drivers/edac: fix edac_pci sysfs
This patch fixes sysfs exit code for the EDAC PCI device in a similiar manner
and the previous fixes for EDAC_MC and EDAC_DEVICE.
It removes the old (and incorrect) completion model and uses reference counts
on per instance kobjects and on the edac core module.
This pattern was applied to the edac_mc and edac_device code, but the EDAC PCI
code was missed. In addition, this fixes a system hang after a low level
driver was unloaded. (A cleanup function was called twice, which really
screwed things up)
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c
index fac94ca..69f5ddd 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 @@
{
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 @@
return -EIO;
}
+/* fs_ops table */
static struct sysfs_ops pci_instance_ops = {
.show = edac_pci_instance_show,
.store = edac_pci_instance_store
@@ -134,48 +143,82 @@
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;
+ debugf0("%s()\n", __func__);
+
+ /* Set the parent and the instance's ktype */
+ pci->kobj.parent = &edac_pci_top_main_kobj;
pci->kobj.ktype = &ktype_pci_instance;
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;
+ }
+
+ /* And now register this new kobject under the main kobj */
err = kobject_register(&pci->kobj);
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;
}
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);
+ debugf0("%s()\n", __func__);
+
+ /* Unregister the instance kobject and allow its release
+ * function release the main reference count and then
+ * kfree the memory
+ */
kobject_unregister(&pci->kobj);
- wait_for_completion(&pci->kobj_complete);
}
/***************************** 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 +310,189 @@
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;
+ /* Need the kobject hook ups, and name setting */
+ edac_pci_top_main_kobj.ktype = &ktype_edac_pci_main_kobj;
+ edac_pci_top_main_kobj.parent = &edac_class->kset.kobj;
- edac_pci_kobj.parent = &edac_class->kset.kobj;
-
- err = kobject_set_name(&edac_pci_kobj, "pci");
+ err = kobject_set_name(&edac_pci_top_main_kobj, "pci");
if (err)
- return err;
+ goto decrement_count_fail;
+
+ /* 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_register(&edac_pci_top_main_kobj);
if (err) {
debugf1("Failed to register '.../edac/pci'\n");
- return err;
+ goto kobject_register_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
+ */
debugf1("Registered '.../edac/pci' kobject\n");
return 0;
+
+ /* Error unwind statck */
+kobject_register_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_unregister on main kobj\n",
+ __func__);
+ kobject_unregister(&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;
- }
- }
-
- 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();
- }
-
debugf0("%s() idx=%d\n", __func__, pci->pci_idx);
+ /* create the top main EDAC PCI kobject, IF needed */
+ err = edac_pci_main_kobj_setup();
+ if (err)
+ return err;
+
+ /* 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__);
+ debugf0("%s() index=%d\n", __func__, pci->pci_idx);
- edac_pci_delete_instance_kobj(pci, 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 +528,14 @@
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 +548,28 @@
/*
* 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 +597,14 @@
}
}
- /* 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 +634,12 @@
}
}
+/* 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 +662,22 @@
*/
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 +687,12 @@
}
}
+/*
+ * 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 +700,12 @@
*/
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 +723,14 @@
*/
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 +748,6 @@
*/
edac_pci_do_parity_check();
}
-
EXPORT_SYMBOL_GPL(edac_pci_handle_npe);
/*