/* * dell_rbu.c * Bios Update driver for Dell systems * Author: Dell Inc * Abhay Salunke <abhay_salunke@dell.com> * * 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/dell_rbu.txt for more info. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2.0 as published by * the Free Software Foundation * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/init.h> #include <linux/module.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> MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>"); MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems"); MODULE_LICENSE("GPL"); MODULE_VERSION("3.2"); #define BIOS_SCAN_LIMIT 0xffffffff #define MAX_IMAGE_LENGTH 16 static struct _rbu_data { void *image_update_buffer; unsigned long image_update_buffer_size; unsigned long bios_image_size; int image_update_ordernum; int dma_alloc; spinlock_t lock; unsigned long packet_read_count; unsigned long num_packets; unsigned long packetsize; unsigned long imagesize; int entry_created; } rbu_data; static char image_type[MAX_IMAGE_LENGTH + 1] = "mono"; module_param_string(image_type, image_type, sizeof (image_type), 0); MODULE_PARM_DESC(image_type, "BIOS image type. choose- mono or packet or init"); static unsigned long allocation_floor = 0x100000; module_param(allocation_floor, ulong, 0644); MODULE_PARM_DESC(allocation_floor, "Minimum address for allocations when using Packet mode"); struct packet_data { struct list_head list; size_t length; void *data; int ordernum; }; static struct packet_data packet_data_head; static struct platform_device *rbu_device; static int context; static dma_addr_t dell_rbu_dmaaddr; static void init_packet_head(void) { INIT_LIST_HEAD(&packet_data_head.list); rbu_data.packet_read_count = 0; rbu_data.num_packets = 0; rbu_data.packetsize = 0; rbu_data.imagesize = 0; } static int create_packet(void *data, size_t length) { struct packet_data *newpacket; int ordernum = 0; int retval = 0; unsigned int packet_array_size = 0; void **invalid_addr_packet_array = NULL; void *packet_data_temp_buf = NULL; unsigned int idx = 0; pr_debug("create_packet: entry \n"); if (!rbu_data.packetsize) { pr_debug("create_packet: packetsize not specified\n"); retval = -EINVAL; goto out_noalloc; } spin_unlock(&rbu_data.lock); newpacket = kzalloc(sizeof (struct packet_data), GFP_KERNEL); if (!newpacket) { printk(KERN_WARNING "dell_rbu:%s: failed to allocate new " "packet\n", __func__); retval = -ENOMEM; spin_lock(&rbu_data.lock); goto out_noalloc; } ordernum = get_order(length); /* * BIOS errata mean we cannot allocate packets below 1MB or they will * be overwritten by BIOS. * * array to temporarily hold packets * that are below the allocation floor * * NOTE: very simplistic because we only need the floor to be at 1MB * due to BIOS errata. This shouldn't be used for higher floors * or you will run out of mem trying to allocate the array. */ packet_array_size = max( (unsigned int)(allocation_floor / rbu_data.packetsize), (unsigned int)1); invalid_addr_packet_array = kzalloc(packet_array_size * sizeof(void*), GFP_KERNEL); if (!invalid_addr_packet_array) { printk(KERN_WARNING "dell_rbu:%s: failed to allocate " "invalid_addr_packet_array \n", __func__); retval = -ENOMEM; spin_lock(&rbu_data.lock); goto out_alloc_packet; } while (!packet_data_temp_buf) { packet_data_temp_buf = (unsigned char *) __get_free_pages(GFP_KERNEL, ordernum); if (!packet_data_temp_buf) { printk(KERN_WARNING "dell_rbu:%s: failed to allocate new " "packet\n", __func__); retval = -ENOMEM; spin_lock(&rbu_data.lock); goto out_alloc_packet_array; } if ((unsigned long)virt_to_phys(packet_data_temp_buf) < allocation_floor) { pr_debug("packet 0x%lx below floor at 0x%lx.\n", (unsigned long)virt_to_phys( packet_data_temp_buf), allocation_floor); invalid_addr_packet_array[idx++] = packet_data_temp_buf; packet_data_temp_buf = NULL; } } spin_lock(&rbu_data.lock); newpacket->data = packet_data_temp_buf; pr_debug("create_packet: newpacket at physical addr %lx\n", (unsigned long)virt_to_phys(newpacket->data)); /* packets may not have fixed size */ newpacket->length = length; newpacket->ordernum = ordernum; ++rbu_data.num_packets; /* initialize the newly created packet headers */ INIT_LIST_HEAD(&newpacket->list); list_add_tail(&newpacket->list, &packet_data_head.list); memcpy(newpacket->data, data, length); pr_debug("create_packet: exit \n"); out_alloc_packet_array: /* always free packet array */ for (;idx>0;idx--) { pr_debug("freeing unused packet below floor 0x%lx.\n", (unsigned long)virt_to_phys( invalid_addr_packet_array[idx-1])); free_pages((unsigned long)invalid_addr_packet_array[idx-1], ordernum); } kfree(invalid_addr_packet_array); out_alloc_packet: /* if error, free data */ if (retval) kfree(newpacket); out_noalloc: return retval; } static int packetize_data(const u8 *data, size_t length) { int rc = 0; int done = 0; int packet_length; u8 *temp; u8 *end = (u8 *) data + length; pr_debug("packetize_data: data length %zd\n", length); if (!rbu_data.packetsize) { printk(KERN_WARNING "dell_rbu: packetsize not specified\n"); return -EIO; } temp = (u8 *) data; /* packetize the hunk */ while (!done) { if ((temp + rbu_data.packetsize) < end) packet_length = rbu_data.packetsize; else { /* this is the last packet */ packet_length = end - temp; done = 1; } if ((rc = create_packet(temp, packet_length))) return rc; pr_debug("%p:%td\n", temp, (end - temp)); temp += packet_length; } rbu_data.imagesize = length; return rc; } static int do_packet_read(char *data, struct list_head *ptemp_list, int length, int bytes_read, int *list_read_count) { void *ptemp_buf; struct packet_data *newpacket = NULL; int bytes_copied = 0; int j = 0; newpacket = list_entry(ptemp_list, struct packet_data, list); *list_read_count += newpacket->length; if (*list_read_count > bytes_read) { /* point to the start of unread data */ j = newpacket->length - (*list_read_count - bytes_read); /* point to the offset in the packet buffer */ ptemp_buf = (u8 *) newpacket->data + j; /* * check if there is enough room in * * the incoming buffer */ if (length > (*list_read_count - bytes_read)) /* * copy what ever is there in this * packet and move on */ bytes_copied = (*list_read_count - bytes_read); else /* copy the remaining */ bytes_copied = length; memcpy(data, ptemp_buf, bytes_copied); } return bytes_copied; } static int packet_read_list(char *data, size_t * pread_length) { struct list_head *ptemp_list; int temp_count = 0; int bytes_copied = 0; int bytes_read = 0; int remaining_bytes = 0; char *pdest = data; /* check if we have any packets */ if (0 == rbu_data.num_packets) return -ENOMEM; remaining_bytes = *pread_length; bytes_read = rbu_data.packet_read_count; ptemp_list = (&packet_data_head.list)->next; while (!list_empty(ptemp_list)) { bytes_copied = do_packet_read(pdest, ptemp_list, remaining_bytes, bytes_read, &temp_count); remaining_bytes -= bytes_copied; bytes_read += bytes_copied; pdest += bytes_copied; /* * check if we reached end of buffer before reaching the * last packet */ if (remaining_bytes == 0) break; ptemp_list = ptemp_list->next; } /*finally set the bytes read */ *pread_length = bytes_read - rbu_data.packet_read_count; rbu_data.packet_read_count = bytes_read; return 0; } static void packet_empty_list(void) { struct list_head *ptemp_list; struct list_head *pnext_list; struct packet_data *newpacket; ptemp_list = (&packet_data_head.list)->next; while (!list_empty(ptemp_list)) { newpacket = list_entry(ptemp_list, struct packet_data, list); pnext_list = ptemp_list->next; list_del(ptemp_list); ptemp_list = pnext_list; /* * zero out the RBU packet memory before freeing * to make sure there are no stale RBU packets left in memory */ memset(newpacket->data, 0, rbu_data.packetsize); free_pages((unsigned long) newpacket->data, newpacket->ordernum); kfree(newpacket); } rbu_data.packet_read_count = 0; rbu_data.num_packets = 0; rbu_data.imagesize = 0; } /* * 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) { if (!rbu_data.image_update_buffer) return; /* * zero out this buffer before freeing it to get rid of any stale * BIOS image copied in memory. */ memset(rbu_data.image_update_buffer, 0, rbu_data.image_update_buffer_size); if (rbu_data.dma_alloc == 1) dma_free_coherent(NULL, rbu_data.bios_image_size, rbu_data.image_update_buffer, dell_rbu_dmaaddr); else free_pages((unsigned long) rbu_data.image_update_buffer, rbu_data.image_update_ordernum); /* * Re-initialize the rbu_data variables after a free */ rbu_data.image_update_ordernum = -1; rbu_data.image_update_buffer = NULL; rbu_data.image_update_buffer_size = 0; rbu_data.bios_image_size = 0; rbu_data.dma_alloc = 0; } /* * 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) { unsigned char *image_update_buffer = NULL; unsigned long rc; unsigned long img_buf_phys_addr; int ordernum; int dma_alloc = 0; /* * check if the buffer of sufficient size has been * already allocated */ if (rbu_data.image_update_buffer_size >= size) { /* * check for corruption */ if ((size != 0) && (rbu_data.image_update_buffer == NULL)) { printk(KERN_ERR "dell_rbu:%s: corruption " "check failed\n", __func__); return -EINVAL; } /* * we have a valid pre-allocated buffer with * sufficient size */ return 0; } /* * free any previously allocated buffer */ img_update_free(); spin_unlock(&rbu_data.lock); ordernum = get_order(size); image_update_buffer = (unsigned char *) __get_free_pages(GFP_KERNEL, ordernum); img_buf_phys_addr = (unsigned long) virt_to_phys(image_update_buffer); if (img_buf_phys_addr > BIOS_SCAN_LIMIT) { free_pages((unsigned long) image_update_buffer, ordernum); ordernum = -1; image_update_buffer = dma_alloc_coherent(NULL, size, &dell_rbu_dmaaddr, GFP_KERNEL); dma_alloc = 1; } spin_lock(&rbu_data.lock); if (image_update_buffer != NULL) { rbu_data.image_update_buffer = image_update_buffer; rbu_data.image_update_buffer_size = size; rbu_data.bios_image_size = rbu_data.image_update_buffer_size; rbu_data.image_update_ordernum = ordernum; rbu_data.dma_alloc = dma_alloc; rc = 0; } else { pr_debug("Not enough memory for image update:" "size = %ld\n", size); rc = -ENOMEM; } return rc; } static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count) { int retval; size_t bytes_left; size_t data_length; char *ptempBuf = buffer; /* check to see if we have something to return */ if (rbu_data.num_packets == 0) { pr_debug("read_packet_data: no packets written\n"); retval = -ENOMEM; goto read_rbu_data_exit; } if (pos > rbu_data.imagesize) { retval = 0; printk(KERN_WARNING "dell_rbu:read_packet_data: " "data underrun\n"); goto read_rbu_data_exit; } bytes_left = rbu_data.imagesize - pos; data_length = min(bytes_left, count); if ((retval = packet_read_list(ptempBuf, &data_length)) < 0) goto read_rbu_data_exit; if ((pos + count) > rbu_data.imagesize) { rbu_data.packet_read_count = 0; /* this was the last copy */ retval = bytes_left; } else retval = count; read_rbu_data_exit: return retval; } static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count) { /* check to see if we have something to return */ if ((rbu_data.image_update_buffer == NULL) || (rbu_data.bios_image_size == 0)) { pr_debug("read_rbu_data_mono: image_update_buffer %p ," "bios_image_size %lu\n", rbu_data.image_update_buffer, rbu_data.bios_image_size); return -ENOMEM; } return memory_read_from_buffer(buffer, count, &pos, rbu_data.image_update_buffer, rbu_data.bios_image_size); } static ssize_t read_rbu_data(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { ssize_t ret_count = 0; spin_lock(&rbu_data.lock); if (!strcmp(image_type, "mono")) ret_count = read_rbu_mono_data(buffer, pos, count); else if (!strcmp(image_type, "packet")) ret_count = read_packet_data(buffer, pos, count); else pr_debug("read_rbu_data: invalid image type specified\n"); spin_unlock(&rbu_data.lock); return ret_count; } static void callbackfn_rbu(const struct firmware *fw, void *context) { rbu_data.entry_created = 0; if (!fw || !fw->size) return; spin_lock(&rbu_data.lock); if (!strcmp(image_type, "mono")) { if (!img_update_realloc(fw->size)) memcpy(rbu_data.image_update_buffer, fw->data, fw->size); } else if (!strcmp(image_type, "packet")) { /* * we need to free previous packets if a * new hunk of packets needs to be downloaded */ packet_empty_list(); if (packetize_data(fw->data, fw->size)) /* Incase something goes wrong when we are * in middle of packetizing the data, we * need to free up whatever packets might * have been created before we quit. */ packet_empty_list(); } else pr_debug("invalid image type specified.\n"); spin_unlock(&rbu_data.lock); } static ssize_t read_rbu_image_type(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { int size = 0; if (!pos) size = scnprintf(buffer, count, "%s\n", image_type); return size; } static ssize_t write_rbu_image_type(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { int rc = count; int req_firm_rc = 0; int i; spin_lock(&rbu_data.lock); /* * Find the first newline or space */ for (i = 0; i < count; ++i) if (buffer[i] == '\n' || buffer[i] == ' ') { buffer[i] = '\0'; break; } if (i == count) buffer[count] = '\0'; if (strstr(buffer, "mono")) strcpy(image_type, "mono"); else if (strstr(buffer, "packet")) strcpy(image_type, "packet"); else if (strstr(buffer, "init")) { /* * If due to the user error the driver gets in a bad * state where even though it is loaded , the * /sys/class/firmware/dell_rbu entries are missing. * to cover this situation the user can recreate entries * by writing init to image_type. */ if (!rbu_data.entry_created) { spin_unlock(&rbu_data.lock); req_firm_rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, "dell_rbu", &rbu_device->dev, &context, callbackfn_rbu); if (req_firm_rc) { printk(KERN_ERR "dell_rbu:%s request_firmware_nowait" " failed %d\n", __func__, rc); rc = -EIO; } else rbu_data.entry_created = 1; spin_lock(&rbu_data.lock); } } else { printk(KERN_WARNING "dell_rbu: image_type is invalid\n"); spin_unlock(&rbu_data.lock); return -EINVAL; } /* we must free all previous allocations */ packet_empty_list(); img_update_free(); spin_unlock(&rbu_data.lock); return rc; } static ssize_t read_rbu_packet_size(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { int size = 0; if (!pos) { spin_lock(&rbu_data.lock); size = scnprintf(buffer, count, "%lu\n", rbu_data.packetsize); spin_unlock(&rbu_data.lock); } return size; } static ssize_t write_rbu_packet_size(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t count) { unsigned long temp; spin_lock(&rbu_data.lock); packet_empty_list(); sscanf(buffer, "%lu", &temp); if (temp < 0xffffffff) rbu_data.packetsize = temp; spin_unlock(&rbu_data.lock); return count; } static struct bin_attribute rbu_data_attr = { .attr = {.name = "data", .mode = 0444}, .read = read_rbu_data, }; static struct bin_attribute rbu_image_type_attr = { .attr = {.name = "image_type", .mode = 0644}, .read = read_rbu_image_type, .write = write_rbu_image_type, }; static struct bin_attribute rbu_packet_size_attr = { .attr = {.name = "packet_size", .mode = 0644}, .read = read_rbu_packet_size, .write = write_rbu_packet_size, }; static int __init dcdrbu_init(void) { int rc; spin_lock_init(&rbu_data.lock); init_packet_head(); rbu_device = platform_device_register_simple("dell_rbu", -1, NULL, 0); if (IS_ERR(rbu_device)) { printk(KERN_ERR "dell_rbu:%s:platform_device_register_simple " "failed\n", __func__); return PTR_ERR(rbu_device); } rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr); if (rc) goto out_devreg; rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr); if (rc) goto out_data; rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_packet_size_attr); if (rc) goto out_imtype; rbu_data.entry_created = 0; return 0; out_imtype: sysfs_remove_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr); out_data: sysfs_remove_bin_file(&rbu_device->dev.kobj, &rbu_data_attr); out_devreg: platform_device_unregister(rbu_device); return rc; } static __exit void dcdrbu_exit(void) { spin_lock(&rbu_data.lock); packet_empty_list(); img_update_free(); spin_unlock(&rbu_data.lock); platform_device_unregister(rbu_device); } module_exit(dcdrbu_exit); module_init(dcdrbu_init); /* vim:noet:ts=8:sw=8 */