/* * Intel Wireless WiMAX Connection 2400m * Handle incoming traffic and deliver it to the control or data planes * * * 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. * * We receive an RX message from the bus-specific driver, which * contains one or more payloads that have potentially different * destinataries (data or control paths). * * So we just take that payload from the transport specific code in * the form of an skb, break it up in chunks (a cloned skb each in the * case of network packets) and pass it to netdev or to the * command/ack handler (and from there to the WiMAX stack). * * PROTOCOL FORMAT * * The format of the buffer is: * * HEADER (struct i2400m_msg_hdr) * PAYLOAD DESCRIPTOR 0 (struct i2400m_pld) * PAYLOAD DESCRIPTOR 1 * ... * PAYLOAD DESCRIPTOR N * PAYLOAD 0 (raw bytes) * PAYLOAD 1 * ... * PAYLOAD N * * See tx.c for a deeper description on alignment requirements and * other fun facts of it. * * ROADMAP * * i2400m_rx * i2400m_rx_msg_hdr_check * i2400m_rx_pl_descr_check * i2400m_rx_payload * i2400m_net_rx * i2400m_rx_ctl * i2400m_msg_size_check * i2400m_report_hook_work [in a workqueue] * i2400m_report_hook * wimax_msg_to_user * i2400m_rx_ctl_ack * wimax_msg_to_user_alloc * i2400m_rx_trace * i2400m_msg_size_check * wimax_msg */ #include #include #include #include #include "i2400m.h" #define D_SUBMODULE rx #include "debug-levels.h" struct i2400m_report_hook_args { struct sk_buff *skb_rx; const struct i2400m_l3l4_hdr *l3l4_hdr; size_t size; }; /* * Execute i2400m_report_hook in a workqueue * * Unpacks arguments from the deferred call, executes it and then * drops the references. * * Obvious NOTE: References are needed because we are a separate * thread; otherwise the buffer changes under us because it is * released by the original caller. */ static void i2400m_report_hook_work(struct work_struct *ws) { struct i2400m_work *iw = container_of(ws, struct i2400m_work, ws); struct i2400m_report_hook_args *args = (void *) iw->pl; i2400m_report_hook(iw->i2400m, args->l3l4_hdr, args->size); kfree_skb(args->skb_rx); i2400m_put(iw->i2400m); kfree(iw); } /* * Process an ack to a command * * @i2400m: device descriptor * @payload: pointer to message * @size: size of the message * * Pass the acknodledgment (in an skb) to the thread that is waiting * for it in i2400m->msg_completion. * * We need to coordinate properly with the thread waiting for the * ack. Check if it is waiting or if it is gone. We loose the spinlock * to avoid allocating on atomic contexts (yeah, could use GFP_ATOMIC, * but this is not so speed critical). */ static void i2400m_rx_ctl_ack(struct i2400m *i2400m, const void *payload, size_t size) { struct device *dev = i2400m_dev(i2400m); struct wimax_dev *wimax_dev = &i2400m->wimax_dev; unsigned long flags; struct sk_buff *ack_skb; /* Anyone waiting for an answer? */ spin_lock_irqsave(&i2400m->rx_lock, flags); if (i2400m->ack_skb != ERR_PTR(-EINPROGRESS)) { dev_err(dev, "Huh? reply to command with no waiters\n"); goto error_no_waiter; } spin_unlock_irqrestore(&i2400m->rx_lock, flags); ack_skb = wimax_msg_alloc(wimax_dev, NULL, payload, size, GFP_KERNEL); /* Check waiter didn't time out waiting for the answer... */ spin_lock_irqsave(&i2400m->rx_lock, flags); if (i2400m->ack_skb != ERR_PTR(-EINPROGRESS)) { d_printf(1, dev, "Huh? waiter for command reply cancelled\n"); goto error_waiter_cancelled; } if (ack_skb == NULL) { dev_err(dev, "CMD/GET/SET ack: cannot allocate SKB\n"); i2400m->ack_skb = ERR_PTR(-ENOMEM); } else i2400m->ack_skb = ack_skb; spin_unlock_irqrestore(&i2400m->rx_lock, flags); complete(&i2400m->msg_completion); return; error_waiter_cancelled: if (ack_skb) kfree_skb(ack_skb); error_no_waiter: spin_unlock_irqrestore(&i2400m->rx_lock, flags); return; } /* * Receive and process a control payload * * @i2400m: device descriptor * @skb_rx: skb that contains the payload (for reference counting) * @payload: pointer to message * @size: size of the message * * There are two types of control RX messages: reports (asynchronous, * like your every day interrupts) and 'acks' (reponses to a command, * get or set request). * * If it is a report, we run hooks on it (to extract information for * things we need to do in the driver) and then pass it over to the * WiMAX stack to send it to user space. * * NOTE: report processing is done in a workqueue specific to the * generic driver, to avoid deadlocks in the system. * * If it is not a report, it is an ack to a previously executed * command, set or get, so wake up whoever is waiting for it from * i2400m_msg_to_dev(). i2400m_rx_ctl_ack() takes care of that. * * Note that the sizes we pass to other functions from here are the * sizes of the _l3l4_hdr + payload, not full buffer sizes, as we have * verified in _msg_size_check() that they are congruent. * * For reports: We can't clone the original skb where the data is * because we need to send this up via netlink; netlink has to add * headers and we can't overwrite what's preceeding the payload...as * it is another message. So we just dup them. */ static void i2400m_rx_ctl(struct i2400m *i2400m, struct sk_buff *skb_rx, const void *payload, size_t size) { int result; struct device *dev = i2400m_dev(i2400m); const struct i2400m_l3l4_hdr *l3l4_hdr = payload; unsigned msg_type; result = i2400m_msg_size_check(i2400m, l3l4_hdr, size); if (result < 0) { dev_err(dev, "HW BUG? device sent a bad message: %d\n", result); goto error_check; } msg_type = le16_to_cpu(l3l4_hdr->type); d_printf(1, dev, "%s 0x%04x: %zu bytes\n", msg_type & I2400M_MT_REPORT_MASK ? "REPORT" : "CMD/SET/GET", msg_type, size); d_dump(2, dev, l3l4_hdr, size); if (msg_type & I2400M_MT_REPORT_MASK) { /* These hooks have to be ran serialized; as well, the * handling might force the execution of commands, and * that might cause reentrancy issues with * bus-specific subdrivers and workqueues. So we run * it in a separate workqueue. */ struct i2400m_report_hook_args args = { .skb_rx = skb_rx, .l3l4_hdr = l3l4_hdr, .size = size }; if (unlikely(i2400m->ready == 0)) /* only send if up */ return; skb_get(skb_rx); i2400m_queue_work(i2400m, i2400m_report_hook_work, GFP_KERNEL, &args, sizeof(args)); result = wimax_msg(&i2400m->wimax_dev, NULL, l3l4_hdr, size, GFP_KERNEL); if (result < 0) dev_err(dev, "error sending report to userspace: %d\n", result); } else /* an ack to a CMD, GET or SET */ i2400m_rx_ctl_ack(i2400m, payload, size); error_check: return; } /* * Receive and send up a trace * * @i2400m: device descriptor * @skb_rx: skb that contains the trace (for reference counting) * @payload: pointer to trace message inside the skb * @size: size of the message * * THe i2400m might produce trace information (diagnostics) and we * send them through a different kernel-to-user pipe (to avoid * clogging it). * * As in i2400m_rx_ctl(), we can't clone the original skb where the * data is because we need to send this up via netlink; netlink has to * add headers and we can't overwrite what's preceeding the * payload...as it is another message. So we just dup them. */ static void i2400m_rx_trace(struct i2400m *i2400m, const void *payload, size_t size) { int result; struct device *dev = i2400m_dev(i2400m); struct wimax_dev *wimax_dev = &i2400m->wimax_dev; const struct i2400m_l3l4_hdr *l3l4_hdr = payload; unsigned msg_type; result = i2400m_msg_size_check(i2400m, l3l4_hdr, size); if (result < 0) { dev_err(dev, "HW BUG? device sent a bad trace message: %d\n", result); goto error_check; } msg_type = le16_to_cpu(l3l4_hdr->type); d_printf(1, dev, "Trace %s 0x%04x: %zu bytes\n", msg_type & I2400M_MT_REPORT_MASK ? "REPORT" : "CMD/SET/GET", msg_type, size); d_dump(2, dev, l3l4_hdr, size); if (unlikely(i2400m->ready == 0)) /* only send if up */ return; result = wimax_msg(wimax_dev, "trace", l3l4_hdr, size, GFP_KERNEL); if (result < 0) dev_err(dev, "error sending trace to userspace: %d\n", result); error_check: return; } /* * Act on a received payload * * @i2400m: device instance * @skb_rx: skb where the transaction was received * @single: 1 if there is only one payload, 0 otherwise * @pld: payload descriptor * @payload: payload data * * Upon reception of a payload, look at its guts in the payload * descriptor and decide what to do with it. */ static void i2400m_rx_payload(struct i2400m *i2400m, struct sk_buff *skb_rx, unsigned single, const struct i2400m_pld *pld, const void *payload) { struct device *dev = i2400m_dev(i2400m); size_t pl_size = i2400m_pld_size(pld); enum i2400m_pt pl_type = i2400m_pld_type(pld); switch (pl_type) { case I2400M_PT_DATA: d_printf(3, dev, "RX: data payload %zu bytes\n", pl_size); i2400m_net_rx(i2400m, skb_rx, single, payload, pl_size); break; case I2400M_PT_CTRL: i2400m_rx_ctl(i2400m, skb_rx, payload, pl_size); break; case I2400M_PT_TRACE: i2400m_rx_trace(i2400m, payload, pl_size); break; default: /* Anything else shouldn't come to the host */ if (printk_ratelimit()) dev_err(dev, "RX: HW BUG? unexpected payload type %u\n", pl_type); } } /* * Check a received transaction's message header * * @i2400m: device descriptor * @msg_hdr: message header * @buf_size: size of the received buffer * * Check that the declarations done by a RX buffer message header are * sane and consistent with the amount of data that was received. */ static int i2400m_rx_msg_hdr_check(struct i2400m *i2400m, const struct i2400m_msg_hdr *msg_hdr, size_t buf_size) { int result = -EIO; struct device *dev = i2400m_dev(i2400m); if (buf_size < sizeof(*msg_hdr)) { dev_err(dev, "RX: HW BUG? message with short header (%zu " "vs %zu bytes expected)\n", buf_size, sizeof(*msg_hdr)); goto error; } if (msg_hdr->barker != cpu_to_le32(I2400M_D2H_MSG_BARKER)) { dev_err(dev, "RX: HW BUG? message received with unknown " "barker 0x%08x (buf_size %zu bytes)\n", le32_to_cpu(msg_hdr->barker), buf_size); goto error; } if (msg_hdr->num_pls == 0) { dev_err(dev, "RX: HW BUG? zero payload packets in message\n"); goto error; } if (le16_to_cpu(msg_hdr->num_pls) > I2400M_MAX_PLS_IN_MSG) { dev_err(dev, "RX: HW BUG? message contains more payload " "than maximum; ignoring.\n"); goto error; } result = 0; error: return result; } /* * Check a payload descriptor against the received data * * @i2400m: device descriptor * @pld: payload descriptor * @pl_itr: offset (in bytes) in the received buffer the payload is * located * @buf_size: size of the received buffer * * Given a payload descriptor (part of a RX buffer), check it is sane * and that the data it declares fits in the buffer. */ static int i2400m_rx_pl_descr_check(struct i2400m *i2400m, const struct i2400m_pld *pld, size_t pl_itr, size_t buf_size) { int result = -EIO; struct device *dev = i2400m_dev(i2400m); size_t pl_size = i2400m_pld_size(pld); enum i2400m_pt pl_type = i2400m_pld_type(pld); if (pl_size > i2400m->bus_pl_size_max) { dev_err(dev, "RX: HW BUG? payload @%zu: size %zu is " "bigger than maximum %zu; ignoring message\n", pl_itr, pl_size, i2400m->bus_pl_size_max); goto error; } if (pl_itr + pl_size > buf_size) { /* enough? */ dev_err(dev, "RX: HW BUG? payload @%zu: size %zu " "goes beyond the received buffer " "size (%zu bytes); ignoring message\n", pl_itr, pl_size, buf_size); goto error; } if (pl_type >= I2400M_PT_ILLEGAL) { dev_err(dev, "RX: HW BUG? illegal payload type %u; " "ignoring message\n", pl_type); goto error; } result = 0; error: return result; } /** * i2400m_rx - Receive a buffer of data from the device * * @i2400m: device descriptor * @skb: skbuff where the data has been received * * Parse in a buffer of data that contains an RX message sent from the * device. See the file header for the format. Run all checks on the * buffer header, then run over each payload's descriptors, verify * their consistency and act on each payload's contents. If * everything is succesful, update the device's statistics. * * Note: You need to set the skb to contain only the length of the * received buffer; for that, use skb_trim(skb, RECEIVED_SIZE). * * Returns: * * 0 if ok, < 0 errno on error * * If ok, this function owns now the skb and the caller DOESN'T have * to run kfree_skb() on it. However, on error, the caller still owns * the skb and it is responsible for releasing it. */ int i2400m_rx(struct i2400m *i2400m, struct sk_buff *skb) { int i, result; struct device *dev = i2400m_dev(i2400m); const struct i2400m_msg_hdr *msg_hdr; size_t pl_itr, pl_size, skb_len; unsigned long flags; unsigned num_pls; skb_len = skb->len; d_fnstart(4, dev, "(i2400m %p skb %p [size %zu])\n", i2400m, skb, skb_len); result = -EIO; msg_hdr = (void *) skb->data; result = i2400m_rx_msg_hdr_check(i2400m, msg_hdr, skb->len); if (result < 0) goto error_msg_hdr_check; result = -EIO; num_pls = le16_to_cpu(msg_hdr->num_pls); pl_itr = sizeof(*msg_hdr) + /* Check payload descriptor(s) */ num_pls * sizeof(msg_hdr->pld[0]); pl_itr = ALIGN(pl_itr, I2400M_PL_PAD); if (pl_itr > skb->len) { /* got all the payload descriptors? */ dev_err(dev, "RX: HW BUG? message too short (%u bytes) for " "%u payload descriptors (%zu each, total %zu)\n", skb->len, num_pls, sizeof(msg_hdr->pld[0]), pl_itr); goto error_pl_descr_short; } /* Walk each payload payload--check we really got it */ for (i = 0; i < num_pls; i++) { /* work around old gcc warnings */ pl_size = i2400m_pld_size(&msg_hdr->pld[i]); result = i2400m_rx_pl_descr_check(i2400m, &msg_hdr->pld[i], pl_itr, skb->len); if (result < 0) goto error_pl_descr_check; i2400m_rx_payload(i2400m, skb, num_pls == 1, &msg_hdr->pld[i], skb->data + pl_itr); pl_itr += ALIGN(pl_size, I2400M_PL_PAD); cond_resched(); /* Don't monopolize */ } kfree_skb(skb); /* Update device statistics */ spin_lock_irqsave(&i2400m->rx_lock, flags); i2400m->rx_pl_num += i; if (i > i2400m->rx_pl_max) i2400m->rx_pl_max = i; if (i < i2400m->rx_pl_min) i2400m->rx_pl_min = i; i2400m->rx_num++; i2400m->rx_size_acc += skb->len; if (skb->len < i2400m->rx_size_min) i2400m->rx_size_min = skb->len; if (skb->len > i2400m->rx_size_max) i2400m->rx_size_max = skb->len; spin_unlock_irqrestore(&i2400m->rx_lock, flags); error_pl_descr_check: error_pl_descr_short: error_msg_hdr_check: d_fnend(4, dev, "(i2400m %p skb %p [size %zu]) = %d\n", i2400m, skb, skb_len, result); return result; } EXPORT_SYMBOL_GPL(i2400m_rx);