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Diffstat (limited to 'drivers/infiniband/hw/hfi1/aspm.c')
-rw-r--r--drivers/infiniband/hw/hfi1/aspm.c270
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 0000000000..a3c53be407
--- /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, &reg32);
+ 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);
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 21:52:09 +0000