From 8737ce95c463c6d8c4307ab3d6858cbf71cd4fc8 Mon Sep 17 00:00:00 2001 From: "Michael J. Ruhl" Date: Thu, 4 May 2017 05:15:15 -0700 Subject: [PATCH] IB/hfi1: Fix an assign/ordering issue with shared context IDs The current algorithm for generating sub-context IDs is FILO. If the contexts are not closed in that order, the uniqueness of the ID will be compromised. I.e. logging the creation/deletion of context IDs with an application that assigns and closes in a FIFO order reveals: cache_id: assign: uctxt: 3 sub_ctxt: 0 cache_id: assign: uctxt: 3 sub_ctxt: 1 cache_id: assign: uctxt: 3 sub_ctxt: 2 cache_id: close: uctxt: 3 sub_ctxt: 0 cache_id: assign: uctxt: 3 sub_ctxt: 2 <<< The sub_ctxt ID 2 is reused incorrectly. Update the sub-context ID assign algorithm to use a bitmask of in_use contexts. The new algorithm will allow the contexts to be closed in any order, and will only re-use unused contexts. Size subctxt and subctxt_cnt to match the user API size. Reviewed-by: Mike Marciniszyn Signed-off-by: Michael J. Ruhl Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/driver.c | 2 +- drivers/infiniband/hw/hfi1/file_ops.c | 51 ++++++++++++++++---------- drivers/infiniband/hw/hfi1/hfi.h | 8 ++-- drivers/infiniband/hw/hfi1/init.c | 3 +- drivers/infiniband/hw/hfi1/intr.c | 3 +- drivers/infiniband/hw/hfi1/user_sdma.h | 2 +- 6 files changed, 41 insertions(+), 28 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/driver.c b/drivers/infiniband/hw/hfi1/driver.c index 566d152e36f2..a50870e455a3 100644 --- a/drivers/infiniband/hw/hfi1/driver.c +++ b/drivers/infiniband/hw/hfi1/driver.c @@ -1289,7 +1289,7 @@ int hfi1_reset_device(int unit) if (dd->rcd) for (i = dd->first_dyn_alloc_ctxt; i < dd->num_rcv_contexts; i++) { - if (!dd->rcd[i] || !dd->rcd[i]->cnt) + if (!dd->rcd[i]) continue; spin_unlock_irqrestore(&dd->uctxt_lock, flags); ret = -EBUSY; diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c index 467f876551ba..9c177ef79db5 100644 --- a/drivers/infiniband/hw/hfi1/file_ops.c +++ b/drivers/infiniband/hw/hfi1/file_ops.c @@ -49,6 +49,7 @@ #include #include #include +#include #include @@ -95,11 +96,10 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd, struct hfi1_user_info *uinfo); static unsigned int poll_urgent(struct file *fp, struct poll_table_struct *pt); static unsigned int poll_next(struct file *fp, struct poll_table_struct *pt); -static int user_event_ack(struct hfi1_ctxtdata *uctxt, int subctxt, +static int user_event_ack(struct hfi1_ctxtdata *uctxt, u16 subctxt, unsigned long events); -static int set_ctxt_pkey(struct hfi1_ctxtdata *uctxt, unsigned subctxt, - u16 pkey); -static int manage_rcvq(struct hfi1_ctxtdata *uctxt, unsigned subctxt, +static int set_ctxt_pkey(struct hfi1_ctxtdata *uctxt, u16 subctxt, u16 pkey); +static int manage_rcvq(struct hfi1_ctxtdata *uctxt, u16 subctxt, int start_stop); static int vma_fault(struct vm_fault *vmf); static long hfi1_file_ioctl(struct file *fp, unsigned int cmd, @@ -773,8 +773,8 @@ static int hfi1_file_close(struct inode *inode, struct file *fp) HFI1_MAX_SHARED_CTXTS) + fdata->subctxt; *ev = 0; - if (--uctxt->cnt) { - uctxt->active_slaves &= ~(1 << fdata->subctxt); + __clear_bit(fdata->subctxt, uctxt->in_use_ctxts); + if (!bitmap_empty(uctxt->in_use_ctxts, HFI1_MAX_SHARED_CTXTS)) { mutex_unlock(&hfi1_mutex); goto done; } @@ -868,7 +868,7 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo) } /* - * Allocate a base context f context sharing is not required or we + * Allocate a base context if context sharing is not required or we * couldn't find a sub context. */ if (!ret) @@ -905,17 +905,24 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo) return ret; } +/* + * The hfi1_mutex must be held when this function is called. It is + * necessary to ensure serialized access to the bitmask in_use_ctxts. + */ static int find_sub_ctxt(struct hfi1_filedata *fd, const struct hfi1_user_info *uinfo) { int i; struct hfi1_devdata *dd = fd->dd; + u16 subctxt; for (i = dd->first_dyn_alloc_ctxt; i < dd->num_rcv_contexts; i++) { struct hfi1_ctxtdata *uctxt = dd->rcd[i]; /* Skip ctxts which are not yet open */ - if (!uctxt || !uctxt->cnt) + if (!uctxt || + bitmap_empty(uctxt->in_use_ctxts, + HFI1_MAX_SHARED_CTXTS)) continue; /* Skip dynamically allocted kernel contexts */ @@ -931,13 +938,19 @@ static int find_sub_ctxt(struct hfi1_filedata *fd, continue; /* Verify the sharing process matches the master */ - if (uctxt->userversion != uinfo->userversion || - uctxt->cnt >= uctxt->subctxt_cnt) { + if (uctxt->userversion != uinfo->userversion) return -EINVAL; - } + + /* Find an unused context */ + subctxt = find_first_zero_bit(uctxt->in_use_ctxts, + HFI1_MAX_SHARED_CTXTS); + if (subctxt >= uctxt->subctxt_cnt) + return -EINVAL; + fd->uctxt = uctxt; - fd->subctxt = uctxt->cnt++; - uctxt->active_slaves |= 1 << fd->subctxt; + fd->subctxt = subctxt; + __set_bit(fd->subctxt, uctxt->in_use_ctxts); + return 1; } @@ -1055,7 +1068,7 @@ ctxdata_free: static int init_subctxts(struct hfi1_ctxtdata *uctxt, const struct hfi1_user_info *uinfo) { - unsigned num_subctxts; + u16 num_subctxts; num_subctxts = uinfo->subctxt_cnt; if (num_subctxts > HFI1_MAX_SHARED_CTXTS) @@ -1063,7 +1076,6 @@ static int init_subctxts(struct hfi1_ctxtdata *uctxt, uctxt->subctxt_cnt = uinfo->subctxt_cnt; uctxt->subctxt_id = uinfo->subctxt_id; - uctxt->active_slaves = 1; uctxt->redirect_seq_cnt = 1; set_bit(HFI1_CTXT_BASE_UNINIT, &uctxt->event_flags); @@ -1073,7 +1085,7 @@ static int init_subctxts(struct hfi1_ctxtdata *uctxt, static int setup_subctxt(struct hfi1_ctxtdata *uctxt) { int ret = 0; - unsigned num_subctxts = uctxt->subctxt_cnt; + u16 num_subctxts = uctxt->subctxt_cnt; uctxt->subctxt_uregbase = vmalloc_user(PAGE_SIZE); if (!uctxt->subctxt_uregbase) @@ -1425,7 +1437,7 @@ done: * overflow conditions. start_stop==1 re-enables, to be used to * re-init the software copy of the head register */ -static int manage_rcvq(struct hfi1_ctxtdata *uctxt, unsigned subctxt, +static int manage_rcvq(struct hfi1_ctxtdata *uctxt, u16 subctxt, int start_stop) { struct hfi1_devdata *dd = uctxt->dd; @@ -1460,7 +1472,7 @@ bail: * User process then performs actions appropriate to bit having been * set, if desired, and checks again in future. */ -static int user_event_ack(struct hfi1_ctxtdata *uctxt, int subctxt, +static int user_event_ack(struct hfi1_ctxtdata *uctxt, u16 subctxt, unsigned long events) { int i; @@ -1481,8 +1493,7 @@ static int user_event_ack(struct hfi1_ctxtdata *uctxt, int subctxt, return 0; } -static int set_ctxt_pkey(struct hfi1_ctxtdata *uctxt, unsigned subctxt, - u16 pkey) +static int set_ctxt_pkey(struct hfi1_ctxtdata *uctxt, u16 subctxt, u16 pkey) { int ret = -ENOENT, i, intable = 0; struct hfi1_pportdata *ppd = uctxt->ppd; diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h index 1b7203a3f1ce..f3d75fcd5f07 100644 --- a/drivers/infiniband/hw/hfi1/hfi.h +++ b/drivers/infiniband/hw/hfi1/hfi.h @@ -228,7 +228,7 @@ struct hfi1_ctxtdata { unsigned ctxt; /* * non-zero if ctxt can be shared, and defines the maximum number of - * sub contexts allowed. + * sub-contexts for this device context. */ u16 subctxt_cnt; /* non-zero if ctxt is being shared. */ @@ -287,10 +287,10 @@ struct hfi1_ctxtdata { void *subctxt_rcvegrbuf; /* An array of pages for the eager header queue entries * N */ void *subctxt_rcvhdr_base; + /* Bitmask of in use context(s) */ + DECLARE_BITMAP(in_use_ctxts, HFI1_MAX_SHARED_CTXTS); /* The version of the library which opened this ctxt */ u32 userversion; - /* Bitmask of active slaves */ - u32 active_slaves; /* Type of packets or conditions we want to poll for */ u16 poll_type; /* receive packet sequence counter */ @@ -1239,9 +1239,9 @@ struct mmu_rb_handler; struct hfi1_filedata { struct hfi1_devdata *dd; struct hfi1_ctxtdata *uctxt; - unsigned subctxt; struct hfi1_user_sdma_comp_q *cq; struct hfi1_user_sdma_pkt_q *pq; + u16 subctxt; /* for cpu affinity; -1 if none */ int rec_cpu_num; u32 tid_n_pinned; diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c index 52a6364c30de..694a8ecf9f26 100644 --- a/drivers/infiniband/hw/hfi1/init.c +++ b/drivers/infiniband/hw/hfi1/init.c @@ -53,6 +53,7 @@ #include #include #include +#include #include #include "hfi.h" @@ -222,7 +223,7 @@ struct hfi1_ctxtdata *hfi1_create_ctxtdata(struct hfi1_pportdata *ppd, u32 ctxt, INIT_LIST_HEAD(&rcd->qp_wait_list); rcd->ppd = ppd; rcd->dd = dd; - rcd->cnt = 1; + __set_bit(0, rcd->in_use_ctxts); rcd->ctxt = ctxt; dd->rcd[ctxt] = rcd; rcd->numa_id = numa; diff --git a/drivers/infiniband/hw/hfi1/intr.c b/drivers/infiniband/hw/hfi1/intr.c index 232014d46f79..ba265d0ae93b 100644 --- a/drivers/infiniband/hw/hfi1/intr.c +++ b/drivers/infiniband/hw/hfi1/intr.c @@ -47,6 +47,7 @@ #include #include +#include #include "hfi.h" #include "common.h" @@ -189,7 +190,7 @@ void handle_user_interrupt(struct hfi1_ctxtdata *rcd) unsigned long flags; spin_lock_irqsave(&dd->uctxt_lock, flags); - if (!rcd->cnt) + if (bitmap_empty(rcd->in_use_ctxts, HFI1_MAX_SHARED_CTXTS)) goto done; if (test_and_clear_bit(HFI1_CTXT_WAITING_RCV, &rcd->event_flags)) { diff --git a/drivers/infiniband/hw/hfi1/user_sdma.h b/drivers/infiniband/hw/hfi1/user_sdma.h index 9181d7cbe8f6..e5b10aefe212 100644 --- a/drivers/infiniband/hw/hfi1/user_sdma.h +++ b/drivers/infiniband/hw/hfi1/user_sdma.h @@ -58,7 +58,7 @@ extern uint extended_psn; struct hfi1_user_sdma_pkt_q { struct list_head list; unsigned ctxt; - unsigned subctxt; + u16 subctxt; u16 n_max_reqs; atomic_t n_reqs; u16 reqidx; -- 2.20.1