#include <linux/module.h>#include <linux/smp.h>#include <linux/time.h>#include <linux/errno.h>#include <linux/timex.h>#include <asm/io.h>/* IBM Summit (EXA) Cyclone counter code*/#define CYCLONE_CBAR_ADDR 0xFEB00CD0#define CYCLONE_PMCC_OFFSET 0x51A0#define CYCLONE_MPMC_OFFSET 0x51D0#define CYCLONE_MPCS_OFFSET 0x51A8#define CYCLONE_TIMER_FREQ 100000000int use_cyclone;void __init cyclone_setup(void){	use_cyclone = 1;}struct time_interpolator cyclone_interpolator = {	.source =	TIME_SOURCE_MMIO64,	.shift =	16,	.frequency =	CYCLONE_TIMER_FREQ,	.drift =	-100,	.mask =		(1LL << 40) - 1};int __init init_cyclone_clock(void){	u64* reg;	u64 base;	/* saved cyclone base address */	u64 offset;	/* offset from pageaddr to cyclone_timer register */	int i;	u32* volatile cyclone_timer;	/* Cyclone MPMC0 register */	if (!use_cyclone)		return -ENODEV;	printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n");	/* find base address */	offset = (CYCLONE_CBAR_ADDR);	reg = (u64*)ioremap_nocache(offset, sizeof(u64));	if(!reg){		printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n");		use_cyclone = 0;		return -ENODEV;	}	base = readq(reg);	if(!base){		printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n");		use_cyclone = 0;		return -ENODEV;	}	iounmap(reg);	/* setup PMCC */	offset = (base + CYCLONE_PMCC_OFFSET);	reg = (u64*)ioremap_nocache(offset, sizeof(u64));	if(!reg){		printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n");		use_cyclone = 0;		return -ENODEV;	}	writel(0x00000001,reg);	iounmap(reg);	/* setup MPCS */	offset = (base + CYCLONE_MPCS_OFFSET);	reg = (u64*)ioremap_nocache(offset, sizeof(u64));	if(!reg){		printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n");		use_cyclone = 0;		return -ENODEV;	}	writel(0x00000001,reg);	iounmap(reg);	/* map in cyclone_timer */	offset = (base + CYCLONE_MPMC_OFFSET);	cyclone_timer = (u32*)ioremap_nocache(offset, sizeof(u32));	if(!cyclone_timer){		printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n");		use_cyclone = 0;		return -ENODEV;	}	/*quick test to make sure its ticking*/	for(i=0; i<3; i++){		u32 old = readl(cyclone_timer);		int stall = 100;		while(stall--) barrier();		if(readl(cyclone_timer) == old){			printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");			iounmap(cyclone_timer);			cyclone_timer = 0;			use_cyclone = 0;			return -ENODEV;		}	}	/* initialize last tick */	cyclone_interpolator.addr = cyclone_timer;	register_time_interpolator(&cyclone_interpolator);	return 0;}__initcall(init_cyclone_clock);