// SPDX-License-Identifier: GPL-2.0-only /* * dell_rbu.c * Bios Update driver for Dell systems * Author: Dell Inc * Abhay Salunke <[email protected]> * * Copyright (C) 2005 Dell Inc. * * Remote BIOS Update (rbu) driver is used for updating DELL BIOS by * creating entries in the /sys file systems on Linux 2.6 and higher * kernels. The driver supports two mechanism to update the BIOS namely * contiguous and packetized. Both these methods still require having some * application to set the CMOS bit indicating the BIOS to update itself * after a reboot. * * Contiguous method: * This driver writes the incoming data in a monolithic image by allocating * contiguous physical pages large enough to accommodate the incoming BIOS * image size. * * Packetized method: * The driver writes the incoming packet image by allocating a new packet * on every time the packet data is written. This driver requires an * application to break the BIOS image in to fixed sized packet chunks. * * See Documentation/admin-guide/dell_rbu.rst for more info. */ #define pr_fmt(fmt) … #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/blkdev.h> #include <linux/platform_device.h> #include <linux/spinlock.h> #include <linux/moduleparam.h> #include <linux/firmware.h> #include <linux/dma-mapping.h> #include <asm/set_memory.h> MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_VERSION(…) …; #define BIOS_SCAN_LIMIT … #define MAX_IMAGE_LENGTH … static struct _rbu_data { … } rbu_data; static char image_type[MAX_IMAGE_LENGTH + 1] = …; module_param_string(…); MODULE_PARM_DESC(…) …; static unsigned long allocation_floor = …; module_param(allocation_floor, ulong, 0644); MODULE_PARM_DESC(…) …; struct packet_data { … }; static struct packet_data packet_data_head; static struct platform_device *rbu_device; static int context; static void init_packet_head(void) { … } static int create_packet(void *data, size_t length) { … } static int packetize_data(const u8 *data, size_t length) { … } static int do_packet_read(char *data, struct packet_data *newpacket, int length, int bytes_read, int *list_read_count) { … } static int packet_read_list(char *data, size_t * pread_length) { … } static void packet_empty_list(void) { … } /* * img_update_free: Frees the buffer allocated for storing BIOS image * Always called with lock held and returned with lock held */ static void img_update_free(void) { … } /* * img_update_realloc: This function allocates the contiguous pages to * accommodate the requested size of data. The memory address and size * values are stored globally and on every call to this function the new * size is checked to see if more data is required than the existing size. * If true the previous memory is freed and new allocation is done to * accommodate the new size. If the incoming size is less then than the * already allocated size, then that memory is reused. This function is * called with lock held and returns with lock held. */ static int img_update_realloc(unsigned long size) { … } static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count) { … } static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count) { … } static ssize_t data_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { … } static BIN_ATTR_RO(data, 0); static void callbackfn_rbu(const struct firmware *fw, void *context) { … } static ssize_t image_type_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { … } static ssize_t image_type_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { … } static BIN_ATTR_RW(image_type, 0); static ssize_t packet_size_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { … } static ssize_t packet_size_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { … } static BIN_ATTR_RW(packet_size, 0); static struct bin_attribute *rbu_bin_attrs[] = …; static const struct attribute_group rbu_group = …; static int __init dcdrbu_init(void) { … } static __exit void dcdrbu_exit(void) { … } module_exit(dcdrbu_exit); module_init(…) …;
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