diff options
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/ipath/ipath_user_sdma.c | 879 |
1 files changed, 879 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 00000000000..86e016916cd --- /dev/null +++ b/drivers/infiniband/hw/ipath/ipath_user_sdma.c @@ -0,0 +1,879 @@ +/* + * 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; +} + +static void ipath_user_sdma_set_complete_counter(struct ipath_user_sdma_queue *pq, + u32 c) +{ + pq->sent_counter = c; +} + +/* 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; +} + +u32 ipath_user_sdma_complete_counter(const struct ipath_user_sdma_queue *pq) +{ + return pq->sent_counter; +} + +u32 ipath_user_sdma_inflight_counter(struct ipath_user_sdma_queue *pq) +{ + return pq->counter; +} + |