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efivars: move efivars globals into struct efivars
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In preparation for abstracting out efivars to be usable by other similar
variable services, move the global lock, list and kset into a structure.
Later patches will change the scope of 'efivars' and have it be passed
by function argument.

Signed-off-by: Mike Waychison <mikew@google.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>,
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Mike Waychison authored and Greg Kroah-Hartman committed Mar 14, 2011
1 parent c1605f2 commit 2942269
Showing 1 changed file with 46 additions and 40 deletions.
86 changes: 46 additions & 40 deletions drivers/firmware/efivars.c
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Original file line number Diff line number Diff line change
Expand Up @@ -89,16 +89,21 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables");
MODULE_LICENSE("GPL");
MODULE_VERSION(EFIVARS_VERSION);

/*
* efivars_lock protects two things:
* 1) efivar_list - adds, removals, reads, writes
* 2) efi.[gs]et_variable() calls.
* It must not be held when creating sysfs entries or calling kmalloc.
* efi.get_next_variable() is only called from efivars_init(),
* which is protected by the BKL, so that path is safe.
*/
static DEFINE_SPINLOCK(efivars_lock);
static LIST_HEAD(efivar_list);
struct efivars {
/*
* ->lock protects two things:
* 1) ->list - adds, removals, reads, writes
* 2) efi.[gs]et_variable() calls.
* It must not be held when creating sysfs entries or calling kmalloc.
* efi.get_next_variable() is only called from efivars_init(),
* which is protected by the BKL, so that path is safe.
*/
spinlock_t lock;
struct list_head list;
struct kset *kset;
};
static struct efivars __efivars;
static struct efivars *efivars = &__efivars;

/*
* The maximum size of VariableName + Data = 1024
Expand Down Expand Up @@ -174,14 +179,14 @@ get_var_data(struct efi_variable *var)
{
efi_status_t status;

spin_lock(&efivars_lock);
spin_lock(&efivars->lock);
var->DataSize = 1024;
status = efi.get_variable(var->VariableName,
&var->VendorGuid,
&var->Attributes,
&var->DataSize,
var->Data);
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
status);
Expand Down Expand Up @@ -291,14 +296,14 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
return -EINVAL;
}

spin_lock(&efivars_lock);
spin_lock(&efivars->lock);
status = efi.set_variable(new_var->VariableName,
&new_var->VendorGuid,
new_var->Attributes,
new_var->DataSize,
new_var->Data);

spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);

if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
Expand Down Expand Up @@ -415,12 +420,12 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
if (!capable(CAP_SYS_ADMIN))
return -EACCES;

spin_lock(&efivars_lock);
spin_lock(&efivars->lock);

/*
* Does this variable already exist?
*/
list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
strsize2 = utf8_strsize(new_var->VariableName, 1024);
if (strsize1 == strsize2 &&
Expand All @@ -433,7 +438,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
}
}
if (found) {
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
return -EINVAL;
}

Expand All @@ -447,10 +452,10 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
status);
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
return -EIO;
}
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);

/* Create the entry in sysfs. Locking is not required here */
status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
Expand All @@ -474,12 +479,12 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
if (!capable(CAP_SYS_ADMIN))
return -EACCES;

spin_lock(&efivars_lock);
spin_lock(&efivars->lock);

/*
* Does this variable already exist?
*/
list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
strsize2 = utf8_strsize(del_var->VariableName, 1024);
if (strsize1 == strsize2 &&
Expand All @@ -492,7 +497,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
}
}
if (!found) {
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
return -EINVAL;
}
/* force the Attributes/DataSize to 0 to ensure deletion */
Expand All @@ -508,12 +513,12 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
if (status != EFI_SUCCESS) {
printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
status);
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
return -EIO;
}
list_del(&search_efivar->list);
/* We need to release this lock before unregistering. */
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
efivar_unregister(search_efivar);

/* It's dead Jim.... */
Expand Down Expand Up @@ -572,8 +577,6 @@ static struct attribute_group efi_subsys_attr_group = {
.attrs = efi_subsys_attrs,
};


static struct kset *vars_kset;
static struct kobject *efi_kobj;

/*
Expand All @@ -582,7 +585,7 @@ static struct kobject *efi_kobj;
* variable_name_size = number of bytes required to hold
* variable_name (not counting the NULL
* character at the end.
* efivars_lock is not held on entry or exit.
* efivars->lock is not held on entry or exit.
* Returns 1 on failure, 0 on success
*/
static int
Expand Down Expand Up @@ -618,7 +621,7 @@ efivar_create_sysfs_entry(unsigned long variable_name_size,
*(short_name + strlen(short_name)) = '-';
efi_guid_unparse(vendor_guid, short_name + strlen(short_name));

new_efivar->kobj.kset = vars_kset;
new_efivar->kobj.kset = efivars->kset;
i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
"%s", short_name);
if (i) {
Expand All @@ -631,9 +634,9 @@ efivar_create_sysfs_entry(unsigned long variable_name_size,
kfree(short_name);
short_name = NULL;

spin_lock(&efivars_lock);
list_add(&new_efivar->list, &efivar_list);
spin_unlock(&efivars_lock);
spin_lock(&efivars->lock);
list_add(&new_efivar->list, &efivars->list);
spin_unlock(&efivars->lock);

return 0;
}
Expand Down Expand Up @@ -674,8 +677,11 @@ efivars_init(void)
goto out_free;
}

vars_kset = kset_create_and_add("vars", NULL, efi_kobj);
if (!vars_kset) {
spin_lock_init(&efivars->lock);
INIT_LIST_HEAD(&efivars->list);

efivars->kset = kset_create_and_add("vars", NULL, efi_kobj);
if (!efivars->kset) {
printk(KERN_ERR "efivars: Subsystem registration failed.\n");
error = -ENOMEM;
goto out_firmware_unregister;
Expand Down Expand Up @@ -712,12 +718,12 @@ efivars_init(void)
* Now add attributes to allow creation of new vars
* and deletion of existing ones...
*/
error = sysfs_create_bin_file(&vars_kset->kobj,
error = sysfs_create_bin_file(&efivars->kset->kobj,
&var_subsys_attr_new_var);
if (error)
printk(KERN_ERR "efivars: unable to create new_var sysfs file"
" due to error %d\n", error);
error = sysfs_create_bin_file(&vars_kset->kobj,
error = sysfs_create_bin_file(&efivars->kset->kobj,
&var_subsys_attr_del_var);
if (error)
printk(KERN_ERR "efivars: unable to create del_var sysfs file"
Expand All @@ -730,7 +736,7 @@ efivars_init(void)
else
goto out_free;

kset_unregister(vars_kset);
kset_unregister(efivars->kset);

out_firmware_unregister:
kobject_put(efi_kobj);
Expand All @@ -746,14 +752,14 @@ efivars_exit(void)
{
struct efivar_entry *entry, *n;

list_for_each_entry_safe(entry, n, &efivar_list, list) {
spin_lock(&efivars_lock);
list_for_each_entry_safe(entry, n, &efivars->list, list) {
spin_lock(&efivars->lock);
list_del(&entry->list);
spin_unlock(&efivars_lock);
spin_unlock(&efivars->lock);
efivar_unregister(entry);
}

kset_unregister(vars_kset);
kset_unregister(efivars->kset);
kobject_put(efi_kobj);
}

Expand Down

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