26  *    .... write() or read() through the pipe.
85 /* A per-pipe command structure, shared with the host */
88 	s32 id;		/* pipe id, guest -> host */
106 /* A single signalled pipe information */
125 /* This data type models a given pipe instance */
127 	/* pipe ID - index into goldfish_pipe_dev::pipes array */
130 	/* The wake flags pipe is waiting for
151 	 * A pipe's own lock. Protects the following:
218 static int goldfish_pipe_cmd_locked(struct goldfish_pipe *pipe,  in goldfish_pipe_cmd_locked()  argument
221 	pipe->command_buffer->cmd = cmd;  in goldfish_pipe_cmd_locked()
223 	pipe->command_buffer->status = PIPE_ERROR_INVAL;  in goldfish_pipe_cmd_locked()
224 	writel(pipe->id, pipe->dev->base + PIPE_REG_CMD);  in goldfish_pipe_cmd_locked()
225 	return pipe->command_buffer->status;  in goldfish_pipe_cmd_locked()
228 static int goldfish_pipe_cmd(struct goldfish_pipe *pipe, enum PipeCmdCode cmd)  in goldfish_pipe_cmd()  argument
232 	if (mutex_lock_interruptible(&pipe->lock))  in goldfish_pipe_cmd()
234 	status = goldfish_pipe_cmd_locked(pipe, cmd);  in goldfish_pipe_cmd()
235 	mutex_unlock(&pipe->lock);  in goldfish_pipe_cmd()
325 static int transfer_max_buffers(struct goldfish_pipe *pipe,  in transfer_max_buffers()  argument
338 	/* Serialize access to the pipe command buffers */  in transfer_max_buffers()
339 	if (mutex_lock_interruptible(&pipe->lock))  in transfer_max_buffers()
344 					 pipe->pages, &iter_last_page_size);  in transfer_max_buffers()
346 		mutex_unlock(&pipe->lock);  in transfer_max_buffers()
350 	populate_rw_params(pipe->pages, pages_count, address, address_end,  in transfer_max_buffers()
352 			   pipe->command_buffer);  in transfer_max_buffers()
355 	*status = goldfish_pipe_cmd_locked(pipe,  in transfer_max_buffers()
358 	*consumed_size = pipe->command_buffer->rw_params.consumed_size;  in transfer_max_buffers()
360 	unpin_user_pages_dirty_lock(pipe->pages, pages_count,  in transfer_max_buffers()
363 	mutex_unlock(&pipe->lock);  in transfer_max_buffers()
367 static int wait_for_host_signal(struct goldfish_pipe *pipe, int is_write)  in wait_for_host_signal()  argument
371 	set_bit(wake_bit, &pipe->flags);  in wait_for_host_signal()
374 	goldfish_pipe_cmd(pipe,  in wait_for_host_signal()
377 	while (test_bit(wake_bit, &pipe->flags)) {  in wait_for_host_signal()
378 		if (wait_event_interruptible(pipe->wake_queue,  in wait_for_host_signal()
379 					     !test_bit(wake_bit, &pipe->flags)))  in wait_for_host_signal()
382 		if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))  in wait_for_host_signal()
394 	struct goldfish_pipe *pipe = filp->private_data;  in goldfish_pipe_read_write()  local
399 	/* If the emulator already closed the pipe, no need to go further */  in goldfish_pipe_read_write()
400 	if (unlikely(test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)))  in goldfish_pipe_read_write()
418 		ret = transfer_max_buffers(pipe, address, address_end, is_write,  in goldfish_pipe_read_write()
446 				dev_err_ratelimited(pipe->dev->pdev_dev,  in goldfish_pipe_read_write()
462 		status = wait_for_host_signal(pipe, is_write);  in goldfish_pipe_read_write()
492 	struct goldfish_pipe *pipe = filp->private_data;  in goldfish_pipe_poll()  local
496 	poll_wait(filp, &pipe->wake_queue, wait);  in goldfish_pipe_poll()
498 	status = goldfish_pipe_cmd(pipe, PIPE_CMD_POLL);  in goldfish_pipe_poll()
508 	if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))  in goldfish_pipe_poll()
517 	struct goldfish_pipe *pipe;  in signalled_pipes_add_locked()  local
522 	pipe = dev->pipes[id];  in signalled_pipes_add_locked()
523 	if (!pipe)  in signalled_pipes_add_locked()
525 	pipe->signalled_flags |= flags;  in signalled_pipes_add_locked()
527 	if (pipe->prev_signalled || pipe->next_signalled ||  in signalled_pipes_add_locked()
528 		dev->first_signalled_pipe == pipe)  in signalled_pipes_add_locked()
530 	pipe->next_signalled = dev->first_signalled_pipe;  in signalled_pipes_add_locked()
532 		dev->first_signalled_pipe->prev_signalled = pipe;  in signalled_pipes_add_locked()
533 	dev->first_signalled_pipe = pipe;  in signalled_pipes_add_locked()
537 					  struct goldfish_pipe *pipe)  in signalled_pipes_remove_locked()  argument
539 	if (pipe->prev_signalled)  in signalled_pipes_remove_locked()
540 		pipe->prev_signalled->next_signalled = pipe->next_signalled;  in signalled_pipes_remove_locked()
541 	if (pipe->next_signalled)  in signalled_pipes_remove_locked()
542 		pipe->next_signalled->prev_signalled = pipe->prev_signalled;  in signalled_pipes_remove_locked()
543 	if (pipe == dev->first_signalled_pipe)  in signalled_pipes_remove_locked()
544 		dev->first_signalled_pipe = pipe->next_signalled;  in signalled_pipes_remove_locked()
545 	pipe->prev_signalled = NULL;  in signalled_pipes_remove_locked()
546 	pipe->next_signalled = NULL;  in signalled_pipes_remove_locked()
552 	struct goldfish_pipe *pipe;  in signalled_pipes_pop_front()  local
557 	pipe = dev->first_signalled_pipe;  in signalled_pipes_pop_front()
558 	if (pipe) {  in signalled_pipes_pop_front()
559 		*wakes = pipe->signalled_flags;  in signalled_pipes_pop_front()
560 		pipe->signalled_flags = 0;  in signalled_pipes_pop_front()
565 		 * wake the sleeping pipe operations faster.  in signalled_pipes_pop_front()
567 		dev->first_signalled_pipe = pipe->next_signalled;  in signalled_pipes_pop_front()
570 		pipe->next_signalled = NULL;  in signalled_pipes_pop_front()
574 	return pipe;  in signalled_pipes_pop_front()
581 	struct goldfish_pipe *pipe;  in goldfish_interrupt_task()  local
584 	while ((pipe = signalled_pipes_pop_front(dev, &wakes)) != NULL) {  in goldfish_interrupt_task()
586 			pipe->flags = 1 << BIT_CLOSED_ON_HOST;  in goldfish_interrupt_task()
589 				clear_bit(BIT_WAKE_ON_READ, &pipe->flags);  in goldfish_interrupt_task()
591 				clear_bit(BIT_WAKE_ON_WRITE, &pipe->flags);  in goldfish_interrupt_task()
597 		wake_up_interruptible(&pipe->wake_queue);  in goldfish_interrupt_task()
608  *  1. device raises an interrupt if there's at least one signalled pipe
689  *	Create a new pipe link between the emulator and the use application.
690  *	Each new request produces a new pipe.
692  *	Note: we use the pipe ID as a mux. All goldfish emulations are 32bit
702 	/* Allocate new pipe kernel object */  in goldfish_pipe_open()
703 	struct goldfish_pipe *pipe = kzalloc(sizeof(*pipe), GFP_KERNEL);  in goldfish_pipe_open()  local
705 	if (!pipe)  in goldfish_pipe_open()
708 	pipe->dev = dev;  in goldfish_pipe_open()
709 	mutex_init(&pipe->lock);  in goldfish_pipe_open()
710 	init_waitqueue_head(&pipe->wake_queue);  in goldfish_pipe_open()
717 	pipe->command_buffer =  in goldfish_pipe_open()
719 	if (!pipe->command_buffer) {  in goldfish_pipe_open()
732 	dev->pipes[id] = pipe;  in goldfish_pipe_open()
733 	pipe->id = id;  in goldfish_pipe_open()
734 	pipe->command_buffer->id = id;  in goldfish_pipe_open()
736 	/* Now tell the emulator we're opening a new pipe. */  in goldfish_pipe_open()
740 			(u64)(unsigned long)__pa(pipe->command_buffer);  in goldfish_pipe_open()
741 	status = goldfish_pipe_cmd_locked(pipe, PIPE_CMD_OPEN);  in goldfish_pipe_open()
745 	/* All is done, save the pipe into the file's private data field */  in goldfish_pipe_open()
746 	file->private_data = pipe;  in goldfish_pipe_open()
754 	free_page((unsigned long)pipe->command_buffer);  in goldfish_pipe_open()
756 	kfree(pipe);  in goldfish_pipe_open()
763 	struct goldfish_pipe *pipe = filp->private_data;  in goldfish_pipe_release()  local
764 	struct goldfish_pipe_dev *dev = pipe->dev;  in goldfish_pipe_release()
767 	goldfish_pipe_cmd(pipe, PIPE_CMD_CLOSE);  in goldfish_pipe_release()
770 	dev->pipes[pipe->id] = NULL;  in goldfish_pipe_release()
771 	signalled_pipes_remove_locked(dev, pipe);  in goldfish_pipe_release()
775 	free_page((unsigned long)pipe->command_buffer);  in goldfish_pipe_release()
776 	kfree(pipe);  in goldfish_pipe_release()
935 	{ .compatible = "google,android-pipe", },