diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h index 691acbdcc46d..84b0f0ac26e7 100644 --- a/drivers/scsi/lpfc/lpfc.h +++ b/drivers/scsi/lpfc/lpfc.h @@ -1209,6 +1209,13 @@ struct lpfc_hba { uint64_t ktime_seg10_min; uint64_t ktime_seg10_max; #endif + + struct hlist_node cpuhp; /* used for cpuhp per hba callback */ + struct timer_list cpuhp_poll_timer; + struct list_head poll_list; /* slowpath eq polling list */ +#define LPFC_POLL_HB 1 /* slowpath heartbeat */ +#define LPFC_POLL_FASTPATH 0 /* called from fastpath */ +#define LPFC_POLL_SLOWPATH 1 /* called from slowpath */ }; static inline struct Scsi_Host * diff --git a/drivers/scsi/lpfc/lpfc_crtn.h b/drivers/scsi/lpfc/lpfc_crtn.h index b2ad8c750486..9e477d766ce9 100644 --- a/drivers/scsi/lpfc/lpfc_crtn.h +++ b/drivers/scsi/lpfc/lpfc_crtn.h @@ -215,6 +215,12 @@ irqreturn_t lpfc_sli_fp_intr_handler(int, void *); irqreturn_t lpfc_sli4_intr_handler(int, void *); irqreturn_t lpfc_sli4_hba_intr_handler(int, void *); +inline void lpfc_sli4_cleanup_poll_list(struct lpfc_hba *phba); +int lpfc_sli4_poll_eq(struct lpfc_queue *q, uint8_t path); +void lpfc_sli4_poll_hbtimer(struct timer_list *t); +void lpfc_sli4_start_polling(struct lpfc_queue *q); +void lpfc_sli4_stop_polling(struct lpfc_queue *q); + void lpfc_read_rev(struct lpfc_hba *, LPFC_MBOXQ_t *); void lpfc_sli4_swap_str(struct lpfc_hba *, LPFC_MBOXQ_t *); void lpfc_config_ring(struct lpfc_hba *, int, LPFC_MBOXQ_t *); diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c index e8813d26e594..1bf79445c15b 100644 --- a/drivers/scsi/lpfc/lpfc_init.c +++ b/drivers/scsi/lpfc/lpfc_init.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include @@ -66,9 +67,13 @@ #include "lpfc_version.h" #include "lpfc_ids.h" +static enum cpuhp_state lpfc_cpuhp_state; /* Used when mapping IRQ vectors in a driver centric manner */ static uint32_t lpfc_present_cpu; +static void __lpfc_cpuhp_remove(struct lpfc_hba *phba); +static void lpfc_cpuhp_remove(struct lpfc_hba *phba); +static void lpfc_cpuhp_add(struct lpfc_hba *phba); static void lpfc_get_hba_model_desc(struct lpfc_hba *, uint8_t *, uint8_t *); static int lpfc_post_rcv_buf(struct lpfc_hba *); static int lpfc_sli4_queue_verify(struct lpfc_hba *); @@ -3387,6 +3392,8 @@ lpfc_online(struct lpfc_hba *phba) if (phba->cfg_xri_rebalancing) lpfc_create_multixri_pools(phba); + lpfc_cpuhp_add(phba); + lpfc_unblock_mgmt_io(phba); return 0; } @@ -3545,6 +3552,7 @@ lpfc_offline(struct lpfc_hba *phba) spin_unlock_irq(shost->host_lock); } lpfc_destroy_vport_work_array(phba, vports); + __lpfc_cpuhp_remove(phba); if (phba->cfg_xri_rebalancing) lpfc_destroy_multixri_pools(phba); @@ -9160,6 +9168,8 @@ lpfc_sli4_queue_destroy(struct lpfc_hba *phba) } spin_unlock_irq(&phba->hbalock); + lpfc_sli4_cleanup_poll_list(phba); + /* Release HBA eqs */ if (phba->sli4_hba.hdwq) lpfc_sli4_release_hdwq(phba); @@ -10962,6 +10972,170 @@ found_any: return; } +/** + * lpfc_cpuhp_get_eq + * + * @phba: pointer to lpfc hba data structure. + * @cpu: cpu going offline + * @eqlist: + */ +static void +lpfc_cpuhp_get_eq(struct lpfc_hba *phba, unsigned int cpu, + struct list_head *eqlist) +{ + struct lpfc_vector_map_info *map; + const struct cpumask *maskp; + struct lpfc_queue *eq; + unsigned int i; + cpumask_t tmp; + u16 idx; + + for (idx = 0; idx < phba->cfg_irq_chann; idx++) { + maskp = pci_irq_get_affinity(phba->pcidev, idx); + if (!maskp) + continue; + /* + * if irq is not affinitized to the cpu going + * then we don't need to poll the eq attached + * to it. + */ + if (!cpumask_and(&tmp, maskp, cpumask_of(cpu))) + continue; + /* get the cpus that are online and are affini- + * tized to this irq vector. If the count is + * more than 1 then cpuhp is not going to shut- + * down this vector. Since this cpu has not + * gone offline yet, we need >1. + */ + cpumask_and(&tmp, maskp, cpu_online_mask); + if (cpumask_weight(&tmp) > 1) + continue; + + /* Now that we have an irq to shutdown, get the eq + * mapped to this irq. Note: multiple hdwq's in + * the software can share an eq, but eventually + * only eq will be mapped to this vector + */ + for_each_possible_cpu(i) { + map = &phba->sli4_hba.cpu_map[i]; + if (!(map->irq == pci_irq_vector(phba->pcidev, idx))) + continue; + eq = phba->sli4_hba.hdwq[map->hdwq].hba_eq; + list_add(&eq->_poll_list, eqlist); + /* 1 is good enough. others will be a copy of this */ + break; + } + } +} + +static void __lpfc_cpuhp_remove(struct lpfc_hba *phba) +{ + if (phba->sli_rev != LPFC_SLI_REV4) + return; + + cpuhp_state_remove_instance_nocalls(lpfc_cpuhp_state, + &phba->cpuhp); + /* + * unregistering the instance doesn't stop the polling + * timer. Wait for the poll timer to retire. + */ + synchronize_rcu(); + del_timer_sync(&phba->cpuhp_poll_timer); +} + +static void lpfc_cpuhp_remove(struct lpfc_hba *phba) +{ + if (phba->pport->fc_flag & FC_OFFLINE_MODE) + return; + + __lpfc_cpuhp_remove(phba); +} + +static void lpfc_cpuhp_add(struct lpfc_hba *phba) +{ + if (phba->sli_rev != LPFC_SLI_REV4) + return; + + rcu_read_lock(); + + if (!list_empty(&phba->poll_list)) { + timer_setup(&phba->cpuhp_poll_timer, lpfc_sli4_poll_hbtimer, 0); + mod_timer(&phba->cpuhp_poll_timer, + jiffies + msecs_to_jiffies(LPFC_POLL_HB)); + } + + rcu_read_unlock(); + + cpuhp_state_add_instance_nocalls(lpfc_cpuhp_state, + &phba->cpuhp); +} + +static int __lpfc_cpuhp_checks(struct lpfc_hba *phba, int *retval) +{ + if (phba->pport->load_flag & FC_UNLOADING) { + *retval = -EAGAIN; + return true; + } + + if (phba->sli_rev != LPFC_SLI_REV4) { + *retval = 0; + return true; + } + + /* proceed with the hotplug */ + return false; +} + +static int lpfc_cpu_offline(unsigned int cpu, struct hlist_node *node) +{ + struct lpfc_hba *phba = hlist_entry_safe(node, struct lpfc_hba, cpuhp); + struct lpfc_queue *eq, *next; + LIST_HEAD(eqlist); + int retval; + + if (!phba) { + WARN_ONCE(!phba, "cpu: %u. phba:NULL", raw_smp_processor_id()); + return 0; + } + + if (__lpfc_cpuhp_checks(phba, &retval)) + return retval; + + lpfc_cpuhp_get_eq(phba, cpu, &eqlist); + + /* start polling on these eq's */ + list_for_each_entry_safe(eq, next, &eqlist, _poll_list) { + list_del_init(&eq->_poll_list); + lpfc_sli4_start_polling(eq); + } + + return 0; +} + +static int lpfc_cpu_online(unsigned int cpu, struct hlist_node *node) +{ + struct lpfc_hba *phba = hlist_entry_safe(node, struct lpfc_hba, cpuhp); + struct lpfc_queue *eq, *next; + unsigned int n; + int retval; + + if (!phba) { + WARN_ONCE(!phba, "cpu: %u. phba:NULL", raw_smp_processor_id()); + return 0; + } + + if (__lpfc_cpuhp_checks(phba, &retval)) + return retval; + + list_for_each_entry_safe(eq, next, &phba->poll_list, _poll_list) { + n = lpfc_find_cpu_handle(phba, eq->hdwq, LPFC_FIND_BY_HDWQ); + if (n == cpu) + lpfc_sli4_stop_polling(eq); + } + + return 0; +} + /** * lpfc_sli4_enable_msix - Enable MSI-X interrupt mode to SLI-4 device * @phba: pointer to lpfc hba data structure. @@ -11367,6 +11541,9 @@ lpfc_sli4_hba_unset(struct lpfc_hba *phba) /* Wait for completion of device XRI exchange busy */ lpfc_sli4_xri_exchange_busy_wait(phba); + /* per-phba callback de-registration for hotplug event */ + lpfc_cpuhp_remove(phba); + /* Disable PCI subsystem interrupt */ lpfc_sli4_disable_intr(phba); @@ -12632,6 +12809,9 @@ lpfc_pci_probe_one_s4(struct pci_dev *pdev, const struct pci_device_id *pid) /* Enable RAS FW log support */ lpfc_sli4_ras_setup(phba); + INIT_LIST_HEAD(&phba->poll_list); + cpuhp_state_add_instance_nocalls(lpfc_cpuhp_state, &phba->cpuhp); + return 0; out_free_sysfs_attr: @@ -13450,11 +13630,24 @@ lpfc_init(void) /* Initialize in case vector mapping is needed */ lpfc_present_cpu = num_present_cpus(); + error = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, + "lpfc/sli4:online", + lpfc_cpu_online, lpfc_cpu_offline); + if (error < 0) + goto cpuhp_failure; + lpfc_cpuhp_state = error; + error = pci_register_driver(&lpfc_driver); - if (error) { - fc_release_transport(lpfc_transport_template); - fc_release_transport(lpfc_vport_transport_template); - } + if (error) + goto unwind; + + return error; + +unwind: + cpuhp_remove_multi_state(lpfc_cpuhp_state); +cpuhp_failure: + fc_release_transport(lpfc_transport_template); + fc_release_transport(lpfc_vport_transport_template); return error; } @@ -13471,6 +13664,7 @@ lpfc_exit(void) { misc_deregister(&lpfc_mgmt_dev); pci_unregister_driver(&lpfc_driver); + cpuhp_remove_multi_state(lpfc_cpuhp_state); fc_release_transport(lpfc_transport_template); fc_release_transport(lpfc_vport_transport_template); idr_destroy(&lpfc_hba_index); diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index e2cec1f6e659..fb2b0dc52d9b 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -485,7 +485,8 @@ lpfc_sli4_eq_flush(struct lpfc_hba *phba, struct lpfc_queue *eq) } static int -lpfc_sli4_process_eq(struct lpfc_hba *phba, struct lpfc_queue *eq) +lpfc_sli4_process_eq(struct lpfc_hba *phba, struct lpfc_queue *eq, + uint8_t rearm) { struct lpfc_eqe *eqe; int count = 0, consumed = 0; @@ -519,8 +520,8 @@ lpfc_sli4_process_eq(struct lpfc_hba *phba, struct lpfc_queue *eq) eq->queue_claimed = 0; rearm_and_exit: - /* Always clear and re-arm the EQ */ - phba->sli4_hba.sli4_write_eq_db(phba, eq, consumed, LPFC_QUEUE_REARM); + /* Always clear the EQ. */ + phba->sli4_hba.sli4_write_eq_db(phba, eq, consumed, rearm); return count; } @@ -7894,7 +7895,7 @@ lpfc_sli4_process_missed_mbox_completions(struct lpfc_hba *phba) if (mbox_pending) /* process and rearm the EQ */ - lpfc_sli4_process_eq(phba, fpeq); + lpfc_sli4_process_eq(phba, fpeq, LPFC_QUEUE_REARM); else /* Always clear and re-arm the EQ */ sli4_hba->sli4_write_eq_db(phba, fpeq, 0, LPFC_QUEUE_REARM); @@ -10055,10 +10056,13 @@ lpfc_sli_issue_iocb(struct lpfc_hba *phba, uint32_t ring_number, struct lpfc_iocbq *piocb, uint32_t flag) { struct lpfc_sli_ring *pring; + struct lpfc_queue *eq; unsigned long iflags; int rc; if (phba->sli_rev == LPFC_SLI_REV4) { + eq = phba->sli4_hba.hdwq[piocb->hba_wqidx].hba_eq; + pring = lpfc_sli4_calc_ring(phba, piocb); if (unlikely(pring == NULL)) return IOCB_ERROR; @@ -10066,6 +10070,8 @@ lpfc_sli_issue_iocb(struct lpfc_hba *phba, uint32_t ring_number, spin_lock_irqsave(&pring->ring_lock, iflags); rc = __lpfc_sli_issue_iocb(phba, ring_number, piocb, flag); spin_unlock_irqrestore(&pring->ring_lock, iflags); + + lpfc_sli4_poll_eq(eq, LPFC_POLL_FASTPATH); } else { /* For now, SLI2/3 will still use hbalock */ spin_lock_irqsave(&phba->hbalock, iflags); @@ -14245,7 +14251,7 @@ lpfc_sli4_hba_intr_handler(int irq, void *dev_id) lpfc_sli4_mod_hba_eq_delay(phba, fpeq, LPFC_MAX_AUTO_EQ_DELAY); /* process and rearm the EQ */ - ecount = lpfc_sli4_process_eq(phba, fpeq); + ecount = lpfc_sli4_process_eq(phba, fpeq, LPFC_QUEUE_REARM); if (unlikely(ecount == 0)) { fpeq->EQ_no_entry++; @@ -14305,6 +14311,147 @@ lpfc_sli4_intr_handler(int irq, void *dev_id) return (hba_handled == true) ? IRQ_HANDLED : IRQ_NONE; } /* lpfc_sli4_intr_handler */ +void lpfc_sli4_poll_hbtimer(struct timer_list *t) +{ + struct lpfc_hba *phba = from_timer(phba, t, cpuhp_poll_timer); + struct lpfc_queue *eq; + int i = 0; + + rcu_read_lock(); + + list_for_each_entry_rcu(eq, &phba->poll_list, _poll_list) + i += lpfc_sli4_poll_eq(eq, LPFC_POLL_SLOWPATH); + if (!list_empty(&phba->poll_list)) + mod_timer(&phba->cpuhp_poll_timer, + jiffies + msecs_to_jiffies(LPFC_POLL_HB)); + + rcu_read_unlock(); +} + +inline int lpfc_sli4_poll_eq(struct lpfc_queue *eq, uint8_t path) +{ + struct lpfc_hba *phba = eq->phba; + int i = 0; + + /* + * Unlocking an irq is one of the entry point to check + * for re-schedule, but we are good for io submission + * path as midlayer does a get_cpu to glue us in. Flush + * out the invalidate queue so we can see the updated + * value for flag. + */ + smp_rmb(); + + if (READ_ONCE(eq->mode) == LPFC_EQ_POLL) + /* We will not likely get the completion for the caller + * during this iteration but i guess that's fine. + * Future io's coming on this eq should be able to + * pick it up. As for the case of single io's, they + * will be handled through a sched from polling timer + * function which is currently triggered every 1msec. + */ + i = lpfc_sli4_process_eq(phba, eq, LPFC_QUEUE_NOARM); + + return i; +} + +static inline void lpfc_sli4_add_to_poll_list(struct lpfc_queue *eq) +{ + struct lpfc_hba *phba = eq->phba; + + if (list_empty(&phba->poll_list)) { + timer_setup(&phba->cpuhp_poll_timer, lpfc_sli4_poll_hbtimer, 0); + /* kickstart slowpath processing for this eq */ + mod_timer(&phba->cpuhp_poll_timer, + jiffies + msecs_to_jiffies(LPFC_POLL_HB)); + } + + list_add_rcu(&eq->_poll_list, &phba->poll_list); + synchronize_rcu(); +} + +static inline void lpfc_sli4_remove_from_poll_list(struct lpfc_queue *eq) +{ + struct lpfc_hba *phba = eq->phba; + + /* Disable slowpath processing for this eq. Kick start the eq + * by RE-ARMING the eq's ASAP + */ + list_del_rcu(&eq->_poll_list); + synchronize_rcu(); + + if (list_empty(&phba->poll_list)) + del_timer_sync(&phba->cpuhp_poll_timer); +} + +inline void lpfc_sli4_cleanup_poll_list(struct lpfc_hba *phba) +{ + struct lpfc_queue *eq, *next; + + list_for_each_entry_safe(eq, next, &phba->poll_list, _poll_list) + list_del(&eq->_poll_list); + + INIT_LIST_HEAD(&phba->poll_list); + synchronize_rcu(); +} + +static inline void +__lpfc_sli4_switch_eqmode(struct lpfc_queue *eq, uint8_t mode) +{ + if (mode == eq->mode) + return; + /* + * currently this function is only called during a hotplug + * event and the cpu on which this function is executing + * is going offline. By now the hotplug has instructed + * the scheduler to remove this cpu from cpu active mask. + * So we don't need to work about being put aside by the + * scheduler for a high priority process. Yes, the inte- + * rrupts could come but they are known to retire ASAP. + */ + + /* Disable polling in the fastpath */ + WRITE_ONCE(eq->mode, mode); + /* flush out the store buffer */ + smp_wmb(); + + /* + * Add this eq to the polling list and start polling. For + * a grace period both interrupt handler and poller will + * try to process the eq _but_ that's fine. We have a + * synchronization mechanism in place (queue_claimed) to + * deal with it. This is just a draining phase for int- + * errupt handler (not eq's) as we have guranteed through + * barrier that all the CPUs have seen the new CQ_POLLED + * state. which will effectively disable the REARMING of + * the EQ. The whole idea is eq's die off eventually as + * we are not rearming EQ's anymore. + */ + mode ? lpfc_sli4_add_to_poll_list(eq) : + lpfc_sli4_remove_from_poll_list(eq); +} + +void lpfc_sli4_start_polling(struct lpfc_queue *eq) +{ + __lpfc_sli4_switch_eqmode(eq, LPFC_EQ_POLL); +} + +void lpfc_sli4_stop_polling(struct lpfc_queue *eq) +{ + struct lpfc_hba *phba = eq->phba; + + __lpfc_sli4_switch_eqmode(eq, LPFC_EQ_INTERRUPT); + + /* Kick start for the pending io's in h/w. + * Once we switch back to interrupt processing on a eq + * the io path completion will only arm eq's when it + * receives a completion. But since eq's are in disa- + * rmed state it doesn't receive a completion. This + * creates a deadlock scenaro. + */ + phba->sli4_hba.sli4_write_eq_db(phba, eq, 0, LPFC_QUEUE_REARM); +} + /** * lpfc_sli4_queue_free - free a queue structure and associated memory * @queue: The queue structure to free. @@ -14379,6 +14526,7 @@ lpfc_sli4_queue_alloc(struct lpfc_hba *phba, uint32_t page_size, return NULL; INIT_LIST_HEAD(&queue->list); + INIT_LIST_HEAD(&queue->_poll_list); INIT_LIST_HEAD(&queue->wq_list); INIT_LIST_HEAD(&queue->wqfull_list); INIT_LIST_HEAD(&queue->page_list); @@ -19698,6 +19846,8 @@ lpfc_sli4_issue_wqe(struct lpfc_hba *phba, struct lpfc_sli4_hdw_queue *qp, lpfc_sli_ringtxcmpl_put(phba, pring, pwqe); spin_unlock_irqrestore(&pring->ring_lock, iflags); + + lpfc_sli4_poll_eq(qp->hba_eq, LPFC_POLL_FASTPATH); return 0; } @@ -19718,6 +19868,8 @@ lpfc_sli4_issue_wqe(struct lpfc_hba *phba, struct lpfc_sli4_hdw_queue *qp, } lpfc_sli_ringtxcmpl_put(phba, pring, pwqe); spin_unlock_irqrestore(&pring->ring_lock, iflags); + + lpfc_sli4_poll_eq(qp->hba_eq, LPFC_POLL_FASTPATH); return 0; } @@ -19746,6 +19898,8 @@ lpfc_sli4_issue_wqe(struct lpfc_hba *phba, struct lpfc_sli4_hdw_queue *qp, } lpfc_sli_ringtxcmpl_put(phba, pring, pwqe); spin_unlock_irqrestore(&pring->ring_lock, iflags); + + lpfc_sli4_poll_eq(qp->hba_eq, LPFC_POLL_FASTPATH); return 0; } return WQE_ERROR; diff --git a/drivers/scsi/lpfc/lpfc_sli4.h b/drivers/scsi/lpfc/lpfc_sli4.h index 0d4882a9e634..c60a636a8894 100644 --- a/drivers/scsi/lpfc/lpfc_sli4.h +++ b/drivers/scsi/lpfc/lpfc_sli4.h @@ -133,6 +133,23 @@ struct lpfc_rqb { struct lpfc_queue { struct list_head list; struct list_head wq_list; + + /* + * If interrupts are in effect on _all_ the eq's the footprint + * of polling code is zero (except mode). This memory is chec- + * ked for every io to see if the io needs to be polled and + * while completion to check if the eq's needs to be rearmed. + * Keep in same cacheline as the queue ptr to avoid cpu fetch + * stalls. Using 1B memory will leave us with 7B hole. Fill + * it with other frequently used members. + */ + uint16_t last_cpu; /* most recent cpu */ + uint16_t hdwq; + uint8_t qe_valid; + uint8_t mode; /* interrupt or polling */ +#define LPFC_EQ_INTERRUPT 0 +#define LPFC_EQ_POLL 1 + struct list_head wqfull_list; enum lpfc_sli4_queue_type type; enum lpfc_sli4_queue_subtype subtype; @@ -239,10 +256,8 @@ struct lpfc_queue { struct delayed_work sched_spwork; uint64_t isr_timestamp; - uint16_t hdwq; - uint16_t last_cpu; /* most recent cpu */ - uint8_t qe_valid; struct lpfc_queue *assoc_qp; + struct list_head _poll_list; void **q_pgs; /* array to index entries per page */ };