linux_dsm_epyc7002/drivers/gpu/drm/msm/msm_gem_vma.c
Jordan Crouse 7ad0e8cf63 drm/msm: Count how many times iova memory is pinned
Add a reference count to track how many times a particular
chunk of iova memory is pinned (mapped) in the iomu and
add msm_gem_unpin_iova to give up references.

It is important to note that msm_gem_unpin_iova replaces
msm_gem_put_iova because the new implicit behavior
that an assigned iova in a given vma is now valid for the
life of the buffer and what we are really focusing on is
the use of that iova.

For now the unmappings are lazy; once the reference counts
go to zero they *COULD* be unmapped dynamically but that
will require an outside force such as a shrinker or
mm_notifiers.  For now, we're just focusing on getting
the counting right and setting ourselves up to be ready
for the future.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
2018-12-11 13:05:32 -05:00

162 lines
3.6 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);
}
/* Actually unmap memory for the vma */
void msm_gem_purge_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma)
{
unsigned size = vma->node.size << PAGE_SHIFT;
/* Print a message if we try to purge a vma in use */
if (WARN_ON(vma->inuse > 0))
return;
/* Don't do anything if the memory isn't mapped */
if (!vma->mapped)
return;
if (aspace->mmu)
aspace->mmu->funcs->unmap(aspace->mmu, vma->iova, size);
vma->mapped = false;
}
/* Remove reference counts for the mapping */
void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma)
{
if (!WARN_ON(!vma->iova))
vma->inuse--;
}
int
msm_gem_map_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma, struct sg_table *sgt, int npages)
{
unsigned size = npages << PAGE_SHIFT;
int ret = 0;
if (WARN_ON(!vma->iova))
return -EINVAL;
/* Increase the usage counter */
vma->inuse++;
if (vma->mapped)
return 0;
vma->mapped = true;
if (aspace->mmu)
ret = aspace->mmu->funcs->map(aspace->mmu, vma->iova, sgt,
size, IOMMU_READ | IOMMU_WRITE);
if (ret)
vma->mapped = false;
return ret;
}
/* Close an iova. Warn if it is still in use */
void msm_gem_close_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma)
{
if (WARN_ON(vma->inuse > 0 || vma->mapped))
return;
spin_lock(&aspace->lock);
if (vma->iova)
drm_mm_remove_node(&vma->node);
spin_unlock(&aspace->lock);
vma->iova = 0;
msm_gem_address_space_put(aspace);
}
/* Initialize a new vma and allocate an iova for it */
int msm_gem_init_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma, int npages)
{
int ret;
if (WARN_ON(vma->iova))
return -EBUSY;
spin_lock(&aspace->lock);
ret = drm_mm_insert_node(&aspace->mm, &vma->node, npages);
spin_unlock(&aspace->lock);
if (ret)
return ret;
vma->iova = vma->node.start << PAGE_SHIFT;
vma->mapped = false;
kref_get(&aspace->kref);
return 0;
}
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;
u64 size = domain->geometry.aperture_end -
domain->geometry.aperture_start;
aspace = kzalloc(sizeof(*aspace), GFP_KERNEL);
if (!aspace)
return ERR_PTR(-ENOMEM);
spin_lock_init(&aspace->lock);
aspace->name = name;
aspace->mmu = msm_iommu_new(dev, domain);
drm_mm_init(&aspace->mm, (domain->geometry.aperture_start >> PAGE_SHIFT),
size >> PAGE_SHIFT);
kref_init(&aspace->kref);
return aspace;
}