Signed-off-by: Bryan O'Sullivan <[EMAIL PROTECTED]>

diff -r 19bdf20bc544 -r 227b3e7c27ce drivers/infiniband/hw/ipath/ipath_copy.c
--- /dev/null   Thu Jan  1 00:00:00 1970 +0000
+++ b/drivers/infiniband/hw/ipath/ipath_copy.c  Thu Mar  9 16:15:23 2006 -0800
@@ -0,0 +1,504 @@
+/*
+ * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ * This file provides support for doing sk_buff buffer swapping between
+ * the low level driver eager buffers, and the network layer.  It's part
+ * of the core driver, rather than the ether driver, because it relies
+ * on variables and functions in the core driver.  It exports a single
+ * entry point for use in the ipath_ether module.
+ */
+
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+
+#include "ipath_kernel.h"
+#include "ips_common.h"
+
+/**
+ * layer_send_getpiobuf - allocate, setup and copy out a PIO send buffer
+ * @dd: the infinipath device
+ * @cdp: the data to copy
+ *
+ * Allocate a PIO send buffer, initialize the header and copy it out.
+ */
+static int layer_send_getpiobuf(struct ipath_devdata *dd,
+                               struct copy_data_s *cdp)
+{
+       u32 extra_bytes;
+       u32 len, nwords, hdrwords;
+       u32 __iomem *piobuf;
+
+       piobuf = ipath_getpiobuf(dd, NULL);
+       if (!piobuf) {
+               cdp->error = -EBUSY;
+               return cdp->error;
+       }
+
+       /*
+        * Compute the max amount of data that can fit into a PIO buffer.
+        * buffer size - header size - trigger qword length & flags - CRC
+        */
+       len = dd->ipath_ibmaxlen -
+               sizeof(struct ether_header) - 8 - (SIZE_OF_CRC << 2);
+       if (len > dd->ipath_rcvegrbufsize)
+               len = dd->ipath_rcvegrbufsize;
+       if (len > (cdp->len + cdp->extra))
+               len = (cdp->len + cdp->extra);
+       /* Compute word aligment (i.e., (len & 3) ? 4 - (len & 3) : 0) */
+       extra_bytes = (4 - len) & 3;
+       nwords = (sizeof(struct ether_header) + len + extra_bytes) >> 2;
+       cdp->hdr->lrh[2] = htons(nwords + SIZE_OF_CRC);
+       cdp->hdr->bth[0] = htonl((OPCODE_ITH4X << 24) +
+                                (extra_bytes << 20) +
+                                IPS_DEFAULT_P_KEY);
+       cdp->hdr->sub_opcode = OPCODE_ENCAP;
+
+       cdp->hdr->bth[2] = 0;
+       /*
+        * Generate an interrupt on the receive side for the last
+        * fragment.
+        */
+       cdp->hdr->iph.pkt_flags = ((cdp->len + cdp->extra) == len)
+               ? INFINIPATH_KPF_INTR : 0;
+       cdp->hdr->iph.chksum =
+               (u16) IPS_LRH_BTH + (u16) (nwords + SIZE_OF_CRC) -
+               (u16) ((cdp->hdr->iph.ver_port_tid_offset >> 16) & 0xFFFF) -
+               (u16) (cdp->hdr->iph.ver_port_tid_offset & 0xFFFF) -
+               (u16) cdp->hdr->iph.pkt_flags;
+
+       ipath_cdbg(VERBOSE, "send %d (%x %x %x %x %x %x %x)\n", nwords,
+                  cdp->hdr->lrh[0], cdp->hdr->lrh[1],
+                  cdp->hdr->lrh[2], cdp->hdr->lrh[3],
+                  cdp->hdr->bth[0], cdp->hdr->bth[1], cdp->hdr->bth[2]);
+       /*
+        * Write len to control qword, no flags.
+        * +1 is for the qword padding of pbc.
+        */
+       writeq(nwords + 1ULL, (u64 __iomem *) piobuf);
+       /* we have to flush after the PBC for correctness on some cpus
+        * or WC buffer can be written out of order */
+       ipath_flush_wc();
+       piobuf += 2;
+       hdrwords = sizeof(struct ether_header) >> 2;
+       __iowrite32_copy(piobuf, cdp->hdr, hdrwords);
+       cdp->csum_pio = &((struct ether_header __iomem *)piobuf)->csum;
+       cdp->to = piobuf + hdrwords;
+       cdp->flen = nwords - hdrwords;
+       cdp->hdr->frag_num++;
+       return 0;
+}
+
+/**
+ * copy_extra_dword - copy the last full dword
+ * @dd: the infinipath device
+ * @cdp: the data to copy
+ * @dosum: write a checksum if true
+ *
+ * copy the last full dword when that's the "extra" word, preceding it
+ * with a memory fence, so that all prior data is written to the PIO
+ * buffer before the trigger word, to enforce the correct bus ordering
+ * of the WC buffer contents on the bus.
+ */
+static inline unsigned copy_extra_dword(struct ipath_devdata *dd,
+                                       struct copy_data_s *cdp,
+                                       unsigned dosum)
+{
+       if (!cdp->flen && layer_send_getpiobuf(dd, cdp) < 0)
+               return 1;
+       /* write the checksum before the last PIO write, if requested. */
+       if (dosum && cdp->flen == 1)
+               __raw_writel(csum_fold(cdp->csum), cdp->csum_pio);
+       cdp->extra = 0;
+       cdp->flen -= 1;
+       if (!cdp->flen) {       /* trigger word being written */
+               ipath_flush_wc();
+               __raw_writel(cdp->u.w, cdp->to++);
+               ipath_flush_wc();
+       } else                  /* still more to copy to pio buf */
+               __raw_writel(cdp->u.w, cdp->to++);
+       return 0;
+}
+
+/**
+ * copy_a_buffer - copy a PIO buffer's worth to the PIO buffer
+ * @dd: the infinipath device
+ * @cdp: the destination
+ * @p: the data to copy
+ * @n: the amount to copy
+ * @dosum: write a checksum if true
+ *
+ * copy a PIO buffer's worth (or the skb fragment, at least) to the PIO
+ * buffer, adding a memory fence before the last word.  We need the fence
+ * as part of forcing the WC ordering on some cpus, for the cases where
+ * it will be the trigger word.  The final fence after the trigger word
+ * will be done either at the next chunk, or on final return from the caller
+ * Takes max byte count, returns byte count actually done (always rounded
+ * to dword multiple).
+ */
+static u32 copy_a_buffer(struct ipath_devdata *dd, struct copy_data_s *cdp,
+                        void *p, u32 n, unsigned dosum)
+{
+       u32 *p32;
+
+       if (!cdp->flen && layer_send_getpiobuf(dd, cdp) < 0)
+               return -1;
+       if (n > cdp->flen)
+               n = cdp->flen;
+       if (dosum && cdp->flen == n)
+               __raw_writel(csum_fold(cdp->csum), cdp->csum_pio);
+       p32 = p;
+       cdp->flen -= n;
+       if (!cdp->flen) {       /* trigger word being written */
+               __iowrite32_copy(cdp->to, p32, n - 1);
+               cdp->to += n - 1;
+               ipath_flush_wc();
+               __raw_writel(p32[n - 1], cdp->to++);
+               ipath_flush_wc();
+       } else {                /* still more to copy to pio buf */
+               __iowrite32_copy(cdp->to, p32, n);
+               cdp->to += n;
+       }
+       n <<= 2;
+       cdp->offset += n;
+       cdp->len -= n;
+       return n;
+}
+
+static inline int copy_bits_internal(struct ipath_devdata *dd,
+                                    struct copy_data_s *cdp, u8 *p,
+                                    unsigned *copyp, unsigned *offsetp,
+                                    unsigned *lenp, int do_csum)
+{
+       unsigned copy = *copyp;
+       unsigned len = *lenp;
+       int ret = 1;
+
+       if (copy > len)
+               copy = len;
+       *offsetp += copy;
+       len -= copy;
+       if (do_csum && !cdp->checksum_calc) {
+               unsigned int csum2;
+
+               cdp->checksum_calc = 1;
+
+               csum2 = csum_partial(p, copy, 0);
+               cdp->csum = csum_block_add(cdp->csum, csum2, cdp->pos);
+               cdp->pos += copy;
+       }
+       /*
+        * If the alignment buffer is not empty, fill it and write it
+        * out.
+        */
+       if (cdp->extra) {
+               if (cdp->extra == 4) {
+                       if (copy_extra_dword(dd, cdp, 1))
+                               goto done;
+               }
+               else while (copy != 0) {
+                       cdp->u.buf[cdp->extra] = *p++;
+                       copy--;
+                       cdp->offset++;
+                       cdp->len--;
+                       if (++cdp->extra == 4) {
+                               if (copy_extra_dword(dd, cdp, 1))
+                                       goto done;
+                               break;
+                       }
+               }
+       }
+
+       while (copy >= 4) {
+               u32 n = copy_a_buffer(dd, cdp, p, copy >> 2, 1);
+               if (n == -1)
+                       goto done;
+               p += n;
+               copy -= n;
+       }
+       /*
+        * Either cdp->extra is zero or copy is zero, which means that
+        * the loop here can't cause the alignment buffer to fill up.
+        */
+       while (copy != 0) {
+               cdp->u.buf[cdp->extra++] = *p++;
+               copy--;
+               cdp->offset++;
+               cdp->len--;
+       }
+
+       if (do_csum)
+               cdp->checksum_calc = 0;
+
+       if (len == 0)
+               goto done;
+
+       ret = 0;
+done:
+       *copyp = copy;
+       *lenp = len;
+       return ret;
+}
+
+/**
+ * copy_and_maybe_csum_bits - copy data into the PIO buffer
+ * @dd: the infinipath device
+ * @skb: the source sk_buff
+ * @offset: the offset within the source
+ * @len: the len of the data to copy
+ * @cdp: the destination
+ * @do_csum: write a checksum if true
+ *
+ * Copy data out of one or a chain of sk_buffs, into the PIO buffer,
+ * generating the checksum as we go if do_csum is non-zero.
+ * Fragment an sk_buff into multiple IB packets if the amount of data
+ * is more than a single eager send.
+ * Offset and len are in bytes.
+ * Note that this function is recursive!
+ */
+static void copy_and_maybe_csum_bits(struct ipath_devdata *dd,
+                                    const struct sk_buff *skb,
+                                    unsigned int offset,
+                                    unsigned int len,
+                                    struct copy_data_s *cdp,
+                                    int do_csum)
+{
+       unsigned int start = skb_headlen(skb);
+       unsigned int i, copy;
+
+       /* Copy header. */
+       copy = start - offset;
+       if ((int) copy > 0) {
+               u8 *p = skb->data + offset;
+
+               if (copy_bits_internal(dd, cdp, p, &copy, &offset, &len,
+                                      do_csum))
+                       goto done;
+       }
+
+       for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+               skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+               unsigned int end;
+
+               end = start + frag->size;
+               copy = end - offset;
+               if ((int) copy > 0) {
+                       u8 *vaddr = kmap_skb_frag(frag);
+                       u8 *p = vaddr + frag->page_offset + offset - start;
+                       int ret;
+
+                       ret = copy_bits_internal(dd, cdp, p, &copy,
+                                                &offset, &len, do_csum);
+
+                       kunmap_skb_frag(vaddr);
+
+                       if (ret)
+                               goto done;
+               }
+               start = end;
+       }
+
+       if (skb_shinfo(skb)->frag_list) {
+               struct sk_buff *list = skb_shinfo(skb)->frag_list;
+
+               for (; list; list = list->next) {
+                       unsigned int end;
+
+                       end = start + list->len;
+                       copy = end - offset;
+                       if ((int) copy > 0) {
+                               if (copy > len)
+                                       copy = len;
+                               copy_and_maybe_csum_bits(dd, list,
+                                                        offset - start,
+                                                        copy, cdp,
+                                                        do_csum);
+                               len -= copy;
+                               if (cdp->error || len == 0)
+                                       goto done;
+                               offset += copy;
+                       }
+                       start = end;
+               }
+       }
+       if (len)
+               cdp->error = -EFAULT;
+done:
+       /* we have to flush after trigger word for correctness on some
+        * cpus or WC buffer can be written out of order; needed even
+        * if there was an error */
+       ipath_flush_wc();
+}
+
+static inline void copy_and_csum_bits(struct ipath_devdata *dd,
+                                     const struct sk_buff *skb,
+                                     unsigned int offset,
+                                     unsigned int len,
+                                     struct copy_data_s *cdp)
+{
+       copy_and_maybe_csum_bits(dd, skb, offset, len, cdp, 1);
+}
+
+static inline void copy_bits(struct ipath_devdata *dd,
+                            const struct sk_buff *skb,
+                            unsigned int offset,
+                            unsigned int len,
+                            struct copy_data_s *cdp)
+{
+       copy_and_maybe_csum_bits(dd, skb, offset, len, cdp, 0);
+}
+
+/**
+ * ipath_layer_send_skb - layered sk_buff send
+ * @dd: the infinipath device
+ * @cdata: the data to send
+ *
+ * This is called by the ipath_ether module.
+ *
+ * Note that the header should have the unchanging parts
+ * initialized but the rest of the header is computed as needed in
+ * order to break up skb data buffers larger than the hardware MTU.
+ * In other words, the Linux network stack MTU can be larger than the
+ * hardware MTU.
+ */
+int ipath_layer_send_skb(struct ipath_devdata *dd,
+                        struct copy_data_s *cdata)
+{
+       int ret = 0;
+       u16 vlsllnh;
+
+       if (!(dd->ipath_flags & IPATH_RCVHDRSZ_SET)) {
+               dev_info(&dd->pcidev->dev, "send while not open\n");
+               ret = -EINVAL;
+       }
+       else if ((dd->ipath_flags & (IPATH_LINKUNK | IPATH_LINKDOWN)) ||
+                dd->ipath_lid == 0) {
+               /* lid check is for when sma hasn't yet configured */
+               ret = -ENETDOWN;
+               ipath_cdbg(VERBOSE, "send while not ready, mylid=%u, "
+                          "flags=0x%x\n", dd->ipath_lid, dd->ipath_flags);
+       }
+       vlsllnh = *((u16 *) cdata->hdr);
+       if (vlsllnh != htons(IPS_LRH_BTH)) {
+               ipath_dbg("Warning: lrh[0] wrong (%x, not %x); "
+                         "not sending\n", vlsllnh, htons(IPS_LRH_BTH));
+               ret = -EINVAL;
+       }
+       if (ret)
+               goto done;
+
+       cdata->error = 0;       /* clear last calls error  */
+
+       if (cdata->skb->ip_summed == CHECKSUM_HW) {
+               unsigned int csstart = cdata->skb->h.raw - cdata->skb->data;
+
+               /*
+                * Computing the checksum is a bit tricky since if we
+                * fragment the packet, the fragment that should contain the
+                * checksum will have already been sent.  The solution is to
+                * store the checksum in the header of the last fragment
+                * just before we write the last data word which triggers
+                * the last fragment to be sent.  The receiver will check
+                * the header "tag" field, see that there is a checksum, and
+                * store the checksum back into the packet.
+                *
+                * Save the offset of the two byte checksum.
+                *
+                * Note that we have to add 2 to account for the two bytes
+                * of the ethernet address we stripped from the packet and
+                * put in the header.
+                */
+
+               cdata->hdr->csum_offset = csstart + cdata->skb->csum + 2;
+
+               if (cdata->offset < csstart)
+                       copy_bits(dd, cdata->skb, cdata->offset,
+                                 csstart - cdata->offset, cdata);
+
+               if (cdata->error) {
+                       ret = cdata->error;
+                       goto done;
+               }
+
+               if (cdata->offset < cdata->skb->len)
+                       copy_and_csum_bits(dd, cdata->skb, cdata->offset,
+                                          cdata->skb->len - cdata->offset,
+                                          cdata);
+
+               if (cdata->error) {
+                       ret = cdata->error;
+                       goto done;
+               }
+
+               if (cdata->extra) {
+                       while (cdata->extra < 4)
+                               cdata->u.buf[cdata->extra++] = 0;
+                       (void)copy_extra_dword(dd, cdata, 1);
+               }
+       } else {
+               copy_bits(dd, cdata->skb, cdata->offset,
+                         cdata->skb->len - cdata->offset, cdata);
+
+               if (cdata->error) {
+                       ret = cdata->error;
+                       goto done;
+               }
+
+               if (cdata->extra) {
+                       while (cdata->extra < 4)
+                               cdata->u.buf[cdata->extra++] = 0;
+                       (void)copy_extra_dword(dd, cdata, 1);
+               }
+       }
+
+       if (cdata->error) {
+               ret = cdata->error;
+               if (cdata->error != -EBUSY)
+                       ipath_dev_err(dd, "layer_send copy_bits failed "
+                                     "with error %d\n", -ret);
+       }
+
+       /* another ether packet sent */
+       ipath_stats.sps_ether_spkts++;
+
+done:
+       /*
+        * we have to flush after trigger word for correctness on
+        * some cpus or WC buffer can be written out of order; needed
+        * even if there was an error
+        */
+       ipath_flush_wc();
+       return ret;
+}
+
+EXPORT_SYMBOL_GPL(ipath_layer_send_skb);
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