From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/net/wimax/i2400m/usb-rx.c | 465 +++++++++++++++++++++++++++++++ 1 file changed, 465 insertions(+) create mode 100644 kernel/drivers/net/wimax/i2400m/usb-rx.c (limited to 'kernel/drivers/net/wimax/i2400m/usb-rx.c') diff --git a/kernel/drivers/net/wimax/i2400m/usb-rx.c b/kernel/drivers/net/wimax/i2400m/usb-rx.c new file mode 100644 index 000000000..b78ee676e --- /dev/null +++ b/kernel/drivers/net/wimax/i2400m/usb-rx.c @@ -0,0 +1,465 @@ +/* + * Intel Wireless WiMAX Connection 2400m + * USB RX handling + * + * + * Copyright (C) 2007-2008 Intel Corporation. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * + * Intel Corporation + * Yanir Lubetkin + * - Initial implementation + * Inaky Perez-Gonzalez + * - Use skb_clone(), break up processing in chunks + * - Split transport/device specific + * - Make buffer size dynamic to exert less memory pressure + * + * + * This handles the RX path on USB. + * + * When a notification is received that says 'there is RX data ready', + * we call i2400mu_rx_kick(); that wakes up the RX kthread, which + * reads a buffer from USB and passes it to i2400m_rx() in the generic + * handling code. The RX buffer has an specific format that is + * described in rx.c. + * + * We use a kernel thread in a loop because: + * + * - we want to be able to call the USB power management get/put + * functions (blocking) before each transaction. + * + * - We might get a lot of notifications and we don't want to submit + * a zillion reads; by serializing, we are throttling. + * + * - RX data processing can get heavy enough so that it is not + * appropriate for doing it in the USB callback; thus we run it in a + * process context. + * + * We provide a read buffer of an arbitrary size (short of a page); if + * the callback reports -EOVERFLOW, it means it was too small, so we + * just double the size and retry (being careful to append, as + * sometimes the device provided some data). Every now and then we + * check if the average packet size is smaller than the current packet + * size and if so, we halve it. At the end, the size of the + * preallocated buffer should be following the average received + * transaction size, adapting dynamically to it. + * + * ROADMAP + * + * i2400mu_rx_kick() Called from notif.c when we get a + * 'data ready' notification + * i2400mu_rxd() Kernel RX daemon + * i2400mu_rx() Receive USB data + * i2400m_rx() Send data to generic i2400m RX handling + * + * i2400mu_rx_setup() called from i2400mu_bus_dev_start() + * + * i2400mu_rx_release() called from i2400mu_bus_dev_stop() + */ +#include +#include +#include +#include "i2400m-usb.h" + + +#define D_SUBMODULE rx +#include "usb-debug-levels.h" + +/* + * Dynamic RX size + * + * We can't let the rx_size be a multiple of 512 bytes (the RX + * endpoint's max packet size). On some USB host controllers (we + * haven't been able to fully characterize which), if the device is + * about to send (for example) X bytes and we only post a buffer to + * receive n*512, it will fail to mark that as babble (so that + * i2400mu_rx() [case -EOVERFLOW] can resize the buffer and get the + * rest). + * + * So on growing or shrinking, if it is a multiple of the + * maxpacketsize, we remove some (instead of incresing some, so in a + * buddy allocator we try to waste less space). + * + * Note we also need a hook for this on i2400mu_rx() -- when we do the + * first read, we are sure we won't hit this spot because + * i240mm->rx_size has been set properly. However, if we have to + * double because of -EOVERFLOW, when we launch the read to get the + * rest of the data, we *have* to make sure that also is not a + * multiple of the max_pkt_size. + */ + +static +size_t i2400mu_rx_size_grow(struct i2400mu *i2400mu) +{ + struct device *dev = &i2400mu->usb_iface->dev; + size_t rx_size; + const size_t max_pkt_size = 512; + + rx_size = 2 * i2400mu->rx_size; + if (rx_size % max_pkt_size == 0) { + rx_size -= 8; + d_printf(1, dev, + "RX: expected size grew to %zu [adjusted -8] " + "from %zu\n", + rx_size, i2400mu->rx_size); + } else + d_printf(1, dev, + "RX: expected size grew to %zu from %zu\n", + rx_size, i2400mu->rx_size); + return rx_size; +} + + +static +void i2400mu_rx_size_maybe_shrink(struct i2400mu *i2400mu) +{ + const size_t max_pkt_size = 512; + struct device *dev = &i2400mu->usb_iface->dev; + + if (unlikely(i2400mu->rx_size_cnt >= 100 + && i2400mu->rx_size_auto_shrink)) { + size_t avg_rx_size = + i2400mu->rx_size_acc / i2400mu->rx_size_cnt; + size_t new_rx_size = i2400mu->rx_size / 2; + if (avg_rx_size < new_rx_size) { + if (new_rx_size % max_pkt_size == 0) { + new_rx_size -= 8; + d_printf(1, dev, + "RX: expected size shrank to %zu " + "[adjusted -8] from %zu\n", + new_rx_size, i2400mu->rx_size); + } else + d_printf(1, dev, + "RX: expected size shrank to %zu " + "from %zu\n", + new_rx_size, i2400mu->rx_size); + i2400mu->rx_size = new_rx_size; + i2400mu->rx_size_cnt = 0; + i2400mu->rx_size_acc = i2400mu->rx_size; + } + } +} + +/* + * Receive a message with payloads from the USB bus into an skb + * + * @i2400mu: USB device descriptor + * @rx_skb: skb where to place the received message + * + * Deals with all the USB-specifics of receiving, dynamically + * increasing the buffer size if so needed. Returns the payload in the + * skb, ready to process. On a zero-length packet, we retry. + * + * On soft USB errors, we retry (until they become too frequent and + * then are promoted to hard); on hard USB errors, we reset the + * device. On other errors (skb realloacation, we just drop it and + * hope for the next invocation to solve it). + * + * Returns: pointer to the skb if ok, ERR_PTR on error. + * NOTE: this function might realloc the skb (if it is too small), + * so always update with the one returned. + * ERR_PTR() is < 0 on error. + * Will return NULL if it cannot reallocate -- this can be + * considered a transient retryable error. + */ +static +struct sk_buff *i2400mu_rx(struct i2400mu *i2400mu, struct sk_buff *rx_skb) +{ + int result = 0; + struct device *dev = &i2400mu->usb_iface->dev; + int usb_pipe, read_size, rx_size, do_autopm; + struct usb_endpoint_descriptor *epd; + const size_t max_pkt_size = 512; + + d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu); + do_autopm = atomic_read(&i2400mu->do_autopm); + result = do_autopm ? + usb_autopm_get_interface(i2400mu->usb_iface) : 0; + if (result < 0) { + dev_err(dev, "RX: can't get autopm: %d\n", result); + do_autopm = 0; + } + epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_in); + usb_pipe = usb_rcvbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress); +retry: + rx_size = skb_end_pointer(rx_skb) - rx_skb->data - rx_skb->len; + if (unlikely(rx_size % max_pkt_size == 0)) { + rx_size -= 8; + d_printf(1, dev, "RX: rx_size adapted to %d [-8]\n", rx_size); + } + result = usb_bulk_msg( + i2400mu->usb_dev, usb_pipe, rx_skb->data + rx_skb->len, + rx_size, &read_size, 200); + usb_mark_last_busy(i2400mu->usb_dev); + switch (result) { + case 0: + if (read_size == 0) + goto retry; /* ZLP, just resubmit */ + skb_put(rx_skb, read_size); + break; + case -EPIPE: + /* + * Stall -- maybe the device is choking with our + * requests. Clear it and give it some time. If they + * happen to often, it might be another symptom, so we + * reset. + * + * No error handling for usb_clear_halt(0; if it + * works, the retry works; if it fails, this switch + * does the error handling for us. + */ + if (edc_inc(&i2400mu->urb_edc, + 10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) { + dev_err(dev, "BM-CMD: too many stalls in " + "URB; resetting device\n"); + goto do_reset; + } + usb_clear_halt(i2400mu->usb_dev, usb_pipe); + msleep(10); /* give the device some time */ + goto retry; + case -EINVAL: /* while removing driver */ + case -ENODEV: /* dev disconnect ... */ + case -ENOENT: /* just ignore it */ + case -ESHUTDOWN: + case -ECONNRESET: + break; + case -EOVERFLOW: { /* too small, reallocate */ + struct sk_buff *new_skb; + rx_size = i2400mu_rx_size_grow(i2400mu); + if (rx_size <= (1 << 16)) /* cap it */ + i2400mu->rx_size = rx_size; + else if (printk_ratelimit()) { + dev_err(dev, "BUG? rx_size up to %d\n", rx_size); + result = -EINVAL; + goto out; + } + skb_put(rx_skb, read_size); + new_skb = skb_copy_expand(rx_skb, 0, rx_size - rx_skb->len, + GFP_KERNEL); + if (new_skb == NULL) { + if (printk_ratelimit()) + dev_err(dev, "RX: Can't reallocate skb to %d; " + "RX dropped\n", rx_size); + kfree_skb(rx_skb); + rx_skb = NULL; + goto out; /* drop it...*/ + } + kfree_skb(rx_skb); + rx_skb = new_skb; + i2400mu->rx_size_cnt = 0; + i2400mu->rx_size_acc = i2400mu->rx_size; + d_printf(1, dev, "RX: size changed to %d, received %d, " + "copied %d, capacity %ld\n", + rx_size, read_size, rx_skb->len, + (long) skb_end_offset(new_skb)); + goto retry; + } + /* In most cases, it happens due to the hardware scheduling a + * read when there was no data - unfortunately, we have no way + * to tell this timeout from a USB timeout. So we just ignore + * it. */ + case -ETIMEDOUT: + dev_err(dev, "RX: timeout: %d\n", result); + result = 0; + break; + default: /* Any error */ + if (edc_inc(&i2400mu->urb_edc, + EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) + goto error_reset; + dev_err(dev, "RX: error receiving URB: %d, retrying\n", result); + goto retry; + } +out: + if (do_autopm) + usb_autopm_put_interface(i2400mu->usb_iface); + d_fnend(4, dev, "(i2400mu %p) = %p\n", i2400mu, rx_skb); + return rx_skb; + +error_reset: + dev_err(dev, "RX: maximum errors in URB exceeded; " + "resetting device\n"); +do_reset: + usb_queue_reset_device(i2400mu->usb_iface); + rx_skb = ERR_PTR(result); + goto out; +} + + +/* + * Kernel thread for USB reception of data + * + * This thread waits for a kick; once kicked, it will allocate an skb + * and receive a single message to it from USB (using + * i2400mu_rx()). Once received, it is passed to the generic i2400m RX + * code for processing. + * + * When done processing, it runs some dirty statistics to verify if + * the last 100 messages received were smaller than half of the + * current RX buffer size. In that case, the RX buffer size is + * halved. This will helps lowering the pressure on the memory + * allocator. + * + * Hard errors force the thread to exit. + */ +static +int i2400mu_rxd(void *_i2400mu) +{ + int result = 0; + struct i2400mu *i2400mu = _i2400mu; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = &i2400mu->usb_iface->dev; + struct net_device *net_dev = i2400m->wimax_dev.net_dev; + size_t pending; + int rx_size; + struct sk_buff *rx_skb; + unsigned long flags; + + d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu); + spin_lock_irqsave(&i2400m->rx_lock, flags); + BUG_ON(i2400mu->rx_kthread != NULL); + i2400mu->rx_kthread = current; + spin_unlock_irqrestore(&i2400m->rx_lock, flags); + while (1) { + d_printf(2, dev, "RX: waiting for messages\n"); + pending = 0; + wait_event_interruptible( + i2400mu->rx_wq, + (kthread_should_stop() /* check this first! */ + || (pending = atomic_read(&i2400mu->rx_pending_count))) + ); + if (kthread_should_stop()) + break; + if (pending == 0) + continue; + rx_size = i2400mu->rx_size; + d_printf(2, dev, "RX: reading up to %d bytes\n", rx_size); + rx_skb = __netdev_alloc_skb(net_dev, rx_size, GFP_KERNEL); + if (rx_skb == NULL) { + dev_err(dev, "RX: can't allocate skb [%d bytes]\n", + rx_size); + msleep(50); /* give it some time? */ + continue; + } + + /* Receive the message with the payloads */ + rx_skb = i2400mu_rx(i2400mu, rx_skb); + result = PTR_ERR(rx_skb); + if (IS_ERR(rx_skb)) + goto out; + atomic_dec(&i2400mu->rx_pending_count); + if (rx_skb == NULL || rx_skb->len == 0) { + /* some "ignorable" condition */ + kfree_skb(rx_skb); + continue; + } + + /* Deliver the message to the generic i2400m code */ + i2400mu->rx_size_cnt++; + i2400mu->rx_size_acc += rx_skb->len; + result = i2400m_rx(i2400m, rx_skb); + if (result == -EIO + && edc_inc(&i2400mu->urb_edc, + EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) { + goto error_reset; + } + + /* Maybe adjust RX buffer size */ + i2400mu_rx_size_maybe_shrink(i2400mu); + } + result = 0; +out: + spin_lock_irqsave(&i2400m->rx_lock, flags); + i2400mu->rx_kthread = NULL; + spin_unlock_irqrestore(&i2400m->rx_lock, flags); + d_fnend(4, dev, "(i2400mu %p) = %d\n", i2400mu, result); + return result; + +error_reset: + dev_err(dev, "RX: maximum errors in received buffer exceeded; " + "resetting device\n"); + usb_queue_reset_device(i2400mu->usb_iface); + goto out; +} + + +/* + * Start reading from the device + * + * @i2400m: device instance + * + * Notify the RX thread that there is data pending. + */ +void i2400mu_rx_kick(struct i2400mu *i2400mu) +{ + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = &i2400mu->usb_iface->dev; + + d_fnstart(3, dev, "(i2400mu %p)\n", i2400m); + atomic_inc(&i2400mu->rx_pending_count); + wake_up_all(&i2400mu->rx_wq); + d_fnend(3, dev, "(i2400m %p) = void\n", i2400m); +} + + +int i2400mu_rx_setup(struct i2400mu *i2400mu) +{ + int result = 0; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = &i2400mu->usb_iface->dev; + struct wimax_dev *wimax_dev = &i2400m->wimax_dev; + struct task_struct *kthread; + + kthread = kthread_run(i2400mu_rxd, i2400mu, "%s-rx", + wimax_dev->name); + /* the kthread function sets i2400mu->rx_thread */ + if (IS_ERR(kthread)) { + result = PTR_ERR(kthread); + dev_err(dev, "RX: cannot start thread: %d\n", result); + } + return result; +} + + +void i2400mu_rx_release(struct i2400mu *i2400mu) +{ + unsigned long flags; + struct i2400m *i2400m = &i2400mu->i2400m; + struct device *dev = i2400m_dev(i2400m); + struct task_struct *kthread; + + spin_lock_irqsave(&i2400m->rx_lock, flags); + kthread = i2400mu->rx_kthread; + i2400mu->rx_kthread = NULL; + spin_unlock_irqrestore(&i2400m->rx_lock, flags); + if (kthread) + kthread_stop(kthread); + else + d_printf(1, dev, "RX: kthread had already exited\n"); +} + -- cgit 1.2.3-korg