linux/drivers/firmware/dell_rbu.c
Abhay Salunke 2c5608404e [PATCH] dell_rbu: fix Bug 5854
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=5854

Root cause:

The dell_rbu driver creates entries in /sys/class/firmware/dell_rbu/ by
calling request_firmware_nowait (without hotplug ) this function inturn
starts a kernel thread which creates the entries in
/sys/class/firmware/dell_rbu/loading , data and the thread waits on the
user action to return control back to the callback fucntion of dell_rbu.
The thread calls wait_on_completion which puts it in a D state until the
user action happens.  If there is no user action happening the load average
goes up as the thread D state is taken in to account.  Also after
downloading the BIOS image the enrties go away momentarily but they are
recreated from the callback function in dell_rbu.  This causes the thread
to get recreated causing the load average to permenently stay around 1.

Fix:

The dell_rbu also creates the entry
/sys/devices/platform/dell_rbu/image_type at driver load time.  The image
type by default is mono if required the user can echo packet to image_type
to make the BIOS update mechanism using packets.  Also by echoing init in
to image_type the /sys/class/firmware/dell_rbu entries can be created.

The driver code was changed to not create /sys/class/firmware/dell_rbu
entries during load time, and also to not create the above entries from the
callback function.  The entries are only created by echoing init to
/sys/devices/platform/dell_rbu/image_type The user now needs to create the
entries to download the image monolithic or packet.  This fixes the issue
since the kernel thread only is created when ever the user is ready to
download the BIOS image; this minimizes the life span of the kernel thread
and the load average goes back to normal.

Signed off by Abhay Salunke <abhay_salunke@dell.com>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14 18:27:13 -08:00

745 lines
19 KiB
C

/*
* 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/config.h>
#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", __FUNCTION__);
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",
__FUNCTION__);
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", __FUNCTION__);
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(void *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 %d\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("%lu:%lu\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", __FUNCTION__);
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)
{
unsigned char *ptemp = NULL;
size_t bytes_left = 0;
size_t data_length = 0;
ssize_t ret_count = 0;
/* 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);
ret_count = -ENOMEM;
goto read_rbu_data_exit;
}
if (pos > rbu_data.bios_image_size) {
ret_count = 0;
goto read_rbu_data_exit;
}
bytes_left = rbu_data.bios_image_size - pos;
data_length = min(bytes_left, count);
ptemp = rbu_data.image_update_buffer;
memcpy(buffer, (ptemp + pos), data_length);
if ((pos + count) > rbu_data.bios_image_size)
/* this was the last copy */
ret_count = bytes_left;
else
ret_count = count;
read_rbu_data_exit:
return ret_count;
}
static ssize_t read_rbu_data(struct kobject *kobj, 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, char *buffer,
loff_t pos, size_t count)
{
int size = 0;
if (!pos)
size = sprintf(buffer, "%s\n", image_type);
return size;
}
static ssize_t write_rbu_image_type(struct kobject *kobj, 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", __FUNCTION__, 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, char *buffer,
loff_t pos, size_t count)
{
int size = 0;
if (!pos) {
spin_lock(&rbu_data.lock);
size = sprintf(buffer, "%lu\n", rbu_data.packetsize);
spin_unlock(&rbu_data.lock);
}
return size;
}
static ssize_t write_rbu_packet_size(struct kobject *kobj, 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",.owner = THIS_MODULE,.mode = 0444},
.read = read_rbu_data,
};
static struct bin_attribute rbu_image_type_attr = {
.attr = {.name = "image_type",.owner = THIS_MODULE,.mode = 0644},
.read = read_rbu_image_type,
.write = write_rbu_image_type,
};
static struct bin_attribute rbu_packet_size_attr = {
.attr = {.name = "packet_size",.owner = THIS_MODULE,.mode = 0644},
.read = read_rbu_packet_size,
.write = write_rbu_packet_size,
};
static int __init dcdrbu_init(void)
{
int rc = 0;
spin_lock_init(&rbu_data.lock);
init_packet_head();
rbu_device =
platform_device_register_simple("dell_rbu", -1, NULL, 0);
if (!rbu_device) {
printk(KERN_ERR
"dell_rbu:%s:platform_device_register_simple "
"failed\n", __FUNCTION__);
return -EIO;
}
sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
sysfs_create_bin_file(&rbu_device->dev.kobj,
&rbu_packet_size_attr);
rbu_data.entry_created = 0;
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
*/