Staging: add CSR wifi module

This consists of two modules, the driver, and a "helper" module that is
just a wrapper around common kernel functions.  The wrapper module will
be removed soon, but for now it's needed.

These files were based on the csr-linux-wifi-5.0.3-oss.tar.gz package
provided by CSR and Blue Giga, and is covered under the license
specified in the LICENSE.txt file (basically dual BSD and GPLv2).  The
files were flattened out of the deep directory mess they were originally
in, and a few EXPORT_SYMBOL_GPL() were added in order for everything to
link properly with the helper module setup.

Cc: Mikko Virkkilä <mikko.virkkila@bluegiga.com>
Cc: Lauri Hintsala <Lauri.Hintsala@bluegiga.com>
Cc: Riku Mettälä <riku.mettala@bluegiga.com>
Cc: Veli-Pekka Peltola <veli-pekka.peltola@bluegiga.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 422 insertions, 0 deletions

diff --git a/drivers/staging/csr/csr_wifi_hip_send.c b/drivers/staging/csr/csr_wifi_hip_send.c
new file mode 100644
index 0000000..624f3bb
--- /dev/null
+++ b/drivers/staging/csr/csr_wifi_hip_send.c
@@ -0,0 +1,422 @@
+/*****************************************************************************
+
+            (c) Cambridge Silicon Radio Limited 2011
+            All rights reserved and confidential information of CSR
+
+            Refer to LICENSE.txt included with this source for details
+            on the license terms.
+
+*****************************************************************************/
+
+/*
+ * ***************************************************************************
+ *
+ *  FILE:     csr_wifi_hip_send.c
+ *
+ *  PURPOSE:
+ *      Code for adding a signal request to the from-host queue.
+ *      When the driver bottom-half is run, it will take requests from the
+ *      queue and pass them to the UniFi.
+ *
+ * ***************************************************************************
+ */
+#include "csr_wifi_hip_unifi.h"
+#include "csr_wifi_hip_conversions.h"
+#include "csr_wifi_hip_sigs.h"
+#include "csr_wifi_hip_card.h"
+
+unifi_TrafficQueue unifi_frame_priority_to_queue(CSR_PRIORITY priority)
+{
+    switch (priority)
+    {
+        case CSR_QOS_UP0:
+        case CSR_QOS_UP3:
+            return UNIFI_TRAFFIC_Q_BE;
+        case CSR_QOS_UP1:
+        case CSR_QOS_UP2:
+            return UNIFI_TRAFFIC_Q_BK;
+        case CSR_QOS_UP4:
+        case CSR_QOS_UP5:
+            return UNIFI_TRAFFIC_Q_VI;
+        case CSR_QOS_UP6:
+        case CSR_QOS_UP7:
+        case CSR_MANAGEMENT:
+            return UNIFI_TRAFFIC_Q_VO;
+        default:
+            return UNIFI_TRAFFIC_Q_BE;
+    }
+}
+
+
+CSR_PRIORITY unifi_get_default_downgrade_priority(unifi_TrafficQueue queue)
+{
+    switch (queue)
+    {
+        case UNIFI_TRAFFIC_Q_BE:
+            return CSR_QOS_UP0;
+        case UNIFI_TRAFFIC_Q_BK:
+            return CSR_QOS_UP1;
+        case UNIFI_TRAFFIC_Q_VI:
+            return CSR_QOS_UP5;
+        case UNIFI_TRAFFIC_Q_VO:
+            return CSR_QOS_UP6;
+        default:
+            return CSR_QOS_UP0;
+    }
+}
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  send_signal
+ *
+ *      This function queues a signal for sending to UniFi.  It first checks
+ *      that there is space on the fh_signal_queue for another entry, then
+ *      claims any bulk data slots required and copies data into them. Then
+ *      increments the fh_signal_queue write count.
+ *
+ *      The fh_signal_queue is later processed by the driver bottom half
+ *      (in unifi_bh()).
+ *
+ *      This function call unifi_pause_xmit() to pause the flow of data plane
+ *      packets when:
+ *        - the fh_signal_queue ring buffer is full
+ *        - there are less than UNIFI_MAX_DATA_REFERENCES (2) bulk data
+ *          slots available.
+ *
+ *  Arguments:
+ *      card            Pointer to card context structure
+ *      sigptr          Pointer to the signal to write to UniFi.
+ *      siglen          Number of bytes pointer to by sigptr.
+ *      bulkdata        Array of pointers to an associated bulk data.
+ *      sigq            To which from-host queue to add the signal.
+ *
+ *  Returns:
+ *      CSR_RESULT_SUCCESS on success
+ *      CSR_WIFI_HIP_RESULT_NO_SPACE if there were insufficient data slots or
+ *                              no free signal queue entry
+ *
+ * Notes:
+ *      Calls unifi_pause_xmit() when the last slots are used.
+ * ---------------------------------------------------------------------------
+ */
+static CsrResult send_signal(card_t *card, const CsrUint8 *sigptr, CsrUint32 siglen,
+                             const bulk_data_param_t *bulkdata,
+                             q_t *sigq, CsrUint32 priority_q, CsrUint32 run_bh)
+{
+    CsrUint16 i, data_slot_size;
+    card_signal_t *csptr;
+    CsrInt16 qe;
+    CsrResult r;
+    CsrInt16 debug_print = 0;
+
+    data_slot_size = CardGetDataSlotSize(card);
+
+    /* Check that the fh_data_queue has a free slot */
+    if (!CSR_WIFI_HIP_Q_SLOTS_FREE(sigq))
+    {
+        unifi_trace(card->ospriv, UDBG3, "send_signal: %s full\n", sigq->name);
+
+        return CSR_WIFI_HIP_RESULT_NO_SPACE;
+    }
+
+    /*
+     * Now add the signal to the From Host signal queue
+     */
+    /* Get next slot on queue */
+    qe = CSR_WIFI_HIP_Q_NEXT_W_SLOT(sigq);
+    csptr = CSR_WIFI_HIP_Q_SLOT_DATA(sigq, qe);
+
+    /* Make up the card_signal struct */
+    csptr->signal_length = (CsrUint16)siglen;
+    CsrMemCpy((void *)csptr->sigbuf, (void *)sigptr, siglen);
+
+    for (i = 0; i < UNIFI_MAX_DATA_REFERENCES; ++i)
+    {
+        if ((bulkdata != NULL) && (bulkdata->d[i].data_length != 0))
+        {
+            CsrUint32 datalen = bulkdata->d[i].data_length;
+
+            /* Make sure data will fit in a bulk data slot */
+            if (bulkdata->d[i].os_data_ptr == NULL)
+            {
+                unifi_error(card->ospriv, "send_signal - NULL bulkdata[%d]\n", i);
+                debug_print++;
+                csptr->bulkdata[i].data_length = 0;
+            }
+            else
+            {
+                if (datalen > data_slot_size)
+                {
+                    unifi_error(card->ospriv,
+                                "send_signal - Invalid data length %u (@%p), "
+                                "truncating\n",
+                                datalen, bulkdata->d[i].os_data_ptr);
+                    datalen = data_slot_size;
+                    debug_print++;
+                }
+                /* Store the bulk data info in the soft queue. */
+                csptr->bulkdata[i].os_data_ptr = (CsrUint8 *)bulkdata->d[i].os_data_ptr;
+                csptr->bulkdata[i].os_net_buf_ptr = (CsrUint8 *)bulkdata->d[i].os_net_buf_ptr;
+                csptr->bulkdata[i].net_buf_length = bulkdata->d[i].net_buf_length;
+                csptr->bulkdata[i].data_length = datalen;
+            }
+        }
+        else
+        {
+            UNIFI_INIT_BULK_DATA(&csptr->bulkdata[i]);
+        }
+    }
+
+    if (debug_print)
+    {
+        const CsrUint8 *sig = sigptr;
+
+        unifi_error(card->ospriv, "Signal(%d): %02x %02x %02x %02x %02x %02x %02x %02x"
+                    " %02x %02x %02x %02x %02x %02x %02x %02x\n",
+                    siglen,
+                    sig[0], sig[1], sig[2], sig[3],
+                    sig[4], sig[5], sig[6], sig[7],
+                    sig[8], sig[9], sig[10], sig[11],
+                    sig[12], sig[13], sig[14], sig[15]);
+        unifi_error(card->ospriv, "Bulkdata pointer %p(%d), %p(%d)\n",
+                    bulkdata != NULL?bulkdata->d[0].os_data_ptr : NULL,
+                    bulkdata != NULL?bulkdata->d[0].data_length : 0,
+                    bulkdata != NULL?bulkdata->d[1].os_data_ptr : NULL,
+                    bulkdata != NULL?bulkdata->d[1].data_length : 0);
+    }
+
+    /* Advance the written count to say there is a new entry */
+    CSR_WIFI_HIP_Q_INC_W(sigq);
+
+    /*
+     * Set the flag to say reason for waking was a host request.
+     * Then ask the OS layer to run the unifi_bh.
+     */
+    if (run_bh == 1)
+    {
+        card->bh_reason_host = 1;
+        r = unifi_run_bh(card->ospriv);
+        if (r != CSR_RESULT_SUCCESS)
+        {
+            unifi_error(card->ospriv, "failed to run bh.\n");
+            card->bh_reason_host = 0;
+
+            /*
+             * The bulk data buffer will be freed by the caller.
+             * We need to invalidate the description of the bulk data in our
+             * soft queue, to prevent the core freeing the bulk data again later.
+             */
+            for (i = 0; i < UNIFI_MAX_DATA_REFERENCES; ++i)
+            {
+                if (csptr->bulkdata[i].data_length != 0)
+                {
+                    csptr->bulkdata[i].os_data_ptr = csptr->bulkdata[i].os_net_buf_ptr = NULL;
+                    csptr->bulkdata[i].net_buf_length = csptr->bulkdata[i].data_length = 0;
+                }
+            }
+            return r;
+        }
+    }
+    else
+    {
+        unifi_error(card->ospriv, "run_bh=%d, bh not called.\n", run_bh);
+    }
+
+    /*
+     * Have we used up all the fh signal list entries?
+     */
+    if (CSR_WIFI_HIP_Q_SLOTS_FREE(sigq) == 0)
+    {
+        /* We have filled the queue, so stop the upper layer. The command queue
+         * is an exception, as suspending due to that being full could delay
+         * resume/retry until new commands or data are received.
+         */
+        if (sigq != &card->fh_command_queue)
+        {
+            /*
+             * Must call unifi_pause_xmit() *before* setting the paused flag.
+             * (the unifi_pause_xmit call should not be after setting the flag because of the possibility of being interrupted
+             * by the bh thread between our setting the flag and the call to unifi_pause_xmit()
+             * If bh thread then cleared the flag, we would end up paused, but without the flag set)
+             * Instead, setting it afterwards means that if this thread is interrupted by the bh thread
+             * the pause flag is still guaranteed to end up set
+             * However the potential deadlock now is that if bh thread emptied the queue and cleared the flag before this thread's
+             * call to unifi_pause_xmit(), then bh thread may not run again because it will be waiting for
+             * a packet to appear in the queue but nothing ever will because xmit is paused.
+             * So we will end up with the queue paused, and the flag set to say it is paused, but bh never runs to unpause it.
+             * (Note even this bad situation would not persist long in practice, because something else (eg rx, or tx in different queue)
+             * is likely to wake bh thread quite soon)
+             * But to avoid this deadlock completely, after setting the flag we check that there is something left in the queue.
+             * If there is, we know that bh thread has not emptied the queue yet.
+             * Since bh thread checks to unpause the queue *after* taking packets from the queue, we know that it is still going to make at
+             * least one more check to see whether it needs to unpause the queue.  So all is well.
+             * If there are no packets in the queue, then the deadlock described above might happen.  To make sure it does not, we
+             * unpause the queue here. A possible side effect is that unifi_restart_xmit() may (rarely) be called for second time
+             *  unnecessarily, which is harmless
+             */
+
+#if defined (CSR_WIFI_HIP_DEBUG_OFFLINE) && defined (CSR_WIFI_HIP_DATA_PLANE_PROFILE)
+            unifi_debug_log_to_buf("P");
+#endif
+            unifi_pause_xmit(card->ospriv, (unifi_TrafficQueue)priority_q);
+            card_tx_q_pause(card, priority_q);
+            if (CSR_WIFI_HIP_Q_SLOTS_USED(sigq) == 0)
+            {
+                card_tx_q_unpause(card, priority_q);
+                unifi_restart_xmit(card->ospriv, (unifi_TrafficQueue) priority_q);
+            }
+        }
+        else
+        {
+            unifi_warning(card->ospriv,
+                          "send_signal: fh_cmd_q full, not pausing (run_bh=%d)\n",
+                          run_bh);
+        }
+    }
+
+    func_exit();
+
+    return CSR_RESULT_SUCCESS;
+} /*  send_signal() */
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  unifi_send_signal
+ *
+ *    Invokes send_signal() to queue a signal in the command or traffic queue
+ *    If sigptr pointer is NULL, it pokes the bh to check if UniFi is responsive.
+ *
+ *  Arguments:
+ *      card        Pointer to card context struct
+ *      sigptr      Pointer to signal from card.
+ *      siglen      Size of the signal
+ *      bulkdata    Pointer to the bulk data of the signal
+ *
+ *  Returns:
+ *      CSR_RESULT_SUCCESS on success
+ *      CSR_WIFI_HIP_RESULT_NO_SPACE if there were insufficient data slots or no free signal queue entry
+ *
+ *  Notes:
+ *      unifi_send_signal() is used to queue signals, created by the driver,
+ *      to the device. Signals are constructed using the UniFi packed structures.
+ * ---------------------------------------------------------------------------
+ */
+CsrResult unifi_send_signal(card_t *card, const CsrUint8 *sigptr, CsrUint32 siglen,
+                            const bulk_data_param_t *bulkdata)
+{
+    q_t *sig_soft_q;
+    CsrUint16 signal_id;
+    CsrResult r;
+    CsrUint32 run_bh;
+    CsrUint32 priority_q;
+
+    /* A NULL signal pointer is a request to check if UniFi is responsive */
+    if (sigptr == NULL)
+    {
+        card->bh_reason_host = 1;
+        return unifi_run_bh(card->ospriv);
+    }
+
+    priority_q = 0;
+    run_bh = 1;
+    signal_id = GET_SIGNAL_ID(sigptr);
+    /*
+     * If the signal is a CSR_MA_PACKET_REQUEST ,
+     * we send it using the traffic soft queue. Else we use the command soft queue.
+     */
+    if (signal_id == CSR_MA_PACKET_REQUEST_ID)
+    {
+        CsrUint16 frame_priority;
+
+        if (card->periodic_wake_mode == UNIFI_PERIODIC_WAKE_HOST_ENABLED)
+        {
+            run_bh = 0;
+        }
+
+#if defined (CSR_WIFI_HIP_DEBUG_OFFLINE) && defined (CSR_WIFI_HIP_DATA_PLANE_PROFILE)
+        unifi_debug_log_to_buf("D");
+#endif
+        /* Sanity check: MA-PACKET.req must have a valid bulk data */
+        if ((bulkdata->d[0].data_length == 0) || (bulkdata->d[0].os_data_ptr == NULL))
+        {
+            unifi_error(card->ospriv, "MA-PACKET.req with empty bulk data (%d bytes in %p)\n",
+                        bulkdata->d[0].data_length, bulkdata->d[0].os_data_ptr);
+            dump((void *)sigptr, siglen);
+            return CSR_RESULT_FAILURE;
+        }
+
+        /* Map the frame priority to a traffic queue index. */
+        frame_priority = GET_PACKED_MA_PACKET_REQUEST_FRAME_PRIORITY(sigptr);
+        priority_q = unifi_frame_priority_to_queue((CSR_PRIORITY)frame_priority);
+
+        sig_soft_q = &card->fh_traffic_queue[priority_q];
+    }
+    else
+    {
+        sig_soft_q = &card->fh_command_queue;
+    }
+
+    r = send_signal(card, sigptr, siglen, bulkdata, sig_soft_q, priority_q, run_bh);
+    /* On error, the caller must free or requeue bulkdata buffers */
+
+    return r;
+} /* unifi_send_signal() */
+
+
+/*
+ * ---------------------------------------------------------------------------
+ *  unifi_send_resources_available
+ *
+ *      Examines whether there is available space to queue
+ *      a signal in the command or traffic queue
+ *
+ *  Arguments:
+ *      card        Pointer to card context struct
+ *      sigptr      Pointer to signal.
+ *
+ *  Returns:
+ *      CSR_RESULT_SUCCESS if resources available
+ *      CSR_WIFI_HIP_RESULT_NO_SPACE if there was no free signal queue entry
+ *
+ *  Notes:
+ * ---------------------------------------------------------------------------
+ */
+CsrResult unifi_send_resources_available(card_t *card, const CsrUint8 *sigptr)
+{
+    q_t *sig_soft_q;
+    CsrUint16 signal_id = GET_SIGNAL_ID(sigptr);
+
+    /*
+     * If the signal is a CSR_MA_PACKET_REQUEST ,
+     * we send it using the traffic soft queue. Else we use the command soft queue.
+     */
+    if (signal_id == CSR_MA_PACKET_REQUEST_ID)
+    {
+        CsrUint16 frame_priority;
+        CsrUint32 priority_q;
+
+        /* Map the frame priority to a traffic queue index. */
+        frame_priority = GET_PACKED_MA_PACKET_REQUEST_FRAME_PRIORITY(sigptr);
+        priority_q = unifi_frame_priority_to_queue((CSR_PRIORITY)frame_priority);
+
+        sig_soft_q = &card->fh_traffic_queue[priority_q];
+    }
+    else
+    {
+        sig_soft_q = &card->fh_command_queue;
+    }
+
+    /* Check that the fh_data_queue has a free slot */
+    if (!CSR_WIFI_HIP_Q_SLOTS_FREE(sig_soft_q))
+    {
+        unifi_notice(card->ospriv, "unifi_send_resources_available: %s full\n",
+                     sig_soft_q->name);
+        return CSR_WIFI_HIP_RESULT_NO_SPACE;
+    }
+
+    return CSR_RESULT_SUCCESS;
+} /* unifi_send_resources_available() */
+
+