summaryrefslogtreecommitdiffstats
path: root/drivers/pci/hotplug/rpaphp_pci.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/pci/hotplug/rpaphp_pci.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/pci/hotplug/rpaphp_pci.c')
-rw-r--r--drivers/pci/hotplug/rpaphp_pci.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/rpaphp_pci.c b/drivers/pci/hotplug/rpaphp_pci.c
new file mode 100644
index 0000000000..bcfd26ec6d
--- /dev/null
+++ b/drivers/pci/hotplug/rpaphp_pci.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
+ * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <lxie@us.ibm.com>
+ *
+ */
+#include <linux/of.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+
+#include <asm/pci-bridge.h>
+#include <asm/rtas.h>
+#include <asm/machdep.h>
+
+#include "../pci.h" /* for pci_add_new_bus */
+#include "rpaphp.h"
+
+/*
+ * RTAS call get-sensor-state(DR_ENTITY_SENSE) return values as per PAPR:
+ * -- generic return codes ---
+ * -1: Hardware Error
+ * -2: RTAS_BUSY
+ * -3: Invalid sensor. RTAS Parameter Error.
+ * -- rtas_get_sensor function specific return codes ---
+ * -9000: Need DR entity to be powered up and unisolated before RTAS call
+ * -9001: Need DR entity to be powered up, but not unisolated, before RTAS call
+ * -9002: DR entity unusable
+ * 990x: Extended delay - where x is a number in the range of 0-5
+ */
+#define RTAS_SLOT_UNISOLATED -9000
+#define RTAS_SLOT_NOT_UNISOLATED -9001
+#define RTAS_SLOT_NOT_USABLE -9002
+
+static int rtas_get_sensor_errno(int rtas_rc)
+{
+ switch (rtas_rc) {
+ case 0:
+ /* Success case */
+ return 0;
+ case RTAS_SLOT_UNISOLATED:
+ case RTAS_SLOT_NOT_UNISOLATED:
+ return -EFAULT;
+ case RTAS_SLOT_NOT_USABLE:
+ return -ENODEV;
+ case RTAS_BUSY:
+ case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:
+ return -EBUSY;
+ default:
+ return rtas_error_rc(rtas_rc);
+ }
+}
+
+/*
+ * get_adapter_status() can be called by the EEH handler during EEH recovery.
+ * On certain PHB failures, the RTAS call rtas_call(get-sensor-state) returns
+ * extended busy error (9902) until PHB is recovered by pHyp. The RTAS call
+ * interface rtas_get_sensor() loops over the RTAS call on extended delay
+ * return code (9902) until the return value is either success (0) or error
+ * (-1). This causes the EEH handler to get stuck for ~6 seconds before it
+ * could notify that the PCI error has been detected and stop any active
+ * operations. This sometimes causes EEH recovery to fail. To avoid this issue,
+ * invoke rtas_call(get-sensor-state) directly if the respective PE is in EEH
+ * recovery state and return -EBUSY error based on RTAS return status. This
+ * will help the EEH handler to notify the driver about the PCI error
+ * immediately and successfully proceed with EEH recovery steps.
+ */
+
+static int __rpaphp_get_sensor_state(struct slot *slot, int *state)
+{
+ int rc;
+ int token = rtas_token("get-sensor-state");
+ struct pci_dn *pdn;
+ struct eeh_pe *pe;
+ struct pci_controller *phb = PCI_DN(slot->dn)->phb;
+
+ if (token == RTAS_UNKNOWN_SERVICE)
+ return -ENOENT;
+
+ /*
+ * Fallback to existing method for empty slot or PE isn't in EEH
+ * recovery.
+ */
+ pdn = list_first_entry_or_null(&PCI_DN(phb->dn)->child_list,
+ struct pci_dn, list);
+ if (!pdn)
+ goto fallback;
+
+ pe = eeh_dev_to_pe(pdn->edev);
+ if (pe && (pe->state & EEH_PE_RECOVERING)) {
+ rc = rtas_call(token, 2, 2, state, DR_ENTITY_SENSE,
+ slot->index);
+ return rtas_get_sensor_errno(rc);
+ }
+fallback:
+ return rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);
+}
+
+int rpaphp_get_sensor_state(struct slot *slot, int *state)
+{
+ int rc;
+ int setlevel;
+
+ rc = __rpaphp_get_sensor_state(slot, state);
+
+ if (rc < 0) {
+ if (rc == -EFAULT || rc == -EEXIST) {
+ dbg("%s: slot must be power up to get sensor-state\n",
+ __func__);
+
+ /* some slots have to be powered up
+ * before get-sensor will succeed.
+ */
+ rc = rtas_set_power_level(slot->power_domain, POWER_ON,
+ &setlevel);
+ if (rc < 0) {
+ dbg("%s: power on slot[%s] failed rc=%d.\n",
+ __func__, slot->name, rc);
+ } else {
+ rc = __rpaphp_get_sensor_state(slot, state);
+ }
+ } else if (rc == -ENODEV)
+ info("%s: slot is unusable\n", __func__);
+ else
+ err("%s failed to get sensor state\n", __func__);
+ }
+ return rc;
+}
+
+/**
+ * rpaphp_enable_slot - record slot state, config pci device
+ * @slot: target &slot
+ *
+ * Initialize values in the slot structure to indicate if there is a pci card
+ * plugged into the slot. If the slot is not empty, run the pcibios routine
+ * to get pcibios stuff correctly set up.
+ */
+int rpaphp_enable_slot(struct slot *slot)
+{
+ int rc, level, state;
+ struct pci_bus *bus;
+
+ slot->state = EMPTY;
+
+ /* Find out if the power is turned on for the slot */
+ rc = rtas_get_power_level(slot->power_domain, &level);
+ if (rc)
+ return rc;
+
+ /* Figure out if there is an adapter in the slot */
+ rc = rpaphp_get_sensor_state(slot, &state);
+ if (rc)
+ return rc;
+
+ bus = pci_find_bus_by_node(slot->dn);
+ if (!bus) {
+ err("%s: no pci_bus for dn %pOF\n", __func__, slot->dn);
+ return -EINVAL;
+ }
+
+ slot->bus = bus;
+ slot->pci_devs = &bus->devices;
+
+ /* if there's an adapter in the slot, go add the pci devices */
+ if (state == PRESENT) {
+ slot->state = NOT_CONFIGURED;
+
+ /* non-empty slot has to have child */
+ if (!slot->dn->child) {
+ err("%s: slot[%s]'s device_node doesn't have child for adapter\n",
+ __func__, slot->name);
+ return -EINVAL;
+ }
+
+ if (list_empty(&bus->devices)) {
+ pseries_eeh_init_edev_recursive(PCI_DN(slot->dn));
+ pci_hp_add_devices(bus);
+ }
+
+ if (!list_empty(&bus->devices)) {
+ slot->state = CONFIGURED;
+ }
+
+ if (rpaphp_debug) {
+ struct pci_dev *dev;
+ dbg("%s: pci_devs of slot[%pOF]\n", __func__, slot->dn);
+ list_for_each_entry(dev, &bus->devices, bus_list)
+ dbg("\t%s\n", pci_name(dev));
+ }
+ }
+
+ return 0;
+}