[PATCH 2/3] drm/msm: add DRM_MSM_GEM_SYNC_CACHE for non-coherent cache maintenance

From: Jonathan Marek
Date: Wed Sep 30 2020 - 20:28:56 EST


This makes it possible to use the non-coherent cached MSM_BO_CACHED mode,
which otherwise doesn't provide any method for cleaning/invalidating the
cache to sync with the device.

Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
---
drivers/gpu/drm/msm/msm_drv.c | 21 +++++++++++++++++++++
drivers/gpu/drm/msm/msm_drv.h | 2 ++
drivers/gpu/drm/msm/msm_gem.c | 15 +++++++++++++++
include/uapi/drm/msm_drm.h | 20 ++++++++++++++++++++
4 files changed, 58 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 9716210495fc..305db1db1064 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -964,6 +964,26 @@ static int msm_ioctl_submitqueue_close(struct drm_device *dev, void *data,
return msm_submitqueue_remove(file->driver_priv, id);
}

+static int msm_ioctl_gem_sync_cache(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_msm_gem_sync_cache *args = data;
+ struct drm_gem_object *obj;
+
+ if (args->flags & ~MSM_GEM_SYNC_CACHE_FLAGS)
+ return -EINVAL;
+
+ obj = drm_gem_object_lookup(file, args->handle);
+ if (!obj)
+ return -ENOENT;
+
+ msm_gem_sync_cache(obj, args->flags, args->offset, args->end);
+
+ drm_gem_object_put(obj);
+
+ return 0;
+}
+
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),
@@ -976,6 +996,7 @@ 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_GEM_SYNC_CACHE, msm_ioctl_gem_sync_cache, DRM_RENDER_ALLOW),
};

static const struct vm_operations_struct vm_ops = {
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 6384844b1696..5e932dae453f 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -314,6 +314,8 @@ void msm_gem_move_to_active(struct drm_gem_object *obj,
void msm_gem_move_to_inactive(struct drm_gem_object *obj);
int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout);
int msm_gem_cpu_fini(struct drm_gem_object *obj);
+void msm_gem_sync_cache(struct drm_gem_object *obj, uint32_t flags,
+ size_t range_start, size_t range_end);
void msm_gem_free_object(struct drm_gem_object *obj);
int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
uint32_t size, uint32_t flags, uint32_t *handle, char *name);
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index ad9a627493ae..93da88b3fc50 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -8,6 +8,7 @@
#include <linux/shmem_fs.h>
#include <linux/dma-buf.h>
#include <linux/pfn_t.h>
+#include <linux/dma-noncoherent.h>

#include <drm/drm_prime.h>

@@ -808,6 +809,20 @@ int msm_gem_cpu_fini(struct drm_gem_object *obj)
return 0;
}

+void msm_gem_sync_cache(struct drm_gem_object *obj, uint32_t flags,
+ size_t range_start, size_t range_end)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+
+ /* TODO: sync only the required range, and don't invalidate on clean */
+
+ if (flags & MSM_GEM_SYNC_CACHE_CLEAN)
+ sync_for_device(msm_obj);
+
+ if (flags & MSM_GEM_SYNC_CACHE_INVALIDATE)
+ sync_for_cpu(msm_obj);
+}
+
#ifdef CONFIG_DEBUG_FS
static void describe_fence(struct dma_fence *fence, const char *type,
struct seq_file *m)
diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
index 474497e8743a..1dfafa71fc94 100644
--- a/include/uapi/drm/msm_drm.h
+++ b/include/uapi/drm/msm_drm.h
@@ -319,6 +319,24 @@ struct drm_msm_submitqueue_query {
__u32 pad;
};

+/*
+ * Host cache maintenance (relevant for MSM_BO_CACHED)
+ * driver may both clean/invalidate (flush) for clean
+ */
+
+#define MSM_GEM_SYNC_CACHE_CLEAN 0x1
+#define MSM_GEM_SYNC_CACHE_INVALIDATE 0x2
+
+#define MSM_GEM_SYNC_CACHE_FLAGS (MSM_GEM_SYNC_CACHE_CLEAN | \
+ MSM_GEM_SYNC_CACHE_INVALIDATE)
+
+struct drm_msm_gem_sync_cache {
+ __u32 handle;
+ __u32 flags;
+ __u64 offset;
+ __u64 end; /* offset + size */
+};
+
#define DRM_MSM_GET_PARAM 0x00
/* placeholder:
#define DRM_MSM_SET_PARAM 0x01
@@ -336,6 +354,7 @@ 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_GEM_SYNC_CACHE 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)
@@ -348,6 +367,7 @@ 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_GEM_SYNC_CACHE DRM_IOW (DRM_COMMAND_BASE + DRM_MSM_GEM_SYNC_CACHE, struct drm_msm_gem_sync_cache)

#if defined(__cplusplus)
}
--
2.26.1