From patchwork Tue Jul 24 09:05:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guido Kiener X-Patchwork-Id: 10541523 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 D3E9014BC for ; Tue, 24 Jul 2018 08:08:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C626628692 for ; Tue, 24 Jul 2018 08:08:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BA8DE28707; Tue, 24 Jul 2018 08:08:32 +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 BA40228692 for ; Tue, 24 Jul 2018 08:08:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388500AbeGXJNp (ORCPT ); Tue, 24 Jul 2018 05:13:45 -0400 Received: from mr08.mx01.tldhost.de ([84.19.26.246]:56996 "EHLO mr08.mx01.tldhost.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388400AbeGXJNp (ORCPT ); Tue, 24 Jul 2018 05:13:45 -0400 Received: from mx01.tldhost.de (localhost [127.0.0.1]) by mx01.tldhost.de (Postfix) with ESMTP id E0658120E8E for ; Tue, 24 Jul 2018 10:08:27 +0200 (CEST) Received: by mx01.tldhost.de (Postfix, from userid 1001) id D270D120E65; Tue, 24 Jul 2018 10:08:27 +0200 (CEST) Received: from server12.tldhost.de (server12.tldhost.de [84.19.26.112]) by mx01.tldhost.de (Postfix) with ESMTPS id C8597120E87; Tue, 24 Jul 2018 10:08:25 +0200 (CEST) From: Guido Kiener To: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, guido.kiener@rohde-schwarz.com, steve_bayless@keysight.com, dpenkler@gmail.com Cc: Guido Kiener Subject: [PATCH v3 03/23] usb: usbtmc: Add ioctl for vendor specific write Date: Tue, 24 Jul 2018 11:05:30 +0200 Message-Id: <20180724090550.29201-4-guido@kiener-muenchen.de> In-Reply-To: <20180724090550.29201-1-guido@kiener-muenchen.de> References: <20180724090550.29201-1-guido@kiener-muenchen.de> X-PPP-Message-ID: <20180724080826.5487.67007@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 new ioctl USBTMC_IOCTL_WRITE sends a generic message to bulk OUT. This ioctl is used for vendor specific or asynchronous I/O as well. The message is split into chunks of 4k (page size). Message size is aligned to 32 bit boundaries. With flag USBTMC_FLAG_ASYNC the ioctl is non blocking. With flag USBTMC_FLAG_APPEND additional urbs are queued and out_status/out_transfer_size is not reset. EPOLLOUT | EPOLLWRNORM is signaled when all submitted urbs are completed. Flush flying urbs when file handle is closed or device is suspended or reset. Signed-off-by: Guido Kiener Reviewed-by: Steve Bayless --- drivers/usb/class/usbtmc.c | 376 ++++++++++++++++++++++++++++++++++- include/uapi/linux/usb/tmc.h | 14 ++ 2 files changed, 388 insertions(+), 2 deletions(-) diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index 3b3b4284d04e..0328f1beb32d 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -37,6 +37,8 @@ /* Default USB timeout (in milliseconds) */ #define USBTMC_TIMEOUT 5000 +/* Max number of urbs used in write transfers */ +#define MAX_URBS_IN_FLIGHT 16 /* I/O buffer size used in generic read/write functions */ #define USBTMC_BUFSIZE (4096) @@ -125,13 +127,24 @@ struct usbtmc_file_data { u32 timeout; u8 srq_byte; atomic_t srq_asserted; + u8 eom_val; u8 term_char; bool term_char_enabled; + + spinlock_t err_lock; /* lock for errors */ + + struct usb_anchor submitted; + + /* data for generic_write */ + struct semaphore limit_write_sem; + u32 out_transfer_size; + int out_status; }; /* Forward declarations */ static struct usb_driver usbtmc_driver; +static void usbtmc_draw_down(struct usbtmc_file_data *file_data); #ifdef CONFIG_COMPAT static void __user *u64_to_uptr(u64 value) @@ -172,6 +185,10 @@ static int usbtmc_open(struct inode *inode, struct file *filp) if (!file_data) return -ENOMEM; + spin_lock_init(&file_data->err_lock); + sema_init(&file_data->limit_write_sem, MAX_URBS_IN_FLIGHT); + init_usb_anchor(&file_data->submitted); + data = usb_get_intfdata(intf); /* Protect reference to data from file structure until release */ kref_get(&data->kref); @@ -197,6 +214,36 @@ static int usbtmc_open(struct inode *inode, struct file *filp) return 0; } +/* + * usbtmc_flush - called before file handle is closed + */ +static int usbtmc_flush(struct file *file, fl_owner_t id) +{ + struct usbtmc_file_data *file_data; + struct usbtmc_device_data *data; + + file_data = file->private_data; + if (file_data == NULL) + return -ENODEV; + + data = file_data->data; + + /* wait for io to stop */ + mutex_lock(&data->io_mutex); + + usbtmc_draw_down(file_data); + + spin_lock_irq(&file_data->err_lock); + file_data->out_status = 0; + file_data->out_transfer_size = 0; + spin_unlock_irq(&file_data->err_lock); + + wake_up_interruptible_all(&data->waitq); + mutex_unlock(&data->io_mutex); + + return 0; +} + static int usbtmc_release(struct inode *inode, struct file *file) { struct usbtmc_file_data *file_data = file->private_data; @@ -629,6 +676,238 @@ static int usbtmc488_ioctl_trigger(struct usbtmc_file_data *file_data) return 0; } +static struct urb *usbtmc_create_urb(void) +{ + const size_t bufsize = USBTMC_BUFSIZE; + u8 *dmabuf = NULL; + struct urb *urb = usb_alloc_urb(0, GFP_KERNEL); + + if (!urb) + return NULL; + + dmabuf = kmalloc(bufsize, GFP_KERNEL); + if (!dmabuf) { + usb_free_urb(urb); + return NULL; + } + + urb->transfer_buffer = dmabuf; + urb->transfer_buffer_length = bufsize; + urb->transfer_flags |= URB_FREE_BUFFER; + return urb; +} + +static void usbtmc_write_bulk_cb(struct urb *urb) +{ + struct usbtmc_file_data *file_data = urb->context; + int wakeup = 0; + unsigned long flags; + + spin_lock_irqsave(&file_data->err_lock, flags); + file_data->out_transfer_size += urb->actual_length; + + /* sync/async unlink faults aren't errors */ + if (urb->status) { + if (!(urb->status == -ENOENT || + urb->status == -ECONNRESET || + urb->status == -ESHUTDOWN)) + dev_err(&file_data->data->intf->dev, + "%s - nonzero write bulk status received: %d\n", + __func__, urb->status); + + if (!file_data->out_status) { + file_data->out_status = urb->status; + wakeup = 1; + } + } + spin_unlock_irqrestore(&file_data->err_lock, flags); + + dev_dbg(&file_data->data->intf->dev, + "%s - write bulk total size: %u\n", + __func__, file_data->out_transfer_size); + + up(&file_data->limit_write_sem); + if (usb_anchor_empty(&file_data->submitted) || wakeup) + wake_up_interruptible(&file_data->data->waitq); +} + +static ssize_t usbtmc_generic_write(struct usbtmc_file_data *file_data, + const void __user *user_buffer, + u32 transfer_size, + u32 *transferred, + u32 flags) +{ + struct usbtmc_device_data *data = file_data->data; + struct device *dev; + u32 done = 0; + u32 remaining; + unsigned long expire; + const u32 bufsize = USBTMC_BUFSIZE; + struct urb *urb = NULL; + int retval = 0; + u32 timeout; + + *transferred = 0; + + /* Get pointer to private data structure */ + dev = &data->intf->dev; + + dev_dbg(dev, "%s: size=%u flags=0x%X sema=%u\n", + __func__, transfer_size, flags, + file_data->limit_write_sem.count); + + if (flags & USBTMC_FLAG_APPEND) { + spin_lock_irq(&file_data->err_lock); + retval = file_data->out_status; + spin_unlock_irq(&file_data->err_lock); + if (retval < 0) + return retval; + } else { + spin_lock_irq(&file_data->err_lock); + file_data->out_transfer_size = 0; + file_data->out_status = 0; + spin_unlock_irq(&file_data->err_lock); + } + + remaining = transfer_size; + if (remaining > INT_MAX) + remaining = INT_MAX; + + timeout = file_data->timeout; + expire = msecs_to_jiffies(timeout); + + while (remaining > 0) { + u32 this_part, aligned; + u8 *buffer = NULL; + + if (flags & USBTMC_FLAG_ASYNC) { + if (down_trylock(&file_data->limit_write_sem)) { + retval = (done)?(0):(-EAGAIN); + goto exit; + } + } else { + retval = down_timeout(&file_data->limit_write_sem, + expire); + if (retval < 0) { + retval = -ETIMEDOUT; + goto error; + } + } + + spin_lock_irq(&file_data->err_lock); + retval = file_data->out_status; + spin_unlock_irq(&file_data->err_lock); + if (retval < 0) { + up(&file_data->limit_write_sem); + goto error; + } + + /* prepare next urb to send */ + urb = usbtmc_create_urb(); + if (!urb) { + retval = -ENOMEM; + up(&file_data->limit_write_sem); + goto error; + } + buffer = urb->transfer_buffer; + + if (remaining > bufsize) + this_part = bufsize; + else + this_part = remaining; + + if (copy_from_user(buffer, user_buffer + done, this_part)) { + retval = -EFAULT; + up(&file_data->limit_write_sem); + goto error; + } + + print_hex_dump_debug("usbtmc ", DUMP_PREFIX_NONE, + 16, 1, buffer, this_part, true); + + /* fill bulk with 32 bit alignment to meet USBTMC specification + * (size + 3 & ~3) rounds up and simplifies user code + */ + aligned = (this_part + 3) & ~3; + dev_dbg(dev, "write(size:%u align:%u done:%u)\n", + (unsigned int)this_part, + (unsigned int)aligned, + (unsigned int)done); + + usb_fill_bulk_urb(urb, data->usb_dev, + usb_sndbulkpipe(data->usb_dev, data->bulk_out), + urb->transfer_buffer, aligned, + usbtmc_write_bulk_cb, file_data); + + usb_anchor_urb(urb, &file_data->submitted); + retval = usb_submit_urb(urb, GFP_KERNEL); + if (unlikely(retval)) { + usb_unanchor_urb(urb); + up(&file_data->limit_write_sem); + goto error; + } + + usb_free_urb(urb); + urb = NULL; /* urb will be finally released by usb driver */ + + remaining -= this_part; + done += this_part; + } + + /* All urbs are on the fly */ + if (!(flags & USBTMC_FLAG_ASYNC)) { + if (!usb_wait_anchor_empty_timeout(&file_data->submitted, + timeout)) { + retval = -ETIMEDOUT; + goto error; + } + } + + retval = 0; + goto exit; + +error: + usb_kill_anchored_urbs(&file_data->submitted); +exit: + usb_free_urb(urb); + + spin_lock_irq(&file_data->err_lock); + if (!(flags & USBTMC_FLAG_ASYNC)) + done = file_data->out_transfer_size; + if (!retval && file_data->out_status) + retval = file_data->out_status; + spin_unlock_irq(&file_data->err_lock); + + *transferred = done; + + dev_dbg(dev, "%s: done=%u, retval=%d, urbstat=%d\n", + __func__, done, retval, file_data->out_status); + + return retval; +} + +static ssize_t usbtmc_ioctl_generic_write(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_write(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; +} + /* * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-OUT endpoint. * @transfer_size: number of bytes to request from the device. @@ -1096,6 +1375,15 @@ static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data) return 0; } +static int usbtmc_ioctl_cancel_io(struct usbtmc_file_data *file_data) +{ + spin_lock_irq(&file_data->err_lock); + file_data->out_status = -ECANCELED; + spin_unlock_irq(&file_data->err_lock); + usb_kill_anchored_urbs(&file_data->submitted); + return 0; +} + static int get_capabilities(struct usbtmc_device_data *data) { struct device *dev = &data->usb_dev->dev; @@ -1470,6 +1758,11 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) (void __user *)arg); break; + case USBTMC_IOCTL_WRITE: + retval = usbtmc_ioctl_generic_write(file_data, + (void __user *)arg); + break; + case USBTMC488_IOCTL_GET_CAPS: retval = copy_to_user((void __user *)arg, &data->usb488_caps, @@ -1530,7 +1823,19 @@ static __poll_t usbtmc_poll(struct file *file, poll_table *wait) poll_wait(file, &data->waitq, wait); - mask = (atomic_read(&file_data->srq_asserted)) ? EPOLLPRI : 0; + mask = 0; + if (atomic_read(&file_data->srq_asserted)) + mask |= EPOLLPRI; + + if (usb_anchor_empty(&file_data->submitted)) + mask |= (EPOLLOUT | EPOLLWRNORM); + + spin_lock_irq(&file_data->err_lock); + if (file_data->out_status) + mask |= EPOLLERR; + spin_unlock_irq(&file_data->err_lock); + + dev_dbg(&data->intf->dev, "poll mask = %x\n", mask); no_poll: mutex_unlock(&data->io_mutex); @@ -1543,6 +1848,7 @@ static const struct file_operations fops = { .write = usbtmc_write, .open = usbtmc_open, .release = usbtmc_release, + .flush = usbtmc_flush, .unlocked_ioctl = usbtmc_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = usbtmc_ioctl, @@ -1768,6 +2074,7 @@ static int usbtmc_probe(struct usb_interface *intf, static void usbtmc_disconnect(struct usb_interface *intf) { struct usbtmc_device_data *data = usb_get_intfdata(intf); + struct list_head *elem; usb_deregister_dev(intf, &usbtmc_class); sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp); @@ -1775,14 +2082,46 @@ static void usbtmc_disconnect(struct usb_interface *intf) mutex_lock(&data->io_mutex); data->zombie = 1; wake_up_interruptible_all(&data->waitq); + list_for_each(elem, &data->file_list) { + struct usbtmc_file_data *file_data; + + file_data = list_entry(elem, + struct usbtmc_file_data, + file_elem); + usb_kill_anchored_urbs(&file_data->submitted); + } mutex_unlock(&data->io_mutex); usbtmc_free_int(data); kref_put(&data->kref, usbtmc_delete); } +static void usbtmc_draw_down(struct usbtmc_file_data *file_data) +{ + int time; + + time = usb_wait_anchor_empty_timeout(&file_data->submitted, 1000); + if (!time) + usb_kill_anchored_urbs(&file_data->submitted); +} + static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message) { - /* this driver does not have pending URBs */ + struct usbtmc_device_data *data = usb_get_intfdata(intf); + struct list_head *elem; + + if (!data) + return 0; + + mutex_lock(&data->io_mutex); + list_for_each(elem, &data->file_list) { + struct usbtmc_file_data *file_data; + + file_data = list_entry(elem, + struct usbtmc_file_data, + file_elem); + usbtmc_draw_down(file_data); + } + mutex_unlock(&data->io_mutex); return 0; } @@ -1791,6 +2130,37 @@ static int usbtmc_resume(struct usb_interface *intf) return 0; } +static int usbtmc_pre_reset(struct usb_interface *intf) +{ + struct usbtmc_device_data *data = usb_get_intfdata(intf); + struct list_head *elem; + + if (!data) + return 0; + + mutex_lock(&data->io_mutex); + + list_for_each(elem, &data->file_list) { + struct usbtmc_file_data *file_data; + + file_data = list_entry(elem, + struct usbtmc_file_data, + file_elem); + usbtmc_ioctl_cancel_io(file_data); + } + + return 0; +} + +static int usbtmc_post_reset(struct usb_interface *intf) +{ + struct usbtmc_device_data *data = usb_get_intfdata(intf); + + mutex_unlock(&data->io_mutex); + + return 0; +} + static struct usb_driver usbtmc_driver = { .name = "usbtmc", .id_table = usbtmc_devices, @@ -1798,6 +2168,8 @@ static struct usb_driver usbtmc_driver = { .disconnect = usbtmc_disconnect, .suspend = usbtmc_suspend, .resume = usbtmc_resume, + .pre_reset = usbtmc_pre_reset, + .post_reset = usbtmc_post_reset, }; module_usb_driver(usbtmc_driver); diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h index 95533118ac34..56faeb3b5f0f 100644 --- a/include/uapi/linux/usb/tmc.h +++ b/include/uapi/linux/usb/tmc.h @@ -59,6 +59,19 @@ struct usbtmc_termchar { __u8 term_char_enabled; } __attribute__ ((packed)); +/* + * usbtmc_message->flags: + */ +#define USBTMC_FLAG_ASYNC 0x0001 +#define USBTMC_FLAG_APPEND 0x0002 + +struct usbtmc_message { + __u32 transfer_size; /* size of bytes to transfer */ + __u32 transferred; /* size of received/written bytes */ + __u32 flags; /* bit 0: 0 = synchronous; 1 = asynchronous */ + __u64 message; /* pointer to header and data in user space */ +} __attribute__ ((packed)); + /* Request values for USBTMC driver's ioctl entry point */ #define USBTMC_IOC_NR 91 #define USBTMC_IOCTL_INDICATOR_PULSE _IO(USBTMC_IOC_NR, 1) @@ -72,6 +85,7 @@ struct usbtmc_termchar { #define USBTMC_IOCTL_SET_TIMEOUT _IOW(USBTMC_IOC_NR, 10, __u32) #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 USBTMC488_IOCTL_GET_CAPS _IOR(USBTMC_IOC_NR, 17, unsigned char) #define USBTMC488_IOCTL_READ_STB _IOR(USBTMC_IOC_NR, 18, unsigned char)