[PATCH] drm/msm: Add MSM_INFO_GET_FLAGS

[PATCH] drm/msm: Add MSM_INFO_GET_FLAGS

[Rob Clark]

From: Rob Clark <robdclark@chromium.org>

In some cases crosvm needs a way to query the cache flags to communicate
them to the guest kernel for guest userspace mapping.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/msm_drv.c | 10 ++++++++++
 include/uapi/drm/msm_drm.h    |  1 +
 2 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 07f66412533b..66b515a956c1 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -818,6 +818,7 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
 	case MSM_INFO_GET_OFFSET:
 	case MSM_INFO_GET_IOVA:
 	case MSM_INFO_SET_IOVA:
+	case MSM_INFO_GET_FLAGS:
 		/* value returned as immediate, not pointer, so len==0: */
 		if (args->len)
 			return -EINVAL;
@@ -845,6 +846,15 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
 	case MSM_INFO_SET_IOVA:
 		ret = msm_ioctl_gem_info_set_iova(dev, file, obj, args->value);
 		break;
+	case MSM_INFO_GET_FLAGS:
+		if (obj->import_attach) {
+			ret = -EINVAL;
+			break;
+		}
+		/* Hide internal kernel-only flags: */
+		args->value = to_msm_bo(obj)->flags & MSM_BO_FLAGS;
+		ret = 0;
+		break;
 	case MSM_INFO_SET_NAME:
 		/* length check should leave room for terminating null: */
 		if (args->len >= sizeof(msm_obj->name)) {
diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
index 3c7b097c4e3d..f54b48ef6a2d 100644
--- a/include/uapi/drm/msm_drm.h
+++ b/include/uapi/drm/msm_drm.h
@@ -138,6 +138,7 @@ struct drm_msm_gem_new {
 #define MSM_INFO_SET_NAME	0x02   /* set the debug name (by pointer) */
 #define MSM_INFO_GET_NAME	0x03   /* get debug name, returned by pointer */
 #define MSM_INFO_SET_IOVA	0x04   /* set the iova, passed by value */
+#define MSM_INFO_GET_FLAGS	0x05   /* get the MSM_BO_x flags */
 
 struct drm_msm_gem_info {
 	__u32 handle;         /* in */
-- 
2.37.2

Re: [PATCH] drm/msm: Add MSM_INFO_GET_FLAGS

[Dmitry Baryshkov]

On 23/09/2022 20:33, Rob Clark wrote:
> From: Rob Clark <robdclark@chromium.org>
> 
> In some cases crosvm needs a way to query the cache flags to communicate
> them to the guest kernel for guest userspace mapping.
> 
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>   drivers/gpu/drm/msm/msm_drv.c | 10 ++++++++++
>   include/uapi/drm/msm_drm.h    |  1 +
>   2 files changed, 11 insertions(+)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

-- 
With best wishes
Dmitry