Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / drivers / misc / cxl / file.c

diff --git a/kernel/drivers/misc/cxl/file.c b/kernel/drivers/misc/cxl/file.c
index 7ccd299..783337d 100644 (file)
--- a/kernel/drivers/misc/cxl/file.c
+++ b/kernel/drivers/misc/cxl/file.c
@@ -67,7 +67,13 @@ static int __afu_open(struct inode *inode, struct file *file, bool master)
                spin_unlock(&adapter->afu_list_lock);
                goto err_put_adapter;
        }
-       get_device(&afu->dev);
+
+       /*
+        * taking a ref to the afu so that it doesn't go away
+        * for rest of the function. This ref is released before
+        * we return.
+        */
+       cxl_afu_get(afu);
        spin_unlock(&adapter->afu_list_lock);
 
        if (!afu->current_mode)
@@ -90,13 +96,12 @@ static int __afu_open(struct inode *inode, struct file *file, bool master)
        file->private_data = ctx;
        cxl_ctx_get();
 
-       /* Our ref on the AFU will now hold the adapter */
-       put_device(&adapter->dev);
-
-       return 0;
+       /* indicate success */
+       rc = 0;
 
 err_put_afu:
-       put_device(&afu->dev);
+       /* release the ref taken earlier */
+       cxl_afu_put(afu);
 err_put_adapter:
        put_device(&adapter->dev);
        return rc;
@@ -131,8 +136,6 @@ int afu_release(struct inode *inode, struct file *file)
                mutex_unlock(&ctx->mapping_lock);
        }
 
-       put_device(&ctx->afu->dev);
-
        /*
         * At this this point all bottom halfs have finished and we should be
         * getting no more IRQs from the hardware for this context.  Once it's
@@ -198,8 +201,12 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
         * where a process (master, some daemon, etc) has opened the chardev on
         * behalf of another process, so the AFU's mm gets bound to the process
         * that performs this ioctl and not the process that opened the file.
+        * Also we grab the PID of the group leader so that if the task that
+        * has performed the attach operation exits the mm context of the
+        * process is still accessible.
         */
-       ctx->pid = get_pid(get_task_pid(current, PIDTYPE_PID));
+       ctx->pid = get_task_pid(current, PIDTYPE_PID);
+       ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
 
        trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);