[PATCH v2 2/2] drm/msm: Add MSM_WAIT_IOVA ioctl

From: Brian Ho
Date: Wed Jan 15 2020 - 15:57:41 EST


Implements an ioctl to wait until a value at a given iova is greater
than or equal to a supplied value.

This will initially be used by turnip (open-source Vulkan driver for
QC in mesa) for occlusion queries where the userspace driver can
block on a query becoming available before continuing via
vkGetQueryPoolResults.

Signed-off-by: Brian Ho <brian@xxxxxxxxx>
---
drivers/gpu/drm/msm/msm_drv.c | 61 +++++++++++++++++++++++++++++++++--
include/uapi/drm/msm_drm.h | 14 ++++++++
2 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index c84f0a8b3f2c..92853c795c5c 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -36,10 +36,11 @@
* MSM_GEM_INFO ioctl.
* - 1.4.0 - softpin, MSM_RELOC_BO_DUMP, and GEM_INFO support to set/get
* GEM object's debug name
- * - 1.5.0 - Add SUBMITQUERY_QUERY ioctl
+ * - 1.5.0 - Add SUBMITQUEUE_QUERY ioctl
+ * - 1.6.0 - Add WAIT_IOVA ioctl
*/
#define MSM_VERSION_MAJOR 1
-#define MSM_VERSION_MINOR 5
+#define MSM_VERSION_MINOR 6
#define MSM_VERSION_PATCHLEVEL 0

static const struct drm_mode_config_funcs mode_config_funcs = {
@@ -952,6 +953,61 @@ static int msm_ioctl_submitqueue_close(struct drm_device *dev, void *data,
return msm_submitqueue_remove(file->driver_priv, id);
}

+static int msm_ioctl_wait_iova(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct msm_drm_private *priv = dev->dev_private;
+ struct drm_gem_object *obj;
+ struct drm_msm_wait_iova *args = data;
+ ktime_t timeout = to_ktime(args->timeout);
+ unsigned long remaining_jiffies = timeout_to_jiffies(&timeout);
+ struct msm_gpu *gpu = priv->gpu;
+ void *base_vaddr;
+ uint64_t ref_value = args->value & args->mask;
+ uint64_t *vaddr;
+ int ret;
+
+ if (args->pad)
+ return -EINVAL;
+
+ if (!gpu)
+ return -ENODEV;
+
+ obj = drm_gem_object_lookup(file, args->handle);
+ if (!obj)
+ return -ENOENT;
+
+ if (args->offset + sizeof(*vaddr) < args->offset ||
+ args->offset + sizeof(*vaddr) > obj->size) {
+ ret = -EINVAL;
+ goto err_put_gem_object;
+ }
+
+ base_vaddr = msm_gem_get_vaddr(obj);
+ if (IS_ERR(base_vaddr)) {
+ ret = PTR_ERR(base_vaddr);
+ goto err_put_gem_object;
+ }
+
+ vaddr = base_vaddr + args->offset;
+
+ /* TODO: Support 64 bit reference values with a flag. */
+ ret = wait_event_interruptible_timeout(gpu->event,
+ (int32_t)((uint32_t)*vaddr - (uint32_t)ref_value) >= 0,
+ remaining_jiffies);
+
+ if (ret == 0)
+ ret = -ETIMEDOUT;
+ else if (ret > 0)
+ ret = 0;
+
+ msm_gem_put_vaddr(obj);
+
+err_put_gem_object:
+ drm_gem_object_put_unlocked(obj);
+ return ret;
+}
+
static const struct drm_ioctl_desc msm_ioctls[] = {
DRM_IOCTL_DEF_DRV(MSM_GET_PARAM, msm_ioctl_get_param, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(MSM_GEM_NEW, msm_ioctl_gem_new, DRM_RENDER_ALLOW),
@@ -964,6 +1020,7 @@ static const struct drm_ioctl_desc msm_ioctls[] = {
DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_NEW, msm_ioctl_submitqueue_new, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_CLOSE, msm_ioctl_submitqueue_close, DRM_RENDER_ALLOW),
DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_QUERY, msm_ioctl_submitqueue_query, DRM_RENDER_ALLOW),
+ DRM_IOCTL_DEF_DRV(MSM_WAIT_IOVA, msm_ioctl_wait_iova, DRM_RENDER_ALLOW),
};

static const struct vm_operations_struct vm_ops = {
diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
index 0b85ed6a3710..d4eac312f56e 100644
--- a/include/uapi/drm/msm_drm.h
+++ b/include/uapi/drm/msm_drm.h
@@ -298,6 +298,18 @@ struct drm_msm_submitqueue_query {
__u32 pad;
};

+/* This ioctl blocks until the value at bo + offset is greater than or equal
+ * to the reference value.
+ */
+struct drm_msm_wait_iova {
+ __u32 handle; /* in, GEM handle */
+ __u32 pad;
+ struct drm_msm_timespec timeout; /* in */
+ __u64 offset; /* in, offset into bo */
+ __u64 mask; /* in, mask of the value at bo + offset */
+ __u64 value; /* in, reference value, 32 bits */
+};
+
#define DRM_MSM_GET_PARAM 0x00
/* placeholder:
#define DRM_MSM_SET_PARAM 0x01
@@ -315,6 +327,7 @@ struct drm_msm_submitqueue_query {
#define DRM_MSM_SUBMITQUEUE_NEW 0x0A
#define DRM_MSM_SUBMITQUEUE_CLOSE 0x0B
#define DRM_MSM_SUBMITQUEUE_QUERY 0x0C
+#define DRM_MSM_WAIT_IOVA 0x0D

#define DRM_IOCTL_MSM_GET_PARAM DRM_IOWR(DRM_COMMAND_BASE + DRM_MSM_GET_PARAM, struct drm_msm_param)
#define DRM_IOCTL_MSM_GEM_NEW DRM_IOWR(DRM_COMMAND_BASE + DRM_MSM_GEM_NEW, struct drm_msm_gem_new)
@@ -327,6 +340,7 @@ struct drm_msm_submitqueue_query {
#define DRM_IOCTL_MSM_SUBMITQUEUE_NEW DRM_IOWR(DRM_COMMAND_BASE + DRM_MSM_SUBMITQUEUE_NEW, struct drm_msm_submitqueue)
#define DRM_IOCTL_MSM_SUBMITQUEUE_CLOSE DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_SUBMITQUEUE_CLOSE, __u32)
#define DRM_IOCTL_MSM_SUBMITQUEUE_QUERY DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_SUBMITQUEUE_QUERY, struct drm_msm_submitqueue_query)
+#define DRM_IOCTL_MSM_WAIT_IOVA DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_WAIT_IOVA, struct drm_msm_wait_iova)

#if defined(__cplusplus)
}
--
2.25.0.rc1.283.g88dfdc4193-goog