1 // SPDX-License-Identifier: GPL-2.0-only
3 #define pr_fmt(fmt) "papr-hvpipe: " fmt
17 #include <asm/rtas-work-area.h>
18 #include <asm/papr-sysparm.h>
19 #include <uapi/asm/papr-hvpipe.h>
21 #include "papr-hvpipe.h"
45  * - One hvpipe per partition for all sources.
46  * - Assume the return status of send HVPIPE as delivered to source
47  * - Assume the return status of recv HVPIPE as ACK to source
48  * - Generates HVPIPE event message when the payload is ready
50  *   event until the partition read the previous payload which
55  * ex: /dev/papr-indices, /dev/papr-vpd, etc.
56  * - /dev/papr-hvpipe is available for the user space.
57  * - devfd = open("/dev/papr-hvpipe", ..)
58  * - fd = ioctl(fd,HVPIPE_IOC_CREATE_HANDLE,&srcID)-for each source
59  * - write(fd, buf, size) --> Issue send HVPIPE RTAS call and
62  * - poll(fd,..) -> wakeup FD if the payload is available to read.
63  *   HVPIPE event message handler wakeup FD based on source ID in
64  *   the event message
65  * - read(fd, buf, size) --> Issue recv HVPIPE RTAS call and
71  * ibm,receive-hvpipe-msg RTAS call.
72  * @area: Caller-provided work area buffer for results.
85 		return -ENOENT;  in rtas_ibm_receive_hvpipe_msg()
101 		ret = -EIO;  in rtas_ibm_receive_hvpipe_msg()
104 		ret = -EINVAL;  in rtas_ibm_receive_hvpipe_msg()
107 		ret = -EOPNOTSUPP;  in rtas_ibm_receive_hvpipe_msg()
110 		ret = -EIO;  in rtas_ibm_receive_hvpipe_msg()
111 		pr_err_ratelimited("unexpected ibm,receive-hvpipe-msg status %d\n", fwrc);  in rtas_ibm_receive_hvpipe_msg()
119  * ibm,send-hvpipe-msg RTAS call
120  * @area: Caller-provided work area buffer to send.
130 		return -ENOENT;  in rtas_ibm_send_hvpipe_msg()
143 		ret = -EIO;  in rtas_ibm_send_hvpipe_msg()
146 		ret = -EINVAL;  in rtas_ibm_send_hvpipe_msg()
149 		ret = -EPIPE;  in rtas_ibm_send_hvpipe_msg()
152 		ret = -EOPNOTSUPP;  in rtas_ibm_send_hvpipe_msg()
155 		ret = -EIO;  in rtas_ibm_send_hvpipe_msg()
156 		pr_err_ratelimited("unexpected ibm,receive-hvpipe-msg status %d\n", fwrc);  in rtas_ibm_send_hvpipe_msg()
168 		if (src_info->srcID == srcID)  in hvpipe_find_source()
190 		return -ENOMEM;  in hvpipe_rtas_recv_msg()
200 		 * so that pipe is not blocked - this func is called  in hvpipe_rtas_recv_msg()
216 		pr_err("ibm,receive-hvpipe-msg failed with %d\n",  in hvpipe_rtas_recv_msg()
225  * papr_hvpipe_handle_write -  Issue send HVPIPE RTAS and return
232 	struct hvpipe_source_info *src_info = file->private_data;  in papr_hvpipe_handle_write()
238 	 * Return -ENXIO during migration  in papr_hvpipe_handle_write()
241 		return -ENXIO;  in papr_hvpipe_handle_write()
244 		return -EIO;  in papr_hvpipe_handle_write()
261 	 * See PAPR 7.3.32.2 ibm,send-hvpipe-msg  in papr_hvpipe_handle_write()
273 		return -EINVAL;  in papr_hvpipe_handle_write()
279 	size -= HVPIPE_HDR_LEN;  in papr_hvpipe_handle_write()
284 		ret = -ENOMEM;  in papr_hvpipe_handle_write()
293 		ret = -ENOMEM;  in papr_hvpipe_handle_write()
302 		ret = rtas_ibm_send_hvpipe_msg(work_area, src_info->srcID);  in papr_hvpipe_handle_write()
306 		ret = -EPERM;  in papr_hvpipe_handle_write()
317  * papr_hvpipe_handle_read - If the payload for the specific
322  * hypervisor notifies HVPIPE event with the source ID
323  * and the event handler wakeup FD(s) that are waiting.
329 	struct hvpipe_source_info *src_info = file->private_data;  in papr_hvpipe_handle_read()
334 	 * Return -ENXIO during migration  in papr_hvpipe_handle_read()
337 		return -ENXIO;  in papr_hvpipe_handle_read()
340 		return -EIO;  in papr_hvpipe_handle_read()
347 		return -EINVAL;  in papr_hvpipe_handle_read()
353 	if (!src_info->hvpipe_status)  in papr_hvpipe_handle_read()
366 	if (src_info->hvpipe_status & HVPIPE_MSG_AVAILABLE)  in papr_hvpipe_handle_read()
368 	else if (src_info->hvpipe_status & HVPIPE_LOST_CONNECTION)  in papr_hvpipe_handle_read()
375 		return -EIO;  in papr_hvpipe_handle_read()
382 	 * Message event has payload, so get the payload with  in papr_hvpipe_handle_read()
387 				size - HVPIPE_HDR_LEN);  in papr_hvpipe_handle_read()
389 			src_info->hvpipe_status &= ~HVPIPE_MSG_AVAILABLE;  in papr_hvpipe_handle_read()
397 		src_info->hvpipe_status &= ~HVPIPE_LOST_CONNECTION;  in papr_hvpipe_handle_read()
406  * The hypervisor sends HVPIPE event message to the partition
407  * when the payload is available. The event handler wakeup FD
408  * depends on the source ID in the message event.
413 	struct hvpipe_source_info *src_info = filp->private_data;  in papr_hvpipe_handle_poll()
429 	if (src_info->hvpipe_status)  in papr_hvpipe_handle_poll()
433 	 * Wait for the message event  in papr_hvpipe_handle_poll()
436 	poll_wait(filp, &src_info->recv_wqh, wait);  in papr_hvpipe_handle_poll()
437 	if (src_info->hvpipe_status)  in papr_hvpipe_handle_poll()
451 	 * with message event IRQ.  in papr_hvpipe_handle_release()
454 	src_info = file->private_data;  in papr_hvpipe_handle_release()
455 	list_del(&src_info->list);  in papr_hvpipe_handle_release()
456 	file->private_data = NULL;  in papr_hvpipe_handle_release()
462 	if (src_info->hvpipe_status & HVPIPE_MSG_AVAILABLE) {  in papr_hvpipe_handle_release()
463 		src_info->hvpipe_status = 0;  in papr_hvpipe_handle_release()
496 				src_info->tsk->pid, srcID);  in papr_hvpipe_dev_create_handle()
497 		return -EALREADY;  in papr_hvpipe_dev_create_handle()
503 		return -ENOMEM;  in papr_hvpipe_dev_create_handle()
505 	src_info->srcID = srcID;  in papr_hvpipe_dev_create_handle()
506 	src_info->tsk = current;  in papr_hvpipe_dev_create_handle()
507 	init_waitqueue_head(&src_info->recv_wqh);  in papr_hvpipe_dev_create_handle()
515 	file = anon_inode_getfile("[papr-hvpipe]",  in papr_hvpipe_dev_create_handle()
531 		err = -EALREADY;  in papr_hvpipe_dev_create_handle()
534 	list_add(&src_info->list, &hvpipe_src_list);  in papr_hvpipe_dev_create_handle()
550  * Top-level ioctl handler for /dev/papr_hvpipe
563 	 * Return -ENXIO during migration  in papr_hvpipe_dev_ioctl()
566 		return -ENXIO;  in papr_hvpipe_dev_ioctl()
569 		return -EFAULT;  in papr_hvpipe_dev_ioctl()
575 		return -EINVAL;  in papr_hvpipe_dev_ioctl()
582 		ret = -ENOIOCTLCMD;  in papr_hvpipe_dev_ioctl()
590  * papr_hvpipe_work_fn - called to issue recv HVPIPE RTAS for
600  * HVPIPE event message IRQ handler.
601  * The hypervisor sends event IRQ if the partition has payload
602  * and generates another event only after payload is read with
619 		pr_err_ratelimited("unexpected hvpipe-event-notification failed %d\n", rc);  in hvpipe_event_interrupt()
625 		pr_warn_ratelimited("Unexpected event type %d\n",  in hvpipe_event_interrupt()
632 	hvpipe_event = (struct hvpipe_event_buf *)pseries_log->data;  in hvpipe_event_interrupt()
637 	 * notify another event for any source until the previous  in hvpipe_event_interrupt()
641 	 * If the source is ready to accept payload and wakeup the  in hvpipe_event_interrupt()
652 	src_info = hvpipe_find_source(be32_to_cpu(hvpipe_event->srcID));  in hvpipe_event_interrupt()
656 		if (hvpipe_event->event_type & HVPIPE_LOST_CONNECTION)  in hvpipe_event_interrupt()
658 		else if (hvpipe_event->event_type & HVPIPE_MSG_AVAILABLE)  in hvpipe_event_interrupt()
661 		src_info->hvpipe_status |= flags;  in hvpipe_event_interrupt()
662 		wake_up(&src_info->recv_wqh);  in hvpipe_event_interrupt()
671 		if (hvpipe_event->event_type & HVPIPE_MSG_AVAILABLE)  in hvpipe_event_interrupt()
691 		return -ENOMEM;  in set_hvpipe_sys_param()
693 	buf->len = cpu_to_be16(1);  in set_hvpipe_sys_param()
694 	buf->val[0] = val;  in set_hvpipe_sys_param()
710 		return -ENODEV;  in enable_hvpipe_IRQ()
713 	np = of_find_node_by_path("/event-sources/ibm,hvpipe-msg-events");  in enable_hvpipe_IRQ()
719 		pr_err("Can not enable hvpipe event IRQ\n");  in enable_hvpipe_IRQ()
720 		return -ENODEV;  in enable_hvpipe_IRQ()
726 void hvpipe_migration_handler(int action)  in hvpipe_migration_handler()  argument
728 	pr_info("hvpipe migration event %d\n", action);  in hvpipe_migration_handler()
731 	 * HVPIPE is not used (Failed to create /dev/papr-hvpipe).  in hvpipe_migration_handler()
737 	switch (action) {  in hvpipe_migration_handler()
742 			 * It will be enabled with RESUME event.  in hvpipe_migration_handler()
770 	.name	=	"papr-hvpipe",
778 	if (!of_find_property(rtas.dev, "ibm,hypervisor-pipe-capable",  in papr_hvpipe_init()
780 		return -ENODEV;  in papr_hvpipe_init()
784 		return -ENODEV;  in papr_hvpipe_init()
788 		return -ENOMEM;  in papr_hvpipe_init()
794 		ret = -ENOMEM;  in papr_hvpipe_init()