diff options
Diffstat (limited to 'drivers/infiniband/sw/rdmavt/mr.c')
| -rw-r--r-- | drivers/infiniband/sw/rdmavt/mr.c | 917 |
1 files changed, 917 insertions, 0 deletions
diff --git a/drivers/infiniband/sw/rdmavt/mr.c b/drivers/infiniband/sw/rdmavt/mr.c new file mode 100644 index 000000000..8a1f2e285 --- /dev/null +++ b/drivers/infiniband/sw/rdmavt/mr.c @@ -0,0 +1,917 @@ +// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause +/* + * Copyright(c) 2016 Intel Corporation. + */ + +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <rdma/ib_umem.h> +#include <rdma/rdma_vt.h> +#include "vt.h" +#include "mr.h" +#include "trace.h" + +/** + * rvt_driver_mr_init - Init MR resources per driver + * @rdi: rvt dev struct + * + * Do any intilization needed when a driver registers with rdmavt. + * + * Return: 0 on success or errno on failure + */ +int rvt_driver_mr_init(struct rvt_dev_info *rdi) +{ + unsigned int lkey_table_size = rdi->dparms.lkey_table_size; + unsigned lk_tab_size; + int i; + + /* + * The top hfi1_lkey_table_size bits are used to index the + * table. The lower 8 bits can be owned by the user (copied from + * the LKEY). The remaining bits act as a generation number or tag. + */ + if (!lkey_table_size) + return -EINVAL; + + spin_lock_init(&rdi->lkey_table.lock); + + /* ensure generation is at least 4 bits */ + if (lkey_table_size > RVT_MAX_LKEY_TABLE_BITS) { + rvt_pr_warn(rdi, "lkey bits %u too large, reduced to %u\n", + lkey_table_size, RVT_MAX_LKEY_TABLE_BITS); + rdi->dparms.lkey_table_size = RVT_MAX_LKEY_TABLE_BITS; + lkey_table_size = rdi->dparms.lkey_table_size; + } + rdi->lkey_table.max = 1 << lkey_table_size; + rdi->lkey_table.shift = 32 - lkey_table_size; + lk_tab_size = rdi->lkey_table.max * sizeof(*rdi->lkey_table.table); + rdi->lkey_table.table = (struct rvt_mregion __rcu **) + vmalloc_node(lk_tab_size, rdi->dparms.node); + if (!rdi->lkey_table.table) + return -ENOMEM; + + RCU_INIT_POINTER(rdi->dma_mr, NULL); + for (i = 0; i < rdi->lkey_table.max; i++) + RCU_INIT_POINTER(rdi->lkey_table.table[i], NULL); + + rdi->dparms.props.max_mr = rdi->lkey_table.max; + return 0; +} + +/** + * rvt_mr_exit - clean up MR + * @rdi: rvt dev structure + * + * called when drivers have unregistered or perhaps failed to register with us + */ +void rvt_mr_exit(struct rvt_dev_info *rdi) +{ + if (rdi->dma_mr) + rvt_pr_err(rdi, "DMA MR not null!\n"); + + vfree(rdi->lkey_table.table); +} + +static void rvt_deinit_mregion(struct rvt_mregion *mr) +{ + int i = mr->mapsz; + + mr->mapsz = 0; + while (i) + kfree(mr->map[--i]); + percpu_ref_exit(&mr->refcount); +} + +static void __rvt_mregion_complete(struct percpu_ref *ref) +{ + struct rvt_mregion *mr = container_of(ref, struct rvt_mregion, + refcount); + + complete(&mr->comp); +} + +static int rvt_init_mregion(struct rvt_mregion *mr, struct ib_pd *pd, + int count, unsigned int percpu_flags) +{ + int m, i = 0; + struct rvt_dev_info *dev = ib_to_rvt(pd->device); + + mr->mapsz = 0; + m = (count + RVT_SEGSZ - 1) / RVT_SEGSZ; + for (; i < m; i++) { + mr->map[i] = kzalloc_node(sizeof(*mr->map[0]), GFP_KERNEL, + dev->dparms.node); + if (!mr->map[i]) + goto bail; + mr->mapsz++; + } + init_completion(&mr->comp); + /* count returning the ptr to user */ + if (percpu_ref_init(&mr->refcount, &__rvt_mregion_complete, + percpu_flags, GFP_KERNEL)) + goto bail; + + atomic_set(&mr->lkey_invalid, 0); + mr->pd = pd; + mr->max_segs = count; + return 0; +bail: + rvt_deinit_mregion(mr); + return -ENOMEM; +} + +/** + * rvt_alloc_lkey - allocate an lkey + * @mr: memory region that this lkey protects + * @dma_region: 0->normal key, 1->restricted DMA key + * + * Returns 0 if successful, otherwise returns -errno. + * + * Increments mr reference count as required. + * + * Sets the lkey field mr for non-dma regions. + * + */ +static int rvt_alloc_lkey(struct rvt_mregion *mr, int dma_region) +{ + unsigned long flags; + u32 r; + u32 n; + int ret = 0; + struct rvt_dev_info *dev = ib_to_rvt(mr->pd->device); + struct rvt_lkey_table *rkt = &dev->lkey_table; + + rvt_get_mr(mr); + spin_lock_irqsave(&rkt->lock, flags); + + /* special case for dma_mr lkey == 0 */ + if (dma_region) { + struct rvt_mregion *tmr; + + tmr = rcu_access_pointer(dev->dma_mr); + if (!tmr) { + mr->lkey_published = 1; + /* Insure published written first */ + rcu_assign_pointer(dev->dma_mr, mr); + rvt_get_mr(mr); + } + goto success; + } + + /* Find the next available LKEY */ + r = rkt->next; + n = r; + for (;;) { + if (!rcu_access_pointer(rkt->table[r])) + break; + r = (r + 1) & (rkt->max - 1); + if (r == n) + goto bail; + } + rkt->next = (r + 1) & (rkt->max - 1); + /* + * Make sure lkey is never zero which is reserved to indicate an + * unrestricted LKEY. + */ + rkt->gen++; + /* + * bits are capped to ensure enough bits for generation number + */ + mr->lkey = (r << (32 - dev->dparms.lkey_table_size)) | + ((((1 << (24 - dev->dparms.lkey_table_size)) - 1) & rkt->gen) + << 8); + if (mr->lkey == 0) { + mr->lkey |= 1 << 8; + rkt->gen++; + } + mr->lkey_published = 1; + /* Insure published written first */ + rcu_assign_pointer(rkt->table[r], mr); +success: + spin_unlock_irqrestore(&rkt->lock, flags); +out: + return ret; +bail: + rvt_put_mr(mr); + spin_unlock_irqrestore(&rkt->lock, flags); + ret = -ENOMEM; + goto out; +} + +/** + * rvt_free_lkey - free an lkey + * @mr: mr to free from tables + */ +static void rvt_free_lkey(struct rvt_mregion *mr) +{ + unsigned long flags; + u32 lkey = mr->lkey; + u32 r; + struct rvt_dev_info *dev = ib_to_rvt(mr->pd->device); + struct rvt_lkey_table *rkt = &dev->lkey_table; + int freed = 0; + + spin_lock_irqsave(&rkt->lock, flags); + if (!lkey) { + if (mr->lkey_published) { + mr->lkey_published = 0; + /* insure published is written before pointer */ + rcu_assign_pointer(dev->dma_mr, NULL); + rvt_put_mr(mr); + } + } else { + if (!mr->lkey_published) + goto out; + r = lkey >> (32 - dev->dparms.lkey_table_size); + mr->lkey_published = 0; + /* insure published is written before pointer */ + rcu_assign_pointer(rkt->table[r], NULL); + } + freed++; +out: + spin_unlock_irqrestore(&rkt->lock, flags); + if (freed) + percpu_ref_kill(&mr->refcount); +} + +static struct rvt_mr *__rvt_alloc_mr(int count, struct ib_pd *pd) +{ + struct rvt_mr *mr; + int rval = -ENOMEM; + int m; + + /* Allocate struct plus pointers to first level page tables. */ + m = (count + RVT_SEGSZ - 1) / RVT_SEGSZ; + mr = kzalloc(struct_size(mr, mr.map, m), GFP_KERNEL); + if (!mr) + goto bail; + + rval = rvt_init_mregion(&mr->mr, pd, count, 0); + if (rval) + goto bail; + /* + * ib_reg_phys_mr() will initialize mr->ibmr except for + * lkey and rkey. + */ + rval = rvt_alloc_lkey(&mr->mr, 0); + if (rval) + goto bail_mregion; + mr->ibmr.lkey = mr->mr.lkey; + mr->ibmr.rkey = mr->mr.lkey; +done: + return mr; + +bail_mregion: + rvt_deinit_mregion(&mr->mr); +bail: + kfree(mr); + mr = ERR_PTR(rval); + goto done; +} + +static void __rvt_free_mr(struct rvt_mr *mr) +{ + rvt_free_lkey(&mr->mr); + rvt_deinit_mregion(&mr->mr); + kfree(mr); +} + +/** + * rvt_get_dma_mr - get a DMA memory region + * @pd: protection domain for this memory region + * @acc: access flags + * + * Return: the memory region on success, otherwise returns an errno. + */ +struct ib_mr *rvt_get_dma_mr(struct ib_pd *pd, int acc) +{ + struct rvt_mr *mr; + struct ib_mr *ret; + int rval; + + if (ibpd_to_rvtpd(pd)->user) + return ERR_PTR(-EPERM); + + mr = kzalloc(sizeof(*mr), GFP_KERNEL); + if (!mr) { + ret = ERR_PTR(-ENOMEM); + goto bail; + } + + rval = rvt_init_mregion(&mr->mr, pd, 0, 0); + if (rval) { + ret = ERR_PTR(rval); + goto bail; + } + + rval = rvt_alloc_lkey(&mr->mr, 1); + if (rval) { + ret = ERR_PTR(rval); + goto bail_mregion; + } + + mr->mr.access_flags = acc; + ret = &mr->ibmr; +done: + return ret; + +bail_mregion: + rvt_deinit_mregion(&mr->mr); +bail: + kfree(mr); + goto done; +} + +/** + * rvt_reg_user_mr - register a userspace memory region + * @pd: protection domain for this memory region + * @start: starting userspace address + * @length: length of region to register + * @virt_addr: associated virtual address + * @mr_access_flags: access flags for this memory region + * @udata: unused by the driver + * + * Return: the memory region on success, otherwise returns an errno. + */ +struct ib_mr *rvt_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, + u64 virt_addr, int mr_access_flags, + struct ib_udata *udata) +{ + struct rvt_mr *mr; + struct ib_umem *umem; + struct sg_page_iter sg_iter; + int n, m; + struct ib_mr *ret; + + if (length == 0) + return ERR_PTR(-EINVAL); + + umem = ib_umem_get(pd->device, start, length, mr_access_flags); + if (IS_ERR(umem)) + return (void *)umem; + + n = ib_umem_num_pages(umem); + + mr = __rvt_alloc_mr(n, pd); + if (IS_ERR(mr)) { + ret = (struct ib_mr *)mr; + goto bail_umem; + } + + mr->mr.user_base = start; + mr->mr.iova = virt_addr; + mr->mr.length = length; + mr->mr.offset = ib_umem_offset(umem); + mr->mr.access_flags = mr_access_flags; + mr->umem = umem; + + mr->mr.page_shift = PAGE_SHIFT; + m = 0; + n = 0; + for_each_sgtable_page (&umem->sgt_append.sgt, &sg_iter, 0) { + void *vaddr; + + vaddr = page_address(sg_page_iter_page(&sg_iter)); + if (!vaddr) { + ret = ERR_PTR(-EINVAL); + goto bail_inval; + } + mr->mr.map[m]->segs[n].vaddr = vaddr; + mr->mr.map[m]->segs[n].length = PAGE_SIZE; + trace_rvt_mr_user_seg(&mr->mr, m, n, vaddr, PAGE_SIZE); + if (++n == RVT_SEGSZ) { + m++; + n = 0; + } + } + return &mr->ibmr; + +bail_inval: + __rvt_free_mr(mr); + +bail_umem: + ib_umem_release(umem); + + return ret; +} + +/** + * rvt_dereg_clean_qp_cb - callback from iterator + * @qp: the qp + * @v: the mregion (as u64) + * + * This routine fields the callback for all QPs and + * for QPs in the same PD as the MR will call the + * rvt_qp_mr_clean() to potentially cleanup references. + */ +static void rvt_dereg_clean_qp_cb(struct rvt_qp *qp, u64 v) +{ + struct rvt_mregion *mr = (struct rvt_mregion *)v; + + /* skip PDs that are not ours */ + if (mr->pd != qp->ibqp.pd) + return; + rvt_qp_mr_clean(qp, mr->lkey); +} + +/** + * rvt_dereg_clean_qps - find QPs for reference cleanup + * @mr: the MR that is being deregistered + * + * This routine iterates RC QPs looking for references + * to the lkey noted in mr. + */ +static void rvt_dereg_clean_qps(struct rvt_mregion *mr) +{ + struct rvt_dev_info *rdi = ib_to_rvt(mr->pd->device); + + rvt_qp_iter(rdi, (u64)mr, rvt_dereg_clean_qp_cb); +} + +/** + * rvt_check_refs - check references + * @mr: the megion + * @t: the caller identification + * + * This routine checks MRs holding a reference during + * when being de-registered. + * + * If the count is non-zero, the code calls a clean routine then + * waits for the timeout for the count to zero. + */ +static int rvt_check_refs(struct rvt_mregion *mr, const char *t) +{ + unsigned long timeout; + struct rvt_dev_info *rdi = ib_to_rvt(mr->pd->device); + + if (mr->lkey) { + /* avoid dma mr */ + rvt_dereg_clean_qps(mr); + /* @mr was indexed on rcu protected @lkey_table */ + synchronize_rcu(); + } + + timeout = wait_for_completion_timeout(&mr->comp, 5 * HZ); + if (!timeout) { + rvt_pr_err(rdi, + "%s timeout mr %p pd %p lkey %x refcount %ld\n", + t, mr, mr->pd, mr->lkey, + atomic_long_read(&mr->refcount.data->count)); + rvt_get_mr(mr); + return -EBUSY; + } + return 0; +} + +/** + * rvt_mr_has_lkey - is MR + * @mr: the mregion + * @lkey: the lkey + */ +bool rvt_mr_has_lkey(struct rvt_mregion *mr, u32 lkey) +{ + return mr && lkey == mr->lkey; +} + +/** + * rvt_ss_has_lkey - is mr in sge tests + * @ss: the sge state + * @lkey: the lkey + * + * This code tests for an MR in the indicated + * sge state. + */ +bool rvt_ss_has_lkey(struct rvt_sge_state *ss, u32 lkey) +{ + int i; + bool rval = false; + + if (!ss->num_sge) + return rval; + /* first one */ + rval = rvt_mr_has_lkey(ss->sge.mr, lkey); + /* any others */ + for (i = 0; !rval && i < ss->num_sge - 1; i++) + rval = rvt_mr_has_lkey(ss->sg_list[i].mr, lkey); + return rval; +} + +/** + * rvt_dereg_mr - unregister and free a memory region + * @ibmr: the memory region to free + * @udata: unused by the driver + * + * Note that this is called to free MRs created by rvt_get_dma_mr() + * or rvt_reg_user_mr(). + * + * Returns 0 on success. + */ +int rvt_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) +{ + struct rvt_mr *mr = to_imr(ibmr); + int ret; + + rvt_free_lkey(&mr->mr); + + rvt_put_mr(&mr->mr); /* will set completion if last */ + ret = rvt_check_refs(&mr->mr, __func__); + if (ret) + goto out; + rvt_deinit_mregion(&mr->mr); + ib_umem_release(mr->umem); + kfree(mr); +out: + return ret; +} + +/** + * rvt_alloc_mr - Allocate a memory region usable with the + * @pd: protection domain for this memory region + * @mr_type: mem region type + * @max_num_sg: Max number of segments allowed + * + * Return: the memory region on success, otherwise return an errno. + */ +struct ib_mr *rvt_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type, + u32 max_num_sg) +{ + struct rvt_mr *mr; + + if (mr_type != IB_MR_TYPE_MEM_REG) + return ERR_PTR(-EINVAL); + + mr = __rvt_alloc_mr(max_num_sg, pd); + if (IS_ERR(mr)) + return (struct ib_mr *)mr; + + return &mr->ibmr; +} + +/** + * rvt_set_page - page assignment function called by ib_sg_to_pages + * @ibmr: memory region + * @addr: dma address of mapped page + * + * Return: 0 on success + */ +static int rvt_set_page(struct ib_mr *ibmr, u64 addr) +{ + struct rvt_mr *mr = to_imr(ibmr); + u32 ps = 1 << mr->mr.page_shift; + u32 mapped_segs = mr->mr.length >> mr->mr.page_shift; + int m, n; + + if (unlikely(mapped_segs == mr->mr.max_segs)) + return -ENOMEM; + + m = mapped_segs / RVT_SEGSZ; + n = mapped_segs % RVT_SEGSZ; + mr->mr.map[m]->segs[n].vaddr = (void *)addr; + mr->mr.map[m]->segs[n].length = ps; + mr->mr.length += ps; + trace_rvt_mr_page_seg(&mr->mr, m, n, (void *)addr, ps); + + return 0; +} + +/** + * rvt_map_mr_sg - map sg list and set it the memory region + * @ibmr: memory region + * @sg: dma mapped scatterlist + * @sg_nents: number of entries in sg + * @sg_offset: offset in bytes into sg + * + * Overwrite rvt_mr length with mr length calculated by ib_sg_to_pages. + * + * Return: number of sg elements mapped to the memory region + */ +int rvt_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, + int sg_nents, unsigned int *sg_offset) +{ + struct rvt_mr *mr = to_imr(ibmr); + int ret; + + mr->mr.length = 0; + mr->mr.page_shift = PAGE_SHIFT; + ret = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset, rvt_set_page); + mr->mr.user_base = ibmr->iova; + mr->mr.iova = ibmr->iova; + mr->mr.offset = ibmr->iova - (u64)mr->mr.map[0]->segs[0].vaddr; + mr->mr.length = (size_t)ibmr->length; + trace_rvt_map_mr_sg(ibmr, sg_nents, sg_offset); + return ret; +} + +/** + * rvt_fast_reg_mr - fast register physical MR + * @qp: the queue pair where the work request comes from + * @ibmr: the memory region to be registered + * @key: updated key for this memory region + * @access: access flags for this memory region + * + * Returns 0 on success. + */ +int rvt_fast_reg_mr(struct rvt_qp *qp, struct ib_mr *ibmr, u32 key, + int access) +{ + struct rvt_mr *mr = to_imr(ibmr); + + if (qp->ibqp.pd != mr->mr.pd) + return -EACCES; + + /* not applicable to dma MR or user MR */ + if (!mr->mr.lkey || mr->umem) + return -EINVAL; + + if ((key & 0xFFFFFF00) != (mr->mr.lkey & 0xFFFFFF00)) + return -EINVAL; + + ibmr->lkey = key; + ibmr->rkey = key; + mr->mr.lkey = key; + mr->mr.access_flags = access; + mr->mr.iova = ibmr->iova; + atomic_set(&mr->mr.lkey_invalid, 0); + + return 0; +} +EXPORT_SYMBOL(rvt_fast_reg_mr); + +/** + * rvt_invalidate_rkey - invalidate an MR rkey + * @qp: queue pair associated with the invalidate op + * @rkey: rkey to invalidate + * + * Returns 0 on success. + */ +int rvt_invalidate_rkey(struct rvt_qp *qp, u32 rkey) +{ + struct rvt_dev_info *dev = ib_to_rvt(qp->ibqp.device); + struct rvt_lkey_table *rkt = &dev->lkey_table; + struct rvt_mregion *mr; + + if (rkey == 0) + return -EINVAL; + + rcu_read_lock(); + mr = rcu_dereference( + rkt->table[(rkey >> (32 - dev->dparms.lkey_table_size))]); + if (unlikely(!mr || mr->lkey != rkey || qp->ibqp.pd != mr->pd)) + goto bail; + + atomic_set(&mr->lkey_invalid, 1); + rcu_read_unlock(); + return 0; + +bail: + rcu_read_unlock(); + return -EINVAL; +} +EXPORT_SYMBOL(rvt_invalidate_rkey); + +/** + * rvt_sge_adjacent - is isge compressible + * @last_sge: last outgoing SGE written + * @sge: SGE to check + * + * If adjacent will update last_sge to add length. + * + * Return: true if isge is adjacent to last sge + */ +static inline bool rvt_sge_adjacent(struct rvt_sge *last_sge, + struct ib_sge *sge) +{ + if (last_sge && sge->lkey == last_sge->mr->lkey && + ((uint64_t)(last_sge->vaddr + last_sge->length) == sge->addr)) { + if (sge->lkey) { + if (unlikely((sge->addr - last_sge->mr->user_base + + sge->length > last_sge->mr->length))) + return false; /* overrun, caller will catch */ + } else { + last_sge->length += sge->length; + } + last_sge->sge_length += sge->length; + trace_rvt_sge_adjacent(last_sge, sge); + return true; + } + return false; +} + +/** + * rvt_lkey_ok - check IB SGE for validity and initialize + * @rkt: table containing lkey to check SGE against + * @pd: protection domain + * @isge: outgoing internal SGE + * @last_sge: last outgoing SGE written + * @sge: SGE to check + * @acc: access flags + * + * Check the IB SGE for validity and initialize our internal version + * of it. + * + * Increments the reference count when a new sge is stored. + * + * Return: 0 if compressed, 1 if added , otherwise returns -errno. + */ +int rvt_lkey_ok(struct rvt_lkey_table *rkt, struct rvt_pd *pd, + struct rvt_sge *isge, struct rvt_sge *last_sge, + struct ib_sge *sge, int acc) +{ + struct rvt_mregion *mr; + unsigned n, m; + size_t off; + + /* + * We use LKEY == zero for kernel virtual addresses + * (see rvt_get_dma_mr()). + */ + if (sge->lkey == 0) { + struct rvt_dev_info *dev = ib_to_rvt(pd->ibpd.device); + + if (pd->user) + return -EINVAL; + if (rvt_sge_adjacent(last_sge, sge)) + return 0; + rcu_read_lock(); + mr = rcu_dereference(dev->dma_mr); + if (!mr) + goto bail; + rvt_get_mr(mr); + rcu_read_unlock(); + + isge->mr = mr; + isge->vaddr = (void *)sge->addr; + isge->length = sge->length; + isge->sge_length = sge->length; + isge->m = 0; + isge->n = 0; + goto ok; + } + if (rvt_sge_adjacent(last_sge, sge)) + return 0; + rcu_read_lock(); + mr = rcu_dereference(rkt->table[sge->lkey >> rkt->shift]); + if (!mr) + goto bail; + rvt_get_mr(mr); + if (!READ_ONCE(mr->lkey_published)) + goto bail_unref; + + if (unlikely(atomic_read(&mr->lkey_invalid) || + mr->lkey != sge->lkey || mr->pd != &pd->ibpd)) + goto bail_unref; + + off = sge->addr - mr->user_base; + if (unlikely(sge->addr < mr->user_base || + off + sge->length > mr->length || + (mr->access_flags & acc) != acc)) + goto bail_unref; + rcu_read_unlock(); + + off += mr->offset; + if (mr->page_shift) { + /* + * page sizes are uniform power of 2 so no loop is necessary + * entries_spanned_by_off is the number of times the loop below + * would have executed. + */ + size_t entries_spanned_by_off; + + entries_spanned_by_off = off >> mr->page_shift; + off -= (entries_spanned_by_off << mr->page_shift); + m = entries_spanned_by_off / RVT_SEGSZ; + n = entries_spanned_by_off % RVT_SEGSZ; + } else { + m = 0; + n = 0; + while (off >= mr->map[m]->segs[n].length) { + off -= mr->map[m]->segs[n].length; + n++; + if (n >= RVT_SEGSZ) { + m++; + n = 0; + } + } + } + isge->mr = mr; + isge->vaddr = mr->map[m]->segs[n].vaddr + off; + isge->length = mr->map[m]->segs[n].length - off; + isge->sge_length = sge->length; + isge->m = m; + isge->n = n; +ok: + trace_rvt_sge_new(isge, sge); + return 1; +bail_unref: + rvt_put_mr(mr); +bail: + rcu_read_unlock(); + return -EINVAL; +} +EXPORT_SYMBOL(rvt_lkey_ok); + +/** + * rvt_rkey_ok - check the IB virtual address, length, and RKEY + * @qp: qp for validation + * @sge: SGE state + * @len: length of data + * @vaddr: virtual address to place data + * @rkey: rkey to check + * @acc: access flags + * + * Return: 1 if successful, otherwise 0. + * + * increments the reference count upon success + */ +int rvt_rkey_ok(struct rvt_qp *qp, struct rvt_sge *sge, + u32 len, u64 vaddr, u32 rkey, int acc) +{ + struct rvt_dev_info *dev = ib_to_rvt(qp->ibqp.device); + struct rvt_lkey_table *rkt = &dev->lkey_table; + struct rvt_mregion *mr; + unsigned n, m; + size_t off; + + /* + * We use RKEY == zero for kernel virtual addresses + * (see rvt_get_dma_mr()). + */ + rcu_read_lock(); + if (rkey == 0) { + struct rvt_pd *pd = ibpd_to_rvtpd(qp->ibqp.pd); + struct rvt_dev_info *rdi = ib_to_rvt(pd->ibpd.device); + + if (pd->user) + goto bail; + mr = rcu_dereference(rdi->dma_mr); + if (!mr) + goto bail; + rvt_get_mr(mr); + rcu_read_unlock(); + + sge->mr = mr; + sge->vaddr = (void *)vaddr; + sge->length = len; + sge->sge_length = len; + sge->m = 0; + sge->n = 0; + goto ok; + } + + mr = rcu_dereference(rkt->table[rkey >> rkt->shift]); + if (!mr) + goto bail; + rvt_get_mr(mr); + /* insure mr read is before test */ + if (!READ_ONCE(mr->lkey_published)) + goto bail_unref; + if (unlikely(atomic_read(&mr->lkey_invalid) || + mr->lkey != rkey || qp->ibqp.pd != mr->pd)) + goto bail_unref; + + off = vaddr - mr->iova; + if (unlikely(vaddr < mr->iova || off + len > mr->length || + (mr->access_flags & acc) == 0)) + goto bail_unref; + rcu_read_unlock(); + + off += mr->offset; + if (mr->page_shift) { + /* + * page sizes are uniform power of 2 so no loop is necessary + * entries_spanned_by_off is the number of times the loop below + * would have executed. + */ + size_t entries_spanned_by_off; + + entries_spanned_by_off = off >> mr->page_shift; + off -= (entries_spanned_by_off << mr->page_shift); + m = entries_spanned_by_off / RVT_SEGSZ; + n = entries_spanned_by_off % RVT_SEGSZ; + } else { + m = 0; + n = 0; + while (off >= mr->map[m]->segs[n].length) { + off -= mr->map[m]->segs[n].length; + n++; + if (n >= RVT_SEGSZ) { + m++; + n = 0; + } + } + } + sge->mr = mr; + sge->vaddr = mr->map[m]->segs[n].vaddr + off; + sge->length = mr->map[m]->segs[n].length - off; + sge->sge_length = len; + sge->m = m; + sge->n = n; +ok: + return 1; +bail_unref: + rvt_put_mr(mr); +bail: + rcu_read_unlock(); + return 0; +} +EXPORT_SYMBOL(rvt_rkey_ok); |