diff options
Diffstat (limited to 'drivers/platform/x86/dell/dell_rbu.c')
-rw-r--r-- | drivers/platform/x86/dell/dell_rbu.c | 677 |
1 files changed, 677 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell/dell_rbu.c b/drivers/platform/x86/dell/dell_rbu.c new file mode 100644 index 0000000000..9f51e0fcab --- /dev/null +++ b/drivers/platform/x86/dell/dell_rbu.c @@ -0,0 +1,677 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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/admin-guide/dell_rbu.rst for more info. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " 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("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; + 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 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("entry\n"); + + if (!rbu_data.packetsize) { + pr_debug("packetsize not specified\n"); + retval = -EINVAL; + goto out_noalloc; + } + + spin_unlock(&rbu_data.lock); + + newpacket = kzalloc(sizeof (struct packet_data), GFP_KERNEL); + + if (!newpacket) { + pr_warn("failed to allocate new packet\n"); + 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_t(unsigned int, allocation_floor / rbu_data.packetsize, 1); + invalid_addr_packet_array = kcalloc(packet_array_size, sizeof(void *), + GFP_KERNEL); + + if (!invalid_addr_packet_array) { + pr_warn("failed to allocate invalid_addr_packet_array\n"); + 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) { + pr_warn("failed to allocate new packet\n"); + 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; + } + } + /* + * set to uncachable or it may never get written back before reboot + */ + set_memory_uc((unsigned long)packet_data_temp_buf, 1 << ordernum); + + spin_lock(&rbu_data.lock); + + newpacket->data = packet_data_temp_buf; + + pr_debug("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("exit\n"); + +out_alloc_packet_array: + /* always free packet array */ + while (idx--) { + pr_debug("freeing unused packet below floor 0x%lx\n", + (unsigned long)virt_to_phys(invalid_addr_packet_array[idx])); + free_pages((unsigned long)invalid_addr_packet_array[idx], 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("data length %zd\n", length); + if (!rbu_data.packetsize) { + pr_warn("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 packet_data *newpacket, + int length, int bytes_read, int *list_read_count) +{ + void *ptemp_buf; + int bytes_copied = 0; + int j = 0; + + *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 packet_data *newpacket; + 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; + + list_for_each_entry(newpacket, (&packet_data_head.list)->next, list) { + bytes_copied = do_packet_read(pdest, newpacket, + 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; + } + /*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 packet_data *newpacket, *tmp; + + list_for_each_entry_safe(newpacket, tmp, (&packet_data_head.list)->next, list) { + list_del(&newpacket->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); + set_memory_wb((unsigned long)newpacket->data, + 1 << newpacket->ordernum); + 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); + 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; +} + +/* + * 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 img_buf_phys_addr; + int ordernum; + + /* + * 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)) { + pr_err("corruption check failed\n"); + 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_DMA32, ordernum); + spin_lock(&rbu_data.lock); + if (!image_update_buffer) { + pr_debug("Not enough memory for image update: size = %ld\n", size); + return -ENOMEM; + } + + img_buf_phys_addr = (unsigned long)virt_to_phys(image_update_buffer); + if (WARN_ON_ONCE(img_buf_phys_addr > BIOS_SCAN_LIMIT)) + return -EINVAL; /* can't happen per definition */ + + 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; + return 0; +} + +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("no packets written\n"); + retval = -ENOMEM; + goto read_rbu_data_exit; + } + + if (pos > rbu_data.imagesize) { + retval = 0; + pr_warn("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("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 data_read(struct file *filp, 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("invalid image type specified\n"); + + spin_unlock(&rbu_data.lock); + return ret_count; +} +static BIN_ATTR_RO(data, 0); + +static void callbackfn_rbu(const struct firmware *fw, void *context) +{ + rbu_data.entry_created = 0; + + if (!fw) + return; + + if (!fw->size) + goto out; + + 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); + out: + release_firmware(fw); +} + +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) +{ + int size = 0; + if (!pos) + size = scnprintf(buffer, count, "%s\n", image_type); + return size; +} + +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) +{ + 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_NOUEVENT, "dell_rbu", + &rbu_device->dev, GFP_KERNEL, &context, + callbackfn_rbu); + if (req_firm_rc) { + pr_err("request_firmware_nowait failed %d\n", rc); + rc = -EIO; + } else + rbu_data.entry_created = 1; + + spin_lock(&rbu_data.lock); + } + } else { + pr_warn("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 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) +{ + 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 packet_size_write(struct file *filp, 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 BIN_ATTR_RW(packet_size, 0); + +static struct bin_attribute *rbu_bin_attrs[] = { + &bin_attr_data, + &bin_attr_image_type, + &bin_attr_packet_size, + NULL +}; + +static const struct attribute_group rbu_group = { + .bin_attrs = rbu_bin_attrs, +}; + +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", PLATFORM_DEVID_NONE, NULL, 0); + if (IS_ERR(rbu_device)) { + pr_err("platform_device_register_simple failed\n"); + return PTR_ERR(rbu_device); + } + + rc = sysfs_create_group(&rbu_device->dev.kobj, &rbu_group); + if (rc) + goto out_devreg; + + rbu_data.entry_created = 0; + return 0; + +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); + sysfs_remove_group(&rbu_device->dev.kobj, &rbu_group); + platform_device_unregister(rbu_device); +} + +module_exit(dcdrbu_exit); +module_init(dcdrbu_init); |