4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tadeusz Struk tadeusz.struk@intel.com
[ Upstream commit 22546b741af8355cd2e16739b6af4a8f17081839 ]
Soft lockups can occur because the mad processing on different CPUs acquire the spin lock dc8051_lock:
[534552.835870] [<ffffffffa026f993>] ? read_dev_port_cntr.isra.37+0x23/0x160 [hfi1] [534552.835880] [<ffffffffa02775af>] read_dev_cntr+0x4f/0x60 [hfi1] [534552.835893] [<ffffffffa028d7cd>] pma_get_opa_portstatus+0x64d/0x8c0 [hfi1] [534552.835904] [<ffffffffa0290e7d>] hfi1_process_mad+0x48d/0x18c0 [hfi1] [534552.835908] [<ffffffff811dc1f1>] ? __slab_free+0x81/0x2f0 [534552.835936] [<ffffffffa024c34e>] ? ib_mad_recv_done+0x21e/0xa30 [ib_core] [534552.835939] [<ffffffff811dd153>] ? __kmalloc+0x1f3/0x240 [534552.835947] [<ffffffffa024c3fb>] ib_mad_recv_done+0x2cb/0xa30 [ib_core] [534552.835955] [<ffffffffa0237c85>] __ib_process_cq+0x55/0xd0 [ib_core] [534552.835962] [<ffffffffa0237d70>] ib_cq_poll_work+0x20/0x60 [ib_core] [534552.835964] [<ffffffff810a7f3b>] process_one_work+0x17b/0x470 [534552.835966] [<ffffffff810a8d76>] worker_thread+0x126/0x410 [534552.835969] [<ffffffff810a8c50>] ? rescuer_thread+0x460/0x460 [534552.835971] [<ffffffff810b052f>] kthread+0xcf/0xe0 [534552.835974] [<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140 [534552.835977] [<ffffffff81696418>] ret_from_fork+0x58/0x90 [534552.835980] [<ffffffff810b0460>] ? 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 michael.j.ruhl@intel.com Reviewed-by: Mike Marciszyn mike.marciniszyn@intel.com Signed-off-by: Tadeusz Struk tadeusz.struk@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- a/drivers/infiniband/hw/hfi1/chip.c +++ b/drivers/infiniband/hw/hfi1/chip.c @@ -6379,18 +6379,17 @@ static void lcb_shutdown(struct hfi1_dev * * 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); /* @@ -6401,35 +6400,45 @@ static void dc_shutdown(struct hfi1_devd 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); }
/* @@ -8418,16 +8427,11 @@ 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) { @@ -8453,10 +8457,8 @@ 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); }
/* @@ -8534,8 +8536,7 @@ 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; }
@@ -11849,6 +11850,10 @@ static void free_cntrs(struct hfi1_devda 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, @@ -12004,7 +12009,7 @@ u64 write_port_cntr(struct hfi1_pportdat 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; @@ -12013,8 +12018,8 @@ static void update_synth_timer(unsigned 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 @@ -12097,7 +12102,13 @@ static void update_synth_timer(unsigned } 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); }
@@ -12333,6 +12344,13 @@ static int init_cntrs(struct hfi1_devdat 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: --- a/drivers/infiniband/hw/hfi1/hfi.h +++ b/drivers/infiniband/hw/hfi1/hfi.h @@ -475,7 +475,7 @@ 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 */ @@ -929,8 +929,9 @@ 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 */ --- a/drivers/infiniband/hw/hfi1/init.c +++ b/drivers/infiniband/hw/hfi1/init.c @@ -1078,11 +1078,11 @@ struct hfi1_devdata *hfi1_alloc_devdata( 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);