git: 011e3d0b8b90 - main - cxgbe(4): Perform Conventional Reset instead of FLR on the device.
Date: Sun, 16 Mar 2025 02:35:18 UTC
The branch main has been updated by np:
URL: https://cgit.FreeBSD.org/src/commit/?id=011e3d0b8b90a4330f14b2cb7da45ed7b805ed10
commit 011e3d0b8b90a4330f14b2cb7da45ed7b805ed10
Author: Navdeep Parhar <np@FreeBSD.org>
AuthorDate: 2024-12-07 08:00:49 +0000
Commit: Navdeep Parhar <np@FreeBSD.org>
CommitDate: 2025-03-16 01:16:42 +0000
cxgbe(4): Perform Conventional Reset instead of FLR on the device.
The driver uses bus_reset_child on its parent to reset itself but that
performs an FLR whereas the hardware needs a Conventional Reset[1] for
full re-initialization. Add routines that perform conventional hot
reset and use them instead. The available reset mechanisms are:
* PCIe secondary bus reset (default)
* PCIe link bounce
hw.cxgbe.reset_method can be used to override the default. The internal
PL_RST is also available but is for testing only.
[1] 6.6.1 in PCI Express® Base Specification 5.0 version 1.0
MFC after: 1 month
Sponsored by: Chelsio Communications
---
sys/dev/cxgbe/t4_main.c | 137 +++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 118 insertions(+), 19 deletions(-)
diff --git a/sys/dev/cxgbe/t4_main.c b/sys/dev/cxgbe/t4_main.c
index 6ee839151db0..20df6a97aa87 100644
--- a/sys/dev/cxgbe/t4_main.c
+++ b/sys/dev/cxgbe/t4_main.c
@@ -633,6 +633,10 @@ static int t4_reset_on_fatal_err = 0;
SYSCTL_INT(_hw_cxgbe, OID_AUTO, reset_on_fatal_err, CTLFLAG_RWTUN,
&t4_reset_on_fatal_err, 0, "reset adapter on fatal errors");
+static int t4_reset_method = 1;
+SYSCTL_INT(_hw_cxgbe, OID_AUTO, reset_method, CTLFLAG_RWTUN, &t4_reset_method,
+ 0, "reset method: 0 = PL_RST, 1 = PCIe secondary bus reset, 2 = PCIe link bounce");
+
static int t4_clock_gate_on_suspend = 0;
SYSCTL_INT(_hw_cxgbe, OID_AUTO, clock_gate_on_suspend, CTLFLAG_RWTUN,
&t4_clock_gate_on_suspend, 0, "gate the clock on suspend");
@@ -2535,40 +2539,135 @@ t4_reset_post(device_t dev, device_t child)
return (0);
}
-static int
-reset_adapter_with_pci_bus_reset(struct adapter *sc)
-{
- int rc;
-
- mtx_lock(&Giant);
- rc = BUS_RESET_CHILD(device_get_parent(sc->dev), sc->dev, 0);
- mtx_unlock(&Giant);
- return (rc);
-}
-
static int
reset_adapter_with_pl_rst(struct adapter *sc)
{
- suspend_adapter(sc);
-
/* This is a t4_write_reg without the hw_off_limits check. */
MPASS(sc->error_flags & HW_OFF_LIMITS);
bus_space_write_4(sc->bt, sc->bh, A_PL_RST,
F_PIORSTMODE | F_PIORST | F_AUTOPCIEPAUSE);
pause("pl_rst", 1 * hz); /* Wait 1s for reset */
+ return (0);
+}
- resume_adapter(sc);
+static int
+reset_adapter_with_pcie_sbr(struct adapter *sc)
+{
+ device_t pdev = device_get_parent(sc->dev);
+ device_t gpdev = device_get_parent(pdev);
+ device_t *children;
+ int rc, i, lcap, lsta, nchildren;
+ uint32_t v;
- return (0);
+ rc = pci_find_cap(gpdev, PCIY_EXPRESS, &v);
+ if (rc != 0) {
+ CH_ERR(sc, "%s: pci_find_cap(%s, pcie) failed: %d\n", __func__,
+ device_get_nameunit(gpdev), rc);
+ return (ENOTSUP);
+ }
+ lcap = v + PCIER_LINK_CAP;
+ lsta = v + PCIER_LINK_STA;
+
+ nchildren = 0;
+ device_get_children(pdev, &children, &nchildren);
+ for (i = 0; i < nchildren; i++)
+ pci_save_state(children[i]);
+ v = pci_read_config(gpdev, PCIR_BRIDGECTL_1, 2);
+ pci_write_config(gpdev, PCIR_BRIDGECTL_1, v | PCIB_BCR_SECBUS_RESET, 2);
+ pause("pcie_sbr1", hz / 10); /* 100ms */
+ pci_write_config(gpdev, PCIR_BRIDGECTL_1, v, 2);
+ pause("pcie_sbr2", hz); /* Wait 1s before restore_state. */
+ v = pci_read_config(gpdev, lsta, 2);
+ if (pci_read_config(gpdev, lcap, 2) & PCIEM_LINK_CAP_DL_ACTIVE)
+ rc = v & PCIEM_LINK_STA_DL_ACTIVE ? 0 : ETIMEDOUT;
+ else if (v & (PCIEM_LINK_STA_TRAINING_ERROR | PCIEM_LINK_STA_TRAINING))
+ rc = ETIMEDOUT;
+ else
+ rc = 0;
+ if (rc != 0)
+ CH_ERR(sc, "%s: PCIe link is down after reset, LINK_STA 0x%x\n",
+ __func__, v);
+ else {
+ for (i = 0; i < nchildren; i++)
+ pci_restore_state(children[i]);
+ }
+ free(children, M_TEMP);
+
+ return (rc);
+}
+
+static int
+reset_adapter_with_pcie_link_bounce(struct adapter *sc)
+{
+ device_t pdev = device_get_parent(sc->dev);
+ device_t gpdev = device_get_parent(pdev);
+ device_t *children;
+ int rc, i, lcap, lctl, lsta, nchildren;
+ uint32_t v;
+
+ rc = pci_find_cap(gpdev, PCIY_EXPRESS, &v);
+ if (rc != 0) {
+ CH_ERR(sc, "%s: pci_find_cap(%s, pcie) failed: %d\n", __func__,
+ device_get_nameunit(gpdev), rc);
+ return (ENOTSUP);
+ }
+ lcap = v + PCIER_LINK_CAP;
+ lctl = v + PCIER_LINK_CTL;
+ lsta = v + PCIER_LINK_STA;
+
+ nchildren = 0;
+ device_get_children(pdev, &children, &nchildren);
+ for (i = 0; i < nchildren; i++)
+ pci_save_state(children[i]);
+ v = pci_read_config(gpdev, lctl, 2);
+ pci_write_config(gpdev, lctl, v | PCIEM_LINK_CTL_LINK_DIS, 2);
+ pause("pcie_lnk1", 100 * hz / 1000); /* 100ms */
+ pci_write_config(gpdev, lctl, v | PCIEM_LINK_CTL_RETRAIN_LINK, 2);
+ pause("pcie_lnk2", hz); /* Wait 1s before restore_state. */
+ v = pci_read_config(gpdev, lsta, 2);
+ if (pci_read_config(gpdev, lcap, 2) & PCIEM_LINK_CAP_DL_ACTIVE)
+ rc = v & PCIEM_LINK_STA_DL_ACTIVE ? 0 : ETIMEDOUT;
+ else if (v & (PCIEM_LINK_STA_TRAINING_ERROR | PCIEM_LINK_STA_TRAINING))
+ rc = ETIMEDOUT;
+ else
+ rc = 0;
+ if (rc != 0)
+ CH_ERR(sc, "%s: PCIe link is down after reset, LINK_STA 0x%x\n",
+ __func__, v);
+ else {
+ for (i = 0; i < nchildren; i++)
+ pci_restore_state(children[i]);
+ }
+ free(children, M_TEMP);
+
+ return (rc);
}
static inline int
reset_adapter(struct adapter *sc)
{
- if (vm_guest == 0)
- return (reset_adapter_with_pci_bus_reset(sc));
- else
- return (reset_adapter_with_pl_rst(sc));
+ int rc;
+ const int reset_method = vm_guest == VM_GUEST_NO ? t4_reset_method : 0;
+
+ rc = suspend_adapter(sc);
+ if (rc != 0)
+ return (rc);
+
+ switch (reset_method) {
+ case 1:
+ rc = reset_adapter_with_pcie_sbr(sc);
+ break;
+ case 2:
+ rc = reset_adapter_with_pcie_link_bounce(sc);
+ break;
+ case 0:
+ default:
+ rc = reset_adapter_with_pl_rst(sc);
+ break;
+ }
+ if (rc == 0)
+ rc = resume_adapter(sc);
+ return (rc);
}
static void