From 22546b741af8355cd2e16739b6af4a8f17081839 Mon Sep 17 00:00:00 2001 From: Tadeusz Struk Date: Fri, 28 Apr 2017 10:40:02 -0700 Subject: [PATCH] IB/hfi1: Fix softlockup issue Soft lockups can occur because the mad processing on different CPUs acquire the spin lock dc8051_lock: [534552.835870] [] ? read_dev_port_cntr.isra.37+0x23/0x160 [hfi1] [534552.835880] [] read_dev_cntr+0x4f/0x60 [hfi1] [534552.835893] [] pma_get_opa_portstatus+0x64d/0x8c0 [hfi1] [534552.835904] [] hfi1_process_mad+0x48d/0x18c0 [hfi1] [534552.835908] [] ? __slab_free+0x81/0x2f0 [534552.835936] [] ? ib_mad_recv_done+0x21e/0xa30 [ib_core] [534552.835939] [] ? __kmalloc+0x1f3/0x240 [534552.835947] [] ib_mad_recv_done+0x2cb/0xa30 [ib_core] [534552.835955] [] __ib_process_cq+0x55/0xd0 [ib_core] [534552.835962] [] ib_cq_poll_work+0x20/0x60 [ib_core] [534552.835964] [] process_one_work+0x17b/0x470 [534552.835966] [] worker_thread+0x126/0x410 [534552.835969] [] ? rescuer_thread+0x460/0x460 [534552.835971] [] kthread+0xcf/0xe0 [534552.835974] [] ? kthread_create_on_node+0x140/0x140 [534552.835977] [] ret_from_fork+0x58/0x90 [534552.835980] [] ? kthread_create_on_node+0x140/0x140 This issue is made worse when the 8051 is busy and the reads take longer. Fix by using a non-spinning lock procure. Reviewed-by: Michael J. Ruhl Reviewed-by: Mike Marciszyn Signed-off-by: Tadeusz Struk Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/chip.c | 86 +++++++++++++++++++------------ drivers/infiniband/hw/hfi1/hfi.h | 7 +-- drivers/infiniband/hw/hfi1/init.c | 2 +- 3 files changed, 57 insertions(+), 38 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c index e520929ac501..07aa76a74f64 100644 --- a/drivers/infiniband/hw/hfi1/chip.c +++ b/drivers/infiniband/hw/hfi1/chip.c @@ -6410,18 +6410,17 @@ static void lcb_shutdown(struct hfi1_devdata *dd, int abort) * * The expectation is that the caller of this routine would have taken * care of properly transitioning the link into the correct state. + * NOTE: the caller needs to acquire the dd->dc8051_lock lock + * before calling this function. */ -static void dc_shutdown(struct hfi1_devdata *dd) +static void _dc_shutdown(struct hfi1_devdata *dd) { - unsigned long flags; + lockdep_assert_held(&dd->dc8051_lock); - spin_lock_irqsave(&dd->dc8051_lock, flags); - if (dd->dc_shutdown) { - spin_unlock_irqrestore(&dd->dc8051_lock, flags); + if (dd->dc_shutdown) return; - } + dd->dc_shutdown = 1; - spin_unlock_irqrestore(&dd->dc8051_lock, flags); /* Shutdown the LCB */ lcb_shutdown(dd, 1); /* @@ -6432,35 +6431,45 @@ static void dc_shutdown(struct hfi1_devdata *dd) write_csr(dd, DC_DC8051_CFG_RST, 0x1); } +static void dc_shutdown(struct hfi1_devdata *dd) +{ + mutex_lock(&dd->dc8051_lock); + _dc_shutdown(dd); + mutex_unlock(&dd->dc8051_lock); +} + /* * Calling this after the DC has been brought out of reset should not * do any damage. + * NOTE: the caller needs to acquire the dd->dc8051_lock lock + * before calling this function. */ -static void dc_start(struct hfi1_devdata *dd) +static void _dc_start(struct hfi1_devdata *dd) { - unsigned long flags; - int ret; + lockdep_assert_held(&dd->dc8051_lock); - spin_lock_irqsave(&dd->dc8051_lock, flags); if (!dd->dc_shutdown) - goto done; - spin_unlock_irqrestore(&dd->dc8051_lock, flags); + return; + /* Take the 8051 out of reset */ write_csr(dd, DC_DC8051_CFG_RST, 0ull); /* Wait until 8051 is ready */ - ret = wait_fm_ready(dd, TIMEOUT_8051_START); - if (ret) { + if (wait_fm_ready(dd, TIMEOUT_8051_START)) dd_dev_err(dd, "%s: timeout starting 8051 firmware\n", __func__); - } + /* Take away reset for LCB and RX FPE (set in lcb_shutdown). */ write_csr(dd, DCC_CFG_RESET, 0x10); /* lcb_shutdown() with abort=1 does not restore these */ write_csr(dd, DC_LCB_ERR_EN, dd->lcb_err_en); - spin_lock_irqsave(&dd->dc8051_lock, flags); dd->dc_shutdown = 0; -done: - spin_unlock_irqrestore(&dd->dc8051_lock, flags); +} + +static void dc_start(struct hfi1_devdata *dd) +{ + mutex_lock(&dd->dc8051_lock); + _dc_start(dd); + mutex_unlock(&dd->dc8051_lock); } /* @@ -8513,16 +8522,11 @@ static int do_8051_command( { u64 reg, completed; int return_code; - unsigned long flags; unsigned long timeout; hfi1_cdbg(DC8051, "type %d, data 0x%012llx", type, in_data); - /* - * Alternative to holding the lock for a long time: - * - keep busy wait - have other users bounce off - */ - spin_lock_irqsave(&dd->dc8051_lock, flags); + mutex_lock(&dd->dc8051_lock); /* We can't send any commands to the 8051 if it's in reset */ if (dd->dc_shutdown) { @@ -8548,10 +8552,8 @@ static int do_8051_command( return_code = -ENXIO; goto fail; } - spin_unlock_irqrestore(&dd->dc8051_lock, flags); - dc_shutdown(dd); - dc_start(dd); - spin_lock_irqsave(&dd->dc8051_lock, flags); + _dc_shutdown(dd); + _dc_start(dd); } /* @@ -8632,8 +8634,7 @@ static int do_8051_command( write_csr(dd, DC_DC8051_CFG_HOST_CMD_0, 0); fail: - spin_unlock_irqrestore(&dd->dc8051_lock, flags); - + mutex_unlock(&dd->dc8051_lock); return return_code; } @@ -12007,6 +12008,10 @@ static void free_cntrs(struct hfi1_devdata *dd) dd->scntrs = NULL; kfree(dd->cntrnames); dd->cntrnames = NULL; + if (dd->update_cntr_wq) { + destroy_workqueue(dd->update_cntr_wq); + dd->update_cntr_wq = NULL; + } } static u64 read_dev_port_cntr(struct hfi1_devdata *dd, struct cntr_entry *entry, @@ -12162,7 +12167,7 @@ u64 write_port_cntr(struct hfi1_pportdata *ppd, int index, int vl, u64 data) return write_dev_port_cntr(ppd->dd, entry, sval, ppd, vl, data); } -static void update_synth_timer(unsigned long opaque) +static void do_update_synth_timer(struct work_struct *work) { u64 cur_tx; u64 cur_rx; @@ -12171,8 +12176,8 @@ static void update_synth_timer(unsigned long opaque) int i, j, vl; struct hfi1_pportdata *ppd; struct cntr_entry *entry; - - struct hfi1_devdata *dd = (struct hfi1_devdata *)opaque; + struct hfi1_devdata *dd = container_of(work, struct hfi1_devdata, + update_cntr_work); /* * Rather than keep beating on the CSRs pick a minimal set that we can @@ -12255,7 +12260,13 @@ static void update_synth_timer(unsigned long opaque) } else { hfi1_cdbg(CNTR, "[%d] No update necessary", dd->unit); } +} +static void update_synth_timer(unsigned long opaque) +{ + struct hfi1_devdata *dd = (struct hfi1_devdata *)opaque; + + queue_work(dd->update_cntr_wq, &dd->update_cntr_work); mod_timer(&dd->synth_stats_timer, jiffies + HZ * SYNTH_CNT_TIME); } @@ -12491,6 +12502,13 @@ static int init_cntrs(struct hfi1_devdata *dd) if (init_cpu_counters(dd)) goto bail; + dd->update_cntr_wq = alloc_ordered_workqueue("hfi1_update_cntr_%d", + WQ_MEM_RECLAIM, dd->unit); + if (!dd->update_cntr_wq) + goto bail; + + INIT_WORK(&dd->update_cntr_work, do_update_synth_timer); + mod_timer(&dd->synth_stats_timer, jiffies + HZ * SYNTH_CNT_TIME); return 0; bail: diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h index 550116fd9d48..d253ea2521a0 100644 --- a/drivers/infiniband/hw/hfi1/hfi.h +++ b/drivers/infiniband/hw/hfi1/hfi.h @@ -484,7 +484,7 @@ struct rvt_sge_state; #define HFI1_PART_ENFORCE_OUT 0x2 /* how often we check for synthetic counter wrap around */ -#define SYNTH_CNT_TIME 2 +#define SYNTH_CNT_TIME 3 /* Counter flags */ #define CNTR_NORMAL 0x0 /* Normal counters, just read register */ @@ -962,8 +962,9 @@ struct hfi1_devdata { spinlock_t rcvctrl_lock; /* protect changes to RcvCtrl */ /* around rcd and (user ctxts) ctxt_cnt use (intr vs free) */ spinlock_t uctxt_lock; /* rcd and user context changes */ - /* exclusive access to 8051 */ - spinlock_t dc8051_lock; + struct mutex dc8051_lock; /* exclusive access to 8051 */ + struct workqueue_struct *update_cntr_wq; + struct work_struct update_cntr_work; /* exclusive access to 8051 memory */ spinlock_t dc8051_memlock; int dc8051_timed_out; /* remember if the 8051 timed out */ diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c index b4c7e04f4578..21dca7ac059c 100644 --- a/drivers/infiniband/hw/hfi1/init.c +++ b/drivers/infiniband/hw/hfi1/init.c @@ -1081,11 +1081,11 @@ struct hfi1_devdata *hfi1_alloc_devdata(struct pci_dev *pdev, size_t extra) spin_lock_init(&dd->uctxt_lock); spin_lock_init(&dd->hfi1_diag_trans_lock); spin_lock_init(&dd->sc_init_lock); - spin_lock_init(&dd->dc8051_lock); spin_lock_init(&dd->dc8051_memlock); seqlock_init(&dd->sc2vl_lock); spin_lock_init(&dd->sde_map_lock); spin_lock_init(&dd->pio_map_lock); + mutex_init(&dd->dc8051_lock); init_waitqueue_head(&dd->event_queue); dd->int_counter = alloc_percpu(u64); -- 2.20.1