diff options
Diffstat (limited to 'drivers/edac/edac_pci.c')
-rw-r--r-- | drivers/edac/edac_pci.c | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/drivers/edac/edac_pci.c b/drivers/edac/edac_pci.c new file mode 100644 index 000000000..2cf44b4db --- /dev/null +++ b/drivers/edac/edac_pci.c @@ -0,0 +1,498 @@ +/* + * 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/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 *p = NULL, *pvt; + unsigned int size; + + edac_dbg(1, "\n"); + + pci = edac_align_ptr(&p, sizeof(*pci), 1); + pvt = edac_align_ptr(&p, 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) +{ + edac_dbg(1, "\n"); + + 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; + + edac_dbg(1, "\n"); + + 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; + + edac_dbg(1, "\n"); + + 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; +} + +/* + * 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); + + /* these are for safe removal of devices from global list while + * NMI handlers may be traversing list + */ + synchronize_rcu(); + INIT_LIST_HEAD(&pci->link); +} + +#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 = to_delayed_work(work_req); + struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work); + int msec; + unsigned long delay; + + edac_dbg(3, "checking\n"); + + 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) +{ + edac_dbg(0, "\n"); + + 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; + + edac_dbg(0, "\n"); + + 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) +{ + edac_dbg(0, "\n"); + + 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) +{ + edac_dbg(0, "\n"); + + 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, pci->dev_name, + 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; + + edac_dbg(0, "\n"); + + 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) +{ + edac_dbg(4, "\n"); + 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; + if (edac_op_state == EDAC_OPSTATE_POLL) + pci->edac_check = edac_pci_generic_check; + + pdata->edac_idx = edac_pci_idx++; + + if (edac_pci_add_device(pci, pdata->edac_idx) > 0) { + edac_dbg(3, "failed edac_pci_add_device()\n"); + 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) +{ + edac_dbg(0, "pci mod=%s\n", pci->mod_name); + + edac_pci_del_device(pci->dev); + edac_pci_free_ctl_info(pci); +} +EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl); 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