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alistair23-linux/drivers/watchdog/hpwdt.c
Linus Torvalds 1f6ef23429 [watchdog] hpwdt: fix use of inline assembly 
The inline assembly in drivers/watchdog/hpwdt.c was incredibly broken,
and included all the function prologue and epilogue stuff, even though
it was itself then inside a C function where the compiler would add its
own prologue and epilogue on top of it all.

This then just _happened_ to work if you had exactly the right compiler
version and exactly the right compiler flags, so that gcc just happened
to not create any prologue at all (the gcc-generated epilogue wouldn't
matter, since it would never be reached).

But the more proper way to fix it is to simply not do this.  Move the
inline asm to the top level, with no surrounding function at all (the
better alternative would be to remove the prologue and make it actually
use proper description of the arguments to the inline asm, but that's a
bigger change than the one I'm willing to make right now).

Tested-by: S.Çağlar Onur <caglar@pardus.org.tr>
Acked-by: Thomas Mingarelli <Thomas.Mingarelli@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20 12:25:34 -07:00

766 lines
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/*
* HP WatchDog Driver
* based on
*
* SoftDog 0.05: A Software Watchdog Device
*
* (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
* Thomas Mingarelli <thomas.mingarelli@hp.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation
*
*/
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/kdebug.h>
#include <linux/moduleparam.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/string.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <asm/dmi.h>
#include <asm/desc.h>
#include <asm/kdebug.h>
#define PCI_BIOS32_SD_VALUE 0x5F32335F /* "_32_" */
#define CRU_BIOS_SIGNATURE_VALUE 0x55524324
#define PCI_BIOS32_PARAGRAPH_LEN 16
#define PCI_ROM_BASE1 0x000F0000
#define ROM_SIZE 0x10000
struct bios32_service_dir {
u32 signature;
u32 entry_point;
u8 revision;
u8 length;
u8 checksum;
u8 reserved[5];
};
/* type 212 */
struct smbios_cru64_info {
u8 type;
u8 byte_length;
u16 handle;
u32 signature;
u64 physical_address;
u32 double_length;
u32 double_offset;
};
#define SMBIOS_CRU64_INFORMATION 212
struct cmn_registers {
union {
struct {
u8 ral;
u8 rah;
u16 rea2;
};
u32 reax;
} u1;
union {
struct {
u8 rbl;
u8 rbh;
u8 reb2l;
u8 reb2h;
};
u32 rebx;
} u2;
union {
struct {
u8 rcl;
u8 rch;
u16 rec2;
};
u32 recx;
} u3;
union {
struct {
u8 rdl;
u8 rdh;
u16 red2;
};
u32 redx;
} u4;
u32 resi;
u32 redi;
u16 rds;
u16 res;
u32 reflags;
} __attribute__((packed));
#define DEFAULT_MARGIN 30
static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
static unsigned int reload; /* the computed soft_margin */
static int nowayout = WATCHDOG_NOWAYOUT;
static char expect_release;
static unsigned long hpwdt_is_open;
static void __iomem *pci_mem_addr; /* the PCI-memory address */
static unsigned long __iomem *hpwdt_timer_reg;
static unsigned long __iomem *hpwdt_timer_con;
static DEFINE_SPINLOCK(rom_lock);
static void *cru_rom_addr;
static struct cmn_registers cmn_regs;
static struct pci_device_id hpwdt_devices[] = {
{
.vendor = PCI_VENDOR_ID_COMPAQ,
.device = 0xB203,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
},
{0}, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, hpwdt_devices);
extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs, unsigned long *pRomEntry);
#ifndef CONFIG_X86_64
/* --32 Bit Bios------------------------------------------------------------ */
#define HPWDT_ARCH 32
asm(".text \n\t"
".align 4 \n"
"asminline_call: \n\t"
"pushl %ebp \n\t"
"movl %esp, %ebp \n\t"
"pusha \n\t"
"pushf \n\t"
"push %es \n\t"
"push %ds \n\t"
"pop %es \n\t"
"movl 8(%ebp),%eax \n\t"
"movl 4(%eax),%ebx \n\t"
"movl 8(%eax),%ecx \n\t"
"movl 12(%eax),%edx \n\t"
"movl 16(%eax),%esi \n\t"
"movl 20(%eax),%edi \n\t"
"movl (%eax),%eax \n\t"
"push %cs \n\t"
"call *12(%ebp) \n\t"
"pushf \n\t"
"pushl %eax \n\t"
"movl 8(%ebp),%eax \n\t"
"movl %ebx,4(%eax) \n\t"
"movl %ecx,8(%eax) \n\t"
"movl %edx,12(%eax) \n\t"
"movl %esi,16(%eax) \n\t"
"movl %edi,20(%eax) \n\t"
"movw %ds,24(%eax) \n\t"
"movw %es,26(%eax) \n\t"
"popl %ebx \n\t"
"movl %ebx,(%eax) \n\t"
"popl %ebx \n\t"
"movl %ebx,28(%eax) \n\t"
"pop %es \n\t"
"popf \n\t"
"popa \n\t"
"leave \n\t"
"ret \n\t"
".previous");
/*
* cru_detect
*
* Routine Description:
* This function uses the 32-bit BIOS Service Directory record to
* search for a $CRU record.
*
* Return Value:
* 0 : SUCCESS
* <0 : FAILURE
*/
static int __devinit cru_detect(unsigned long map_entry,
unsigned long map_offset)
{
void *bios32_map;
unsigned long *bios32_entrypoint;
unsigned long cru_physical_address;
unsigned long cru_length;
unsigned long physical_bios_base = 0;
unsigned long physical_bios_offset = 0;
int retval = -ENODEV;
bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
if (bios32_map == NULL)
return -ENODEV;
bios32_entrypoint = bios32_map + map_offset;
cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
asminline_call(&cmn_regs, bios32_entrypoint);
if (cmn_regs.u1.ral != 0) {
printk(KERN_WARNING
"hpwdt: Call succeeded but with an error: 0x%x\n",
cmn_regs.u1.ral);
} else {
physical_bios_base = cmn_regs.u2.rebx;
physical_bios_offset = cmn_regs.u4.redx;
cru_length = cmn_regs.u3.recx;
cru_physical_address =
physical_bios_base + physical_bios_offset;
/* If the values look OK, then map it in. */
if ((physical_bios_base + physical_bios_offset)) {
cru_rom_addr =
ioremap(cru_physical_address, cru_length);
if (cru_rom_addr)
retval = 0;
}
printk(KERN_DEBUG "hpwdt: CRU Base Address: 0x%lx\n",
physical_bios_base);
printk(KERN_DEBUG "hpwdt: CRU Offset Address: 0x%lx\n",
physical_bios_offset);
printk(KERN_DEBUG "hpwdt: CRU Length: 0x%lx\n",
cru_length);
printk(KERN_DEBUG "hpwdt: CRU Mapped Address: 0x%x\n",
(unsigned int)&cru_rom_addr);
}
iounmap(bios32_map);
return retval;
}
/*
* bios_checksum
*/
static int __devinit bios_checksum(const char __iomem *ptr, int len)
{
char sum = 0;
int i;
/*
* calculate checksum of size bytes. This should add up
* to zero if we have a valid header.
*/
for (i = 0; i < len; i++)
sum += ptr[i];
return ((sum == 0) && (len > 0));
}
/*
* bios32_present
*
* Routine Description:
* This function finds the 32-bit BIOS Service Directory
*
* Return Value:
* 0 : SUCCESS
* <0 : FAILURE
*/
static int __devinit bios32_present(const char __iomem *p)
{
struct bios32_service_dir *bios_32_ptr;
int length;
unsigned long map_entry, map_offset;
bios_32_ptr = (struct bios32_service_dir *) p;
/*
* Search for signature by checking equal to the swizzled value
* instead of calling another routine to perform a strcmp.
*/
if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
if (bios_checksum(p, length)) {
/*
* According to the spec, we're looking for the
* first 4KB-aligned address below the entrypoint
* listed in the header. The Service Directory code
* is guaranteed to occupy no more than 2 4KB pages.
*/
map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
map_offset = bios_32_ptr->entry_point - map_entry;
return cru_detect(map_entry, map_offset);
}
}
return -ENODEV;
}
static int __devinit detect_cru_service(void)
{
char __iomem *p, *q;
int rc = -1;
/*
* Search from 0x0f0000 through 0x0fffff, inclusive.
*/
p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
if (p == NULL)
return -ENOMEM;
for (q = p; q < p + ROM_SIZE; q += 16) {
rc = bios32_present(q);
if (!rc)
break;
}
iounmap(p);
return rc;
}
#else
/* --64 Bit Bios------------------------------------------------------------ */
#define HPWDT_ARCH 64
asm(".text \n\t"
".align 4 \n"
"asminline_call: \n\t"
"pushq %rbp \n\t"
"movq %rsp, %rbp \n\t"
"pushq %rax \n\t"
"pushq %rbx \n\t"
"pushq %rdx \n\t"
"pushq %r12 \n\t"
"pushq %r9 \n\t"
"movq %rsi, %r12 \n\t"
"movq %rdi, %r9 \n\t"
"movl 4(%r9),%ebx \n\t"
"movl 8(%r9),%ecx \n\t"
"movl 12(%r9),%edx \n\t"
"movl 16(%r9),%esi \n\t"
"movl 20(%r9),%edi \n\t"
"movl (%r9),%eax \n\t"
"call *%r12 \n\t"
"pushfq \n\t"
"popq %r12 \n\t"
"popfq \n\t"
"movl %eax, (%r9) \n\t"
"movl %ebx, 4(%r9) \n\t"
"movl %ecx, 8(%r9) \n\t"
"movl %edx, 12(%r9) \n\t"
"movl %esi, 16(%r9) \n\t"
"movl %edi, 20(%r9) \n\t"
"movq %r12, %rax \n\t"
"movl %eax, 28(%r9) \n\t"
"popq %r9 \n\t"
"popq %r12 \n\t"
"popq %rdx \n\t"
"popq %rbx \n\t"
"popq %rax \n\t"
"leave \n\t"
"ret \n\t"
".previous");
/*
* dmi_find_cru
*
* Routine Description:
* This function checks whether or not a SMBIOS/DMI record is
* the 64bit CRU info or not
*/
static void __devinit dmi_find_cru(const struct dmi_header *dm)
{
struct smbios_cru64_info *smbios_cru64_ptr;
unsigned long cru_physical_address;
if (dm->type == SMBIOS_CRU64_INFORMATION) {
smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
cru_physical_address =
smbios_cru64_ptr->physical_address +
smbios_cru64_ptr->double_offset;
cru_rom_addr = ioremap(cru_physical_address,
smbios_cru64_ptr->double_length);
}
}
}
static int __devinit detect_cru_service(void)
{
cru_rom_addr = NULL;
dmi_walk(dmi_find_cru);
/* if cru_rom_addr has been set then we found a CRU service */
return ((cru_rom_addr != NULL)? 0: -ENODEV);
}
/* ------------------------------------------------------------------------- */
#endif
/*
* NMI Handler
*/
static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
void *data)
{
static unsigned long rom_pl;
static int die_nmi_called;
if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
return NOTIFY_OK;
spin_lock_irqsave(&rom_lock, rom_pl);
if (!die_nmi_called)
asminline_call(&cmn_regs, cru_rom_addr);
die_nmi_called = 1;
spin_unlock_irqrestore(&rom_lock, rom_pl);
if (cmn_regs.u1.ral == 0) {
printk(KERN_WARNING "hpwdt: An NMI occurred, "
"but unable to determine source.\n");
} else {
panic("An NMI occurred, please see the Integrated "
"Management Log for details.\n");
}
return NOTIFY_STOP;
}
/*
* Watchdog operations
*/
static void hpwdt_start(void)
{
reload = (soft_margin * 1000) / 128;
iowrite16(reload, hpwdt_timer_reg);
iowrite16(0x85, hpwdt_timer_con);
}
static void hpwdt_stop(void)
{
unsigned long data;
data = ioread16(hpwdt_timer_con);
data &= 0xFE;
iowrite16(data, hpwdt_timer_con);
}
static void hpwdt_ping(void)
{
iowrite16(reload, hpwdt_timer_reg);
}
static int hpwdt_change_timer(int new_margin)
{
/* Arbitrary, can't find the card's limits */
if (new_margin < 30 || new_margin > 600) {
printk(KERN_WARNING
"hpwdt: New value passed in is invalid: %d seconds.\n",
new_margin);
return -EINVAL;
}
soft_margin = new_margin;
printk(KERN_DEBUG
"hpwdt: New timer passed in is %d seconds.\n",
new_margin);
reload = (soft_margin * 1000) / 128;
return 0;
}
/*
* /dev/watchdog handling
*/
static int hpwdt_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &hpwdt_is_open))
return -EBUSY;
/* Start the watchdog */
hpwdt_start();
hpwdt_ping();
return nonseekable_open(inode, file);
}
static int hpwdt_release(struct inode *inode, struct file *file)
{
/* Stop the watchdog */
if (expect_release == 42) {
hpwdt_stop();
} else {
printk(KERN_CRIT
"hpwdt: Unexpected close, not stopping watchdog!\n");
hpwdt_ping();
}
expect_release = 0;
/* /dev/watchdog is being closed, make sure it can be re-opened */
clear_bit(0, &hpwdt_is_open);
return 0;
}
static ssize_t hpwdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (len) {
if (!nowayout) {
size_t i;
/* note: just in case someone wrote the magic character
* five months ago... */
expect_release = 0;
/* scan to see whether or not we got the magic char. */
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data+i))
return -EFAULT;
if (c == 'V')
expect_release = 42;
}
}
/* someone wrote to us, we should reload the timer */
hpwdt_ping();
}
return len;
}
static struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "HP iLO2 HW Watchdog Timer",
};
static long hpwdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_margin;
int ret = -ENOTTY;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = 0;
if (copy_to_user(argp, &ident, sizeof(ident)))
ret = -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, p);
break;
case WDIOC_KEEPALIVE:
hpwdt_ping();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(new_margin, p);
if (ret)
break;
ret = hpwdt_change_timer(new_margin);
if (ret)
break;
hpwdt_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
ret = put_user(soft_margin, p);
break;
}
return ret;
}
/*
* Kernel interfaces
*/
static struct file_operations hpwdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = hpwdt_write,
.unlocked_ioctl = hpwdt_ioctl,
.open = hpwdt_open,
.release = hpwdt_release,
};
static struct miscdevice hpwdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &hpwdt_fops,
};
static struct notifier_block die_notifier = {
.notifier_call = hpwdt_pretimeout,
.priority = 0x7FFFFFFF,
};
/*
* Init & Exit
*/
static int __devinit hpwdt_init_one(struct pci_dev *dev,
const struct pci_device_id *ent)
{
int retval;
/*
* First let's find out if we are on an iLO2 server. We will
* not run on a legacy ASM box.
*/
if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
dev_warn(&dev->dev,
"This server does not have an iLO2 ASIC.\n");
return -ENODEV;
}
if (pci_enable_device(dev)) {
dev_warn(&dev->dev,
"Not possible to enable PCI Device: 0x%x:0x%x.\n",
ent->vendor, ent->device);
return -ENODEV;
}
pci_mem_addr = pci_iomap(dev, 1, 0x80);
if (!pci_mem_addr) {
dev_warn(&dev->dev,
"Unable to detect the iLO2 server memory.\n");
retval = -ENOMEM;
goto error_pci_iomap;
}
hpwdt_timer_reg = pci_mem_addr + 0x70;
hpwdt_timer_con = pci_mem_addr + 0x72;
/* Make sure that we have a valid soft_margin */
if (hpwdt_change_timer(soft_margin))
hpwdt_change_timer(DEFAULT_MARGIN);
/*
* We need to map the ROM to get the CRU service.
* For 32 bit Operating Systems we need to go through the 32 Bit
* BIOS Service Directory
* For 64 bit Operating Systems we get that service through SMBIOS.
*/
retval = detect_cru_service();
if (retval < 0) {
dev_warn(&dev->dev,
"Unable to detect the %d Bit CRU Service.\n",
HPWDT_ARCH);
goto error_get_cru;
}
/*
* We know this is the only CRU call we need to make so lets keep as
* few instructions as possible once the NMI comes in.
*/
cmn_regs.u1.rah = 0x0D;
cmn_regs.u1.ral = 0x02;
retval = register_die_notifier(&die_notifier);
if (retval != 0) {
dev_warn(&dev->dev,
"Unable to register a die notifier (err=%d).\n",
retval);
goto error_die_notifier;
}
retval = misc_register(&hpwdt_miscdev);
if (retval < 0) {
dev_warn(&dev->dev,
"Unable to register miscdev on minor=%d (err=%d).\n",
WATCHDOG_MINOR, retval);
goto error_misc_register;
}
printk(KERN_INFO
"hp Watchdog Timer Driver: 1.00"
", timer margin: %d seconds( nowayout=%d).\n",
soft_margin, nowayout);
return 0;
error_misc_register:
unregister_die_notifier(&die_notifier);
error_die_notifier:
if (cru_rom_addr)
iounmap(cru_rom_addr);
error_get_cru:
pci_iounmap(dev, pci_mem_addr);
error_pci_iomap:
pci_disable_device(dev);
return retval;
}
static void __devexit hpwdt_exit(struct pci_dev *dev)
{
if (!nowayout)
hpwdt_stop();
misc_deregister(&hpwdt_miscdev);
unregister_die_notifier(&die_notifier);
if (cru_rom_addr)
iounmap(cru_rom_addr);
pci_iounmap(dev, pci_mem_addr);
pci_disable_device(dev);
}
static struct pci_driver hpwdt_driver = {
.name = "hpwdt",
.id_table = hpwdt_devices,
.probe = hpwdt_init_one,
.remove = __devexit_p(hpwdt_exit),
};
static void __exit hpwdt_cleanup(void)
{
pci_unregister_driver(&hpwdt_driver);
}
static int __init hpwdt_init(void)
{
return pci_register_driver(&hpwdt_driver);
}
MODULE_AUTHOR("Tom Mingarelli");
MODULE_DESCRIPTION("hp watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
module_param(soft_margin, int, 0);
MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
module_init(hpwdt_init);
module_exit(hpwdt_cleanup);
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