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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/infiniband/hw/hfi1/aspm.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/infiniband/hw/hfi1/aspm.c')
-rw-r--r-- | drivers/infiniband/hw/hfi1/aspm.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/aspm.c b/drivers/infiniband/hw/hfi1/aspm.c new file mode 100644 index 000000000..a3c53be40 --- /dev/null +++ b/drivers/infiniband/hw/hfi1/aspm.c @@ -0,0 +1,270 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +/* + * Copyright(c) 2019 Intel Corporation. + * + */ + +#include "aspm.h" + +/* 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) + +uint aspm_mode = ASPM_MODE_DISABLED; +module_param_named(aspm, aspm_mode, uint, 0444); +MODULE_PARM_DESC(aspm, "PCIe ASPM: 0: disable, 1: enable, 2: dynamic"); + +static 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 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 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); +} + +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 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 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 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 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 */ +void __aspm_ctx_disable(struct hfi1_ctxtdata *rcd) +{ + bool restart_timer; + bool close_interrupts; + unsigned long flags; + ktime_t now, prev; + + 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 void aspm_ctx_timer_function(struct timer_list *t) +{ + struct hfi1_ctxtdata *rcd = from_timer(rcd, t, aspm_timer); + 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 or VNIC contexts + * are open. + */ +void aspm_disable_all(struct hfi1_devdata *dd) +{ + struct hfi1_ctxtdata *rcd; + unsigned long flags; + u16 i; + + for (i = 0; i < dd->first_dyn_alloc_ctxt; i++) { + rcd = hfi1_rcd_get_by_index(dd, i); + if (rcd) { + 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); + hfi1_rcd_put(rcd); + } + } + + aspm_disable(dd); + atomic_set(&dd->aspm_disabled_cnt, 0); +} + +/* Re-enable interrupt processing for verbs contexts */ +void aspm_enable_all(struct hfi1_devdata *dd) +{ + struct hfi1_ctxtdata *rcd; + unsigned long flags; + u16 i; + + aspm_enable(dd); + + if (aspm_mode != ASPM_MODE_DYNAMIC) + return; + + for (i = 0; i < dd->first_dyn_alloc_ctxt; i++) { + rcd = hfi1_rcd_get_by_index(dd, i); + if (rcd) { + spin_lock_irqsave(&rcd->aspm_lock, flags); + rcd->aspm_intr_enable = true; + rcd->aspm_enabled = true; + spin_unlock_irqrestore(&rcd->aspm_lock, flags); + hfi1_rcd_put(rcd); + } + } +} + +static void aspm_ctx_init(struct hfi1_ctxtdata *rcd) +{ + spin_lock_init(&rcd->aspm_lock); + timer_setup(&rcd->aspm_timer, aspm_ctx_timer_function, 0); + rcd->aspm_intr_supported = rcd->dd->aspm_supported && + aspm_mode == ASPM_MODE_DYNAMIC && + rcd->ctxt < rcd->dd->first_dyn_alloc_ctxt; +} + +void aspm_init(struct hfi1_devdata *dd) +{ + struct hfi1_ctxtdata *rcd; + u16 i; + + spin_lock_init(&dd->aspm_lock); + dd->aspm_supported = aspm_hw_l1_supported(dd); + + for (i = 0; i < dd->first_dyn_alloc_ctxt; i++) { + rcd = hfi1_rcd_get_by_index(dd, i); + if (rcd) + aspm_ctx_init(rcd); + hfi1_rcd_put(rcd); + } + + /* 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); +} + +void aspm_exit(struct hfi1_devdata *dd) +{ + aspm_disable_all(dd); + + /* Turn on ASPM on exit to conserve power */ + aspm_enable(dd); +} + |