diff options
Diffstat (limited to 'drivers/infiniband/hw/hfi1/user_sdma.c')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/user_sdma.c | 1694 |
1 files changed, 1694 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c new file mode 100644 index 000000000..a67791187 --- /dev/null +++ b/drivers/infiniband/hw/hfi1/user_sdma.c @@ -0,0 +1,1694 @@ +/* + * Copyright(c) 2020 - Cornelis Networks, Inc. + * Copyright(c) 2015 - 2018 Intel Corporation. + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * BSD LICENSE + * + * 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. + * - Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ +#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 <linux/kthread.h> +#include <linux/mmu_context.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/string.h> + +#include "hfi.h" +#include "sdma.h" +#include "user_sdma.h" +#include "verbs.h" /* for the headers */ +#include "common.h" /* for struct hfi1_tid_info */ +#include "trace.h" + +static uint hfi1_sdma_comp_ring_size = 128; +module_param_named(sdma_comp_size, hfi1_sdma_comp_ring_size, uint, S_IRUGO); +MODULE_PARM_DESC(sdma_comp_size, "Size of User SDMA completion ring. Default: 128"); + +static unsigned initial_pkt_count = 8; + +static int user_sdma_send_pkts(struct user_sdma_request *req, u16 maxpkts); +static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status); +static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq); +static void user_sdma_free_request(struct user_sdma_request *req); +static int check_header_template(struct user_sdma_request *req, + struct hfi1_pkt_header *hdr, u32 lrhlen, + u32 datalen); +static int set_txreq_header(struct user_sdma_request *req, + struct user_sdma_txreq *tx, u32 datalen); +static int set_txreq_header_ahg(struct user_sdma_request *req, + struct user_sdma_txreq *tx, u32 len); +static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq, + struct hfi1_user_sdma_comp_q *cq, + u16 idx, enum hfi1_sdma_comp_state state, + int ret); +static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags); +static inline u32 get_lrh_len(struct hfi1_pkt_header, u32 len); + +static int defer_packet_queue( + struct sdma_engine *sde, + struct iowait_work *wait, + struct sdma_txreq *txreq, + uint seq, + bool pkts_sent); +static void activate_packet_queue(struct iowait *wait, int reason); +static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr, + unsigned long len); +static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode, + void *arg2, bool *stop); +static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode); + +static struct mmu_rb_ops sdma_rb_ops = { + .filter = sdma_rb_filter, + .evict = sdma_rb_evict, + .remove = sdma_rb_remove, +}; + +static int add_system_pages_to_sdma_packet(struct user_sdma_request *req, + struct user_sdma_txreq *tx, + struct user_sdma_iovec *iovec, + u32 *pkt_remaining); + +static int defer_packet_queue( + struct sdma_engine *sde, + struct iowait_work *wait, + struct sdma_txreq *txreq, + uint seq, + bool pkts_sent) +{ + struct hfi1_user_sdma_pkt_q *pq = + container_of(wait->iow, struct hfi1_user_sdma_pkt_q, busy); + + write_seqlock(&sde->waitlock); + trace_hfi1_usdma_defer(pq, sde, &pq->busy); + if (sdma_progress(sde, seq, txreq)) + goto eagain; + /* + * We are assuming that if the list is enqueued somewhere, it + * is to the dmawait list since that is the only place where + * it is supposed to be enqueued. + */ + xchg(&pq->state, SDMA_PKT_Q_DEFERRED); + if (list_empty(&pq->busy.list)) { + pq->busy.lock = &sde->waitlock; + iowait_get_priority(&pq->busy); + iowait_queue(pkts_sent, &pq->busy, &sde->dmawait); + } + write_sequnlock(&sde->waitlock); + return -EBUSY; +eagain: + write_sequnlock(&sde->waitlock); + return -EAGAIN; +} + +static void activate_packet_queue(struct iowait *wait, int reason) +{ + struct hfi1_user_sdma_pkt_q *pq = + container_of(wait, struct hfi1_user_sdma_pkt_q, busy); + + trace_hfi1_usdma_activate(pq, wait, reason); + xchg(&pq->state, SDMA_PKT_Q_ACTIVE); + wake_up(&wait->wait_dma); +}; + +int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt, + struct hfi1_filedata *fd) +{ + int ret = -ENOMEM; + char buf[64]; + struct hfi1_devdata *dd; + struct hfi1_user_sdma_comp_q *cq; + struct hfi1_user_sdma_pkt_q *pq; + + if (!uctxt || !fd) + return -EBADF; + + if (!hfi1_sdma_comp_ring_size) + return -EINVAL; + + dd = uctxt->dd; + + pq = kzalloc(sizeof(*pq), GFP_KERNEL); + if (!pq) + return -ENOMEM; + pq->dd = dd; + pq->ctxt = uctxt->ctxt; + pq->subctxt = fd->subctxt; + pq->n_max_reqs = hfi1_sdma_comp_ring_size; + atomic_set(&pq->n_reqs, 0); + init_waitqueue_head(&pq->wait); + atomic_set(&pq->n_locked, 0); + + iowait_init(&pq->busy, 0, NULL, NULL, defer_packet_queue, + activate_packet_queue, NULL, NULL); + pq->reqidx = 0; + + pq->reqs = kcalloc(hfi1_sdma_comp_ring_size, + sizeof(*pq->reqs), + GFP_KERNEL); + if (!pq->reqs) + goto pq_reqs_nomem; + + pq->req_in_use = bitmap_zalloc(hfi1_sdma_comp_ring_size, GFP_KERNEL); + if (!pq->req_in_use) + goto pq_reqs_no_in_use; + + snprintf(buf, 64, "txreq-kmem-cache-%u-%u-%u", dd->unit, uctxt->ctxt, + fd->subctxt); + pq->txreq_cache = kmem_cache_create(buf, + sizeof(struct user_sdma_txreq), + L1_CACHE_BYTES, + SLAB_HWCACHE_ALIGN, + NULL); + if (!pq->txreq_cache) { + dd_dev_err(dd, "[%u] Failed to allocate TxReq cache\n", + uctxt->ctxt); + goto pq_txreq_nomem; + } + + cq = kzalloc(sizeof(*cq), GFP_KERNEL); + if (!cq) + goto cq_nomem; + + cq->comps = vmalloc_user(PAGE_ALIGN(sizeof(*cq->comps) + * hfi1_sdma_comp_ring_size)); + if (!cq->comps) + goto cq_comps_nomem; + + cq->nentries = hfi1_sdma_comp_ring_size; + + ret = hfi1_mmu_rb_register(pq, &sdma_rb_ops, dd->pport->hfi1_wq, + &pq->handler); + if (ret) { + dd_dev_err(dd, "Failed to register with MMU %d", ret); + goto pq_mmu_fail; + } + + rcu_assign_pointer(fd->pq, pq); + fd->cq = cq; + + return 0; + +pq_mmu_fail: + vfree(cq->comps); +cq_comps_nomem: + kfree(cq); +cq_nomem: + kmem_cache_destroy(pq->txreq_cache); +pq_txreq_nomem: + bitmap_free(pq->req_in_use); +pq_reqs_no_in_use: + kfree(pq->reqs); +pq_reqs_nomem: + kfree(pq); + + return ret; +} + +static void flush_pq_iowait(struct hfi1_user_sdma_pkt_q *pq) +{ + unsigned long flags; + seqlock_t *lock = pq->busy.lock; + + if (!lock) + return; + write_seqlock_irqsave(lock, flags); + if (!list_empty(&pq->busy.list)) { + list_del_init(&pq->busy.list); + pq->busy.lock = NULL; + } + write_sequnlock_irqrestore(lock, flags); +} + +int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd, + struct hfi1_ctxtdata *uctxt) +{ + struct hfi1_user_sdma_pkt_q *pq; + + trace_hfi1_sdma_user_free_queues(uctxt->dd, uctxt->ctxt, fd->subctxt); + + spin_lock(&fd->pq_rcu_lock); + pq = srcu_dereference_check(fd->pq, &fd->pq_srcu, + lockdep_is_held(&fd->pq_rcu_lock)); + if (pq) { + rcu_assign_pointer(fd->pq, NULL); + spin_unlock(&fd->pq_rcu_lock); + synchronize_srcu(&fd->pq_srcu); + /* at this point there can be no more new requests */ + iowait_sdma_drain(&pq->busy); + /* Wait until all requests have been freed. */ + wait_event_interruptible( + pq->wait, + !atomic_read(&pq->n_reqs)); + kfree(pq->reqs); + if (pq->handler) + hfi1_mmu_rb_unregister(pq->handler); + bitmap_free(pq->req_in_use); + kmem_cache_destroy(pq->txreq_cache); + flush_pq_iowait(pq); + kfree(pq); + } else { + spin_unlock(&fd->pq_rcu_lock); + } + if (fd->cq) { + vfree(fd->cq->comps); + kfree(fd->cq); + fd->cq = NULL; + } + return 0; +} + +static u8 dlid_to_selector(u16 dlid) +{ + static u8 mapping[256]; + static int initialized; + static u8 next; + int hash; + + if (!initialized) { + memset(mapping, 0xFF, 256); + initialized = 1; + } + + hash = ((dlid >> 8) ^ dlid) & 0xFF; + if (mapping[hash] == 0xFF) { + mapping[hash] = next; + next = (next + 1) & 0x7F; + } + + return mapping[hash]; +} + +/** + * hfi1_user_sdma_process_request() - Process and start a user sdma request + * @fd: valid file descriptor + * @iovec: array of io vectors to process + * @dim: overall iovec array size + * @count: number of io vector array entries processed + */ +int hfi1_user_sdma_process_request(struct hfi1_filedata *fd, + struct iovec *iovec, unsigned long dim, + unsigned long *count) +{ + int ret = 0, i; + struct hfi1_ctxtdata *uctxt = fd->uctxt; + struct hfi1_user_sdma_pkt_q *pq = + srcu_dereference(fd->pq, &fd->pq_srcu); + struct hfi1_user_sdma_comp_q *cq = fd->cq; + struct hfi1_devdata *dd = pq->dd; + unsigned long idx = 0; + u8 pcount = initial_pkt_count; + struct sdma_req_info info; + struct user_sdma_request *req; + u8 opcode, sc, vl; + u16 pkey; + u32 slid; + u16 dlid; + u32 selector; + + if (iovec[idx].iov_len < sizeof(info) + sizeof(req->hdr)) { + hfi1_cdbg( + SDMA, + "[%u:%u:%u] First vector not big enough for header %lu/%lu", + dd->unit, uctxt->ctxt, fd->subctxt, + iovec[idx].iov_len, sizeof(info) + sizeof(req->hdr)); + return -EINVAL; + } + ret = copy_from_user(&info, iovec[idx].iov_base, sizeof(info)); + if (ret) { + hfi1_cdbg(SDMA, "[%u:%u:%u] Failed to copy info QW (%d)", + dd->unit, uctxt->ctxt, fd->subctxt, ret); + return -EFAULT; + } + + trace_hfi1_sdma_user_reqinfo(dd, uctxt->ctxt, fd->subctxt, + (u16 *)&info); + if (info.comp_idx >= hfi1_sdma_comp_ring_size) { + hfi1_cdbg(SDMA, + "[%u:%u:%u:%u] Invalid comp index", + dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx); + return -EINVAL; + } + + /* + * Sanity check the header io vector count. Need at least 1 vector + * (header) and cannot be larger than the actual io vector count. + */ + if (req_iovcnt(info.ctrl) < 1 || req_iovcnt(info.ctrl) > dim) { + hfi1_cdbg(SDMA, + "[%u:%u:%u:%u] Invalid iov count %d, dim %ld", + dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx, + req_iovcnt(info.ctrl), dim); + return -EINVAL; + } + + if (!info.fragsize) { + hfi1_cdbg(SDMA, + "[%u:%u:%u:%u] Request does not specify fragsize", + dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx); + return -EINVAL; + } + + /* Try to claim the request. */ + if (test_and_set_bit(info.comp_idx, pq->req_in_use)) { + hfi1_cdbg(SDMA, "[%u:%u:%u] Entry %u is in use", + dd->unit, uctxt->ctxt, fd->subctxt, + info.comp_idx); + return -EBADSLT; + } + /* + * All safety checks have been done and this request has been claimed. + */ + trace_hfi1_sdma_user_process_request(dd, uctxt->ctxt, fd->subctxt, + info.comp_idx); + req = pq->reqs + info.comp_idx; + req->data_iovs = req_iovcnt(info.ctrl) - 1; /* subtract header vector */ + req->data_len = 0; + req->pq = pq; + req->cq = cq; + req->ahg_idx = -1; + req->iov_idx = 0; + req->sent = 0; + req->seqnum = 0; + req->seqcomp = 0; + req->seqsubmitted = 0; + req->tids = NULL; + req->has_error = 0; + INIT_LIST_HEAD(&req->txps); + + memcpy(&req->info, &info, sizeof(info)); + + /* The request is initialized, count it */ + atomic_inc(&pq->n_reqs); + + if (req_opcode(info.ctrl) == EXPECTED) { + /* expected must have a TID info and at least one data vector */ + if (req->data_iovs < 2) { + SDMA_DBG(req, + "Not enough vectors for expected request"); + ret = -EINVAL; + goto free_req; + } + req->data_iovs--; + } + + if (!info.npkts || req->data_iovs > MAX_VECTORS_PER_REQ) { + SDMA_DBG(req, "Too many vectors (%u/%u)", req->data_iovs, + MAX_VECTORS_PER_REQ); + ret = -EINVAL; + goto free_req; + } + + /* Copy the header from the user buffer */ + ret = copy_from_user(&req->hdr, iovec[idx].iov_base + sizeof(info), + sizeof(req->hdr)); + if (ret) { + SDMA_DBG(req, "Failed to copy header template (%d)", ret); + ret = -EFAULT; + goto free_req; + } + + /* If Static rate control is not enabled, sanitize the header. */ + if (!HFI1_CAP_IS_USET(STATIC_RATE_CTRL)) + req->hdr.pbc[2] = 0; + + /* Validate the opcode. Do not trust packets from user space blindly. */ + opcode = (be32_to_cpu(req->hdr.bth[0]) >> 24) & 0xff; + if ((opcode & USER_OPCODE_CHECK_MASK) != + USER_OPCODE_CHECK_VAL) { + SDMA_DBG(req, "Invalid opcode (%d)", opcode); + ret = -EINVAL; + goto free_req; + } + /* + * Validate the vl. Do not trust packets from user space blindly. + * VL comes from PBC, SC comes from LRH, and the VL needs to + * match the SC look up. + */ + vl = (le16_to_cpu(req->hdr.pbc[0]) >> 12) & 0xF; + sc = (((be16_to_cpu(req->hdr.lrh[0]) >> 12) & 0xF) | + (((le16_to_cpu(req->hdr.pbc[1]) >> 14) & 0x1) << 4)); + if (vl >= dd->pport->vls_operational || + vl != sc_to_vlt(dd, sc)) { + SDMA_DBG(req, "Invalid SC(%u)/VL(%u)", sc, vl); + ret = -EINVAL; + goto free_req; + } + + /* Checking P_KEY for requests from user-space */ + pkey = (u16)be32_to_cpu(req->hdr.bth[0]); + slid = be16_to_cpu(req->hdr.lrh[3]); + if (egress_pkey_check(dd->pport, slid, pkey, sc, PKEY_CHECK_INVALID)) { + ret = -EINVAL; + goto free_req; + } + + /* + * Also should check the BTH.lnh. If it says the next header is GRH then + * the RXE parsing will be off and will land in the middle of the KDETH + * or miss it entirely. + */ + if ((be16_to_cpu(req->hdr.lrh[0]) & 0x3) == HFI1_LRH_GRH) { + SDMA_DBG(req, "User tried to pass in a GRH"); + ret = -EINVAL; + goto free_req; + } + + req->koffset = le32_to_cpu(req->hdr.kdeth.swdata[6]); + /* + * Calculate the initial TID offset based on the values of + * KDETH.OFFSET and KDETH.OM that are passed in. + */ + req->tidoffset = KDETH_GET(req->hdr.kdeth.ver_tid_offset, OFFSET) * + (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ? + KDETH_OM_LARGE : KDETH_OM_SMALL); + trace_hfi1_sdma_user_initial_tidoffset(dd, uctxt->ctxt, fd->subctxt, + info.comp_idx, req->tidoffset); + idx++; + + /* Save all the IO vector structures */ + for (i = 0; i < req->data_iovs; i++) { + req->iovs[i].offset = 0; + INIT_LIST_HEAD(&req->iovs[i].list); + memcpy(&req->iovs[i].iov, + iovec + idx++, + sizeof(req->iovs[i].iov)); + if (req->iovs[i].iov.iov_len == 0) { + ret = -EINVAL; + goto free_req; + } + req->data_len += req->iovs[i].iov.iov_len; + } + trace_hfi1_sdma_user_data_length(dd, uctxt->ctxt, fd->subctxt, + info.comp_idx, req->data_len); + if (pcount > req->info.npkts) + pcount = req->info.npkts; + /* + * Copy any TID info + * User space will provide the TID info only when the + * request type is EXPECTED. This is true even if there is + * only one packet in the request and the header is already + * setup. The reason for the singular TID case is that the + * driver needs to perform safety checks. + */ + if (req_opcode(req->info.ctrl) == EXPECTED) { + u16 ntids = iovec[idx].iov_len / sizeof(*req->tids); + u32 *tmp; + + if (!ntids || ntids > MAX_TID_PAIR_ENTRIES) { + ret = -EINVAL; + goto free_req; + } + + /* + * We have to copy all of the tids because they may vary + * in size and, therefore, the TID count might not be + * equal to the pkt count. However, there is no way to + * tell at this point. + */ + tmp = memdup_user(iovec[idx].iov_base, + ntids * sizeof(*req->tids)); + if (IS_ERR(tmp)) { + ret = PTR_ERR(tmp); + SDMA_DBG(req, "Failed to copy %d TIDs (%d)", + ntids, ret); + goto free_req; + } + req->tids = tmp; + req->n_tids = ntids; + req->tididx = 0; + idx++; + } + + dlid = be16_to_cpu(req->hdr.lrh[1]); + selector = dlid_to_selector(dlid); + selector += uctxt->ctxt + fd->subctxt; + req->sde = sdma_select_user_engine(dd, selector, vl); + + if (!req->sde || !sdma_running(req->sde)) { + ret = -ECOMM; + goto free_req; + } + + /* We don't need an AHG entry if the request contains only one packet */ + if (req->info.npkts > 1 && HFI1_CAP_IS_USET(SDMA_AHG)) + req->ahg_idx = sdma_ahg_alloc(req->sde); + + set_comp_state(pq, cq, info.comp_idx, QUEUED, 0); + pq->state = SDMA_PKT_Q_ACTIVE; + + /* + * This is a somewhat blocking send implementation. + * The driver will block the caller until all packets of the + * request have been submitted to the SDMA engine. However, it + * will not wait for send completions. + */ + while (req->seqsubmitted != req->info.npkts) { + ret = user_sdma_send_pkts(req, pcount); + if (ret < 0) { + int we_ret; + + if (ret != -EBUSY) + goto free_req; + we_ret = wait_event_interruptible_timeout( + pq->busy.wait_dma, + pq->state == SDMA_PKT_Q_ACTIVE, + msecs_to_jiffies( + SDMA_IOWAIT_TIMEOUT)); + trace_hfi1_usdma_we(pq, we_ret); + if (we_ret <= 0) + flush_pq_iowait(pq); + } + } + *count += idx; + return 0; +free_req: + /* + * If the submitted seqsubmitted == npkts, the completion routine + * controls the final state. If sequbmitted < npkts, wait for any + * outstanding packets to finish before cleaning up. + */ + if (req->seqsubmitted < req->info.npkts) { + if (req->seqsubmitted) + wait_event(pq->busy.wait_dma, + (req->seqcomp == req->seqsubmitted - 1)); + user_sdma_free_request(req); + pq_update(pq); + set_comp_state(pq, cq, info.comp_idx, ERROR, ret); + } + return ret; +} + +static inline u32 compute_data_length(struct user_sdma_request *req, + struct user_sdma_txreq *tx) +{ + /* + * Determine the proper size of the packet data. + * The size of the data of the first packet is in the header + * template. However, it includes the header and ICRC, which need + * to be subtracted. + * The minimum representable packet data length in a header is 4 bytes, + * therefore, when the data length request is less than 4 bytes, there's + * only one packet, and the packet data length is equal to that of the + * request data length. + * The size of the remaining packets is the minimum of the frag + * size (MTU) or remaining data in the request. + */ + u32 len; + + if (!req->seqnum) { + if (req->data_len < sizeof(u32)) + len = req->data_len; + else + len = ((be16_to_cpu(req->hdr.lrh[2]) << 2) - + (sizeof(tx->hdr) - 4)); + } else if (req_opcode(req->info.ctrl) == EXPECTED) { + u32 tidlen = EXP_TID_GET(req->tids[req->tididx], LEN) * + PAGE_SIZE; + /* + * Get the data length based on the remaining space in the + * TID pair. + */ + len = min(tidlen - req->tidoffset, (u32)req->info.fragsize); + /* If we've filled up the TID pair, move to the next one. */ + if (unlikely(!len) && ++req->tididx < req->n_tids && + req->tids[req->tididx]) { + tidlen = EXP_TID_GET(req->tids[req->tididx], + LEN) * PAGE_SIZE; + req->tidoffset = 0; + len = min_t(u32, tidlen, req->info.fragsize); + } + /* + * Since the TID pairs map entire pages, make sure that we + * are not going to try to send more data that we have + * remaining. + */ + len = min(len, req->data_len - req->sent); + } else { + len = min(req->data_len - req->sent, (u32)req->info.fragsize); + } + trace_hfi1_sdma_user_compute_length(req->pq->dd, + req->pq->ctxt, + req->pq->subctxt, + req->info.comp_idx, + len); + return len; +} + +static inline u32 pad_len(u32 len) +{ + if (len & (sizeof(u32) - 1)) + len += sizeof(u32) - (len & (sizeof(u32) - 1)); + return len; +} + +static inline u32 get_lrh_len(struct hfi1_pkt_header hdr, u32 len) +{ + /* (Size of complete header - size of PBC) + 4B ICRC + data length */ + return ((sizeof(hdr) - sizeof(hdr.pbc)) + 4 + len); +} + +static int user_sdma_txadd_ahg(struct user_sdma_request *req, + struct user_sdma_txreq *tx, + u32 datalen) +{ + int ret; + u16 pbclen = le16_to_cpu(req->hdr.pbc[0]); + u32 lrhlen = get_lrh_len(req->hdr, pad_len(datalen)); + struct hfi1_user_sdma_pkt_q *pq = req->pq; + + /* + * Copy the request header into the tx header + * because the HW needs a cacheline-aligned + * address. + * This copy can be optimized out if the hdr + * member of user_sdma_request were also + * cacheline aligned. + */ + memcpy(&tx->hdr, &req->hdr, sizeof(tx->hdr)); + if (PBC2LRH(pbclen) != lrhlen) { + pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen); + tx->hdr.pbc[0] = cpu_to_le16(pbclen); + } + ret = check_header_template(req, &tx->hdr, lrhlen, datalen); + if (ret) + return ret; + ret = sdma_txinit_ahg(&tx->txreq, SDMA_TXREQ_F_AHG_COPY, + sizeof(tx->hdr) + datalen, req->ahg_idx, + 0, NULL, 0, user_sdma_txreq_cb); + if (ret) + return ret; + ret = sdma_txadd_kvaddr(pq->dd, &tx->txreq, &tx->hdr, sizeof(tx->hdr)); + if (ret) + sdma_txclean(pq->dd, &tx->txreq); + return ret; +} + +static int user_sdma_send_pkts(struct user_sdma_request *req, u16 maxpkts) +{ + int ret = 0; + u16 count; + unsigned npkts = 0; + struct user_sdma_txreq *tx = NULL; + struct hfi1_user_sdma_pkt_q *pq = NULL; + struct user_sdma_iovec *iovec = NULL; + + if (!req->pq) + return -EINVAL; + + pq = req->pq; + + /* If tx completion has reported an error, we are done. */ + if (READ_ONCE(req->has_error)) + return -EFAULT; + + /* + * Check if we might have sent the entire request already + */ + if (unlikely(req->seqnum == req->info.npkts)) { + if (!list_empty(&req->txps)) + goto dosend; + return ret; + } + + if (!maxpkts || maxpkts > req->info.npkts - req->seqnum) + maxpkts = req->info.npkts - req->seqnum; + + while (npkts < maxpkts) { + u32 datalen = 0; + + /* + * Check whether any of the completions have come back + * with errors. If so, we are not going to process any + * more packets from this request. + */ + if (READ_ONCE(req->has_error)) + return -EFAULT; + + tx = kmem_cache_alloc(pq->txreq_cache, GFP_KERNEL); + if (!tx) + return -ENOMEM; + + tx->flags = 0; + tx->req = req; + INIT_LIST_HEAD(&tx->list); + + /* + * For the last packet set the ACK request + * and disable header suppression. + */ + if (req->seqnum == req->info.npkts - 1) + tx->flags |= (TXREQ_FLAGS_REQ_ACK | + TXREQ_FLAGS_REQ_DISABLE_SH); + + /* + * Calculate the payload size - this is min of the fragment + * (MTU) size or the remaining bytes in the request but only + * if we have payload data. + */ + if (req->data_len) { + iovec = &req->iovs[req->iov_idx]; + if (READ_ONCE(iovec->offset) == iovec->iov.iov_len) { + if (++req->iov_idx == req->data_iovs) { + ret = -EFAULT; + goto free_tx; + } + iovec = &req->iovs[req->iov_idx]; + WARN_ON(iovec->offset); + } + + datalen = compute_data_length(req, tx); + + /* + * Disable header suppression for the payload <= 8DWS. + * If there is an uncorrectable error in the receive + * data FIFO when the received payload size is less than + * or equal to 8DWS then the RxDmaDataFifoRdUncErr is + * not reported.There is set RHF.EccErr if the header + * is not suppressed. + */ + if (!datalen) { + SDMA_DBG(req, + "Request has data but pkt len is 0"); + ret = -EFAULT; + goto free_tx; + } else if (datalen <= 32) { + tx->flags |= TXREQ_FLAGS_REQ_DISABLE_SH; + } + } + + if (req->ahg_idx >= 0) { + if (!req->seqnum) { + ret = user_sdma_txadd_ahg(req, tx, datalen); + if (ret) + goto free_tx; + } else { + int changes; + + changes = set_txreq_header_ahg(req, tx, + datalen); + if (changes < 0) { + ret = changes; + goto free_tx; + } + } + } else { + ret = sdma_txinit(&tx->txreq, 0, sizeof(req->hdr) + + datalen, user_sdma_txreq_cb); + if (ret) + goto free_tx; + /* + * Modify the header for this packet. This only needs + * to be done if we are not going to use AHG. Otherwise, + * the HW will do it based on the changes we gave it + * during sdma_txinit_ahg(). + */ + ret = set_txreq_header(req, tx, datalen); + if (ret) + goto free_txreq; + } + + req->koffset += datalen; + if (req_opcode(req->info.ctrl) == EXPECTED) + req->tidoffset += datalen; + req->sent += datalen; + while (datalen) { + ret = add_system_pages_to_sdma_packet(req, tx, iovec, + &datalen); + if (ret) + goto free_txreq; + iovec = &req->iovs[req->iov_idx]; + } + list_add_tail(&tx->txreq.list, &req->txps); + /* + * It is important to increment this here as it is used to + * generate the BTH.PSN and, therefore, can't be bulk-updated + * outside of the loop. + */ + tx->seqnum = req->seqnum++; + npkts++; + } +dosend: + ret = sdma_send_txlist(req->sde, + iowait_get_ib_work(&pq->busy), + &req->txps, &count); + req->seqsubmitted += count; + if (req->seqsubmitted == req->info.npkts) { + /* + * The txreq has already been submitted to the HW queue + * so we can free the AHG entry now. Corruption will not + * happen due to the sequential manner in which + * descriptors are processed. + */ + if (req->ahg_idx >= 0) + sdma_ahg_free(req->sde, req->ahg_idx); + } + return ret; + +free_txreq: + sdma_txclean(pq->dd, &tx->txreq); +free_tx: + kmem_cache_free(pq->txreq_cache, tx); + return ret; +} + +static u32 sdma_cache_evict(struct hfi1_user_sdma_pkt_q *pq, u32 npages) +{ + struct evict_data evict_data; + struct mmu_rb_handler *handler = pq->handler; + + evict_data.cleared = 0; + evict_data.target = npages; + hfi1_mmu_rb_evict(handler, &evict_data); + return evict_data.cleared; +} + +static int check_header_template(struct user_sdma_request *req, + struct hfi1_pkt_header *hdr, u32 lrhlen, + u32 datalen) +{ + /* + * Perform safety checks for any type of packet: + * - transfer size is multiple of 64bytes + * - packet length is multiple of 4 bytes + * - packet length is not larger than MTU size + * + * These checks are only done for the first packet of the + * transfer since the header is "given" to us by user space. + * For the remainder of the packets we compute the values. + */ + if (req->info.fragsize % PIO_BLOCK_SIZE || lrhlen & 0x3 || + lrhlen > get_lrh_len(*hdr, req->info.fragsize)) + return -EINVAL; + + if (req_opcode(req->info.ctrl) == EXPECTED) { + /* + * The header is checked only on the first packet. Furthermore, + * we ensure that at least one TID entry is copied when the + * request is submitted. Therefore, we don't have to verify that + * tididx points to something sane. + */ + u32 tidval = req->tids[req->tididx], + tidlen = EXP_TID_GET(tidval, LEN) * PAGE_SIZE, + tididx = EXP_TID_GET(tidval, IDX), + tidctrl = EXP_TID_GET(tidval, CTRL), + tidoff; + __le32 kval = hdr->kdeth.ver_tid_offset; + + tidoff = KDETH_GET(kval, OFFSET) * + (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ? + KDETH_OM_LARGE : KDETH_OM_SMALL); + /* + * Expected receive packets have the following + * additional checks: + * - offset is not larger than the TID size + * - TIDCtrl values match between header and TID array + * - TID indexes match between header and TID array + */ + if ((tidoff + datalen > tidlen) || + KDETH_GET(kval, TIDCTRL) != tidctrl || + KDETH_GET(kval, TID) != tididx) + return -EINVAL; + } + return 0; +} + +/* + * Correctly set the BTH.PSN field based on type of + * transfer - eager packets can just increment the PSN but + * expected packets encode generation and sequence in the + * BTH.PSN field so just incrementing will result in errors. + */ +static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags) +{ + u32 val = be32_to_cpu(bthpsn), + mask = (HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffffull : + 0xffffffull), + psn = val & mask; + if (expct) + psn = (psn & ~HFI1_KDETH_BTH_SEQ_MASK) | + ((psn + frags) & HFI1_KDETH_BTH_SEQ_MASK); + else + psn = psn + frags; + return psn & mask; +} + +static int set_txreq_header(struct user_sdma_request *req, + struct user_sdma_txreq *tx, u32 datalen) +{ + struct hfi1_user_sdma_pkt_q *pq = req->pq; + struct hfi1_pkt_header *hdr = &tx->hdr; + u8 omfactor; /* KDETH.OM */ + u16 pbclen; + int ret; + u32 tidval = 0, lrhlen = get_lrh_len(*hdr, pad_len(datalen)); + + /* Copy the header template to the request before modification */ + memcpy(hdr, &req->hdr, sizeof(*hdr)); + + /* + * Check if the PBC and LRH length are mismatched. If so + * adjust both in the header. + */ + pbclen = le16_to_cpu(hdr->pbc[0]); + if (PBC2LRH(pbclen) != lrhlen) { + pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen); + hdr->pbc[0] = cpu_to_le16(pbclen); + hdr->lrh[2] = cpu_to_be16(lrhlen >> 2); + /* + * Third packet + * This is the first packet in the sequence that has + * a "static" size that can be used for the rest of + * the packets (besides the last one). + */ + if (unlikely(req->seqnum == 2)) { + /* + * From this point on the lengths in both the + * PBC and LRH are the same until the last + * packet. + * Adjust the template so we don't have to update + * every packet + */ + req->hdr.pbc[0] = hdr->pbc[0]; + req->hdr.lrh[2] = hdr->lrh[2]; + } + } + /* + * We only have to modify the header if this is not the + * first packet in the request. Otherwise, we use the + * header given to us. + */ + if (unlikely(!req->seqnum)) { + ret = check_header_template(req, hdr, lrhlen, datalen); + if (ret) + return ret; + goto done; + } + + hdr->bth[2] = cpu_to_be32( + set_pkt_bth_psn(hdr->bth[2], + (req_opcode(req->info.ctrl) == EXPECTED), + req->seqnum)); + + /* Set ACK request on last packet */ + if (unlikely(tx->flags & TXREQ_FLAGS_REQ_ACK)) + hdr->bth[2] |= cpu_to_be32(1UL << 31); + + /* Set the new offset */ + hdr->kdeth.swdata[6] = cpu_to_le32(req->koffset); + /* Expected packets have to fill in the new TID information */ + if (req_opcode(req->info.ctrl) == EXPECTED) { + tidval = req->tids[req->tididx]; + /* + * If the offset puts us at the end of the current TID, + * advance everything. + */ + if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) * + PAGE_SIZE)) { + req->tidoffset = 0; + /* + * Since we don't copy all the TIDs, all at once, + * we have to check again. + */ + if (++req->tididx > req->n_tids - 1 || + !req->tids[req->tididx]) { + return -EINVAL; + } + tidval = req->tids[req->tididx]; + } + omfactor = EXP_TID_GET(tidval, LEN) * PAGE_SIZE >= + KDETH_OM_MAX_SIZE ? KDETH_OM_LARGE_SHIFT : + KDETH_OM_SMALL_SHIFT; + /* Set KDETH.TIDCtrl based on value for this TID. */ + KDETH_SET(hdr->kdeth.ver_tid_offset, TIDCTRL, + EXP_TID_GET(tidval, CTRL)); + /* Set KDETH.TID based on value for this TID */ + KDETH_SET(hdr->kdeth.ver_tid_offset, TID, + EXP_TID_GET(tidval, IDX)); + /* Clear KDETH.SH when DISABLE_SH flag is set */ + if (unlikely(tx->flags & TXREQ_FLAGS_REQ_DISABLE_SH)) + KDETH_SET(hdr->kdeth.ver_tid_offset, SH, 0); + /* + * Set the KDETH.OFFSET and KDETH.OM based on size of + * transfer. + */ + trace_hfi1_sdma_user_tid_info( + pq->dd, pq->ctxt, pq->subctxt, req->info.comp_idx, + req->tidoffset, req->tidoffset >> omfactor, + omfactor != KDETH_OM_SMALL_SHIFT); + KDETH_SET(hdr->kdeth.ver_tid_offset, OFFSET, + req->tidoffset >> omfactor); + KDETH_SET(hdr->kdeth.ver_tid_offset, OM, + omfactor != KDETH_OM_SMALL_SHIFT); + } +done: + trace_hfi1_sdma_user_header(pq->dd, pq->ctxt, pq->subctxt, + req->info.comp_idx, hdr, tidval); + return sdma_txadd_kvaddr(pq->dd, &tx->txreq, hdr, sizeof(*hdr)); +} + +static int set_txreq_header_ahg(struct user_sdma_request *req, + struct user_sdma_txreq *tx, u32 datalen) +{ + u32 ahg[AHG_KDETH_ARRAY_SIZE]; + int idx = 0; + u8 omfactor; /* KDETH.OM */ + struct hfi1_user_sdma_pkt_q *pq = req->pq; + struct hfi1_pkt_header *hdr = &req->hdr; + u16 pbclen = le16_to_cpu(hdr->pbc[0]); + u32 val32, tidval = 0, lrhlen = get_lrh_len(*hdr, pad_len(datalen)); + size_t array_size = ARRAY_SIZE(ahg); + + if (PBC2LRH(pbclen) != lrhlen) { + /* PBC.PbcLengthDWs */ + idx = ahg_header_set(ahg, idx, array_size, 0, 0, 12, + (__force u16)cpu_to_le16(LRH2PBC(lrhlen))); + if (idx < 0) + return idx; + /* LRH.PktLen (we need the full 16 bits due to byte swap) */ + idx = ahg_header_set(ahg, idx, array_size, 3, 0, 16, + (__force u16)cpu_to_be16(lrhlen >> 2)); + if (idx < 0) + return idx; + } + + /* + * Do the common updates + */ + /* BTH.PSN and BTH.A */ + val32 = (be32_to_cpu(hdr->bth[2]) + req->seqnum) & + (HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffff : 0xffffff); + if (unlikely(tx->flags & TXREQ_FLAGS_REQ_ACK)) + val32 |= 1UL << 31; + idx = ahg_header_set(ahg, idx, array_size, 6, 0, 16, + (__force u16)cpu_to_be16(val32 >> 16)); + if (idx < 0) + return idx; + idx = ahg_header_set(ahg, idx, array_size, 6, 16, 16, + (__force u16)cpu_to_be16(val32 & 0xffff)); + if (idx < 0) + return idx; + /* KDETH.Offset */ + idx = ahg_header_set(ahg, idx, array_size, 15, 0, 16, + (__force u16)cpu_to_le16(req->koffset & 0xffff)); + if (idx < 0) + return idx; + idx = ahg_header_set(ahg, idx, array_size, 15, 16, 16, + (__force u16)cpu_to_le16(req->koffset >> 16)); + if (idx < 0) + return idx; + if (req_opcode(req->info.ctrl) == EXPECTED) { + __le16 val; + + tidval = req->tids[req->tididx]; + + /* + * If the offset puts us at the end of the current TID, + * advance everything. + */ + if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) * + PAGE_SIZE)) { + req->tidoffset = 0; + /* + * Since we don't copy all the TIDs, all at once, + * we have to check again. + */ + if (++req->tididx > req->n_tids - 1 || + !req->tids[req->tididx]) + return -EINVAL; + tidval = req->tids[req->tididx]; + } + omfactor = ((EXP_TID_GET(tidval, LEN) * + PAGE_SIZE) >= + KDETH_OM_MAX_SIZE) ? KDETH_OM_LARGE_SHIFT : + KDETH_OM_SMALL_SHIFT; + /* KDETH.OM and KDETH.OFFSET (TID) */ + idx = ahg_header_set( + ahg, idx, array_size, 7, 0, 16, + ((!!(omfactor - KDETH_OM_SMALL_SHIFT)) << 15 | + ((req->tidoffset >> omfactor) + & 0x7fff))); + if (idx < 0) + return idx; + /* KDETH.TIDCtrl, KDETH.TID, KDETH.Intr, KDETH.SH */ + val = cpu_to_le16(((EXP_TID_GET(tidval, CTRL) & 0x3) << 10) | + (EXP_TID_GET(tidval, IDX) & 0x3ff)); + + if (unlikely(tx->flags & TXREQ_FLAGS_REQ_DISABLE_SH)) { + val |= cpu_to_le16((KDETH_GET(hdr->kdeth.ver_tid_offset, + INTR) << + AHG_KDETH_INTR_SHIFT)); + } else { + val |= KDETH_GET(hdr->kdeth.ver_tid_offset, SH) ? + cpu_to_le16(0x1 << AHG_KDETH_SH_SHIFT) : + cpu_to_le16((KDETH_GET(hdr->kdeth.ver_tid_offset, + INTR) << + AHG_KDETH_INTR_SHIFT)); + } + + idx = ahg_header_set(ahg, idx, array_size, + 7, 16, 14, (__force u16)val); + if (idx < 0) + return idx; + } + + trace_hfi1_sdma_user_header_ahg(pq->dd, pq->ctxt, pq->subctxt, + req->info.comp_idx, req->sde->this_idx, + req->ahg_idx, ahg, idx, tidval); + sdma_txinit_ahg(&tx->txreq, + SDMA_TXREQ_F_USE_AHG, + datalen, req->ahg_idx, idx, + ahg, sizeof(req->hdr), + user_sdma_txreq_cb); + + return idx; +} + +/** + * user_sdma_txreq_cb() - SDMA tx request completion callback. + * @txreq: valid sdma tx request + * @status: success/failure of request + * + * Called when the SDMA progress state machine gets notification that + * the SDMA descriptors for this tx request have been processed by the + * DMA engine. Called in interrupt context. + * Only do work on completed sequences. + */ +static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status) +{ + struct user_sdma_txreq *tx = + container_of(txreq, struct user_sdma_txreq, txreq); + struct user_sdma_request *req; + struct hfi1_user_sdma_pkt_q *pq; + struct hfi1_user_sdma_comp_q *cq; + enum hfi1_sdma_comp_state state = COMPLETE; + + if (!tx->req) + return; + + req = tx->req; + pq = req->pq; + cq = req->cq; + + if (status != SDMA_TXREQ_S_OK) { + SDMA_DBG(req, "SDMA completion with error %d", + status); + WRITE_ONCE(req->has_error, 1); + state = ERROR; + } + + req->seqcomp = tx->seqnum; + kmem_cache_free(pq->txreq_cache, tx); + + /* sequence isn't complete? We are done */ + if (req->seqcomp != req->info.npkts - 1) + return; + + user_sdma_free_request(req); + set_comp_state(pq, cq, req->info.comp_idx, state, status); + pq_update(pq); +} + +static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq) +{ + if (atomic_dec_and_test(&pq->n_reqs)) + wake_up(&pq->wait); +} + +static void user_sdma_free_request(struct user_sdma_request *req) +{ + if (!list_empty(&req->txps)) { + struct sdma_txreq *t, *p; + + list_for_each_entry_safe(t, p, &req->txps, list) { + struct user_sdma_txreq *tx = + container_of(t, struct user_sdma_txreq, txreq); + list_del_init(&t->list); + sdma_txclean(req->pq->dd, t); + kmem_cache_free(req->pq->txreq_cache, tx); + } + } + + kfree(req->tids); + clear_bit(req->info.comp_idx, req->pq->req_in_use); +} + +static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq, + struct hfi1_user_sdma_comp_q *cq, + u16 idx, enum hfi1_sdma_comp_state state, + int ret) +{ + if (state == ERROR) + cq->comps[idx].errcode = -ret; + smp_wmb(); /* make sure errcode is visible first */ + cq->comps[idx].status = state; + trace_hfi1_sdma_user_completion(pq->dd, pq->ctxt, pq->subctxt, + idx, state, ret); +} + +static void unpin_vector_pages(struct mm_struct *mm, struct page **pages, + unsigned int start, unsigned int npages) +{ + hfi1_release_user_pages(mm, pages + start, npages, false); + kfree(pages); +} + +static void free_system_node(struct sdma_mmu_node *node) +{ + if (node->npages) { + unpin_vector_pages(mm_from_sdma_node(node), node->pages, 0, + node->npages); + atomic_sub(node->npages, &node->pq->n_locked); + } + kfree(node); +} + +/* + * kref_get()'s an additional kref on the returned rb_node to prevent rb_node + * from being released until after rb_node is assigned to an SDMA descriptor + * (struct sdma_desc) under add_system_iovec_to_sdma_packet(), even if the + * virtual address range for rb_node is invalidated between now and then. + */ +static struct sdma_mmu_node *find_system_node(struct mmu_rb_handler *handler, + unsigned long start, + unsigned long end) +{ + struct mmu_rb_node *rb_node; + unsigned long flags; + + spin_lock_irqsave(&handler->lock, flags); + rb_node = hfi1_mmu_rb_get_first(handler, start, (end - start)); + if (!rb_node) { + spin_unlock_irqrestore(&handler->lock, flags); + return NULL; + } + + /* "safety" kref to prevent release before add_system_iovec_to_sdma_packet() */ + kref_get(&rb_node->refcount); + spin_unlock_irqrestore(&handler->lock, flags); + + return container_of(rb_node, struct sdma_mmu_node, rb); +} + +static int pin_system_pages(struct user_sdma_request *req, + uintptr_t start_address, size_t length, + struct sdma_mmu_node *node, int npages) +{ + struct hfi1_user_sdma_pkt_q *pq = req->pq; + int pinned, cleared; + struct page **pages; + + pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL); + if (!pages) + return -ENOMEM; + +retry: + if (!hfi1_can_pin_pages(pq->dd, current->mm, atomic_read(&pq->n_locked), + npages)) { + SDMA_DBG(req, "Evicting: nlocked %u npages %u", + atomic_read(&pq->n_locked), npages); + cleared = sdma_cache_evict(pq, npages); + if (cleared >= npages) + goto retry; + } + + SDMA_DBG(req, "Acquire user pages start_address %lx node->npages %u npages %u", + start_address, node->npages, npages); + pinned = hfi1_acquire_user_pages(current->mm, start_address, npages, 0, + pages); + + if (pinned < 0) { + kfree(pages); + SDMA_DBG(req, "pinned %d", pinned); + return pinned; + } + if (pinned != npages) { + unpin_vector_pages(current->mm, pages, node->npages, pinned); + SDMA_DBG(req, "npages %u pinned %d", npages, pinned); + return -EFAULT; + } + node->rb.addr = start_address; + node->rb.len = length; + node->pages = pages; + node->npages = npages; + atomic_add(pinned, &pq->n_locked); + SDMA_DBG(req, "done. pinned %d", pinned); + return 0; +} + +/* + * kref refcount on *node_p will be 2 on successful addition: one kref from + * kref_init() for mmu_rb_handler and one kref to prevent *node_p from being + * released until after *node_p is assigned to an SDMA descriptor (struct + * sdma_desc) under add_system_iovec_to_sdma_packet(), even if the virtual + * address range for *node_p is invalidated between now and then. + */ +static int add_system_pinning(struct user_sdma_request *req, + struct sdma_mmu_node **node_p, + unsigned long start, unsigned long len) + +{ + struct hfi1_user_sdma_pkt_q *pq = req->pq; + struct sdma_mmu_node *node; + int ret; + + node = kzalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return -ENOMEM; + + /* First kref "moves" to mmu_rb_handler */ + kref_init(&node->rb.refcount); + + /* "safety" kref to prevent release before add_system_iovec_to_sdma_packet() */ + kref_get(&node->rb.refcount); + + node->pq = pq; + ret = pin_system_pages(req, start, len, node, PFN_DOWN(len)); + if (ret == 0) { + ret = hfi1_mmu_rb_insert(pq->handler, &node->rb); + if (ret) + free_system_node(node); + else + *node_p = node; + + return ret; + } + + kfree(node); + return ret; +} + +static int get_system_cache_entry(struct user_sdma_request *req, + struct sdma_mmu_node **node_p, + size_t req_start, size_t req_len) +{ + struct hfi1_user_sdma_pkt_q *pq = req->pq; + u64 start = ALIGN_DOWN(req_start, PAGE_SIZE); + u64 end = PFN_ALIGN(req_start + req_len); + struct mmu_rb_handler *handler = pq->handler; + int ret; + + if ((end - start) == 0) { + SDMA_DBG(req, + "Request for empty cache entry req_start %lx req_len %lx start %llx end %llx", + req_start, req_len, start, end); + return -EINVAL; + } + + SDMA_DBG(req, "req_start %lx req_len %lu", req_start, req_len); + + while (1) { + struct sdma_mmu_node *node = + find_system_node(handler, start, end); + u64 prepend_len = 0; + + SDMA_DBG(req, "node %p start %llx end %llu", node, start, end); + if (!node) { + ret = add_system_pinning(req, node_p, start, + end - start); + if (ret == -EEXIST) { + /* + * Another execution context has inserted a + * conficting entry first. + */ + continue; + } + return ret; + } + + if (node->rb.addr <= start) { + /* + * This entry covers at least part of the region. If it doesn't extend + * to the end, then this will be called again for the next segment. + */ + *node_p = node; + return 0; + } + + SDMA_DBG(req, "prepend: node->rb.addr %lx, node->rb.refcount %d", + node->rb.addr, kref_read(&node->rb.refcount)); + prepend_len = node->rb.addr - start; + + /* + * This node will not be returned, instead a new node + * will be. So release the reference. + */ + kref_put(&node->rb.refcount, hfi1_mmu_rb_release); + + /* Prepend a node to cover the beginning of the allocation */ + ret = add_system_pinning(req, node_p, start, prepend_len); + if (ret == -EEXIST) { + /* Another execution context has inserted a conficting entry first. */ + continue; + } + return ret; + } +} + +static void sdma_mmu_rb_node_get(void *ctx) +{ + struct mmu_rb_node *node = ctx; + + kref_get(&node->refcount); +} + +static void sdma_mmu_rb_node_put(void *ctx) +{ + struct sdma_mmu_node *node = ctx; + + kref_put(&node->rb.refcount, hfi1_mmu_rb_release); +} + +static int add_mapping_to_sdma_packet(struct user_sdma_request *req, + struct user_sdma_txreq *tx, + struct sdma_mmu_node *cache_entry, + size_t start, + size_t from_this_cache_entry) +{ + struct hfi1_user_sdma_pkt_q *pq = req->pq; + unsigned int page_offset; + unsigned int from_this_page; + size_t page_index; + void *ctx; + int ret; + + /* + * Because the cache may be more fragmented than the memory that is being accessed, + * it's not strictly necessary to have a descriptor per cache entry. + */ + + while (from_this_cache_entry) { + page_index = PFN_DOWN(start - cache_entry->rb.addr); + + if (page_index >= cache_entry->npages) { + SDMA_DBG(req, + "Request for page_index %zu >= cache_entry->npages %u", + page_index, cache_entry->npages); + return -EINVAL; + } + + page_offset = start - ALIGN_DOWN(start, PAGE_SIZE); + from_this_page = PAGE_SIZE - page_offset; + + if (from_this_page < from_this_cache_entry) { + ctx = NULL; + } else { + /* + * In the case they are equal the next line has no practical effect, + * but it's better to do a register to register copy than a conditional + * branch. + */ + from_this_page = from_this_cache_entry; + ctx = cache_entry; + } + + ret = sdma_txadd_page(pq->dd, &tx->txreq, + cache_entry->pages[page_index], + page_offset, from_this_page, + ctx, + sdma_mmu_rb_node_get, + sdma_mmu_rb_node_put); + if (ret) { + /* + * When there's a failure, the entire request is freed by + * user_sdma_send_pkts(). + */ + SDMA_DBG(req, + "sdma_txadd_page failed %d page_index %lu page_offset %u from_this_page %u", + ret, page_index, page_offset, from_this_page); + return ret; + } + start += from_this_page; + from_this_cache_entry -= from_this_page; + } + return 0; +} + +static int add_system_iovec_to_sdma_packet(struct user_sdma_request *req, + struct user_sdma_txreq *tx, + struct user_sdma_iovec *iovec, + size_t from_this_iovec) +{ + while (from_this_iovec > 0) { + struct sdma_mmu_node *cache_entry; + size_t from_this_cache_entry; + size_t start; + int ret; + + start = (uintptr_t)iovec->iov.iov_base + iovec->offset; + ret = get_system_cache_entry(req, &cache_entry, start, + from_this_iovec); + if (ret) { + SDMA_DBG(req, "pin system segment failed %d", ret); + return ret; + } + + from_this_cache_entry = cache_entry->rb.len - (start - cache_entry->rb.addr); + if (from_this_cache_entry > from_this_iovec) + from_this_cache_entry = from_this_iovec; + + ret = add_mapping_to_sdma_packet(req, tx, cache_entry, start, + from_this_cache_entry); + + /* + * Done adding cache_entry to zero or more sdma_desc. Can + * kref_put() the "safety" kref taken under + * get_system_cache_entry(). + */ + kref_put(&cache_entry->rb.refcount, hfi1_mmu_rb_release); + + if (ret) { + SDMA_DBG(req, "add system segment failed %d", ret); + return ret; + } + + iovec->offset += from_this_cache_entry; + from_this_iovec -= from_this_cache_entry; + } + + return 0; +} + +static int add_system_pages_to_sdma_packet(struct user_sdma_request *req, + struct user_sdma_txreq *tx, + struct user_sdma_iovec *iovec, + u32 *pkt_data_remaining) +{ + size_t remaining_to_add = *pkt_data_remaining; + /* + * Walk through iovec entries, ensure the associated pages + * are pinned and mapped, add data to the packet until no more + * data remains to be added. + */ + while (remaining_to_add > 0) { + struct user_sdma_iovec *cur_iovec; + size_t from_this_iovec; + int ret; + + cur_iovec = iovec; + from_this_iovec = iovec->iov.iov_len - iovec->offset; + + if (from_this_iovec > remaining_to_add) { + from_this_iovec = remaining_to_add; + } else { + /* The current iovec entry will be consumed by this pass. */ + req->iov_idx++; + iovec++; + } + + ret = add_system_iovec_to_sdma_packet(req, tx, cur_iovec, + from_this_iovec); + if (ret) + return ret; + + remaining_to_add -= from_this_iovec; + } + *pkt_data_remaining = remaining_to_add; + + return 0; +} + +static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr, + unsigned long len) +{ + return (bool)(node->addr == addr); +} + +/* + * Return 1 to remove the node from the rb tree and call the remove op. + * + * Called with the rb tree lock held. + */ +static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode, + void *evict_arg, bool *stop) +{ + struct sdma_mmu_node *node = + container_of(mnode, struct sdma_mmu_node, rb); + struct evict_data *evict_data = evict_arg; + + /* this node will be evicted, add its pages to our count */ + evict_data->cleared += node->npages; + + /* have enough pages been cleared? */ + if (evict_data->cleared >= evict_data->target) + *stop = true; + + return 1; /* remove this node */ +} + +static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode) +{ + struct sdma_mmu_node *node = + container_of(mnode, struct sdma_mmu_node, rb); + + free_system_node(node); +} |