text: #ifndef _SYSTEMCFG_H
  #define _SYSTEMCFG_H
  
  /* 
   * Copyright (C) 2002 Peter Bergner <bergner@vnet.ibm.com>, IBM
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  
  /* Change Activity:
   * 2002/09/30 : bergner  : Created
   * End Change Activity 
   */
  
  
  #ifndef __KERNEL__
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/mman.h>
  #include <linux/types.h>
  #endif
  
  /*
   * If the major version changes we are incompatible.
   * Minor version changes are a hint.
   */
  #define SYSTEMCFG_MAJOR 1
  #define SYSTEMCFG_MINOR 0
  
  #ifndef __ASSEMBLY__
  
  struct systemcfg {
  	__u8  eye_catcher[16];		/* Eyecatcher: SYSTEMCFG:PPC64	0x00 */
  	struct {			/* Systemcfg version numbers	     */
  		__u32 major;		/* Major number			0x10 */
  		__u32 minor;		/* Minor number			0x14 */
  	} version;
  
  	__u32 platform;			/* Platform flags		0x18 */
  	__u32 processor;		/* Processor type		0x1C */
  	__u64 processorCount;		/* # of physical processors	0x20 */
  	__u64 physicalMemorySize;	/* Size of real memory(B)	0x28 */
  	__u64 tb_orig_stamp;		/* Timebase at boot		0x30 */
  	__u64 tb_ticks_per_sec;		/* Timebase tics / sec		0x38 */
  	__u64 tb_to_xs;			/* Inverse of TB to 2^20	0x40 */
  	__u64 stamp_xsec;		/*				0x48 */
  	__u64 tb_update_count;		/* Timebase atomicity ctr	0x50 */
  	__u32 tz_minuteswest;		/* Minutes west of Greenwich	0x58 */
  	__u32 tz_dsttime;		/* Type of dst correction	0x5C */
  	__u32 dCacheL1Size;		/* L1 d-cache size		0x60 */
  	__u32 dCacheL1LineSize;		/* L1 d-cache line size		0x64 */
  	__u32 iCacheL1Size;		/* L1 i-cache size		0x68 */
  	__u32 iCacheL1LineSize;		/* L1 i-cache line size		0x6C */
  	__u8  reserved0[3984];		/* Reserve rest of page		0x70 */
  };
  
  #ifdef __KERNEL__
  extern struct systemcfg *systemcfg;
  #else
  
  /* Processor Version Register (PVR) field extraction */
  #define PVR_VER(pvr)  (((pvr) >>  16) & 0xFFFF) /* Version field */
  #define PVR_REV(pvr)  (((pvr) >>   0) & 0xFFFF) /* Revison field */
  
  /* Processor Version Numbers */
  #define PV_NORTHSTAR    0x0033
  #define PV_PULSAR       0x0034
  #define PV_POWER4       0x0035
  #define PV_ICESTAR      0x0036
  #define PV_SSTAR        0x0037
  #define PV_POWER4p      0x0038
  #define PV_630          0x0040
  #define PV_630p         0x0041
  
  /* Platforms supported by PPC64 */
  #define PLATFORM_PSERIES      0x0100
  #define PLATFORM_PSERIES_LPAR 0x0101
  #define PLATFORM_ISERIES_LPAR 0x0201
  
  
  static inline volatile struct systemcfg *systemcfg_init(void)
  {
  	int fd = open("/proc/ppc64/systemcfg", O_RDONLY);
  	volatile struct systemcfg *ret;
  
  	if (fd == -1)
  		return 0;
  	ret = mmap(0, sizeof(struct systemcfg), PROT_READ, MAP_SHARED, fd, 0);
  	close(fd);
  	if (!ret)
  		return 0;
  	if (ret->version.major != SYSTEMCFG_MAJOR || ret->version.minor < SYSTEMCFG_MINOR) {
  		munmap((void *)ret, sizeof(struct systemcfg));
  		return 0;
  	}
  	return ret;
  }
  #endif /* __KERNEL__ */
  
  #endif /* __ASSEMBLY__ */
  
  #define SYSTEMCFG_PAGE      0x5
  #define SYSTEMCFG_PHYS_ADDR (SYSTEMCFG_PAGE<<PAGE_SHIFT)
  #define SYSTEMCFG_VIRT_ADDR (KERNELBASE+SYSTEMCFG_PHYS_ADDR)
  
  #endif /* _SYSTEMCFG_H */
  