tools/testing/selftests/powerpc/dscr/dscr.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * POWER Data Stream Control Register (DSCR)
   4  *
   5  * This header file contains helper functions and macros
   6  * required for all the DSCR related test cases.
   7  *
   8  * Copyright 2012, Anton Blanchard, IBM Corporation.
   9  * Copyright 2015, Anshuman Khandual, IBM Corporation.
  10  */
  11 #ifndef _SELFTESTS_POWERPC_DSCR_DSCR_H
  12 #define _SELFTESTS_POWERPC_DSCR_DSCR_H
  13
  14 #include <unistd.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <fcntl.h>
  19 #include <dirent.h>
  20 #include <pthread.h>
  21 #include <sched.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <sys/wait.h>
  25
  26 #include "utils.h"
  27
  28 #define THREADS         100     /* Max threads */
  29 #define COUNT           100     /* Max iterations */
  30 #define DSCR_MAX        16      /* Max DSCR value */
  31 #define LEN_MAX         100     /* Max name length */
  32
  33 #define DSCR_DEFAULT    "/sys/devices/system/cpu/dscr_default"
  34 #define CPU_PATH        "/sys/devices/system/cpu/"
  35
  36 #define rmb()  asm volatile("lwsync":::"memory")
  37 #define wmb()  asm volatile("lwsync":::"memory")
  38
  39 #define READ_ONCE(x) (*(volatile typeof(x) *)&(x))
  40
  41 /* Prilvilege state DSCR access */
  42 inline unsigned long get_dscr(void)
  43 {
  44         unsigned long ret;
  45
  46         asm volatile("mfspr %0,%1" : "=r" (ret) : "i" (SPRN_DSCR_PRIV));
  47
  48         return ret;
  49 }
  50
  51 inline void set_dscr(unsigned long val)
  52 {
  53         asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR_PRIV));
  54 }
  55
  56 /* Problem state DSCR access */
  57 inline unsigned long get_dscr_usr(void)
  58 {
  59         unsigned long ret;
  60
  61         asm volatile("mfspr %0,%1" : "=r" (ret) : "i" (SPRN_DSCR));
  62
  63         return ret;
  64 }
  65
  66 inline void set_dscr_usr(unsigned long val)
  67 {
  68         asm volatile("mtspr %1,%0" : : "r" (val), "i" (SPRN_DSCR));
  69 }
  70
  71 /* Default DSCR access */
  72 unsigned long get_default_dscr(void)
  73 {
  74         int fd = -1, ret;
  75         char buf[16];
  76         unsigned long val;
  77
  78         if (fd == -1) {
  79                 fd = open(DSCR_DEFAULT, O_RDONLY);
  80                 if (fd == -1) {
  81                         perror("open() failed");
  82                         exit(1);
  83                 }
  84         }
  85         memset(buf, 0, sizeof(buf));
  86         lseek(fd, 0, SEEK_SET);
  87         ret = read(fd, buf, sizeof(buf));
  88         if (ret == -1) {
  89                 perror("read() failed");
  90                 exit(1);
  91         }
  92         sscanf(buf, "%lx", &val);
  93         close(fd);
  94         return val;
  95 }
  96
  97 void set_default_dscr(unsigned long val)
  98 {
  99         int fd = -1, ret;
 100         char buf[16];
 101
 102         if (fd == -1) {
 103                 fd = open(DSCR_DEFAULT, O_RDWR);
 104                 if (fd == -1) {
 105                         perror("open() failed");
 106                         exit(1);
 107                 }
 108         }
 109         sprintf(buf, "%lx\n", val);
 110         ret = write(fd, buf, strlen(buf));
 111         if (ret == -1) {
 112                 perror("write() failed");
 113                 exit(1);
 114         }
 115         close(fd);
 116 }
 117
 118 double uniform_deviate(int seed)
 119 {
 120         return seed * (1.0 / (RAND_MAX + 1.0));
 121 }
 122 #endif  /* _SELFTESTS_POWERPC_DSCR_DSCR_H */