[ofa-general] [PATCH 17/20] IB/ipath - user mode send DMA
Ralph Campbell
ralph.campbell at qlogic.com
Wed Apr 2 15:50:28 PDT 2008
From: Arthur Jones <arthur.jones at qlogic.com>
A new file which allows the iba7220 send DMA engine
to be used from userland. The routines here are not
linked in yet, that will happen in a follow-on patch...
Signed-off-by: Arthur Jones <arthur.jones at qlogic.com>
---
drivers/infiniband/hw/ipath/ipath_user_sdma.c | 888 +++++++++++++++++++++++++
1 files changed, 888 insertions(+), 0 deletions(-)
diff --git a/drivers/infiniband/hw/ipath/ipath_user_sdma.c b/drivers/infiniband/hw/ipath/ipath_user_sdma.c
new file mode 100644
index 0000000..44020c8
--- /dev/null
+++ b/drivers/infiniband/hw/ipath/ipath_user_sdma.c
@@ -0,0 +1,888 @@
+/*
+ * Copyright (c) 2007, 2008 QLogic Corporation. 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.
+ */
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/uio.h>
+#include <linux/rbtree.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+
+#include "ipath_kernel.h"
+#include "ipath_user_sdma.h"
+
+/* minimum size of header */
+#define IPATH_USER_SDMA_MIN_HEADER_LENGTH 64
+/* expected size of headers (for dma_pool) */
+#define IPATH_USER_SDMA_EXP_HEADER_LENGTH 64
+/* length mask in PBC (lower 11 bits) */
+#define IPATH_PBC_LENGTH_MASK ((1 << 11) - 1)
+
+struct ipath_user_sdma_pkt {
+ u8 naddr; /* dimension of addr (1..3) ... */
+ u32 counter; /* sdma pkts queued counter for this entry */
+ u64 added; /* global descq number of entries */
+
+ struct {
+ u32 offset; /* offset for kvaddr, addr */
+ u32 length; /* length in page */
+ u8 put_page; /* should we put_page? */
+ u8 dma_mapped; /* is page dma_mapped? */
+ struct page *page; /* may be NULL (coherent mem) */
+ void *kvaddr; /* FIXME: only for pio hack */
+ dma_addr_t addr;
+ } addr[4]; /* max pages, any more and we coalesce */
+ struct list_head list; /* list element */
+};
+
+struct ipath_user_sdma_queue {
+ /*
+ * pkts sent to dma engine are queued on this
+ * list head. the type of the elements of this
+ * list are struct ipath_user_sdma_pkt...
+ */
+ struct list_head sent;
+
+ /* headers with expected length are allocated from here... */
+ char header_cache_name[64];
+ struct dma_pool *header_cache;
+
+ /* packets are allocated from the slab cache... */
+ char pkt_slab_name[64];
+ struct kmem_cache *pkt_slab;
+
+ /* as packets go on the queued queue, they are counted... */
+ u32 counter;
+ u32 sent_counter;
+
+ /* dma page table */
+ struct rb_root dma_pages_root;
+
+ /* protect everything above... */
+ struct mutex lock;
+};
+
+struct ipath_user_sdma_queue *
+ipath_user_sdma_queue_create(struct device *dev, int unit, int port, int sport)
+{
+ struct ipath_user_sdma_queue *pq =
+ kmalloc(sizeof(struct ipath_user_sdma_queue), GFP_KERNEL);
+
+ if (!pq)
+ goto done;
+
+ pq->counter = 0;
+ pq->sent_counter = 0;
+ INIT_LIST_HEAD(&pq->sent);
+
+ mutex_init(&pq->lock);
+
+ snprintf(pq->pkt_slab_name, sizeof(pq->pkt_slab_name),
+ "ipath-user-sdma-pkts-%u-%02u.%02u", unit, port, sport);
+ pq->pkt_slab = kmem_cache_create(pq->pkt_slab_name,
+ sizeof(struct ipath_user_sdma_pkt),
+ 0, 0, NULL);
+
+ if (!pq->pkt_slab)
+ goto err_kfree;
+
+ snprintf(pq->header_cache_name, sizeof(pq->header_cache_name),
+ "ipath-user-sdma-headers-%u-%02u.%02u", unit, port, sport);
+ pq->header_cache = dma_pool_create(pq->header_cache_name,
+ dev,
+ IPATH_USER_SDMA_EXP_HEADER_LENGTH,
+ 4, 0);
+ if (!pq->header_cache)
+ goto err_slab;
+
+ pq->dma_pages_root = RB_ROOT;
+
+ goto done;
+
+err_slab:
+ kmem_cache_destroy(pq->pkt_slab);
+err_kfree:
+ kfree(pq);
+ pq = NULL;
+
+done:
+ return pq;
+}
+
+static void ipath_user_sdma_init_frag(struct ipath_user_sdma_pkt *pkt,
+ int i, size_t offset, size_t len,
+ int put_page, int dma_mapped,
+ struct page *page,
+ void *kvaddr, dma_addr_t dma_addr)
+{
+ pkt->addr[i].offset = offset;
+ pkt->addr[i].length = len;
+ pkt->addr[i].put_page = put_page;
+ pkt->addr[i].dma_mapped = dma_mapped;
+ pkt->addr[i].page = page;
+ pkt->addr[i].kvaddr = kvaddr;
+ pkt->addr[i].addr = dma_addr;
+}
+
+static void ipath_user_sdma_init_header(struct ipath_user_sdma_pkt *pkt,
+ u32 counter, size_t offset,
+ size_t len, int dma_mapped,
+ struct page *page,
+ void *kvaddr, dma_addr_t dma_addr)
+{
+ pkt->naddr = 1;
+ pkt->counter = counter;
+ ipath_user_sdma_init_frag(pkt, 0, offset, len, 0, dma_mapped, page,
+ kvaddr, dma_addr);
+}
+
+/* we've too many pages in the iovec, coalesce to a single page */
+static int ipath_user_sdma_coalesce(const struct ipath_devdata *dd,
+ struct ipath_user_sdma_pkt *pkt,
+ const struct iovec *iov,
+ unsigned long niov) {
+ int ret = 0;
+ struct page *page = alloc_page(GFP_KERNEL);
+ void *mpage_save;
+ char *mpage;
+ int i;
+ int len = 0;
+ dma_addr_t dma_addr;
+
+ if (!page) {
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ mpage = kmap(page);
+ mpage_save = mpage;
+ for (i = 0; i < niov; i++) {
+ int cfur;
+
+ cfur = copy_from_user(mpage,
+ iov[i].iov_base, iov[i].iov_len);
+ if (cfur) {
+ ret = -EFAULT;
+ goto free_unmap;
+ }
+
+ mpage += iov[i].iov_len;
+ len += iov[i].iov_len;
+ }
+
+ dma_addr = dma_map_page(&dd->pcidev->dev, page, 0, len,
+ DMA_TO_DEVICE);
+ if (dma_mapping_error(dma_addr)) {
+ ret = -ENOMEM;
+ goto free_unmap;
+ }
+
+ ipath_user_sdma_init_frag(pkt, 1, 0, len, 0, 1, page, mpage_save,
+ dma_addr);
+ pkt->naddr = 2;
+
+ goto done;
+
+free_unmap:
+ kunmap(page);
+ __free_page(page);
+done:
+ return ret;
+}
+
+/* how many pages in this iovec element? */
+static int ipath_user_sdma_num_pages(const struct iovec *iov)
+{
+ const unsigned long addr = (unsigned long) iov->iov_base;
+ const unsigned long len = iov->iov_len;
+ const unsigned long spage = addr & PAGE_MASK;
+ const unsigned long epage = (addr + len - 1) & PAGE_MASK;
+
+ return 1 + ((epage - spage) >> PAGE_SHIFT);
+}
+
+/* truncate length to page boundry */
+static int ipath_user_sdma_page_length(unsigned long addr, unsigned long len)
+{
+ const unsigned long offset = addr & ~PAGE_MASK;
+
+ return ((offset + len) > PAGE_SIZE) ? (PAGE_SIZE - offset) : len;
+}
+
+static void ipath_user_sdma_free_pkt_frag(struct device *dev,
+ struct ipath_user_sdma_queue *pq,
+ struct ipath_user_sdma_pkt *pkt,
+ int frag)
+{
+ const int i = frag;
+
+ if (pkt->addr[i].page) {
+ if (pkt->addr[i].dma_mapped)
+ dma_unmap_page(dev,
+ pkt->addr[i].addr,
+ pkt->addr[i].length,
+ DMA_TO_DEVICE);
+
+ if (pkt->addr[i].kvaddr)
+ kunmap(pkt->addr[i].page);
+
+ if (pkt->addr[i].put_page)
+ put_page(pkt->addr[i].page);
+ else
+ __free_page(pkt->addr[i].page);
+ } else if (pkt->addr[i].kvaddr)
+ /* free coherent mem from cache... */
+ dma_pool_free(pq->header_cache,
+ pkt->addr[i].kvaddr, pkt->addr[i].addr);
+}
+
+/* return number of pages pinned... */
+static int ipath_user_sdma_pin_pages(const struct ipath_devdata *dd,
+ struct ipath_user_sdma_pkt *pkt,
+ unsigned long addr, int tlen, int npages)
+{
+ struct page *pages[2];
+ int j;
+ int ret;
+
+ ret = get_user_pages(current, current->mm, addr,
+ npages, 0, 1, pages, NULL);
+
+ if (ret != npages) {
+ int i;
+
+ for (i = 0; i < ret; i++)
+ put_page(pages[i]);
+
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ for (j = 0; j < npages; j++) {
+ /* map the pages... */
+ const int flen =
+ ipath_user_sdma_page_length(addr, tlen);
+ dma_addr_t dma_addr =
+ dma_map_page(&dd->pcidev->dev,
+ pages[j], 0, flen, DMA_TO_DEVICE);
+ unsigned long fofs = addr & ~PAGE_MASK;
+
+ if (dma_mapping_error(dma_addr)) {
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ ipath_user_sdma_init_frag(pkt, pkt->naddr, fofs, flen, 1, 1,
+ pages[j], kmap(pages[j]),
+ dma_addr);
+
+ pkt->naddr++;
+ addr += flen;
+ tlen -= flen;
+ }
+
+done:
+ return ret;
+}
+
+static int ipath_user_sdma_pin_pkt(const struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq,
+ struct ipath_user_sdma_pkt *pkt,
+ const struct iovec *iov,
+ unsigned long niov)
+{
+ int ret = 0;
+ unsigned long idx;
+
+ for (idx = 0; idx < niov; idx++) {
+ const int npages = ipath_user_sdma_num_pages(iov + idx);
+ const unsigned long addr = (unsigned long) iov[idx].iov_base;
+
+ ret = ipath_user_sdma_pin_pages(dd, pkt,
+ addr, iov[idx].iov_len,
+ npages);
+ if (ret < 0)
+ goto free_pkt;
+ }
+
+ goto done;
+
+free_pkt:
+ for (idx = 0; idx < pkt->naddr; idx++)
+ ipath_user_sdma_free_pkt_frag(&dd->pcidev->dev, pq, pkt, idx);
+
+done:
+ return ret;
+}
+
+static int ipath_user_sdma_init_payload(const struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq,
+ struct ipath_user_sdma_pkt *pkt,
+ const struct iovec *iov,
+ unsigned long niov, int npages)
+{
+ int ret = 0;
+
+ if (npages >= ARRAY_SIZE(pkt->addr))
+ ret = ipath_user_sdma_coalesce(dd, pkt, iov, niov);
+ else
+ ret = ipath_user_sdma_pin_pkt(dd, pq, pkt, iov, niov);
+
+ return ret;
+}
+
+/* free a packet list -- return counter value of last packet */
+static void ipath_user_sdma_free_pkt_list(struct device *dev,
+ struct ipath_user_sdma_queue *pq,
+ struct list_head *list)
+{
+ struct ipath_user_sdma_pkt *pkt, *pkt_next;
+
+ list_for_each_entry_safe(pkt, pkt_next, list, list) {
+ int i;
+
+ for (i = 0; i < pkt->naddr; i++)
+ ipath_user_sdma_free_pkt_frag(dev, pq, pkt, i);
+
+ kmem_cache_free(pq->pkt_slab, pkt);
+ }
+}
+
+/*
+ * copy headers, coalesce etc -- pq->lock must be held
+ *
+ * we queue all the packets to list, returning the
+ * number of bytes total. list must be empty initially,
+ * as, if there is an error we clean it...
+ */
+static int ipath_user_sdma_queue_pkts(const struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq,
+ struct list_head *list,
+ const struct iovec *iov,
+ unsigned long niov,
+ int maxpkts)
+{
+ unsigned long idx = 0;
+ int ret = 0;
+ int npkts = 0;
+ struct page *page = NULL;
+ __le32 *pbc;
+ dma_addr_t dma_addr;
+ struct ipath_user_sdma_pkt *pkt = NULL;
+ size_t len;
+ size_t nw;
+ u32 counter = pq->counter;
+ int dma_mapped = 0;
+
+ while (idx < niov && npkts < maxpkts) {
+ const unsigned long addr = (unsigned long) iov[idx].iov_base;
+ const unsigned long idx_save = idx;
+ unsigned pktnw;
+ unsigned pktnwc;
+ int nfrags = 0;
+ int npages = 0;
+ int cfur;
+
+ dma_mapped = 0;
+ len = iov[idx].iov_len;
+ nw = len >> 2;
+ page = NULL;
+
+ pkt = kmem_cache_alloc(pq->pkt_slab, GFP_KERNEL);
+ if (!pkt) {
+ ret = -ENOMEM;
+ goto free_list;
+ }
+
+ if (len < IPATH_USER_SDMA_MIN_HEADER_LENGTH ||
+ len > PAGE_SIZE || len & 3 || addr & 3) {
+ ret = -EINVAL;
+ goto free_pkt;
+ }
+
+ if (len == IPATH_USER_SDMA_EXP_HEADER_LENGTH)
+ pbc = dma_pool_alloc(pq->header_cache, GFP_KERNEL,
+ &dma_addr);
+ else
+ pbc = NULL;
+
+ if (!pbc) {
+ page = alloc_page(GFP_KERNEL);
+ if (!page) {
+ ret = -ENOMEM;
+ goto free_pkt;
+ }
+ pbc = kmap(page);
+ }
+
+ cfur = copy_from_user(pbc, iov[idx].iov_base, len);
+ if (cfur) {
+ ret = -EFAULT;
+ goto free_pbc;
+ }
+
+ /*
+ * this assignment is a bit strange. it's because the
+ * the pbc counts the number of 32 bit words in the full
+ * packet _except_ the first word of the pbc itself...
+ */
+ pktnwc = nw - 1;
+
+ /*
+ * pktnw computation yields the number of 32 bit words
+ * that the caller has indicated in the PBC. note that
+ * this is one less than the total number of words that
+ * goes to the send DMA engine as the first 32 bit word
+ * of the PBC itself is not counted. Armed with this count,
+ * we can verify that the packet is consistent with the
+ * iovec lengths.
+ */
+ pktnw = le32_to_cpu(*pbc) & IPATH_PBC_LENGTH_MASK;
+ if (pktnw < pktnwc || pktnw > pktnwc + (PAGE_SIZE >> 2)) {
+ ret = -EINVAL;
+ goto free_pbc;
+ }
+
+
+ idx++;
+ while (pktnwc < pktnw && idx < niov) {
+ const size_t slen = iov[idx].iov_len;
+ const unsigned long faddr =
+ (unsigned long) iov[idx].iov_base;
+
+ if (slen & 3 || faddr & 3 || !slen ||
+ slen > PAGE_SIZE) {
+ ret = -EINVAL;
+ goto free_pbc;
+ }
+
+ npages++;
+ if ((faddr & PAGE_MASK) !=
+ ((faddr + slen - 1) & PAGE_MASK))
+ npages++;
+
+ pktnwc += slen >> 2;
+ idx++;
+ nfrags++;
+ }
+
+ if (pktnwc != pktnw) {
+ ret = -EINVAL;
+ goto free_pbc;
+ }
+
+ if (page) {
+ dma_addr = dma_map_page(&dd->pcidev->dev,
+ page, 0, len, DMA_TO_DEVICE);
+ if (dma_mapping_error(dma_addr)) {
+ ret = -ENOMEM;
+ goto free_pbc;
+ }
+
+ dma_mapped = 1;
+ }
+
+ ipath_user_sdma_init_header(pkt, counter, 0, len, dma_mapped,
+ page, pbc, dma_addr);
+
+ if (nfrags) {
+ ret = ipath_user_sdma_init_payload(dd, pq, pkt,
+ iov + idx_save + 1,
+ nfrags, npages);
+ if (ret < 0)
+ goto free_pbc_dma;
+ }
+
+ counter++;
+ npkts++;
+
+ list_add_tail(&pkt->list, list);
+ }
+
+ ret = idx;
+ goto done;
+
+free_pbc_dma:
+ if (dma_mapped)
+ dma_unmap_page(&dd->pcidev->dev, dma_addr, len, DMA_TO_DEVICE);
+free_pbc:
+ if (page) {
+ kunmap(page);
+ __free_page(page);
+ } else
+ dma_pool_free(pq->header_cache, pbc, dma_addr);
+free_pkt:
+ kmem_cache_free(pq->pkt_slab, pkt);
+free_list:
+ ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, list);
+done:
+ return ret;
+}
+
+/* try to clean out queue -- needs pq->lock */
+static int ipath_user_sdma_queue_clean(const struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq)
+{
+ struct list_head free_list;
+ struct ipath_user_sdma_pkt *pkt;
+ struct ipath_user_sdma_pkt *pkt_prev;
+ int ret = 0;
+
+ INIT_LIST_HEAD(&free_list);
+
+ list_for_each_entry_safe(pkt, pkt_prev, &pq->sent, list) {
+ s64 descd = dd->ipath_sdma_descq_removed - pkt->added;
+
+ if (descd < 0)
+ break;
+
+ list_move_tail(&pkt->list, &free_list);
+
+ /* one more packet cleaned */
+ ret++;
+ }
+
+ if (!list_empty(&free_list)) {
+ u32 counter;
+
+ pkt = list_entry(free_list.prev,
+ struct ipath_user_sdma_pkt, list);
+ counter = pkt->counter;
+
+ ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
+ ipath_user_sdma_set_complete_counter(pq, counter);
+ }
+
+ return ret;
+}
+
+void ipath_user_sdma_queue_destroy(struct ipath_user_sdma_queue *pq)
+{
+ if (!pq)
+ return;
+
+ kmem_cache_destroy(pq->pkt_slab);
+ dma_pool_destroy(pq->header_cache);
+ kfree(pq);
+}
+
+/* clean descriptor queue, returns > 0 if some elements cleaned */
+static int ipath_user_sdma_hwqueue_clean(struct ipath_devdata *dd)
+{
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
+ ret = ipath_sdma_make_progress(dd);
+ spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
+
+ return ret;
+}
+
+/* we're in close, drain packets so that we can cleanup successfully... */
+void ipath_user_sdma_queue_drain(struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq)
+{
+ int i;
+
+ if (!pq)
+ return;
+
+ for (i = 0; i < 100; i++) {
+ mutex_lock(&pq->lock);
+ if (list_empty(&pq->sent)) {
+ mutex_unlock(&pq->lock);
+ break;
+ }
+ ipath_user_sdma_hwqueue_clean(dd);
+ ipath_user_sdma_queue_clean(dd, pq);
+ mutex_unlock(&pq->lock);
+ msleep(10);
+ }
+
+ if (!list_empty(&pq->sent)) {
+ struct list_head free_list;
+
+ printk(KERN_INFO "drain: lists not empty: forcing!\n");
+ INIT_LIST_HEAD(&free_list);
+ mutex_lock(&pq->lock);
+ list_splice_init(&pq->sent, &free_list);
+ ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &free_list);
+ mutex_unlock(&pq->lock);
+ }
+}
+
+static inline __le64 ipath_sdma_make_desc0(struct ipath_devdata *dd,
+ u64 addr, u64 dwlen, u64 dwoffset)
+{
+ return cpu_to_le64(/* SDmaPhyAddr[31:0] */
+ ((addr & 0xfffffffcULL) << 32) |
+ /* SDmaGeneration[1:0] */
+ ((dd->ipath_sdma_generation & 3ULL) << 30) |
+ /* SDmaDwordCount[10:0] */
+ ((dwlen & 0x7ffULL) << 16) |
+ /* SDmaBufOffset[12:2] */
+ (dwoffset & 0x7ffULL));
+}
+
+static inline __le64 ipath_sdma_make_first_desc0(__le64 descq)
+{
+ return descq | __constant_cpu_to_le64(1ULL << 12);
+}
+
+static inline __le64 ipath_sdma_make_last_desc0(__le64 descq)
+{
+ /* last */ /* dma head */
+ return descq | __constant_cpu_to_le64(1ULL << 11 | 1ULL << 13);
+}
+
+static inline __le64 ipath_sdma_make_desc1(u64 addr)
+{
+ /* SDmaPhyAddr[47:32] */
+ return cpu_to_le64(addr >> 32);
+}
+
+static void ipath_user_sdma_send_frag(struct ipath_devdata *dd,
+ struct ipath_user_sdma_pkt *pkt, int idx,
+ unsigned ofs, u16 tail)
+{
+ const u64 addr = (u64) pkt->addr[idx].addr +
+ (u64) pkt->addr[idx].offset;
+ const u64 dwlen = (u64) pkt->addr[idx].length / 4;
+ __le64 *descqp;
+ __le64 descq0;
+
+ descqp = &dd->ipath_sdma_descq[tail].qw[0];
+
+ descq0 = ipath_sdma_make_desc0(dd, addr, dwlen, ofs);
+ if (idx == 0)
+ descq0 = ipath_sdma_make_first_desc0(descq0);
+ if (idx == pkt->naddr - 1)
+ descq0 = ipath_sdma_make_last_desc0(descq0);
+
+ descqp[0] = descq0;
+ descqp[1] = ipath_sdma_make_desc1(addr);
+}
+
+/* pq->lock must be held, get packets on the wire... */
+static int ipath_user_sdma_push_pkts(struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq,
+ struct list_head *pktlist)
+{
+ int ret = 0;
+ unsigned long flags;
+ u16 tail;
+
+ if (list_empty(pktlist))
+ return 0;
+
+ if (unlikely(!(dd->ipath_flags & IPATH_LINKACTIVE)))
+ return -ECOMM;
+
+ spin_lock_irqsave(&dd->ipath_sdma_lock, flags);
+
+ if (unlikely(dd->ipath_sdma_status & IPATH_SDMA_ABORT_MASK)) {
+ ret = -ECOMM;
+ goto unlock;
+ }
+
+ tail = dd->ipath_sdma_descq_tail;
+ while (!list_empty(pktlist)) {
+ struct ipath_user_sdma_pkt *pkt =
+ list_entry(pktlist->next, struct ipath_user_sdma_pkt,
+ list);
+ int i;
+ unsigned ofs = 0;
+ u16 dtail = tail;
+
+ if (pkt->naddr > ipath_sdma_descq_freecnt(dd))
+ goto unlock_check_tail;
+
+ for (i = 0; i < pkt->naddr; i++) {
+ ipath_user_sdma_send_frag(dd, pkt, i, ofs, tail);
+ ofs += pkt->addr[i].length >> 2;
+
+ if (++tail == dd->ipath_sdma_descq_cnt) {
+ tail = 0;
+ ++dd->ipath_sdma_generation;
+ }
+ }
+
+ if ((ofs<<2) > dd->ipath_ibmaxlen) {
+ ipath_dbg("packet size %X > ibmax %X, fail\n",
+ ofs<<2, dd->ipath_ibmaxlen);
+ ret = -EMSGSIZE;
+ goto unlock;
+ }
+
+ /*
+ * if the packet is >= 2KB mtu equivalent, we have to use
+ * the large buffers, and have to mark each descriptor as
+ * part of a large buffer packet.
+ */
+ if (ofs >= IPATH_SMALLBUF_DWORDS) {
+ for (i = 0; i < pkt->naddr; i++) {
+ dd->ipath_sdma_descq[dtail].qw[0] |=
+ __constant_cpu_to_le64(1ULL << 14);
+ if (++dtail == dd->ipath_sdma_descq_cnt)
+ dtail = 0;
+ }
+ }
+
+ dd->ipath_sdma_descq_added += pkt->naddr;
+ pkt->added = dd->ipath_sdma_descq_added;
+ list_move_tail(&pkt->list, &pq->sent);
+ ret++;
+ }
+
+unlock_check_tail:
+ /* advance the tail on the chip if necessary */
+ if (dd->ipath_sdma_descq_tail != tail) {
+ wmb();
+ ipath_write_kreg(dd, dd->ipath_kregs->kr_senddmatail, tail);
+ dd->ipath_sdma_descq_tail = tail;
+ }
+
+unlock:
+ spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);
+
+ return ret;
+}
+
+int ipath_user_sdma_writev(struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq,
+ const struct iovec *iov,
+ unsigned long dim)
+{
+ int ret = 0;
+ struct list_head list;
+ int npkts = 0;
+
+ INIT_LIST_HEAD(&list);
+
+ mutex_lock(&pq->lock);
+
+ if (dd->ipath_sdma_descq_added != dd->ipath_sdma_descq_removed) {
+ ipath_user_sdma_hwqueue_clean(dd);
+ ipath_user_sdma_queue_clean(dd, pq);
+ }
+
+ while (dim) {
+ const int mxp = 8;
+
+ down_write(¤t->mm->mmap_sem);
+ ret = ipath_user_sdma_queue_pkts(dd, pq, &list, iov, dim, mxp);
+ up_write(¤t->mm->mmap_sem);
+
+ if (ret <= 0)
+ goto done_unlock;
+ else {
+ dim -= ret;
+ iov += ret;
+ }
+
+ /* force packets onto the sdma hw queue... */
+ if (!list_empty(&list)) {
+ /*
+ * lazily clean hw queue. the 4 is a guess of about
+ * how many sdma descriptors a packet will take (it
+ * doesn't have to be perfect).
+ */
+ if (ipath_sdma_descq_freecnt(dd) < ret * 4) {
+ ipath_user_sdma_hwqueue_clean(dd);
+ ipath_user_sdma_queue_clean(dd, pq);
+ }
+
+ ret = ipath_user_sdma_push_pkts(dd, pq, &list);
+ if (ret < 0)
+ goto done_unlock;
+ else {
+ npkts += ret;
+ pq->counter += ret;
+
+ if (!list_empty(&list))
+ goto done_unlock;
+ }
+ }
+ }
+
+done_unlock:
+ if (!list_empty(&list))
+ ipath_user_sdma_free_pkt_list(&dd->pcidev->dev, pq, &list);
+ mutex_unlock(&pq->lock);
+
+ return (ret < 0) ? ret : npkts;
+}
+
+int ipath_user_sdma_make_progress(struct ipath_devdata *dd,
+ struct ipath_user_sdma_queue *pq)
+{
+ int ret = 0;
+
+ mutex_lock(&pq->lock);
+ ipath_user_sdma_hwqueue_clean(dd);
+ ret = ipath_user_sdma_queue_clean(dd, pq);
+ mutex_unlock(&pq->lock);
+
+ return ret;
+}
+
+int ipath_user_sdma_pkt_sent(const struct ipath_user_sdma_queue *pq,
+ u32 counter)
+{
+ const u32 scounter = ipath_user_sdma_complete_counter(pq);
+ const s32 dcounter = scounter - counter;
+
+ return dcounter >= 0;
+}
+
+u32 ipath_user_sdma_complete_counter(const struct ipath_user_sdma_queue *pq)
+{
+ return pq->sent_counter;
+}
+
+void ipath_user_sdma_set_complete_counter(struct ipath_user_sdma_queue *pq,
+ u32 c)
+{
+ pq->sent_counter = c;
+}
+
+u32 ipath_user_sdma_inflight_counter(struct ipath_user_sdma_queue *pq)
+{
+ return pq->counter;
+}
+
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