/* SlimCPU - utility to access SKX CPU registers  
 *  
 * (C) Netapp Copyright 2018
 *
 * 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.
 */

#include "slimCPU.h"
#define MSRACC_NODE_NAME  "/dev/msrAccessDrv"

using namespace std;

int proc_GetCPUCount (unsigned int * retV)
{
    FILE* file;
    char temp[8];

    file = popen("cat /proc/cpuinfo | grep \"physical id\" | sort | uniq | wc -l", "r");
    if (file == NULL)
        return -1;

    fgets(temp, sizeof(temp), file);
    sscanf(temp, "%d", retV);

    pclose(file);

    return 0;

}


unsigned int proc_GetTargetCPUID(unsigned int phyID)
{
    unsigned int count;
  
    if (proc_GetCPUCount(&count) != 0)
    {
        printf("Error: can not find valid CPU count\n");
        return 0xFFFFFFFF;
    }
    else if (phyID >= count)
    {
        printf("Error: CPU ID not valid - %x\n", phyID);
        return 0xFFFFFFFF;
    }
    else
    {
        return (sysconf(_SC_NPROCESSORS_ONLN)/count)*phyID;
    }
}

unsigned int proc_ReadRegister( unsigned int cpu, unsigned int addr, unsigned long long * retV)
{

    FILE* file;
    struct msracc_drv_cmd msrCmd;
    unsigned int targetCPU;

    if ((targetCPU = proc_GetTargetCPUID(cpu)) == 0xFFFFFFFF)
        return -1;

    file = fopen(MSRACC_NODE_NAME, "r");
    if (file == NULL)
        return -1;

    msrCmd.cpu_id = targetCPU;
    msrCmd.msr_offset = addr;
    
    if (0 != ioctl(fileno(file), MSRACC_IOCTL_GET_MSR, &msrCmd))
		return -1;

    *retV = ((unsigned long long)msrCmd.val_high << 32) | (unsigned long long)msrCmd.val_low;
    
    fclose(file);
	
    return 0;

}

unsigned int proc_WriteRegister( unsigned int cpu, unsigned int addr, unsigned long long value)
{

    FILE* file;
    struct msracc_drv_cmd msrCmd;
    unsigned int targetCPU;

    if ((targetCPU = proc_GetTargetCPUID(cpu)) == 0xFFFFFFFF)
        return -1;
    
    file = fopen(MSRACC_NODE_NAME, "r");
    if (file == NULL)
    	return -1;

    msrCmd.cpu_id = targetCPU;
    msrCmd.msr_offset = addr;
    msrCmd.val_low = (unsigned int)value;
    msrCmd.val_high = (unsigned int)(value >> 32);
    
    if (0 != ioctl(fileno(file), MSRACC_IOCTL_SET_MSR, &msrCmd))
    {   
        fclose(file);
        return -1;
    }

    fclose(file);
	
    return 0;
}

void show_usage(unsigned int cnt)
{
    printf("Syntax: \n");
    printf("  Read - cpuID  rd  startRegAddr(HEX)  [endRegAddr(HEX)]\n");
    printf(" Write - cpuID  wr  regAddr  writeValue(HEX)\n ");
    printf("         cpuID: 0 ~ %d\n", cnt-1 ); 
    return ;
}

int main ( int argc, char *argv[] )
{
   unsigned long addr, addrEnd; 
   unsigned long parm[5];
   unsigned long long value64;
   
   unsigned int id,count;
   char * op;

   if (proc_GetCPUCount(&count) != 0)
   {
       printf("Error: can not find valid CPU count\n");
       return 0xFF;
   }

   // param: main cpuID rd regAddr [endAddr]
   //        main cpuID wr regAddr writeValue  

   op = argv[2]; 


   if ( ((argc != 4 ) && ( 5 != argc) ) || 
        ( strcasecmp( op, "rd") && strcasecmp( op, "wr") ) )
   {

       show_usage(count);
       return 1;
   } 
 
   for (int i = 1; i < argc; i++)
   {
       if (i != 2 )
         sscanf(argv[i], "%lX", &parm[i]);
       else
         parm[2] = 0;
   }

   id = (unsigned int)parm[1]; 
 
   if ( id >= count )
   {
       printf("Error: not a valid CPU ID: %X\n", id);
       printf("\n");
       show_usage(count);
       return 0xFF;  
   }
   
   if ( !strcasecmp( op , "rd") )  //read operation
   {
      addr = parm[3];
      if ( argc == 4 )
         addrEnd = addr;
      else if ( argc == 5 )
         addrEnd = parm[4];

      while(addr <= addrEnd)
      {
         if ( proc_ReadRegister(id, addr, &value64) != 0 )
         {
             printf("Read Error! \n");
             return 2; 
         }
         printf("%lx: %16llx\n", addr, value64); 
         addr++;
      }
   }
   else
   {
      if ( argc != 5 )
      {
         printf("Error: input pamameter not correct! \n"); 
         show_usage(count);
         return 0xFF;
      }
      addr = parm[3];
      value64 = parm[4];
      if ( proc_WriteRegister(id, addr, value64) != 0 )   
      {
          printf("Write failed! \n" );
          return 2;
      }       

   }

   return 0;

}