X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fedac%2Fedac_pci_sysfs.c;h=5b075da9914511ffebcb3f2de1362988957a9c3c;hb=4f4ae0d42680889c62db4e1f3e6b4aa7787a7257;hp=fac94cae2c3d5cb126707c3435a5822c9e3cec03;hpb=2e85622042cb5fd56a606e884651ffde52f21028;p=linux-2.6 diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c index fac94cae2c..5b075da991 100644 --- a/drivers/edac/edac_pci_sysfs.c +++ b/drivers/edac/edac_pci_sysfs.c @@ -13,22 +13,25 @@ #include "edac_core.h" #include "edac_module.h" +/* Turn off this whole feature if PCI is not configured */ #ifdef CONFIG_PCI #define EDAC_PCI_SYMLINK "device" -static int check_pci_errors; /* default YES check PCI parity */ -static int edac_pci_panic_on_pe; /* default no panic on PCI Parity */ -static int edac_pci_log_pe = 1; /* log PCI parity errors */ +/* data variables exported via sysfs */ +static int check_pci_errors; /* default NO check PCI parity */ +static int edac_pci_panic_on_pe; /* default NO panic on PCI Parity */ +static int edac_pci_log_pe = 1; /* log PCI parity errors */ static int edac_pci_log_npe = 1; /* log PCI non-parity error errors */ +static int edac_pci_poll_msec = 1000; /* one second workq period */ + static atomic_t pci_parity_count = ATOMIC_INIT(0); static atomic_t pci_nonparity_count = ATOMIC_INIT(0); -static int edac_pci_poll_msec = 1000; -static struct kobject edac_pci_kobj; /* /sys/devices/system/edac/pci */ -static struct completion edac_pci_kobj_complete; +static struct kobject edac_pci_top_main_kobj; static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0); +/* getter functions for the data variables */ int edac_pci_get_check_errors(void) { return check_pci_errors; @@ -74,17 +77,22 @@ static void edac_pci_instance_release(struct kobject *kobj) { struct edac_pci_ctl_info *pci; - debugf1("%s()\n", __func__); + debugf0("%s()\n", __func__); + /* Form pointer to containing struct, the pci control struct */ pci = to_instance(kobj); - complete(&pci->kobj_complete); + + /* decrement reference count on top main kobj */ + kobject_put(&edac_pci_top_main_kobj); + + kfree(pci); /* Free the control struct */ } /* instance specific attribute structure */ struct instance_attribute { struct attribute attr; - ssize_t(*show) (struct edac_pci_ctl_info *, char *); - ssize_t(*store) (struct edac_pci_ctl_info *, const char *, size_t); + ssize_t(*show) (struct edac_pci_ctl_info *, char *); + ssize_t(*store) (struct edac_pci_ctl_info *, const char *, size_t); }; /* Function to 'show' fields from the edac_pci 'instance' structure */ @@ -112,6 +120,7 @@ static ssize_t edac_pci_instance_store(struct kobject *kobj, return -EIO; } +/* fs_ops table */ static struct sysfs_ops pci_instance_ops = { .show = edac_pci_instance_show, .store = edac_pci_instance_store @@ -134,48 +143,76 @@ static struct instance_attribute *pci_instance_attr[] = { NULL }; -/* the ktype for pci instance */ +/* the ktype for a pci instance */ static struct kobj_type ktype_pci_instance = { .release = edac_pci_instance_release, .sysfs_ops = &pci_instance_ops, .default_attrs = (struct attribute **)pci_instance_attr, }; +/* + * edac_pci_create_instance_kobj + * + * construct one EDAC PCI instance's kobject for use + */ static int edac_pci_create_instance_kobj(struct edac_pci_ctl_info *pci, int idx) { + struct kobject *main_kobj; int err; - pci->kobj.parent = &edac_pci_kobj; - pci->kobj.ktype = &ktype_pci_instance; + debugf0("%s()\n", __func__); - err = kobject_set_name(&pci->kobj, "pci%d", idx); - if (err) - return err; + /* First bump the ref count on the top main kobj, which will + * track the number of PCI instances we have, and thus nest + * properly on keeping the module loaded + */ + main_kobj = kobject_get(&edac_pci_top_main_kobj); + if (!main_kobj) { + err = -ENODEV; + goto error_out; + } - err = kobject_register(&pci->kobj); + /* And now register this new kobject under the main kobj */ + err = kobject_init_and_add(&pci->kobj, &ktype_pci_instance, + &edac_pci_top_main_kobj, "pci%d", idx); if (err != 0) { debugf2("%s() failed to register instance pci%d\n", __func__, idx); - return err; + kobject_put(&edac_pci_top_main_kobj); + goto error_out; } + kobject_uevent(&pci->kobj, KOBJ_ADD); debugf1("%s() Register instance 'pci%d' kobject\n", __func__, idx); return 0; + + /* Error unwind statck */ +error_out: + return err; } -static void -edac_pci_delete_instance_kobj(struct edac_pci_ctl_info *pci, int idx) +/* + * edac_pci_unregister_sysfs_instance_kobj + * + * unregister the kobj for the EDAC PCI instance + */ +void edac_pci_unregister_sysfs_instance_kobj(struct edac_pci_ctl_info *pci) { - init_completion(&pci->kobj_complete); - kobject_unregister(&pci->kobj); - wait_for_completion(&pci->kobj_complete); + debugf0("%s()\n", __func__); + + /* Unregister the instance kobject and allow its release + * function release the main reference count and then + * kfree the memory + */ + kobject_put(&pci->kobj); } /***************************** EDAC PCI sysfs root **********************/ #define to_edacpci(k) container_of(k, struct edac_pci_ctl_info, kobj) #define to_edacpci_attr(a) container_of(a, struct edac_pci_attr, attr) +/* simple show/store functions for attributes */ static ssize_t edac_pci_int_show(void *ptr, char *buffer) { int *value = ptr; @@ -267,118 +304,182 @@ static struct edac_pci_dev_attribute *edac_pci_attr[] = { NULL, }; -/* No memory to release */ -static void edac_pci_release(struct kobject *kobj) +/* + * edac_pci_release_main_kobj + * + * This release function is called when the reference count to the + * passed kobj goes to zero. + * + * This kobj is the 'main' kobject that EDAC PCI instances + * link to, and thus provide for proper nesting counts + */ +static void edac_pci_release_main_kobj(struct kobject *kobj) { - struct edac_pci_ctl_info *pci; - pci = to_edacpci(kobj); + debugf0("%s() here to module_put(THIS_MODULE)\n", __func__); - debugf1("%s()\n", __func__); - complete(&pci->kobj_complete); + /* last reference to top EDAC PCI kobject has been removed, + * NOW release our ref count on the core module + */ + module_put(THIS_MODULE); } -static struct kobj_type ktype_edac_pci = { - .release = edac_pci_release, +/* ktype struct for the EDAC PCI main kobj */ +static struct kobj_type ktype_edac_pci_main_kobj = { + .release = edac_pci_release_main_kobj, .sysfs_ops = &edac_pci_sysfs_ops, .default_attrs = (struct attribute **)edac_pci_attr, }; /** - * edac_sysfs_pci_setup() + * edac_pci_main_kobj_setup() * * setup the sysfs for EDAC PCI attributes * assumes edac_class has already been initialized */ -int edac_pci_register_main_kobj(void) +int edac_pci_main_kobj_setup(void) { int err; struct sysdev_class *edac_class; - debugf1("%s()\n", __func__); + debugf0("%s()\n", __func__); + + /* check and count if we have already created the main kobject */ + if (atomic_inc_return(&edac_pci_sysfs_refcount) != 1) + return 0; + /* First time, so create the main kobject and its + * controls and atributes + */ edac_class = edac_get_edac_class(); if (edac_class == NULL) { debugf1("%s() no edac_class\n", __func__); - return -ENODEV; + err = -ENODEV; + goto decrement_count_fail; } - edac_pci_kobj.ktype = &ktype_edac_pci; - - edac_pci_kobj.parent = &edac_class->kset.kobj; - - err = kobject_set_name(&edac_pci_kobj, "pci"); - if (err) - return err; + /* Bump the reference count on this module to ensure the + * modules isn't unloaded until we deconstruct the top + * level main kobj for EDAC PCI + */ + if (!try_module_get(THIS_MODULE)) { + debugf1("%s() try_module_get() failed\n", __func__); + err = -ENODEV; + goto decrement_count_fail; + } /* Instanstiate the pci object */ - /* FIXME: maybe new sysdev_create_subdir() */ - err = kobject_register(&edac_pci_kobj); - + err = kobject_init_and_add(&edac_pci_top_main_kobj, &ktype_edac_pci_main_kobj, + &edac_class->kset.kobj, "pci"); if (err) { debugf1("Failed to register '.../edac/pci'\n"); - return err; + goto kobject_init_and_add_fail; } + /* At this point, to 'release' the top level kobject + * for EDAC PCI, then edac_pci_main_kobj_teardown() + * must be used, for resources to be cleaned up properly + */ + kobject_uevent(&edac_pci_top_main_kobj, KOBJ_ADD); debugf1("Registered '.../edac/pci' kobject\n"); return 0; + + /* Error unwind statck */ +kobject_init_and_add_fail: + module_put(THIS_MODULE); + +decrement_count_fail: + /* if are on this error exit, nothing to tear down */ + atomic_dec(&edac_pci_sysfs_refcount); + + return err; } /* - * edac_pci_unregister_main_kobj() + * edac_pci_main_kobj_teardown() * - * perform the sysfs teardown for the PCI attributes + * if no longer linked (needed) remove the top level EDAC PCI + * kobject with its controls and attributes */ -void edac_pci_unregister_main_kobj(void) +static void edac_pci_main_kobj_teardown(void) { debugf0("%s()\n", __func__); - init_completion(&edac_pci_kobj_complete); - kobject_unregister(&edac_pci_kobj); - wait_for_completion(&edac_pci_kobj_complete); + + /* Decrement the count and only if no more controller instances + * are connected perform the unregisteration of the top level + * main kobj + */ + if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) { + debugf0("%s() called kobject_put on main kobj\n", + __func__); + kobject_put(&edac_pci_top_main_kobj); + } } +/* + * + * edac_pci_create_sysfs + * + * Create the controls/attributes for the specified EDAC PCI device + */ int edac_pci_create_sysfs(struct edac_pci_ctl_info *pci) { int err; struct kobject *edac_kobj = &pci->kobj; - if (atomic_inc_return(&edac_pci_sysfs_refcount) == 1) { - err = edac_pci_register_main_kobj(); - if (err) { - atomic_dec(&edac_pci_sysfs_refcount); - return err; - } - } + debugf0("%s() idx=%d\n", __func__, pci->pci_idx); - err = edac_pci_create_instance_kobj(pci, pci->pci_idx); - if (err) { - if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) - edac_pci_unregister_main_kobj(); - } + /* create the top main EDAC PCI kobject, IF needed */ + err = edac_pci_main_kobj_setup(); + if (err) + return err; - debugf0("%s() idx=%d\n", __func__, pci->pci_idx); + /* Create this instance's kobject under the MAIN kobject */ + err = edac_pci_create_instance_kobj(pci, pci->pci_idx); + if (err) + goto unregister_cleanup; err = sysfs_create_link(edac_kobj, &pci->dev->kobj, EDAC_PCI_SYMLINK); if (err) { debugf0("%s() sysfs_create_link() returned err= %d\n", __func__, err); - return err; + goto symlink_fail; } return 0; + + /* Error unwind stack */ +symlink_fail: + edac_pci_unregister_sysfs_instance_kobj(pci); + +unregister_cleanup: + edac_pci_main_kobj_teardown(); + + return err; } +/* + * edac_pci_remove_sysfs + * + * remove the controls and attributes for this EDAC PCI device + */ void edac_pci_remove_sysfs(struct edac_pci_ctl_info *pci) { - debugf0("%s()\n", __func__); - - edac_pci_delete_instance_kobj(pci, pci->pci_idx); + debugf0("%s() index=%d\n", __func__, pci->pci_idx); + /* Remove the symlink */ sysfs_remove_link(&pci->kobj, EDAC_PCI_SYMLINK); - if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) - edac_pci_unregister_main_kobj(); + /* remove this PCI instance's sysfs entries */ + edac_pci_unregister_sysfs_instance_kobj(pci); + + /* Call the main unregister function, which will determine + * if this 'pci' is the last instance. + * If it is, the main kobject will be unregistered as a result + */ + debugf0("%s() calling edac_pci_main_kobj_teardown()\n", __func__); + edac_pci_main_kobj_teardown(); } /************************ PCI error handling *************************/ @@ -414,13 +515,14 @@ static u16 get_pci_parity_status(struct pci_dev *dev, int secondary) return status; } -typedef void (*pci_parity_check_fn_t) (struct pci_dev * dev); /* Clear any PCI parity errors logged by this device. */ static void edac_pci_dev_parity_clear(struct pci_dev *dev) { u8 header_type; + debugf0("%s()\n", __func__); + get_pci_parity_status(dev, 0); /* read the device TYPE, looking for bridges */ @@ -433,17 +535,28 @@ static void edac_pci_dev_parity_clear(struct pci_dev *dev) /* * PCI Parity polling * + * Fucntion to retrieve the current parity status + * and decode it + * */ static void edac_pci_dev_parity_test(struct pci_dev *dev) { + unsigned long flags; u16 status; u8 header_type; - /* read the STATUS register on this device - */ + /* stop any interrupts until we can acquire the status */ + local_irq_save(flags); + + /* read the STATUS register on this device */ status = get_pci_parity_status(dev, 0); - debugf2("PCI STATUS= 0x%04x %s\n", status, dev->dev.bus_id); + /* read the device TYPE, looking for bridges */ + pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type); + + local_irq_restore(flags); + + debugf4("PCI STATUS= 0x%04x %s\n", status, dev->dev.bus_id); /* check the status reg for errors */ if (status) { @@ -471,16 +584,14 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) } } - /* read the device TYPE, looking for bridges */ - pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type); - debugf2("PCI HEADER TYPE= 0x%02x %s\n", header_type, dev->dev.bus_id); + debugf4("PCI HEADER TYPE= 0x%02x %s\n", header_type, dev->dev.bus_id); if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) { /* On bridges, need to examine secondary status register */ status = get_pci_parity_status(dev, 1); - debugf2("PCI SEC_STATUS= 0x%04x %s\n", status, dev->dev.bus_id); + debugf4("PCI SEC_STATUS= 0x%04x %s\n", status, dev->dev.bus_id); /* check the secondary status reg for errors */ if (status) { @@ -510,9 +621,12 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) } } +/* reduce some complexity in definition of the iterator */ +typedef void (*pci_parity_check_fn_t) (struct pci_dev *dev); + /* * pci_dev parity list iterator - * Scan the PCI device list for one iteration, looking for SERRORs + * Scan the PCI device list for one pass, looking for SERRORs * Master Parity ERRORS or Parity ERRORs on primary or secondary devices */ static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn) @@ -535,22 +649,22 @@ static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn) */ void edac_pci_do_parity_check(void) { - unsigned long flags; int before_count; debugf3("%s()\n", __func__); + /* if policy has PCI check off, leave now */ if (!check_pci_errors) return; before_count = atomic_read(&pci_parity_count); /* scan all PCI devices looking for a Parity Error on devices and - * bridges + * bridges. + * The iterator calls pci_get_device() which might sleep, thus + * we cannot disable interrupts in this scan. */ - local_irq_save(flags); edac_pci_dev_parity_iterator(edac_pci_dev_parity_test); - local_irq_restore(flags); /* Only if operator has selected panic on PCI Error */ if (edac_pci_get_panic_on_pe()) { @@ -560,6 +674,12 @@ void edac_pci_do_parity_check(void) } } +/* + * edac_pci_clear_parity_errors + * + * function to perform an iteration over the PCI devices + * and clearn their current status + */ void edac_pci_clear_parity_errors(void) { /* Clear any PCI bus parity errors that devices initially have logged @@ -567,6 +687,12 @@ void edac_pci_clear_parity_errors(void) */ edac_pci_dev_parity_iterator(edac_pci_dev_parity_clear); } + +/* + * edac_pci_handle_pe + * + * Called to handle a PARITY ERROR event + */ void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg) { @@ -584,9 +710,14 @@ void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg) */ edac_pci_do_parity_check(); } - EXPORT_SYMBOL_GPL(edac_pci_handle_pe); + +/* + * edac_pci_handle_npe + * + * Called to handle a NON-PARITY ERROR event + */ void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg) { @@ -604,7 +735,6 @@ void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg) */ edac_pci_do_parity_check(); } - EXPORT_SYMBOL_GPL(edac_pci_handle_npe); /*