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

[Gerd Hoffmann]

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 <kra...@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

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