On 9/9/20 3:47 AM, Dmitry Osipenko wrote:
05.09.2020 13:34, Mikko Perttunen пишет:
+static int submit_process_bufs(struct drm_device *drm, struct gather_bo *bo,
+ struct tegra_drm_job_data *job_data,
+ struct tegra_drm_channel_ctx *ctx,
+ struct drm_tegra_channel_submit *args,
+ struct ww_acquire_ctx *acquire_ctx)
+{
+ struct drm_tegra_submit_buf __user *user_bufs_ptr =
+ u64_to_user_ptr(args->bufs_ptr);
If assignment makes line too long, then factor it out.
struct drm_tegra_submit_buf __user *user_bufs_ptr;
user_bufs_ptr = u64_to_user_ptr(args->bufs_ptr);
+ struct tegra_drm_mapping *mapping;
+ struct drm_tegra_submit_buf buf;
+ unsigned long copy_err;
+ int err;
+ u32 i;
+
+ job_data->used_mappings =
+ kcalloc(args->num_bufs, sizeof(*job_data->used_mappings), GFP_KERNEL);
The checkpatch should disallow this coding style. I'd write it as:
size_t size;
size = sizeof(*job_data->used_mappings);
job_data->used_mappings = kcalloc(args->num_bufs, size..);
I'll make these cleaner for next version.
+ if (!job_data->used_mappings)
+ return -ENOMEM;
+
+ for (i = 0; i < args->num_bufs; i++) {
+ copy_err = copy_from_user(&buf, user_bufs_ptr+i, sizeof(buf));
Whole array always should be copied at once. Please keep in mind that
each copy_from_user() has a cpu-time cost, there should maximum up to 2
copyings per job.
OK. BTW, do you have some reference/numbers for this or is it based on
grate-driver experience?
Mikko
