[PATCH 3/6] drm/msm: Split msm_gem_get_iova into two steps

Jordan Crouse
2018-10-31T17:05:49Z

Split the operation of msm_gem_get_iova into two operations:
1) allocate an iova and 2) map (pin) the backing memory int the
iommu. This is the first step toward allowing memory pinning
to occur independently of the iova management.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
---
drivers/gpu/drm/msm/msm_drv.h | 2 +
drivers/gpu/drm/msm/msm_gem.c | 80 ++++++++++++++++++++-----------
drivers/gpu/drm/msm/msm_gem.h | 1 +
drivers/gpu/drm/msm/msm_gem_vma.c | 44 ++++++++++++-----
4 files changed, 86 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 3a0f2119127b..63b28b69b2ab 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -241,6 +241,8 @@ struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev);
void msm_atomic_state_clear(struct drm_atomic_state *state);
void msm_atomic_state_free(struct drm_atomic_state *state);

+int msm_gem_init_vma(struct msm_gem_address_space *aspace,
+ struct msm_gem_vma *vma, int npages);
void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma);
int msm_gem_map_vma(struct msm_gem_address_space *aspace,
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index ff75e557b708..189d7f0f1aad 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -357,52 +357,76 @@ put_iova(struct drm_gem_object *obj)
}
}

-/* get iova, taking a reference. Should have a matching put */
-int msm_gem_get_iova(struct drm_gem_object *obj,
+static int msm_gem_get_iova_locked(struct drm_gem_object *obj,
struct msm_gem_address_space *aspace, uint64_t *iova)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_gem_vma *vma;
int ret = 0;

- mutex_lock(&msm_obj->lock);
-
- if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
- mutex_unlock(&msm_obj->lock);
- return -EBUSY;
- }
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));

vma = lookup_vma(obj, aspace);

if (!vma) {
- struct page **pages;
-
vma = add_vma(obj, aspace);
- if (IS_ERR(vma)) {
- ret = PTR_ERR(vma);
- goto unlock;
- }
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);

- pages = get_pages(obj);
- if (IS_ERR(pages)) {
- ret = PTR_ERR(pages);
- goto fail;
+ ret = msm_gem_init_vma(aspace, vma, obj->size >> PAGE_SHIFT);
+ if (ret) {
+ del_vma(vma);
+ return ret;
}
-
- ret = msm_gem_map_vma(aspace, vma, msm_obj->sgt,
- obj->size >> PAGE_SHIFT);
- if (ret)
- goto fail;
}

*iova = vma->iova;
-
- mutex_unlock(&msm_obj->lock);
return 0;
+}
+
+static int msm_gem_pin_iova(struct drm_gem_object *obj,
+ struct msm_gem_address_space *aspace)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ struct msm_gem_vma *vma;
+ struct page **pages;
+
+ WARN_ON(!mutex_is_locked(&msm_obj->lock));
+
+ if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED))
+ return -EBUSY;
+
+ vma = lookup_vma(obj, aspace);
+ if (WARN_ON(!vma))
+ return -EINVAL;
+
+ pages = get_pages(obj);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+
+ return msm_gem_map_vma(aspace, vma, msm_obj->sgt,
+ obj->size >> PAGE_SHIFT);
+}
+
+
+/* get iova, taking a reference. Should have a matching put */
+int msm_gem_get_iova(struct drm_gem_object *obj,
+ struct msm_gem_address_space *aspace, uint64_t *iova)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ u64 local;
+ int ret;
+
+ mutex_lock(&msm_obj->lock);
+
+ ret = msm_gem_get_iova_locked(obj, aspace, &local);
+
+ if (!ret)
+ ret = msm_gem_pin_iova(obj, aspace);
+
+ if (!ret)
+ *iova = local;

-fail:
- del_vma(vma);
-unlock:
mutex_unlock(&msm_obj->lock);
return ret;
}
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index c5d9bd3e47a8..32c13e6559b5 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -41,6 +41,7 @@ struct msm_gem_vma {
uint64_t iova;
struct msm_gem_address_space *aspace;
struct list_head list; /* node in msm_gem_object::vmas */
+ bool mapped;
};

struct msm_gem_object {
diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index 704ae7e69500..c4c42bf0db0e 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -55,6 +55,7 @@ msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
spin_unlock(&aspace->lock);

vma->iova = 0;
+ vma->mapped = false;

msm_gem_address_space_put(aspace);
}
@@ -63,14 +64,37 @@ int
msm_gem_map_vma(struct msm_gem_address_space *aspace,
struct msm_gem_vma *vma, struct sg_table *sgt, int npages)
{
- int ret;
+ unsigned size = npages << PAGE_SHIFT;
+ int ret = 0;

- spin_lock(&aspace->lock);
- if (WARN_ON(drm_mm_node_allocated(&vma->node))) {
- spin_unlock(&aspace->lock);
+ if (WARN_ON(!vma->iova))
+ return -EINVAL;
+
+ 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;
+}
+
+/* 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);

@@ -78,17 +102,11 @@ msm_gem_map_vma(struct msm_gem_address_space *aspace,
return ret;

vma->iova = vma->node.start << PAGE_SHIFT;
+ vma->mapped = false;

- 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;
+ return 0;
}

struct msm_gem_address_space *