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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/firmware/efi/vars.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/vars.c')
-rw-r--r--drivers/firmware/efi/vars.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
new file mode 100644
index 000000000..0ba9f1831
--- /dev/null
+++ b/drivers/firmware/efi/vars.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Originally from efivars.c
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ */
+
+#include <linux/types.h>
+#include <linux/sizes.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/smp.h>
+#include <linux/efi.h>
+#include <linux/ucs2_string.h>
+
+/* Private pointer to registered efivars */
+static struct efivars *__efivars;
+
+static DEFINE_SEMAPHORE(efivars_lock);
+
+static efi_status_t check_var_size(bool nonblocking, u32 attributes,
+ unsigned long size)
+{
+ const struct efivar_operations *fops;
+ efi_status_t status;
+
+ fops = __efivars->ops;
+
+ if (!fops->query_variable_store)
+ status = EFI_UNSUPPORTED;
+ else
+ status = fops->query_variable_store(attributes, size,
+ nonblocking);
+ if (status == EFI_UNSUPPORTED)
+ return (size <= SZ_64K) ? EFI_SUCCESS : EFI_OUT_OF_RESOURCES;
+ return status;
+}
+
+/**
+ * efivars_kobject - get the kobject for the registered efivars
+ *
+ * If efivars_register() has not been called we return NULL,
+ * otherwise return the kobject used at registration time.
+ */
+struct kobject *efivars_kobject(void)
+{
+ if (!__efivars)
+ return NULL;
+
+ return __efivars->kobject;
+}
+EXPORT_SYMBOL_GPL(efivars_kobject);
+
+/**
+ * efivars_register - register an efivars
+ * @efivars: efivars to register
+ * @ops: efivars operations
+ * @kobject: @efivars-specific kobject
+ *
+ * Only a single efivars can be registered at any time.
+ */
+int efivars_register(struct efivars *efivars,
+ const struct efivar_operations *ops,
+ struct kobject *kobject)
+{
+ if (down_interruptible(&efivars_lock))
+ return -EINTR;
+
+ efivars->ops = ops;
+ efivars->kobject = kobject;
+
+ __efivars = efivars;
+
+ pr_info("Registered efivars operations\n");
+
+ up(&efivars_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(efivars_register);
+
+/**
+ * efivars_unregister - unregister an efivars
+ * @efivars: efivars to unregister
+ *
+ * The caller must have already removed every entry from the list,
+ * failure to do so is an error.
+ */
+int efivars_unregister(struct efivars *efivars)
+{
+ int rv;
+
+ if (down_interruptible(&efivars_lock))
+ return -EINTR;
+
+ if (!__efivars) {
+ printk(KERN_ERR "efivars not registered\n");
+ rv = -EINVAL;
+ goto out;
+ }
+
+ if (__efivars != efivars) {
+ rv = -EINVAL;
+ goto out;
+ }
+
+ pr_info("Unregistered efivars operations\n");
+ __efivars = NULL;
+
+ rv = 0;
+out:
+ up(&efivars_lock);
+ return rv;
+}
+EXPORT_SYMBOL_GPL(efivars_unregister);
+
+int efivar_supports_writes(void)
+{
+ return __efivars && __efivars->ops->set_variable;
+}
+EXPORT_SYMBOL_GPL(efivar_supports_writes);
+
+/*
+ * efivar_lock() - obtain the efivar lock, wait for it if needed
+ * @return 0 on success, error code on failure
+ */
+int efivar_lock(void)
+{
+ if (down_interruptible(&efivars_lock))
+ return -EINTR;
+ if (!__efivars->ops) {
+ up(&efivars_lock);
+ return -ENODEV;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(efivar_lock, EFIVAR);
+
+/*
+ * efivar_lock() - obtain the efivar lock if it is free
+ * @return 0 on success, error code on failure
+ */
+int efivar_trylock(void)
+{
+ if (down_trylock(&efivars_lock))
+ return -EBUSY;
+ if (!__efivars->ops) {
+ up(&efivars_lock);
+ return -ENODEV;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(efivar_trylock, EFIVAR);
+
+/*
+ * efivar_unlock() - release the efivar lock
+ */
+void efivar_unlock(void)
+{
+ up(&efivars_lock);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_unlock, EFIVAR);
+
+/*
+ * efivar_get_variable() - retrieve a variable identified by name/vendor
+ *
+ * Must be called with efivars_lock held.
+ */
+efi_status_t efivar_get_variable(efi_char16_t *name, efi_guid_t *vendor,
+ u32 *attr, unsigned long *size, void *data)
+{
+ return __efivars->ops->get_variable(name, vendor, attr, size, data);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_get_variable, EFIVAR);
+
+/*
+ * efivar_get_next_variable() - enumerate the next name/vendor pair
+ *
+ * Must be called with efivars_lock held.
+ */
+efi_status_t efivar_get_next_variable(unsigned long *name_size,
+ efi_char16_t *name, efi_guid_t *vendor)
+{
+ return __efivars->ops->get_next_variable(name_size, name, vendor);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_get_next_variable, EFIVAR);
+
+/*
+ * efivar_set_variable_locked() - set a variable identified by name/vendor
+ *
+ * Must be called with efivars_lock held. If @nonblocking is set, it will use
+ * non-blocking primitives so it is guaranteed not to sleep.
+ */
+efi_status_t efivar_set_variable_locked(efi_char16_t *name, efi_guid_t *vendor,
+ u32 attr, unsigned long data_size,
+ void *data, bool nonblocking)
+{
+ efi_set_variable_t *setvar;
+ efi_status_t status;
+
+ if (data_size > 0) {
+ status = check_var_size(nonblocking, attr,
+ data_size + ucs2_strsize(name, 1024));
+ if (status != EFI_SUCCESS)
+ return status;
+ }
+
+ /*
+ * If no _nonblocking variant exists, the ordinary one
+ * is assumed to be non-blocking.
+ */
+ setvar = __efivars->ops->set_variable_nonblocking;
+ if (!setvar || !nonblocking)
+ setvar = __efivars->ops->set_variable;
+
+ return setvar(name, vendor, attr, data_size, data);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_set_variable_locked, EFIVAR);
+
+/*
+ * efivar_set_variable() - set a variable identified by name/vendor
+ *
+ * Can be called without holding the efivars_lock. Will sleep on obtaining the
+ * lock, or on obtaining other locks that are needed in order to complete the
+ * call.
+ */
+efi_status_t efivar_set_variable(efi_char16_t *name, efi_guid_t *vendor,
+ u32 attr, unsigned long data_size, void *data)
+{
+ efi_status_t status;
+
+ if (efivar_lock())
+ return EFI_ABORTED;
+
+ status = efivar_set_variable_locked(name, vendor, attr, data_size,
+ data, false);
+ efivar_unlock();
+ return status;
+}
+EXPORT_SYMBOL_NS_GPL(efivar_set_variable, EFIVAR);