/* * 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 struct list_head edac_pci_list = LIST_HEAD_INIT(edac_pci_list); /* * 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", rover->dev->bus_id, 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); } /* * 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); /* * 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_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, 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, dev_name(pci)); return pci; } EXPORT_SYMBOL_GPL(edac_pci_del_device); /* * edac_pci_generic_check * * a Generic parity check API */ 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);