diff options
Diffstat (limited to 'drivers/staging/rdma/hfi1/aspm.h')
-rw-r--r-- | drivers/staging/rdma/hfi1/aspm.h | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/staging/rdma/hfi1/aspm.h b/drivers/staging/rdma/hfi1/aspm.h new file mode 100644 index 0000000..0d58fe3 --- /dev/null +++ b/drivers/staging/rdma/hfi1/aspm.h @@ -0,0 +1,309 @@ +/* + * Copyright(c) 2015, 2016 Intel Corporation. + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * BSD LICENSE + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * - Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ +#ifndef _ASPM_H +#define _ASPM_H + +#include "hfi.h" + +extern uint aspm_mode; + +enum aspm_mode { + ASPM_MODE_DISABLED = 0, /* ASPM always disabled, performance mode */ + ASPM_MODE_ENABLED = 1, /* ASPM always enabled, power saving mode */ + ASPM_MODE_DYNAMIC = 2, /* ASPM enabled/disabled dynamically */ +}; + +/* Time after which the timer interrupt will re-enable ASPM */ +#define ASPM_TIMER_MS 1000 +/* Time for which interrupts are ignored after a timer has been scheduled */ +#define ASPM_RESCHED_TIMER_MS (ASPM_TIMER_MS / 2) +/* Two interrupts within this time trigger ASPM disable */ +#define ASPM_TRIGGER_MS 1 +#define ASPM_TRIGGER_NS (ASPM_TRIGGER_MS * 1000 * 1000ull) +#define ASPM_L1_SUPPORTED(reg) \ + (((reg & PCI_EXP_LNKCAP_ASPMS) >> 10) & 0x2) + +static inline bool aspm_hw_l1_supported(struct hfi1_devdata *dd) +{ + struct pci_dev *parent = dd->pcidev->bus->self; + u32 up, dn; + + /* + * If the driver does not have access to the upstream component, + * it cannot support ASPM L1 at all. + */ + if (!parent) + return false; + + pcie_capability_read_dword(dd->pcidev, PCI_EXP_LNKCAP, &dn); + dn = ASPM_L1_SUPPORTED(dn); + + pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &up); + up = ASPM_L1_SUPPORTED(up); + + /* ASPM works on A-step but is reported as not supported */ + return (!!dn || is_ax(dd)) && !!up; +} + +/* Set L1 entrance latency for slower entry to L1 */ +static inline void aspm_hw_set_l1_ent_latency(struct hfi1_devdata *dd) +{ + u32 l1_ent_lat = 0x4u; + u32 reg32; + + pci_read_config_dword(dd->pcidev, PCIE_CFG_REG_PL3, ®32); + reg32 &= ~PCIE_CFG_REG_PL3_L1_ENT_LATENCY_SMASK; + reg32 |= l1_ent_lat << PCIE_CFG_REG_PL3_L1_ENT_LATENCY_SHIFT; + pci_write_config_dword(dd->pcidev, PCIE_CFG_REG_PL3, reg32); +} + +static inline void aspm_hw_enable_l1(struct hfi1_devdata *dd) +{ + struct pci_dev *parent = dd->pcidev->bus->self; + + /* + * If the driver does not have access to the upstream component, + * it cannot support ASPM L1 at all. + */ + if (!parent) + return; + + /* Enable ASPM L1 first in upstream component and then downstream */ + pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC, + PCI_EXP_LNKCTL_ASPM_L1); + pcie_capability_clear_and_set_word(dd->pcidev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC, + PCI_EXP_LNKCTL_ASPM_L1); +} + +static inline void aspm_hw_disable_l1(struct hfi1_devdata *dd) +{ + struct pci_dev *parent = dd->pcidev->bus->self; + + /* Disable ASPM L1 first in downstream component and then upstream */ + pcie_capability_clear_and_set_word(dd->pcidev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC, 0x0); + if (parent) + pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_ASPMC, 0x0); +} + +static inline void aspm_enable(struct hfi1_devdata *dd) +{ + if (dd->aspm_enabled || aspm_mode == ASPM_MODE_DISABLED || + !dd->aspm_supported) + return; + + aspm_hw_enable_l1(dd); + dd->aspm_enabled = true; +} + +static inline void aspm_disable(struct hfi1_devdata *dd) +{ + if (!dd->aspm_enabled || aspm_mode == ASPM_MODE_ENABLED) + return; + + aspm_hw_disable_l1(dd); + dd->aspm_enabled = false; +} + +static inline void aspm_disable_inc(struct hfi1_devdata *dd) +{ + unsigned long flags; + + spin_lock_irqsave(&dd->aspm_lock, flags); + aspm_disable(dd); + atomic_inc(&dd->aspm_disabled_cnt); + spin_unlock_irqrestore(&dd->aspm_lock, flags); +} + +static inline void aspm_enable_dec(struct hfi1_devdata *dd) +{ + unsigned long flags; + + spin_lock_irqsave(&dd->aspm_lock, flags); + if (atomic_dec_and_test(&dd->aspm_disabled_cnt)) + aspm_enable(dd); + spin_unlock_irqrestore(&dd->aspm_lock, flags); +} + +/* ASPM processing for each receive context interrupt */ +static inline void aspm_ctx_disable(struct hfi1_ctxtdata *rcd) +{ + bool restart_timer; + bool close_interrupts; + unsigned long flags; + ktime_t now, prev; + + /* Quickest exit for minimum impact */ + if (!rcd->aspm_intr_supported) + return; + + spin_lock_irqsave(&rcd->aspm_lock, flags); + /* PSM contexts are open */ + if (!rcd->aspm_intr_enable) + goto unlock; + + prev = rcd->aspm_ts_last_intr; + now = ktime_get(); + rcd->aspm_ts_last_intr = now; + + /* An interrupt pair close together in time */ + close_interrupts = ktime_to_ns(ktime_sub(now, prev)) < ASPM_TRIGGER_NS; + + /* Don't push out our timer till this much time has elapsed */ + restart_timer = ktime_to_ns(ktime_sub(now, rcd->aspm_ts_timer_sched)) > + ASPM_RESCHED_TIMER_MS * NSEC_PER_MSEC; + restart_timer = restart_timer && close_interrupts; + + /* Disable ASPM and schedule timer */ + if (rcd->aspm_enabled && close_interrupts) { + aspm_disable_inc(rcd->dd); + rcd->aspm_enabled = false; + restart_timer = true; + } + + if (restart_timer) { + mod_timer(&rcd->aspm_timer, + jiffies + msecs_to_jiffies(ASPM_TIMER_MS)); + rcd->aspm_ts_timer_sched = now; + } +unlock: + spin_unlock_irqrestore(&rcd->aspm_lock, flags); +} + +/* Timer function for re-enabling ASPM in the absence of interrupt activity */ +static inline void aspm_ctx_timer_function(unsigned long data) +{ + struct hfi1_ctxtdata *rcd = (struct hfi1_ctxtdata *)data; + unsigned long flags; + + spin_lock_irqsave(&rcd->aspm_lock, flags); + aspm_enable_dec(rcd->dd); + rcd->aspm_enabled = true; + spin_unlock_irqrestore(&rcd->aspm_lock, flags); +} + +/* Disable interrupt processing for verbs contexts when PSM contexts are open */ +static inline void aspm_disable_all(struct hfi1_devdata *dd) +{ + struct hfi1_ctxtdata *rcd; + unsigned long flags; + unsigned i; + + for (i = 0; i < dd->first_user_ctxt; i++) { + rcd = dd->rcd[i]; + del_timer_sync(&rcd->aspm_timer); + spin_lock_irqsave(&rcd->aspm_lock, flags); + rcd->aspm_intr_enable = false; + spin_unlock_irqrestore(&rcd->aspm_lock, flags); + } + + aspm_disable(dd); + atomic_set(&dd->aspm_disabled_cnt, 0); +} + +/* Re-enable interrupt processing for verbs contexts */ +static inline void aspm_enable_all(struct hfi1_devdata *dd) +{ + struct hfi1_ctxtdata *rcd; + unsigned long flags; + unsigned i; + + aspm_enable(dd); + + if (aspm_mode != ASPM_MODE_DYNAMIC) + return; + + for (i = 0; i < dd->first_user_ctxt; i++) { + rcd = dd->rcd[i]; + spin_lock_irqsave(&rcd->aspm_lock, flags); + rcd->aspm_intr_enable = true; + rcd->aspm_enabled = true; + spin_unlock_irqrestore(&rcd->aspm_lock, flags); + } +} + +static inline void aspm_ctx_init(struct hfi1_ctxtdata *rcd) +{ + spin_lock_init(&rcd->aspm_lock); + setup_timer(&rcd->aspm_timer, aspm_ctx_timer_function, + (unsigned long)rcd); + rcd->aspm_intr_supported = rcd->dd->aspm_supported && + aspm_mode == ASPM_MODE_DYNAMIC && + rcd->ctxt < rcd->dd->first_user_ctxt; +} + +static inline void aspm_init(struct hfi1_devdata *dd) +{ + unsigned i; + + spin_lock_init(&dd->aspm_lock); + dd->aspm_supported = aspm_hw_l1_supported(dd); + + for (i = 0; i < dd->first_user_ctxt; i++) + aspm_ctx_init(dd->rcd[i]); + + /* Start with ASPM disabled */ + aspm_hw_set_l1_ent_latency(dd); + dd->aspm_enabled = false; + aspm_hw_disable_l1(dd); + + /* Now turn on ASPM if configured */ + aspm_enable_all(dd); +} + +static inline void aspm_exit(struct hfi1_devdata *dd) +{ + aspm_disable_all(dd); + + /* Turn on ASPM on exit to conserve power */ + aspm_enable(dd); +} + +#endif /* _ASPM_H */ |