/*
* EDAC PCI component
*
* Author: Dave Jiang <djiang@mvista.com>
*
* 2007 (c) MontaVista Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/sysdev.h>
#include <linux/ctype.h>
#include <linux/workqueue.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include "edac_core.h"
#include "edac_module.h"
static DEFINE_MUTEX(edac_pci_ctls_mutex);
static LIST_HEAD(edac_pci_list);
static atomic_t pci_indexes = ATOMIC_INIT(0);
/*
* edac_pci_alloc_ctl_info
*
* The alloc() function for the 'edac_pci' control info
* structure. The chip driver will allocate one of these for each
* edac_pci it is going to control/register with the EDAC CORE.
*/
struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
const char *edac_pci_name)
{
struct edac_pci_ctl_info *pci;
void *pvt;
unsigned int size;
debugf1("%s()\n", __func__);
pci = (struct edac_pci_ctl_info *)0;
pvt = edac_align_ptr(&pci[1], sz_pvt);
size = ((unsigned long)pvt) + sz_pvt;
/* Alloc the needed control struct memory */
pci = kzalloc(size, GFP_KERNEL);
if (pci == NULL)
return NULL;
/* Now much private space */
pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;
pci->pvt_info = pvt;
pci->op_state = OP_ALLOC;
snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);
return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);
/*
* edac_pci_free_ctl_info()
*
* Last action on the pci control structure.
*
* call the remove sysfs information, which will unregister
* this control struct's kobj. When that kobj's ref count
* goes to zero, its release function will be call and then
* kfree() the memory.
*/
void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
{
debugf1("%s()\n", __func__);
edac_pci_remove_sysfs(pci);
}
EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);
/*
* find_edac_pci_by_dev()
* scans the edac_pci list for a specific 'struct device *'
*
* return NULL if not found, or return control struct pointer
*/
static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
{
struct edac_pci_ctl_info *pci;
struct list_head *item;
debugf1("%s()\n", __func__);
list_for_each(item, &edac_pci_list) {
pci = list_entry(item, struct edac_pci_ctl_info, link);
if (pci->dev == dev)
return pci;
}
return NULL;
}
/*
* add_edac_pci_to_global_list
* Before calling this function, caller must assign a unique value to
* edac_dev->pci_idx.
* Return:
* 0 on success
* 1 on failure
*/
static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
{
struct list_head *item, *insert_before;
struct edac_pci_ctl_info *rover;
debugf1("%s()\n", __func__);
insert_before = &edac_pci_list;
/* Determine if already on the list */
rover = find_edac_pci_by_dev(pci->dev);
if (unlikely(rover != NULL))
goto fail0;
/* Insert in ascending order by 'pci_idx', so find position */
list_for_each(item, &edac_pci_list) {
rover = list_entry(item, struct edac_pci_ctl_info, link);
if (rover->pci_idx >= pci->pci_idx) {
if (unlikely(rover->pci_idx == pci->pci_idx))
goto fail1;
insert_before = item;
break;
}
}
list_add_tail_rcu(&pci->link, insert_before);
return 0;
fail0:
edac_printk(KERN_WARNING, EDAC_PCI,
"%s (%s) %s %s already assigned %d\n",
dev_name(rover->dev), edac_dev_name(rover),
rover->mod_name, rover->ctl_name, rover->pci_idx);
return 1;
fail1:
edac_printk(KERN_WARNING, EDAC_PCI,
"but in low-level driver: attempt to assign\n"
"\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
__func__);
return 1;
}
/*
* complete_edac_pci_list_del
*
* RCU completion callback to indicate item is deleted
*/
static void complete_edac_pci_list_del(struct rcu_head *head)
{
struct edac_pci_ctl_info *pci;
pci = container_of(head, struct edac_pci_ctl_info, rcu);
INIT_LIST_HEAD(&pci->link);
complete(&pci->complete);
}
/*
* del_edac_pci_from_global_list
*
* remove the PCI control struct from the global list
*/
static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
{
list_del_rcu(&pci->link);
init_completion(&pci->complete);
call_rcu(&pci->rcu, complete_edac_pci_list_del);
wait_for_completion(&pci->complete);
}
#if 0
/* Older code, but might use in the future */
/*
* edac_pci_find()
* Search for an edac_pci_ctl_info structure whose index is 'idx'
*
* If found, return a pointer to the structure
* Else return NULL.
*
* Caller must hold pci_ctls_mutex.
*/
struct edac_pci_ctl_info *edac_pci_find(int idx)
{
struct list_head *item;
struct edac_pci_ctl_info *pci;
/* Iterage over list, looking for exact match of ID */
list_for_each(item, &edac_pci_list) {
pci = list_entry(item, struct edac_pci_ctl_info, link);
if (pci->pci_idx >= idx) {
if (pci->pci_idx == idx)
return pci;
/* not on list, so terminate early */
break;
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(edac_pci_find);
#endif
/*
* edac_pci_workq_function()
*
* periodic function that performs the operation
* scheduled by a workq request, for a given PCI control struct
*/
static void edac_pci_workq_function(struct work_struct *work_req)
{
struct delayed_work *d_work = (struct delayed_work *)work_req;
struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
int msec;
unsigned long delay;
debugf3("%s() checking\n", __func__);
mutex_lock(&edac_pci_ctls_mutex);
if (pci->op_state == OP_RUNNING_POLL) {
/* we might be in POLL mode, but there may NOT be a poll func
*/
if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
pci->edac_check(pci);
/* if we are on a one second period, then use round */
msec = edac_pci_get_poll_msec();
if (msec == 1000)
delay = round_jiffies_relative(msecs_to_jiffies(msec));
else
delay = msecs_to_jiffies(msec);
/* Reschedule only if we are in POLL mode */
queue_delayed_work(edac_workqueue, &pci->work, delay);
}
mutex_unlock(&edac_pci_ctls_mutex);
}
/*
* edac_pci_workq_setup()
* initialize a workq item for this edac_pci instance
* passing in the new delay period in msec
*
* locking model:
* called when 'edac_pci_ctls_mutex' is locked
*/
static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
unsigned int msec)
{
debugf0("%s()\n", __func__);
INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
queue_delayed_work(edac_workqueue, &pci->work,
msecs_to_jiffies(edac_pci_get_poll_msec()));
}
/*
* edac_pci_workq_teardown()
* stop the workq processing on this edac_pci instance
*/
static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
{
int status;
debugf0("%s()\n", __func__);
status = cancel_delayed_work(&pci->work);
if (status == 0)
flush_workqueue(edac_workqueue);
}
/*
* edac_pci_reset_delay_period
*
* called with a new period value for the workq period
* a) stop current workq timer
* b) restart workq timer with new value
*/
void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
unsigned long value)
{
debugf0("%s()\n", __func__);
edac_pci_workq_teardown(pci);
/* need to lock for the setup */
mutex_lock(&edac_pci_ctls_mutex);
edac_pci_workq_setup(pci, value);
mutex_unlock(&edac_pci_ctls_mutex);
}
EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
/*
* edac_pci_alloc_index: Allocate a unique PCI index number
*
* Return:
* allocated index number
*
*/
int edac_pci_alloc_index(void)
{
return atomic_inc_return(&pci_indexes) - 1;
}
EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
/*
* edac_pci_add_device: Insert the 'edac_dev' structure into the
* edac_pci global list and create sysfs entries associated with
* edac_pci structure.
* @pci: pointer to the edac_device structure to be added to the list
* @edac_idx: A unique numeric identifier to be assigned to the
* 'edac_pci' structure.
*
* Return:
* 0 Success
* !0 Failure
*/
int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
{
debugf0("%s()\n", __func__);
pci->pci_idx = edac_idx;
pci->start_time = jiffies;
mutex_lock(&edac_pci_ctls_mutex);
if (add_edac_pci_to_global_list(pci))
goto fail0;
if (edac_pci_create_sysfs(pci)) {
edac_pci_printk(pci, KERN_WARNING,
"failed to create sysfs pci\n");
goto fail1;
}
if (pci->edac_check != NULL) {
pci->op_state = OP_RUNNING_POLL;
edac_pci_workq_setup(pci, 1000);
} else {
pci->op_state = OP_RUNNING_INTERRUPT;
}
edac_pci_printk(pci, KERN_INFO,
"Giving out device to module '%s' controller '%s':"
" DEV '%s' (%s)\n",
pci->mod_name,
pci->ctl_name,
edac_dev_name(pci), edac_op_state_to_string(pci->op_state));
mutex_unlock(&edac_pci_ctls_mutex);
return 0;
/* error unwind stack */
fail1:
del_edac_pci_from_global_list(pci);
fail0:
mutex_unlock(&edac_pci_ctls_mutex);
return 1;
}
EXPORT_SYMBOL_GPL(edac_pci_add_device);
/*
* edac_pci_del_device()
* Remove sysfs entries for specified edac_pci structure and
* then remove edac_pci structure from global list
*
* @dev:
* Pointer to 'struct device' representing edac_pci structure
* to remove
*
* Return:
* Pointer to removed edac_pci structure,
* or NULL if device not found
*/
struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
{
struct edac_pci_ctl_info *pci;
debugf0("%s()\n", __func__);
mutex_lock(&edac_pci_ctls_mutex);
/* ensure the control struct is on the global list
* if not, then leave
*/
pci = find_edac_pci_by_dev(dev);
if (pci == NULL) {
mutex_unlock(&edac_pci_ctls_mutex);
return NULL;
}
pci->op_state = OP_OFFLINE;
del_edac_pci_from_global_list(pci);
mutex_unlock(&edac_pci_ctls_mutex);
/* stop the workq timer */
edac_pci_workq_teardown(pci);
edac_printk(KERN_INFO, EDAC_PCI,
"Removed device %d for %s %s: DEV %s\n",
pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_del_device);
/*
* edac_pci_generic_check
*
* a Generic parity check API
*/
static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
{
debugf4("%s()\n", __func__);
edac_pci_do_parity_check();
}
/* free running instance index counter */
static int edac_pci_idx;
#define EDAC_PCI_GENCTL_NAME "EDAC PCI controller"
struct edac_pci_gen_data {
int edac_idx;
};
/*
* edac_pci_create_generic_ctl
*
* A generic constructor for a PCI parity polling device
* Some systems have more than one domain of PCI busses.
* For systems with one domain, then this API will
* provide for a generic poller.
*
* This routine calls the edac_pci_alloc_ctl_info() for
* the generic device, with default values
*/
struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
const char *mod_name)
{
struct edac_pci_ctl_info *pci;
struct edac_pci_gen_data *pdata;
pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
if (!pci)
return NULL;
pdata = pci->pvt_info;
pci->dev = dev;
dev_set_drvdata(pci->dev, pci);
pci->dev_name = pci_name(to_pci_dev(dev));
pci->mod_name = mod_name;
pci->ctl_name = EDAC_PCI_GENCTL_NAME;
pci->edac_check = edac_pci_generic_check;
pdata->edac_idx = edac_pci_idx++;
if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
debugf3("%s(): failed edac_pci_add_device()\n", __func__);
edac_pci_free_ctl_info(pci);
return NULL;
}
return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
/*
* edac_pci_release_generic_ctl
*
* The release function of a generic EDAC PCI polling device
*/
void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
{
debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
edac_pci_del_device(pci->dev);
edac_pci_free_ctl_info(pci);
}
EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);
