[PATCH v2 01/12] efivars: move efivars globals into struct efivars

From: Mike Waychison
Date: Fri Mar 11 2011 - 20:43:24 EST


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@xxxxxxxxxx>
---
drivers/firmware/efivars.c | 86 ++++++++++++++++++++++++--------------------
1 files changed, 46 insertions(+), 40 deletions(-)

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 2a62ec6..f10ecb6 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -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
@@ -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);
@@ -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",
@@ -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 &&
@@ -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;
}

@@ -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,
@@ -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 &&
@@ -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 */
@@ -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.... */
@@ -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;

/*
@@ -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
@@ -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) {
@@ -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;
}
@@ -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;
@@ -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"
@@ -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);
@@ -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);
}


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