+/**
+ * ipath_diagpkt_write - write an IB packet
+ * @fp: the diag data device file pointer
+ * @data: ipath_diag_pkt structure saying where to get the packet
+ * @count: size of data to write
+ * @off: unused by this code
+ */
+static ssize_t ipath_diagpkt_write(struct file *fp,
+ const char __user *data,
+ size_t count, loff_t *off)
+{
+ u32 __iomem *piobuf;
+ u32 plen, clen, pbufn;
+ struct ipath_diag_pkt dp;
+ u32 *tmpbuf = NULL;
+ struct ipath_devdata *dd;
+ ssize_t ret = 0;
+ u64 val;
+
+ if (count < sizeof(dp)) {
+ ret = -EINVAL;
+ goto bail;
+ }
+
+ if (copy_from_user(&dp, data, sizeof(dp))) {
+ ret = -EFAULT;
+ goto bail;
+ }
+
+ /* send count must be an exact number of dwords */
+ if (dp.len & 3) {
+ ret = -EINVAL;
+ goto bail;
+ }
+
+ clen = dp.len >> 2;
+
+ dd = ipath_lookup(dp.unit);
+ if (!dd || !(dd->ipath_flags & IPATH_PRESENT) ||
+ !dd->ipath_kregbase) {
+ ipath_cdbg(VERBOSE, "illegal unit %u for diag data send\n",
+ dp.unit);
+ ret = -ENODEV;
+ goto bail;
+ }
+
+ if (ipath_diag_inuse && !diag_set_link &&
+ !(dd->ipath_flags & IPATH_LINKACTIVE)) {
+ diag_set_link = 1;
+ ipath_cdbg(VERBOSE, "Trying to set to set link active for "
+ "diag pkt\n");
+ ipath_set_linkstate(dd, IPATH_IB_LINKARM);
+ ipath_set_linkstate(dd, IPATH_IB_LINKACTIVE);
+ }
+
+ if (!(dd->ipath_flags & IPATH_INITTED)) {
+ /* no hardware, freeze, etc. */
+ ipath_cdbg(VERBOSE, "unit %u not usable\n", dd->ipath_unit);
+ ret = -ENODEV;
+ goto bail;
+ }
+ val = dd->ipath_lastibcstat & IPATH_IBSTATE_MASK;
+ if (val != IPATH_IBSTATE_INIT && val != IPATH_IBSTATE_ARM &&
+ val != IPATH_IBSTATE_ACTIVE) {
+ ipath_cdbg(VERBOSE, "unit %u not ready (state %llx)\n",
+ dd->ipath_unit, (unsigned long long) val);
+ ret = -EINVAL;
+ goto bail;
+ }
+
+ /* need total length before first word written */
+ /* +1 word is for the qword padding */
+ plen = sizeof(u32) + dp.len;
+
+ if ((plen + 4) > dd->ipath_ibmaxlen) {
+ ipath_dbg("Pkt len 0x%x > ibmaxlen %x\n",
+ plen - 4, dd->ipath_ibmaxlen);
+ ret = -EINVAL;
+ goto bail; /* before writing pbc */
+ }
+ tmpbuf = vmalloc(plen);
+ if (!tmpbuf) {
+ dev_info(&dd->pcidev->dev, "Unable to allocate tmp buffer, "
+ "failing\n");
+ ret = -ENOMEM;
+ goto bail;
+ }
+
+ if (copy_from_user(tmpbuf,
+ (const void __user *) (unsigned long) dp.data,
+ dp.len)) {
+ ret = -EFAULT;
+ goto bail;
+ }
+
+ piobuf = ipath_getpiobuf(dd, &pbufn);
+ if (!piobuf) {
+ ipath_cdbg(VERBOSE, "No PIO buffers avail unit for %u\n",
+ dd->ipath_unit);
+ ret = -EBUSY;
+ goto bail;
+ }
+
+ plen >>= 2; /* in dwords */
+
+ if (ipath_debug & __IPATH_PKTDBG)
+ ipath_cdbg(VERBOSE, "unit %u 0x%x+1w pio%d\n",
+ dd->ipath_unit, plen - 1, pbufn);
+
+ /* we have to flush after the PBC for correctness on some cpus
+ * or WC buffer can be written out of order */
+ writeq(plen, piobuf);
+ ipath_flush_wc();
+ /* copy all by the trigger word, then flush, so it's written
+ * to chip before trigger word, then write trigger word, then
+ * flush again, so packet is sent. */
+ __iowrite32_copy(piobuf + 2, tmpbuf, clen - 1);
+ ipath_flush_wc();
+ __raw_writel(tmpbuf[clen - 1], piobuf + clen + 1);
+ ipath_flush_wc();
+
+ ret = sizeof(dp);
+
+bail:
+ vfree(tmpbuf);
+ return ret;
+}
+