RDMA/hfi1: Use mmu_interval_notifier_insert for user_exp_rcv

This converts one of the two users of mmu_notifiers to use the new API.
The conversion is fairly straightforward, however the existing use of
notifiers here seems to be racey.

Link: https://lore.kernel.org/r/20191112202231.3856-7-jgg@ziepe.ca
Tested-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
index f9a7e9d..7c5e3fb 100644 (file)
--- a/drivers/infiniband/hw/hfi1/file_ops.c
+++ b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -1138,7 +1138,7 @@ static int get_ctxt_info(struct hfi1_filedata *fd, unsigned long arg, u32 len)
                        HFI1_CAP_UGET_MASK(uctxt->flags, MASK) |
                        HFI1_CAP_KGET_MASK(uctxt->flags, K2U);
        /* adjust flag if this fd is not able to cache */
-       if (!fd->handler)
+       if (!fd->use_mn)
                cinfo.runtime_flags |= HFI1_CAP_TID_UNMAP; /* no caching */
 
        cinfo.num_active = hfi1_count_active_units();

diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index fa45350..fc10d65 100644 (file)
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -1444,7 +1444,7 @@ struct hfi1_filedata {
        /* for cpu affinity; -1 if none */
        int rec_cpu_num;
        u32 tid_n_pinned;
-       struct mmu_rb_handler *handler;
+       bool use_mn;
        struct tid_rb_node **entry_to_rb;
        spinlock_t tid_lock; /* protect tid_[limit,used] counters */
        u32 tid_limit;

diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
index 3592a9e..f05742a 100644 (file)
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.c
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
@@ -59,11 +59,11 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
                              struct tid_user_buf *tbuf,
                              u32 rcventry, struct tid_group *grp,
                              u16 pageidx, unsigned int npages);
-static int tid_rb_insert(void *arg, struct mmu_rb_node *node);
 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
                                    struct tid_rb_node *tnode);
-static void tid_rb_remove(void *arg, struct mmu_rb_node *node);
-static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode);
+static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
+                             const struct mmu_notifier_range *range,
+                             unsigned long cur_seq);
 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *,
                            struct tid_group *grp,
                            unsigned int start, u16 count,
@@ -73,10 +73,8 @@ static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
                              struct tid_group **grp);
 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node);
 
-static struct mmu_rb_ops tid_rb_ops = {
-       .insert = tid_rb_insert,
-       .remove = tid_rb_remove,
-       .invalidate = tid_rb_invalidate
+static const struct mmu_interval_notifier_ops tid_mn_ops = {
+       .invalidate = tid_rb_invalidate,
 };
 
 /*
@@ -87,7 +85,6 @@ static struct mmu_rb_ops tid_rb_ops = {
 int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
                           struct hfi1_ctxtdata *uctxt)
 {
-       struct hfi1_devdata *dd = uctxt->dd;
        int ret = 0;
 
        spin_lock_init(&fd->tid_lock);
@@ -109,20 +106,7 @@ int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
                        fd->entry_to_rb = NULL;
                        return -ENOMEM;
                }
-
-               /*
-                * Register MMU notifier callbacks. If the registration
-                * fails, continue without TID caching for this context.
-                */
-               ret = hfi1_mmu_rb_register(fd, fd->mm, &tid_rb_ops,
-                                          dd->pport->hfi1_wq,
-                                          &fd->handler);
-               if (ret) {
-                       dd_dev_info(dd,
-                                   "Failed MMU notifier registration %d\n",
-                                   ret);
-                       ret = 0;
-               }
+               fd->use_mn = true;
        }
 
        /*
@@ -139,7 +123,7 @@ int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
         * init.
         */
        spin_lock(&fd->tid_lock);
-       if (uctxt->subctxt_cnt && fd->handler) {
+       if (uctxt->subctxt_cnt && fd->use_mn) {
                u16 remainder;
 
                fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
@@ -158,18 +142,10 @@ void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
 {
        struct hfi1_ctxtdata *uctxt = fd->uctxt;
 
-       /*
-        * The notifier would have been removed when the process'es mm
-        * was freed.
-        */
-       if (fd->handler) {
-               hfi1_mmu_rb_unregister(fd->handler);
-       } else {
-               if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
-                       unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
-               if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
-                       unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
-       }
+       if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
+               unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
+       if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
+               unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
 
        kfree(fd->invalid_tids);
        fd->invalid_tids = NULL;
@@ -201,7 +177,7 @@ static void unpin_rcv_pages(struct hfi1_filedata *fd,
 
        if (mapped) {
                pci_unmap_single(dd->pcidev, node->dma_addr,
-                                node->mmu.len, PCI_DMA_FROMDEVICE);
+                                node->npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
                pages = &node->pages[idx];
        } else {
                pages = &tidbuf->pages[idx];
@@ -777,8 +753,7 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
                return -EFAULT;
        }
 
-       node->mmu.addr = tbuf->vaddr + (pageidx * PAGE_SIZE);
-       node->mmu.len = npages * PAGE_SIZE;
+       node->fdata = fd;
        node->phys = page_to_phys(pages[0]);
        node->npages = npages;
        node->rcventry = rcventry;
@@ -787,23 +762,35 @@ static int set_rcvarray_entry(struct hfi1_filedata *fd,
        node->freed = false;
        memcpy(node->pages, pages, sizeof(struct page *) * npages);
 
-       if (!fd->handler)
-               ret = tid_rb_insert(fd, &node->mmu);
-       else
-               ret = hfi1_mmu_rb_insert(fd->handler, &node->mmu);
-
-       if (ret) {
-               hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
-                         node->rcventry, node->mmu.addr, node->phys, ret);
-               pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
-                                PCI_DMA_FROMDEVICE);
-               kfree(node);
-               return -EFAULT;
+       if (fd->use_mn) {
+               ret = mmu_interval_notifier_insert(
+                       &node->notifier, fd->mm,
+                       tbuf->vaddr + (pageidx * PAGE_SIZE), npages * PAGE_SIZE,
+                       &tid_mn_ops);
+               if (ret)
+                       goto out_unmap;
+               /*
+                * FIXME: This is in the wrong order, the notifier should be
+                * established before the pages are pinned by pin_rcv_pages.
+                */
+               mmu_interval_read_begin(&node->notifier);
        }
+       fd->entry_to_rb[node->rcventry - uctxt->expected_base] = node;
+
        hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
        trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
-                              node->mmu.addr, node->phys, phys);
+                              node->notifier.interval_tree.start, node->phys,
+                              phys);
        return 0;
+
+out_unmap:
+       hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
+                 node->rcventry, node->notifier.interval_tree.start,
+                 node->phys, ret);
+       pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
+                        PCI_DMA_FROMDEVICE);
+       kfree(node);
+       return -EFAULT;
 }
 
 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
@@ -833,10 +820,9 @@ static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
        if (grp)
                *grp = node->grp;
 
-       if (!fd->handler)
-               cacheless_tid_rb_remove(fd, node);
-       else
-               hfi1_mmu_rb_remove(fd->handler, &node->mmu);
+       if (fd->use_mn)
+               mmu_interval_notifier_remove(&node->notifier);
+       cacheless_tid_rb_remove(fd, node);
 
        return 0;
 }
@@ -847,7 +833,8 @@ static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
        struct hfi1_devdata *dd = uctxt->dd;
 
        trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
-                                node->npages, node->mmu.addr, node->phys,
+                                node->npages,
+                                node->notifier.interval_tree.start, node->phys,
                                 node->dma_addr);
 
        /*
@@ -894,30 +881,29 @@ static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
                                if (!node || node->rcventry != rcventry)
                                        continue;
 
+                               if (fd->use_mn)
+                                       mmu_interval_notifier_remove(
+                                               &node->notifier);
                                cacheless_tid_rb_remove(fd, node);
                        }
                }
        }
 }
 
-/*
- * Always return 0 from this function.  A non-zero return indicates that the
- * remove operation will be called and that memory should be unpinned.
- * However, the driver cannot unpin out from under PSM.  Instead, retain the
- * memory (by returning 0) and inform PSM that the memory is going away.  PSM
- * will call back later when it has removed the memory from its list.
- */
-static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
+static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
+                             const struct mmu_notifier_range *range,
+                             unsigned long cur_seq)
 {
-       struct hfi1_filedata *fdata = arg;
-       struct hfi1_ctxtdata *uctxt = fdata->uctxt;
        struct tid_rb_node *node =
-               container_of(mnode, struct tid_rb_node, mmu);
+               container_of(mni, struct tid_rb_node, notifier);
+       struct hfi1_filedata *fdata = node->fdata;
+       struct hfi1_ctxtdata *uctxt = fdata->uctxt;
 
        if (node->freed)
-               return 0;
+               return true;
 
-       trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt, node->mmu.addr,
+       trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt,
+                                node->notifier.interval_tree.start,
                                 node->rcventry, node->npages, node->dma_addr);
        node->freed = true;
 
@@ -946,18 +932,7 @@ static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
                fdata->invalid_tid_idx++;
        }
        spin_unlock(&fdata->invalid_lock);
-       return 0;
-}
-
-static int tid_rb_insert(void *arg, struct mmu_rb_node *node)
-{
-       struct hfi1_filedata *fdata = arg;
-       struct tid_rb_node *tnode =
-               container_of(node, struct tid_rb_node, mmu);
-       u32 base = fdata->uctxt->expected_base;
-
-       fdata->entry_to_rb[tnode->rcventry - base] = tnode;
-       return 0;
+       return true;
 }
 
 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
@@ -968,12 +943,3 @@ static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
        fdata->entry_to_rb[tnode->rcventry - base] = NULL;
        clear_tid_node(fdata, tnode);
 }
-
-static void tid_rb_remove(void *arg, struct mmu_rb_node *node)
-{
-       struct hfi1_filedata *fdata = arg;
-       struct tid_rb_node *tnode =
-               container_of(node, struct tid_rb_node, mmu);
-
-       cacheless_tid_rb_remove(fdata, tnode);
-}

diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.h b/drivers/infiniband/hw/hfi1/user_exp_rcv.h
index 43b105d..6257eee 100644 (file)
--- a/drivers/infiniband/hw/hfi1/user_exp_rcv.h
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.h
@@ -65,7 +65,8 @@ struct tid_user_buf {
 };
 
 struct tid_rb_node {
-       struct mmu_rb_node mmu;
+       struct mmu_interval_notifier notifier;
+       struct hfi1_filedata *fdata;
        unsigned long phys;
        struct tid_group *grp;
        u32 rcventry;