From patchwork Mon Jul 30 08:04:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Guido Kiener X-Patchwork-Id: 10548485 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A465513BB for ; Mon, 30 Jul 2018 07:07:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 95871298F1 for ; Mon, 30 Jul 2018 07:07:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8A68029900; Mon, 30 Jul 2018 07:07:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8326E298F1 for ; Mon, 30 Jul 2018 07:07:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726532AbeG3IlM (ORCPT ); Mon, 30 Jul 2018 04:41:12 -0400 Received: from mr03.mx01.tldhost.de ([62.108.44.115]:33051 "EHLO mr03.mx01.tldhost.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726476AbeG3IlL (ORCPT ); Mon, 30 Jul 2018 04:41:11 -0400 Received: from mx01.tldhost.de (localhost [127.0.0.1]) by mx01.tldhost.de (Postfix) with ESMTP id 19B10120EC6 for ; Mon, 30 Jul 2018 09:07:37 +0200 (CEST) Received: by mx01.tldhost.de (Postfix, from userid 1001) id 0F3D5120EE2; Mon, 30 Jul 2018 09:07:37 +0200 (CEST) Received: from server12.tldhost.de (server12.tldhost.de [84.19.26.112]) by mx01.tldhost.de (Postfix) with ESMTPS id 0ADA0120EC0; Mon, 30 Jul 2018 09:07:35 +0200 (CEST) From: Guido Kiener To: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, guido.kiener@rohde-schwarz.com, pankaj.adhikari@ni.com, steve_bayless@keysight.com, dpenkler@gmail.com Cc: Guido Kiener Subject: [PATCH v4 04/22] usb: usbtmc: Add ioctl for vendor specific read Date: Mon, 30 Jul 2018 10:04:34 +0200 Message-Id: <20180730080452.15150-5-guido@kiener-muenchen.de> In-Reply-To: <20180730080452.15150-1-guido@kiener-muenchen.de> References: <20180730080452.15150-1-guido@kiener-muenchen.de> MIME-Version: 1.0 X-PPP-Message-ID: <20180730070735.16430.97962@server12.tldhost.de> X-PPP-Vhost: kiener-muenchen.de X-POWERED-BY: TLDHost.de - AV:CLEAN SPAM:OK Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The USBTMC_IOCTL_READ call provides for generic synchronous and asynchronous reads on bulk IN to implement vendor specific library routines. Depending on transfer_size the function submits one or more urbs (up to 16) each with a size of up to 4kB. The flag USBTMC_FLAG_IGNORE_TRAILER can be used when the transmission size is already known. Then the function does not truncate the transfer_size to a multiple of 4 kB, but does reserve extra space to receive the final short or zero length packet. Note that the instrument is allowed to send up to wMaxPacketSize - 1 bytes at the end of a message to avoid sending a zero length packet. With flag USBTMC_FLAG_ASYNC the ioctl is non blocking. When no received data is available, the read function submits as many urbs as needed to receive transfer_size bytes. However the number of flying urbs (=4kB) is limited to 16 even with subsequent calls of this ioctl. Returns -EAGAIN when non blocking and no data is received. Signals EPOLLIN | EPOLLRDNORM when asynchronous urbs are ready to be read. In non blocking mode the usbtmc_message.message pointer may be NULL and the ioctl just submits urbs to initiate receiving data. However if data is already available due to a previous non blocking call the ioctl will return -EINVAL when the message pointer is NULL. Signed-off-by: Guido Kiener Reviewed-by: Steve Bayless --- drivers/usb/class/usbtmc.c | 336 ++++++++++++++++++++++++++++++++++- include/uapi/linux/usb/tmc.h | 2 + 2 files changed, 337 insertions(+), 1 deletion(-) diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index 32aef9e53bc5..5edb548d9122 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -85,6 +85,9 @@ struct usbtmc_device_data { u8 bTag_last_write; /* needed for abort */ u8 bTag_last_read; /* needed for abort */ + /* packet size of IN bulk */ + u16 wMaxPacketSize; + /* data for interrupt in endpoint handling */ u8 bNotify1; u8 bNotify2; @@ -140,6 +143,13 @@ struct usbtmc_file_data { struct semaphore limit_write_sem; u32 out_transfer_size; int out_status; + + /* data for generic_read */ + u32 in_transfer_size; + int in_status; + int in_urbs_used; + struct usb_anchor in_anchor; + wait_queue_head_t wait_bulk_in; }; /* Forward declarations */ @@ -181,6 +191,8 @@ static int usbtmc_open(struct inode *inode, struct file *filp) spin_lock_init(&file_data->err_lock); sema_init(&file_data->limit_write_sem, MAX_URBS_IN_FLIGHT); init_usb_anchor(&file_data->submitted); + init_usb_anchor(&file_data->in_anchor); + init_waitqueue_head(&file_data->wait_bulk_in); data = usb_get_intfdata(intf); /* Protect reference to data from file structure until release */ @@ -227,6 +239,9 @@ static int usbtmc_flush(struct file *file, fl_owner_t id) usbtmc_draw_down(file_data); spin_lock_irq(&file_data->err_lock); + file_data->in_status = 0; + file_data->in_transfer_size = 0; + file_data->in_urbs_used = 0; file_data->out_status = 0; file_data->out_transfer_size = 0; spin_unlock_irq(&file_data->err_lock); @@ -690,6 +705,307 @@ static struct urb *usbtmc_create_urb(void) return urb; } +static void usbtmc_read_bulk_cb(struct urb *urb) +{ + struct usbtmc_file_data *file_data = urb->context; + int status = urb->status; + unsigned long flags; + + /* sync/async unlink faults aren't errors */ + if (status) { + if (!(/* status == -ENOENT || */ + status == -ECONNRESET || + status == -EREMOTEIO || /* Short packet */ + status == -ESHUTDOWN)) + dev_err(&file_data->data->intf->dev, + "%s - nonzero read bulk status received: %d\n", + __func__, status); + + spin_lock_irqsave(&file_data->err_lock, flags); + if (!file_data->in_status) + file_data->in_status = status; + spin_unlock_irqrestore(&file_data->err_lock, flags); + } + + spin_lock_irqsave(&file_data->err_lock, flags); + file_data->in_transfer_size += urb->actual_length; + dev_dbg(&file_data->data->intf->dev, + "%s - total size: %u current: %d status: %d\n", + __func__, file_data->in_transfer_size, + urb->actual_length, status); + spin_unlock_irqrestore(&file_data->err_lock, flags); + usb_anchor_urb(urb, &file_data->in_anchor); + + wake_up_interruptible(&file_data->wait_bulk_in); + wake_up_interruptible(&file_data->data->waitq); +} + +static inline bool usbtmc_do_transfer(struct usbtmc_file_data *file_data) +{ + bool data_or_error; + + spin_lock_irq(&file_data->err_lock); + data_or_error = !usb_anchor_empty(&file_data->in_anchor) + || file_data->in_status; + spin_unlock_irq(&file_data->err_lock); + dev_dbg(&file_data->data->intf->dev, "%s: returns %d\n", __func__, + data_or_error); + return data_or_error; +} + +static ssize_t usbtmc_generic_read(struct usbtmc_file_data *file_data, + void __user *user_buffer, + u32 transfer_size, + u32 *transferred, + u32 flags) +{ + struct usbtmc_device_data *data = file_data->data; + struct device *dev = &data->intf->dev; + u32 done = 0; + u32 remaining; + const u32 bufsize = USBTMC_BUFSIZE; + int retval = 0; + u32 max_transfer_size; + unsigned long expire; + int bufcount = 1; + int again = 0; + + /* mutex already locked */ + + *transferred = done; + + max_transfer_size = transfer_size; + + if (flags & USBTMC_FLAG_IGNORE_TRAILER) { + /* The device may send extra alignment bytes (up to + * wMaxPacketSize – 1) to avoid sending a zero-length + * packet + */ + remaining = transfer_size; + if ((max_transfer_size % data->wMaxPacketSize) == 0) + max_transfer_size += (data->wMaxPacketSize - 1); + } else { + /* round down to bufsize to avoid truncated data left */ + if (max_transfer_size > bufsize) { + max_transfer_size = + roundup(max_transfer_size + 1 - bufsize, + bufsize); + } + remaining = max_transfer_size; + } + + spin_lock_irq(&file_data->err_lock); + + if (file_data->in_status) { + /* return the very first error */ + retval = file_data->in_status; + spin_unlock_irq(&file_data->err_lock); + goto error; + } + + if (flags & USBTMC_FLAG_ASYNC) { + if (usb_anchor_empty(&file_data->in_anchor)) + again = 1; + + if (file_data->in_urbs_used == 0) { + file_data->in_transfer_size = 0; + file_data->in_status = 0; + } + } else { + file_data->in_transfer_size = 0; + file_data->in_status = 0; + } + + if (max_transfer_size == 0) { + bufcount = 0; + } else { + bufcount = roundup(max_transfer_size, bufsize) / bufsize; + if (bufcount > file_data->in_urbs_used) + bufcount -= file_data->in_urbs_used; + else + bufcount = 0; + + if (bufcount + file_data->in_urbs_used > MAX_URBS_IN_FLIGHT) { + bufcount = MAX_URBS_IN_FLIGHT - + file_data->in_urbs_used; + } + } + spin_unlock_irq(&file_data->err_lock); + + dev_dbg(dev, "%s: requested=%u flags=0x%X size=%u bufs=%d used=%d\n", + __func__, transfer_size, flags, + max_transfer_size, bufcount, file_data->in_urbs_used); + + while (bufcount > 0) { + u8 *dmabuf = NULL; + struct urb *urb = usbtmc_create_urb(); + + if (!urb) { + retval = -ENOMEM; + goto error; + } + + dmabuf = urb->transfer_buffer; + + usb_fill_bulk_urb(urb, data->usb_dev, + usb_rcvbulkpipe(data->usb_dev, data->bulk_in), + dmabuf, bufsize, + usbtmc_read_bulk_cb, file_data); + + usb_anchor_urb(urb, &file_data->submitted); + retval = usb_submit_urb(urb, GFP_KERNEL); + /* urb is anchored. We can release our reference. */ + usb_free_urb(urb); + if (unlikely(retval)) { + usb_unanchor_urb(urb); + goto error; + } + file_data->in_urbs_used++; + bufcount--; + } + + if (again) { + dev_dbg(dev, "%s: ret=again\n", __func__); + return -EAGAIN; + } + + if (user_buffer == NULL) + return -EINVAL; + + expire = msecs_to_jiffies(file_data->timeout); + + while (max_transfer_size > 0) { + u32 this_part; + struct urb *urb = NULL; + + if (!(flags & USBTMC_FLAG_ASYNC)) { + dev_dbg(dev, "%s: before wait time %lu\n", + __func__, expire); + retval = wait_event_interruptible_timeout( + file_data->wait_bulk_in, + usbtmc_do_transfer(file_data), + expire); + + dev_dbg(dev, "%s: wait returned %d\n", + __func__, retval); + + if (retval <= 0) { + if (retval == 0) + retval = -ETIMEDOUT; + goto error; + } + } + + urb = usb_get_from_anchor(&file_data->in_anchor); + if (!urb) { + if (!(flags & USBTMC_FLAG_ASYNC)) { + /* synchronous case: must not happen */ + retval = -EFAULT; + goto error; + } + + /* asynchronous case: ready, do not block or wait */ + *transferred = done; + dev_dbg(dev, "%s: (async) done=%u ret=0\n", + __func__, done); + return 0; + } + + file_data->in_urbs_used--; + + if (max_transfer_size > urb->actual_length) + max_transfer_size -= urb->actual_length; + else + max_transfer_size = 0; + + if (remaining > urb->actual_length) + this_part = urb->actual_length; + else + this_part = remaining; + + print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE, 16, 1, + urb->transfer_buffer, urb->actual_length, true); + + if (copy_to_user(user_buffer + done, + urb->transfer_buffer, this_part)) { + usb_free_urb(urb); + retval = -EFAULT; + goto error; + } + + remaining -= this_part; + done += this_part; + + spin_lock_irq(&file_data->err_lock); + if (urb->status) { + /* return the very first error */ + retval = file_data->in_status; + spin_unlock_irq(&file_data->err_lock); + usb_free_urb(urb); + goto error; + } + spin_unlock_irq(&file_data->err_lock); + + if (urb->actual_length < bufsize) { + /* short packet or ZLP received => ready */ + usb_free_urb(urb); + retval = 1; + break; + } + + if (!(flags & USBTMC_FLAG_ASYNC) && + max_transfer_size > (bufsize * file_data->in_urbs_used)) { + /* resubmit, since other buffers still not enough */ + usb_anchor_urb(urb, &file_data->submitted); + retval = usb_submit_urb(urb, GFP_KERNEL); + if (unlikely(retval)) { + usb_unanchor_urb(urb); + usb_free_urb(urb); + goto error; + } + file_data->in_urbs_used++; + } + usb_free_urb(urb); + retval = 0; + } + +error: + *transferred = done; + + dev_dbg(dev, "%s: before kill\n", __func__); + /* Attention: killing urbs can take long time (2 ms) */ + usb_kill_anchored_urbs(&file_data->submitted); + dev_dbg(dev, "%s: after kill\n", __func__); + usb_scuttle_anchored_urbs(&file_data->in_anchor); + file_data->in_urbs_used = 0; + file_data->in_status = 0; /* no spinlock needed here */ + dev_dbg(dev, "%s: done=%u ret=%d\n", __func__, done, retval); + + return retval; +} + +static ssize_t usbtmc_ioctl_generic_read(struct usbtmc_file_data *file_data, + void __user *arg) +{ + struct usbtmc_message msg; + ssize_t retval = 0; + + /* mutex already locked */ + + if (copy_from_user(&msg, arg, sizeof(struct usbtmc_message))) + return -EFAULT; + + retval = usbtmc_generic_read(file_data, u64_to_uptr(msg.message), + msg.transfer_size, &msg.transferred, + msg.flags); + + if (put_user(msg.transferred, + &((struct usbtmc_message __user *)arg)->transferred)) + return -EFAULT; + + return retval; +} + static void usbtmc_write_bulk_cb(struct urb *urb) { struct usbtmc_file_data *file_data = urb->context; @@ -1391,6 +1707,7 @@ static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data) static int usbtmc_ioctl_cancel_io(struct usbtmc_file_data *file_data) { spin_lock_irq(&file_data->err_lock); + file_data->in_status = -ECANCELED; file_data->out_status = -ECANCELED; spin_unlock_irq(&file_data->err_lock); usb_kill_anchored_urbs(&file_data->submitted); @@ -1776,6 +2093,11 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) (void __user *)arg); break; + case USBTMC_IOCTL_READ: + retval = usbtmc_ioctl_generic_read(file_data, + (void __user *)arg); + break; + case USBTMC_IOCTL_WRITE_RESULT: retval = usbtmc_ioctl_write_result(file_data, (void __user *)arg); @@ -1841,15 +2163,24 @@ static __poll_t usbtmc_poll(struct file *file, poll_table *wait) poll_wait(file, &data->waitq, wait); + /* Note that EPOLLPRI is now assigned to SRQ, and + * EPOLLIN|EPOLLRDNORM to normal read data. + */ mask = 0; if (atomic_read(&file_data->srq_asserted)) mask |= EPOLLPRI; + /* Note that the anchor submitted includes all urbs for BULK IN + * and OUT. So EPOLLOUT is signaled when BULK OUT is empty and + * all BULK IN urbs are completed and moved to in_anchor. + */ if (usb_anchor_empty(&file_data->submitted)) mask |= (EPOLLOUT | EPOLLWRNORM); + if (!usb_anchor_empty(&file_data->in_anchor)) + mask |= (EPOLLIN | EPOLLRDNORM); spin_lock_irq(&file_data->err_lock); - if (file_data->out_status) + if (file_data->in_status || file_data->out_status) mask |= EPOLLERR; spin_unlock_irq(&file_data->err_lock); @@ -2011,6 +2342,7 @@ static int usbtmc_probe(struct usb_interface *intf, } data->bulk_in = bulk_in->bEndpointAddress; + data->wMaxPacketSize = usb_endpoint_maxp(bulk_in); dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n", data->bulk_in); data->bulk_out = bulk_out->bEndpointAddress; @@ -2107,6 +2439,7 @@ static void usbtmc_disconnect(struct usb_interface *intf) struct usbtmc_file_data, file_elem); usb_kill_anchored_urbs(&file_data->submitted); + usb_scuttle_anchored_urbs(&file_data->in_anchor); } mutex_unlock(&data->io_mutex); usbtmc_free_int(data); @@ -2120,6 +2453,7 @@ static void usbtmc_draw_down(struct usbtmc_file_data *file_data) time = usb_wait_anchor_empty_timeout(&file_data->submitted, 1000); if (!time) usb_kill_anchored_urbs(&file_data->submitted); + usb_scuttle_anchored_urbs(&file_data->in_anchor); } static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message) diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h index 4a47b11e4a7e..c75354dfd592 100644 --- a/include/uapi/linux/usb/tmc.h +++ b/include/uapi/linux/usb/tmc.h @@ -64,6 +64,7 @@ struct usbtmc_termchar { */ #define USBTMC_FLAG_ASYNC 0x0001 #define USBTMC_FLAG_APPEND 0x0002 +#define USBTMC_FLAG_IGNORE_TRAILER 0x0004 struct usbtmc_message { __u32 transfer_size; /* size of bytes to transfer */ @@ -86,6 +87,7 @@ struct usbtmc_message { #define USBTMC_IOCTL_EOM_ENABLE _IOW(USBTMC_IOC_NR, 11, __u8) #define USBTMC_IOCTL_CONFIG_TERMCHAR _IOW(USBTMC_IOC_NR, 12, struct usbtmc_termchar) #define USBTMC_IOCTL_WRITE _IOWR(USBTMC_IOC_NR, 13, struct usbtmc_message) +#define USBTMC_IOCTL_READ _IOWR(USBTMC_IOC_NR, 14, struct usbtmc_message) #define USBTMC_IOCTL_WRITE_RESULT _IOWR(USBTMC_IOC_NR, 15, __u32) #define USBTMC488_IOCTL_GET_CAPS _IOR(USBTMC_IOC_NR, 17, unsigned char)