[PATCH 2/7] drm/panthor: Add flag to map GEM object Write-Back Cacheable

[Faith Ekstrand]

From: Loïc Molinari <loic.molin...@collabora.com>

Signed-off-by: Loïc Molinari <loic.molin...@collabora.com>
Signed-off-by: Faith Ekstrand <faith.ekstr...@collabora.com>
---
 drivers/gpu/drm/panthor/panthor_drv.c |  7 ++++++-
 drivers/gpu/drm/panthor/panthor_gem.c |  3 +++
 include/uapi/drm/panthor_drm.h        | 10 ++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c 
b/drivers/gpu/drm/panthor/panthor_drv.c
index 1116f2d2826e..06ae6a2aeb16 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -899,7 +899,8 @@ static int panthor_ioctl_vm_destroy(struct drm_device 
*ddev, void *data,
        return panthor_vm_pool_destroy_vm(pfile->vms, args->id);
 }
 
-#define PANTHOR_BO_FLAGS               DRM_PANTHOR_BO_NO_MMAP
+#define PANTHOR_BO_FLAGS               (DRM_PANTHOR_BO_NO_MMAP | \
+                                        DRM_PANTHOR_BO_WB_MMAP)
 
 static int panthor_ioctl_bo_create(struct drm_device *ddev, void *data,
                                   struct drm_file *file)
@@ -918,6 +919,10 @@ static int panthor_ioctl_bo_create(struct drm_device 
*ddev, void *data,
                goto out_dev_exit;
        }
 
+       if ((args->flags & DRM_PANTHOR_BO_NO_MMAP) &&
+           (args->flags & DRM_PANTHOR_BO_WB_MMAP))
+               return -EINVAL;
+
        if (args->exclusive_vm_id) {
                vm = panthor_vm_pool_get_vm(pfile->vms, args->exclusive_vm_id);
                if (!vm) {
diff --git a/drivers/gpu/drm/panthor/panthor_gem.c 
b/drivers/gpu/drm/panthor/panthor_gem.c
index a123bc740ba1..530bad12d545 100644
--- a/drivers/gpu/drm/panthor/panthor_gem.c
+++ b/drivers/gpu/drm/panthor/panthor_gem.c
@@ -283,6 +283,9 @@ panthor_gem_create_with_handle(struct drm_file *file,
        bo = to_panthor_bo(&shmem->base);
        bo->flags = flags;
 
+       if (flags & DRM_PANTHOR_BO_WB_MMAP)
+               shmem->map_wc = false;
+
        if (exclusive_vm) {
                bo->exclusive_vm_root_gem = panthor_vm_root_gem(exclusive_vm);
                drm_gem_object_get(bo->exclusive_vm_root_gem);
diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index e1f43deb7eca..bf47369c0220 100644
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -635,6 +635,16 @@ struct drm_panthor_vm_get_state {
 enum drm_panthor_bo_flags {
        /** @DRM_PANTHOR_BO_NO_MMAP: The buffer object will never be CPU-mapped 
in userspace. */
        DRM_PANTHOR_BO_NO_MMAP = (1 << 0),
+
+       /**
+        *@DRM_PANTHOR_BO_WB_MMAP: Force "Write-Back Cacheable" CPU mapping.
+        *
+        * CPU map the buffer object in userspace by forcing the "Write-Back
+        * Cacheable" cacheability attribute. The mapping otherwise uses the
+        * "Non-Cacheable" attribute if the ACE-Lite coherency protocol isn't
+        * supported by the GPU.
+        */
+       DRM_PANTHOR_BO_WB_MMAP = (1 << 1),
 };
 
 /**
-- 
2.50.1