[PATCH v3 16/23] drm/qxl: implement prime kmap/kunmap

Gerd Hoffmann
2019-01-18T12:21:53Z

Generic fbdev emulation needs this. Also: We must keep track of the
number of mappings now, so we don't unmap early in case two users want a
kmap of the same bo. Add a sanity check to destroy callback to make
sure kmap/kunmap is balanced.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
drivers/gpu/drm/qxl/qxl_drv.h | 1 +
drivers/gpu/drm/qxl/qxl_object.c | 6 ++++++
drivers/gpu/drm/qxl/qxl_prime.c | 17 +++++++++++++----
3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
index 43c6df9cf9..8c3af1cdbe 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.h
+++ b/drivers/gpu/drm/qxl/qxl_drv.h
@@ -84,6 +84,7 @@ struct qxl_bo {
struct ttm_bo_kmap_obj kmap;
unsigned int pin_count;
void *kptr;
+ unsigned int map_count;
int type;

/* Constant after initialization */
diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
index 024c8dd317..4928fa6029 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -36,6 +36,7 @@ static void qxl_ttm_bo_destroy(struct ttm_buffer_object *tbo)
qdev = (struct qxl_device *)bo->gem_base.dev->dev_private;

qxl_surface_evict(qdev, bo, false);
+ WARN_ON_ONCE(bo->map_count > 0);
mutex_lock(&qdev->gem.mutex);
list_del_init(&bo->list);
mutex_unlock(&qdev->gem.mutex);
@@ -131,6 +132,7 @@ int qxl_bo_kmap(struct qxl_bo *bo, void **ptr)
if (bo->kptr) {
if (ptr)
*ptr = bo->kptr;
+ bo->map_count++;
return 0;
}
r = ttm_bo_kmap(&bo->tbo, 0, bo->tbo.num_pages, &bo->kmap);
@@ -139,6 +141,7 @@ int qxl_bo_kmap(struct qxl_bo *bo, void **ptr)
bo->kptr = ttm_kmap_obj_virtual(&bo->kmap, &is_iomem);
if (ptr)
*ptr = bo->kptr;
+ bo->map_count = 1;
return 0;
}

@@ -180,6 +183,9 @@ void qxl_bo_kunmap(struct qxl_bo *bo)
{
if (bo->kptr == NULL)
return;
+ bo->map_count--;
+ if (bo->map_count > 0)
+ return;
bo->kptr = NULL;
ttm_bo_kunmap(&bo->kmap);
}
diff --git a/drivers/gpu/drm/qxl/qxl_prime.c b/drivers/gpu/drm/qxl/qxl_prime.c
index a55dece118..708378844c 100644
--- a/drivers/gpu/drm/qxl/qxl_prime.c
+++ b/drivers/gpu/drm/qxl/qxl_prime.c
@@ -22,7 +22,7 @@
* Authors: Andreas Pokorny
*/

-#include "qxl_drv.h"
+#include "qxl_object.h"

/* Empty Implementations as there should not be any other driver for a virtual
* device that might share buffers with qxl */
@@ -54,13 +54,22 @@ struct drm_gem_object *qxl_gem_prime_import_sg_table(

void *qxl_gem_prime_vmap(struct drm_gem_object *obj)
{
- WARN_ONCE(1, "not implemented");
- return ERR_PTR(-ENOSYS);
+ struct qxl_bo *bo = gem_to_qxl_bo(obj);
+ void *ptr;
+ int ret;
+
+ ret = qxl_bo_kmap(bo, &ptr);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ return ptr;
}

void qxl_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
{
- WARN_ONCE(1, "not implemented");
+ struct qxl_bo *bo = gem_to_qxl_bo(obj);
+
+ qxl_bo_kunmap(bo);
}

int qxl_gem_prime_mmap(struct drm_gem_object *obj,
--
2.9.3