// SPDX-License-Identifier: GPL-2.0+
/*
* PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
* Copyright (C) 2003 Linda Xie <[email protected]>
*
* All rights reserved.
*
* Send feedback to <[email protected]>
*
*/
#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;
}
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