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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221/* * Timer device implementation for SGI UV platform. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (c) 2009 Silicon Graphics, Inc. All rights reserved. * */
#include <linux/types.h>#include <linux/kernel.h>#include <linux/ioctl.h>#include <linux/module.h>#include <linux/init.h>#include <linux/errno.h>#include <linux/mm.h>#include <linux/fs.h>#include <linux/mmtimer.h>#include <linux/miscdevice.h>#include <linux/posix-timers.h>#include <linux/interrupt.h>#include <linux/time.h>#include <linux/math64.h>
#include <asm/genapic.h>#include <asm/uv/uv_hub.h>#include <asm/uv/bios.h>#include <asm/uv/uv.h>
MODULE_AUTHOR("Dimitri Sivanich <sivanich@sgi.com>");MODULE_DESCRIPTION("SGI UV Memory Mapped RTC Timer");MODULE_LICENSE("GPL");
/* name of the device, usually in /dev */#define UV_MMTIMER_NAME "mmtimer"#define UV_MMTIMER_DESC "SGI UV Memory Mapped RTC Timer"#define UV_MMTIMER_VERSION "1.0"
static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd, unsigned long arg);static int uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma);
/* * Period in femtoseconds (10^-15 s) */static unsigned long uv_mmtimer_femtoperiod;
static const struct file_operations uv_mmtimer_fops = { .owner = THIS_MODULE, .mmap = uv_mmtimer_mmap, .unlocked_ioctl = uv_mmtimer_ioctl, .llseek = noop_llseek,};
/** * uv_mmtimer_ioctl - ioctl interface for /dev/uv_mmtimer * @file: file structure for the device * @cmd: command to execute * @arg: optional argument to command * * Executes the command specified by @cmd. Returns 0 for success, < 0 for * failure. * * Valid commands: * * %MMTIMER_GETOFFSET - Should return the offset (relative to the start * of the page where the registers are mapped) for the counter in question. * * %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15) * seconds * * %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address * specified by @arg * * %MMTIMER_GETBITS - Returns the number of bits in the clock's counter * * %MMTIMER_MMAPAVAIL - Returns 1 if registers can be mmap'd into userspace * * %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it * in the address specified by @arg. */static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ int ret = 0;
switch (cmd) { case MMTIMER_GETOFFSET: /* offset of the counter */ /* * Starting with HUB rev 2.0, the UV RTC register is * replicated across all cachelines of it's own page. * This allows faster simultaneous reads from a given socket. * * The offset returned is in 64 bit units. */ if (uv_get_min_hub_revision_id() == 1) ret = 0; else ret = ((uv_blade_processor_id() * L1_CACHE_BYTES) % PAGE_SIZE) / 8; break;
case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */ if (copy_to_user((unsigned long __user *)arg, &uv_mmtimer_femtoperiod, sizeof(unsigned long))) ret = -EFAULT; break;
case MMTIMER_GETFREQ: /* frequency in Hz */ if (copy_to_user((unsigned long __user *)arg, &sn_rtc_cycles_per_second, sizeof(unsigned long))) ret = -EFAULT; break;
case MMTIMER_GETBITS: /* number of bits in the clock */ ret = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK); break;
case MMTIMER_MMAPAVAIL: ret = 1; break;
case MMTIMER_GETCOUNTER: if (copy_to_user((unsigned long __user *)arg, (unsigned long *)uv_local_mmr_address(UVH_RTC), sizeof(unsigned long))) ret = -EFAULT; break; default: ret = -ENOTTY; break; } return ret;}
/** * uv_mmtimer_mmap - maps the clock's registers into userspace * @file: file structure for the device * @vma: VMA to map the registers into * * Calls remap_pfn_range() to map the clock's registers into * the calling process' address space. */static int uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma){ unsigned long uv_mmtimer_addr;
if (vma->vm_end - vma->vm_start != PAGE_SIZE) return -EINVAL;
if (vma->vm_flags & VM_WRITE) return -EPERM;
if (PAGE_SIZE > (1 << 16)) return -ENOSYS;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
uv_mmtimer_addr = UV_LOCAL_MMR_BASE | UVH_RTC; uv_mmtimer_addr &= ~(PAGE_SIZE - 1); uv_mmtimer_addr &= 0xfffffffffffffffUL;
if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT, PAGE_SIZE, vma->vm_page_prot)) { printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n"); return -EAGAIN; }
return 0;}
static struct miscdevice uv_mmtimer_miscdev = { MISC_DYNAMIC_MINOR, UV_MMTIMER_NAME, &uv_mmtimer_fops};
/** * uv_mmtimer_init - device initialization routine * * Does initial setup for the uv_mmtimer device. */static int __init uv_mmtimer_init(void){ if (!is_uv_system()) { printk(KERN_ERR "%s: Hardware unsupported\n", UV_MMTIMER_NAME); return -1; }
/* * Sanity check the cycles/sec variable */ if (sn_rtc_cycles_per_second < 100000) { printk(KERN_ERR "%s: unable to determine clock frequency\n", UV_MMTIMER_NAME); return -1; }
uv_mmtimer_femtoperiod = ((unsigned long)1E15 + sn_rtc_cycles_per_second / 2) / sn_rtc_cycles_per_second;
if (misc_register(&uv_mmtimer_miscdev)) { printk(KERN_ERR "%s: failed to register device\n", UV_MMTIMER_NAME); return -1; }
printk(KERN_INFO "%s: v%s, %ld MHz\n", UV_MMTIMER_DESC, UV_MMTIMER_VERSION, sn_rtc_cycles_per_second/(unsigned long)1E6);
return 0;}
module_init(uv_mmtimer_init);