49ab972aea
commit ab772027 (sparc: arch/sparc/kernel/apc.c to unlocked_ioctl)
added lock/unlock_kernel() to the apc ioctl code.
The code needs no serialization at all. Neither put/get_user nor the
read/write access to the sbus devices require it. Remove BKL.
cycle_kernel_lock() was added during the big BKL pushdown. It should
ensure the serializiation against driver init code. In this case there
is nothing to serialize. Remove it as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
191 lines
4.1 KiB
C
191 lines
4.1 KiB
C
/* apc - Driver implementation for power management functions
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* of Aurora Personality Chip (APC) on SPARCstation-4/5 and
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* derivatives.
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*
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* Copyright (c) 2002 Eric Brower (ebrower@usa.net)
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*/
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/miscdevice.h>
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#include <linux/pm.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <asm/io.h>
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#include <asm/oplib.h>
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#include <asm/uaccess.h>
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#include <asm/auxio.h>
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#include <asm/apc.h>
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/* Debugging
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*
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* #define APC_DEBUG_LED
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*/
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#define APC_MINOR MISC_DYNAMIC_MINOR
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#define APC_OBPNAME "power-management"
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#define APC_DEVNAME "apc"
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static u8 __iomem *regs;
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static int apc_no_idle __devinitdata = 0;
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#define apc_readb(offs) (sbus_readb(regs+offs))
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#define apc_writeb(val, offs) (sbus_writeb(val, regs+offs))
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/* Specify "apc=noidle" on the kernel command line to
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* disable APC CPU standby support. Certain prototype
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* systems (SPARCstation-Fox) do not play well with APC
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* CPU idle, so disable this if your system has APC and
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* crashes randomly.
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*/
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static int __init apc_setup(char *str)
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{
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if(!strncmp(str, "noidle", strlen("noidle"))) {
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apc_no_idle = 1;
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return 1;
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}
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return 0;
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}
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__setup("apc=", apc_setup);
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/*
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* CPU idle callback function
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* See .../arch/sparc/kernel/process.c
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*/
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static void apc_swift_idle(void)
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{
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#ifdef APC_DEBUG_LED
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set_auxio(0x00, AUXIO_LED);
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#endif
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apc_writeb(apc_readb(APC_IDLE_REG) | APC_IDLE_ON, APC_IDLE_REG);
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#ifdef APC_DEBUG_LED
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set_auxio(AUXIO_LED, 0x00);
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#endif
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}
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static inline void apc_free(struct of_device *op)
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{
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of_iounmap(&op->resource[0], regs, resource_size(&op->resource[0]));
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}
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static int apc_open(struct inode *inode, struct file *f)
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{
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return 0;
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}
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static int apc_release(struct inode *inode, struct file *f)
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{
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return 0;
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}
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static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg)
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{
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__u8 inarg, __user *arg = (__u8 __user *) __arg;
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switch (cmd) {
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case APCIOCGFANCTL:
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if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg))
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return -EFAULT;
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break;
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case APCIOCGCPWR:
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if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg))
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return -EFAULT;
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break;
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case APCIOCGBPORT:
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if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg))
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return -EFAULT;
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break;
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case APCIOCSFANCTL:
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if (get_user(inarg, arg))
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return -EFAULT;
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apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);
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break;
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case APCIOCSCPWR:
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if (get_user(inarg, arg))
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return -EFAULT;
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apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
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break;
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case APCIOCSBPORT:
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if (get_user(inarg, arg))
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return -EFAULT;
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apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
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break;
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default:
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return -EINVAL;
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};
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return 0;
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}
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static const struct file_operations apc_fops = {
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.unlocked_ioctl = apc_ioctl,
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.open = apc_open,
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.release = apc_release,
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};
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static struct miscdevice apc_miscdev = { APC_MINOR, APC_DEVNAME, &apc_fops };
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static int __devinit apc_probe(struct of_device *op,
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const struct of_device_id *match)
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{
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int err;
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regs = of_ioremap(&op->resource[0], 0,
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resource_size(&op->resource[0]), APC_OBPNAME);
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if (!regs) {
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printk(KERN_ERR "%s: unable to map registers\n", APC_DEVNAME);
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return -ENODEV;
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}
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err = misc_register(&apc_miscdev);
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if (err) {
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printk(KERN_ERR "%s: unable to register device\n", APC_DEVNAME);
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apc_free(op);
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return -ENODEV;
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}
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/* Assign power management IDLE handler */
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if (!apc_no_idle)
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pm_idle = apc_swift_idle;
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printk(KERN_INFO "%s: power management initialized%s\n",
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APC_DEVNAME, apc_no_idle ? " (CPU idle disabled)" : "");
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return 0;
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}
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static struct of_device_id __initdata apc_match[] = {
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{
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.name = APC_OBPNAME,
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, apc_match);
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static struct of_platform_driver apc_driver = {
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.name = "apc",
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.match_table = apc_match,
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.probe = apc_probe,
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};
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static int __init apc_init(void)
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{
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return of_register_driver(&apc_driver, &of_bus_type);
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}
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/* This driver is not critical to the boot process
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* and is easiest to ioremap when SBus is already
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* initialized, so we install ourselves thusly:
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*/
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__initcall(apc_init);
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