/*
* The file intends to implement PE based on the information from
* platforms. Basically, there have 3 types of PEs: PHB/Bus/Device.
* All the PEs should be organized as hierarchy tree. The first level
* of the tree will be associated to existing PHBs since the particular
* PE is only meaningful in one PHB domain.
*
* Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
static LIST_HEAD(eeh_phb_pe);
/**
* eeh_pe_alloc - Allocate PE
* @phb: PCI controller
* @type: PE type
*
* Allocate PE instance dynamically.
*/
static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type)
{
struct eeh_pe *pe;
/* Allocate PHB PE */
pe = kzalloc(sizeof(struct eeh_pe), GFP_KERNEL);
if (!pe) return NULL;
/* Initialize PHB PE */
pe->type = type;
pe->phb = phb;
INIT_LIST_HEAD(&pe->child_list);
INIT_LIST_HEAD(&pe->child);
INIT_LIST_HEAD(&pe->edevs);
return pe;
}
/**
* eeh_phb_pe_create - Create PHB PE
* @phb: PCI controller
*
* The function should be called while the PHB is detected during
* system boot or PCI hotplug in order to create PHB PE.
*/
int __devinit eeh_phb_pe_create(struct pci_controller *phb)
{
struct eeh_pe *pe;
/* Allocate PHB PE */
pe = eeh_pe_alloc(phb, EEH_PE_PHB);
if (!pe) {
pr_err("%s: out of memory!\n", __func__);
return -ENOMEM;
}
/* Put it into the list */
eeh_lock();
list_add_tail(&pe->child, &eeh_phb_pe);
eeh_unlock();
pr_debug("EEH: Add PE for PHB#%d\n", phb->global_number);
return 0;
}
/**
* eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
* @phb: PCI controller
*
* The overall PEs form hierarchy tree. The first layer of the
* hierarchy tree is composed of PHB PEs. The function is used
* to retrieve the corresponding PHB PE according to the given PHB.
*/
static struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb)
{
struct eeh_pe *pe;
eeh_lock();
list_for_each_entry(pe, &eeh_phb_pe, child) {
/*
* Actually, we needn't check the type since
* the PE for PHB has been determined when that
* was created.
*/
if (pe->type == EEH_PE_PHB &&
pe->phb == phb) {
eeh_unlock();
return pe;
}
}
eeh_unlock();
return NULL;
}
/**
* eeh_pe_next - Retrieve the next PE in the tree
* @pe: current PE
* @root: root PE
*
* The function is used to retrieve the next PE in the
* hierarchy PE tree.
*/
static struct eeh_pe *eeh_pe_next(struct eeh_pe *pe,
struct eeh_pe *root)
{
struct list_head *next = pe->child_list.next;
if (next == &pe->child_list) {
while (1) {
if (pe == root)
return NULL;
next = pe->child.next;
if (next != &pe->parent->child_list)
break;
pe = pe->parent;
}
}
return list_entry(next, struct eeh_pe, child);
}
/**
* eeh_pe_traverse - Traverse PEs in the specified PHB
* @root: root PE
* @fn: callback
* @flag: extra parameter to callback
*
* The function is used to traverse the specified PE and its
* child PEs. The traversing is to be terminated once the
* callback returns something other than NULL, or no more PEs
* to be traversed.
*/
static void *eeh_pe_traverse(struct eeh_pe *root,
eeh_traverse_func fn, void *flag)
{
struct eeh_pe *pe;
void *ret;
for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
ret = fn(pe, flag);
if (ret) return ret;
}
return NULL;
}
/**
* __eeh_pe_get - Check the PE address
* @data: EEH PE
* @flag: EEH device
*
* For one particular PE, it can be identified by PE address
* or tranditional BDF address. BDF address is composed of
* Bus/Device/Function number. The extra data referred by flag
* indicates which type of address should be used.
*/
static void *__eeh_pe_get(void *data, void *flag)
{
struct eeh_pe *pe = (struct eeh_pe *)data;
struct eeh_dev *edev = (struct eeh_dev *)flag;
/* Unexpected PHB PE */
if (pe->type == EEH_PE_PHB)
return NULL;
/* We prefer PE address */
if (edev->pe_config_addr &&
(edev->pe_config_addr == pe->addr))
return pe;
/* Try BDF address */
if (edev->pe_config_addr &&
(edev->config_addr == pe->config_addr))
return pe;
return NULL;
}
/**
* eeh_pe_get - Search PE based on the given address
* @edev: EEH device
*
* Search the corresponding PE based on the specified address which
* is included in the eeh device. The function is used to check if
* the associated PE has been created against the PE address. It's
* notable that the PE address has 2 format: traditional PE address
* which is composed of PCI bus/device/function number, or unified
* PE address.
*/
static struct eeh_pe *eeh_pe_get(struct eeh_dev *edev)
{
struct eeh_pe *root = eeh_phb_pe_get(edev->phb);
struct eeh_pe *pe;
eeh_lock();
pe = eeh_pe_traverse(root, __eeh_pe_get, edev);
eeh_unlock();
return pe;
}
/**
* eeh_pe_get_parent - Retrieve the parent PE
* @edev: EEH device
*
* The whole PEs existing in the system are organized as hierarchy
* tree. The function is used to retrieve the parent PE according
* to the parent EEH device.
*/
static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
{
struct device_node *dn;
struct eeh_dev *parent;
/*
* It might have the case for the indirect parent
* EEH device already having associated PE, but
* the direct parent EEH device doesn't have yet.
*/
dn = edev->dn->parent;
while (dn) {
/* We're poking out of PCI territory */
if (!PCI_DN(dn)) return NULL;
parent = of_node_to_eeh_dev(dn);
/* We're poking out of PCI territory */
if (!parent) return NULL;
if (parent->pe)
return parent->pe;
dn = dn->parent;
}
return NULL;
}
/**
* eeh_add_to_parent_pe - Add EEH device to parent PE
* @edev: EEH device
*
* Add EEH device to the parent PE. If the parent PE already
* exists, the PE type will be changed to EEH_PE_BUS. Otherwise,
* we have to create new PE to hold the EEH device and the new
* PE will be linked to its parent PE as well.
*/
int eeh_add_to_parent_pe(struct eeh_dev *edev)
{
struct eeh_pe *pe, *parent;
/*
* Search the PE has been existing or not according
* to the PE address. If that has been existing, the
* PE should be composed of PCI bus and its subordinate
* components.
*/
pe = eeh_pe_get(edev);
if (pe) {
if (!edev->pe_config_addr) {
pr_err("%s: PE with addr 0x%x already exists\n",
__func__, edev->config_addr);
return -EEXIST;
}
/* Mark the PE as type of PCI bus */
pe->type = EEH_PE_BUS;
edev->pe = pe;
/* Put the edev to PE */
list_add_tail(&edev->list, &pe->edevs);
pr_debug("EEH: Add %s to Bus PE#%x\n",
edev->dn->full_name, pe->addr);
return 0;
}
/* Create a new EEH PE */
pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE);
if (!pe) {
pr_err("%s: out of memory!\n", __func__);
return -ENOMEM;
}
pe->addr = edev->pe_config_addr;
pe->config_addr = edev->config_addr;
/*
* Put the new EEH PE into hierarchy tree. If the parent
* can't be found, the newly created PE will be attached
* to PHB directly. Otherwise, we have to associate the
* PE with its parent.
*/
parent = eeh_pe_get_parent(edev);
if (!parent) {
parent = eeh_phb_pe_get(edev->phb);
if (!parent) {
pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",
__func__, edev->phb->global_number);
edev->pe = NULL;
kfree(pe);
return -EEXIST;
}
}
pe->parent = parent;
/*
* Put the newly created PE into the child list and
* link the EEH device accordingly.
*/
list_add_tail(&pe->child, &parent->child_list);
list_add_tail(&edev->list, &pe->edevs);
edev->pe = pe;
pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n",
edev->dn->full_name, pe->addr, pe->parent->addr);
return 0;
}
/**
* eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE
* @edev: EEH device
*
* The PE hierarchy tree might be changed when doing PCI hotplug.
* Also, the PCI devices or buses could be removed from the system
* during EEH recovery. So we have to call the function remove the
* corresponding PE accordingly if necessary.
*/
int eeh_rmv_from_parent_pe(struct eeh_dev *edev)
{
struct eeh_pe *pe, *parent;
if (!edev->pe) {
pr_warning("%s: No PE found for EEH device %s\n",
__func__, edev->dn->full_name);
return -EEXIST;
}
/* Remove the EEH device */
pe = edev->pe;
edev->pe = NULL;
list_del(&edev->list);
/*
* Check if the parent PE includes any EEH devices.
* If not, we should delete that. Also, we should
* delete the parent PE if it doesn't have associated
* child PEs and EEH devices.
*/
while (1) {
parent = pe->parent;
if (pe->type == EEH_PE_PHB)
break;
if (list_empty(&pe->edevs) &&
list_empty(&pe->child_list)) {
list_del(&pe->child);
kfree(pe);
}
pe = parent;
}
return 0;
}
/**
* __eeh_pe_state_mark - Mark the state for the PE
* @data: EEH PE
* @flag: state
*
* The function is used to mark the indicated state for the given
* PE. Also, the associated PCI devices will be put into IO frozen
* state as well.
*/
static void *__eeh_pe_state_mark(void *data, void *flag)
{
struct eeh_pe *pe = (struct eeh_pe *)data;
int state = *((int *)flag);
struct eeh_dev *tmp;
struct pci_dev *pdev;
/*
* Mark the PE with the indicated state. Also,
* the associated PCI device will be put into
* I/O frozen state to avoid I/O accesses from
* the PCI device driver.
*/
pe->state |= state;
eeh_pe_for_each_dev(pe, tmp) {
pdev = eeh_dev_to_pci_dev(tmp);
if (pdev)
pdev->error_state = pci_channel_io_frozen;
}
return NULL;
}
/**
* eeh_pe_state_mark - Mark specified state for PE and its associated device
* @pe: EEH PE
*
* EEH error affects the current PE and its child PEs. The function
* is used to mark appropriate state for the affected PEs and the
* associated devices.
*/
void eeh_pe_state_mark(struct eeh_pe *pe, int state)
{
eeh_pe_traverse(pe, __eeh_pe_state_mark, &state);
}
/**
* __eeh_pe_state_clear - Clear state for the PE
* @data: EEH PE
* @flag: state
*
* The function is used to clear the indicated state from the
* given PE. Besides, we also clear the check count of the PE
* as well.
*/
static void *__eeh_pe_state_clear(void *data, void *flag)
{
struct eeh_pe *pe = (struct eeh_pe *)data;
int state = *((int *)flag);
pe->state &= ~state;
pe->check_count = 0;
return NULL;
}
/**
* eeh_pe_state_clear - Clear state for the PE and its children
* @pe: PE
* @state: state to be cleared
*
* When the PE and its children has been recovered from error,
* we need clear the error state for that. The function is used
* for the purpose.
*/
void eeh_pe_state_clear(struct eeh_pe *pe, int state)
{
eeh_pe_traverse(pe, __eeh_pe_state_clear, &state);
}
