove_node(&vma->node);
vma->iova = 0;
msm_gem_address_space_put(aspace);
}
int
msm_gem_map_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma, struct sg_table *sgt, int npages)
{
int ret;
if (WARN_ON(drm_mm_node_allocated(&vma->node)))
return 0;
ret = drm_mm_insert_node(&aspace->mm, &vma->node, npages);
if (ret)
return ret;
vma->iova = vma->node.start << PAGE_SHIFT;
if (aspace->mmu) {
unsigned size = npages << PAGE_SHIFT;
ret = aspace->mmu->funcs->map(aspace->mmu, vma->iova, sgt,
size, IOMMU_READ | IOMMU_WRITE);
}
/* Get a reference to the aspace to keep it around */
kref_get(&aspace->kref);
return ret;
}
struct msm_gem_address_space *
msm_gem_address_space_create(struct device *dev, struct iommu_domain *domain,
const char *name)
{
struct msm_gem_address_space *aspace;
aspace = kzalloc(sizeof(*aspace), GFP_KERNEL);
if (!aspace)
return ERR_PTR(-ENOMEM);
aspace->name = name;
aspace->mmu = msm_iommu_new(dev, domain);
drm_mm_init(&aspace->mm, (domain->geometry.aperture_start >> PAGE_SHIFT),
(domain->geometry.aperture_end >> PAGE_SHIFT) - 1);
kref_init(&aspace->kref);
return aspace;
}