sysdeps/powerpc/tst-set_ppr.c

   1 /* Test the implementation of __ppc_set_ppr_* functions.
   2    Copyright (C) 2017-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <inttypes.h>
  20 #include <stdio.h>
  21 #include <stdint.h>
  22 #include <sys/auxv.h>
  23
  24 #include <sys/platform/ppc.h>
  25
  26 #include <support/test-driver.h>
  27
  28 #ifdef __powerpc64__
  29   typedef uint64_t ppr_t;
  30 # define MFPPR "mfppr"
  31   /* The thread priority value is obtained from bits 11:13.  */
  32 # define EXTRACT_THREAD_PRIORITY(x) ((x >> 50) & 7)
  33 #else
  34   typedef uint32_t ppr_t;
  35 # define MFPPR "mfppr32"
  36   /* For 32-bit, the upper 32 bits of the Program Priority Register (PPR)
  37      are used, so the thread priority value is obtained from bits 43:46.  */
  38 # define EXTRACT_THREAD_PRIORITY(x) ((x >> 18) & 7)
  39 #endif /* !__powerpc64__ */
  40
  41 /* Read the thread priority value set in the PPR.  */
  42 static __inline__ ppr_t
  43 get_thread_priority (void)
  44 {
  45   /* Read the PPR.  */
  46   ppr_t ppr;
  47   asm volatile (".machine push; .machine power7; "MFPPR" %0; .machine pop"
  48                 : "=r"(ppr));
  49   /* Return the thread priority value.  */
  50   return EXTRACT_THREAD_PRIORITY (ppr);
  51 }
  52
  53 /* Check the thread priority bits of PPR are set as expected. */
  54 uint8_t
  55 check_thread_priority (uint8_t expected)
  56 {
  57   ppr_t actual = get_thread_priority ();
  58
  59   if (actual != expected)
  60     {
  61       printf ("FAIL: Expected %"PRIu8" got %"PRIuMAX".\n", expected,
  62               (uintmax_t) actual);
  63       return 1;
  64     }
  65   printf ("PASS: Thread priority set to %"PRIu8" correctly.\n", expected);
  66   return 0;
  67 }
  68
  69 /* The Power ISA 2.06 allows the following thread priorities for any
  70    problem state program: low (2), medium low (3), and medium (4).
  71    Power ISA 2.07b added very low (1).
  72    Check whether the values set by __ppc_set_ppr_* are correct.  */
  73 static int
  74 do_test (void)
  75 {
  76   /* Check for the minimum required Power ISA to run these tests.  */
  77   if ((getauxval (AT_HWCAP) & PPC_FEATURE_ARCH_2_06) == 0)
  78     {
  79       printf ("Requires an environment that implements the Power ISA version"
  80               " 2.06 or greater.\n");
  81       return EXIT_UNSUPPORTED;
  82     }
  83
  84   uint8_t rc = 0;
  85
  86 #ifdef _ARCH_PWR8
  87   __ppc_set_ppr_very_low ();
  88   rc |= check_thread_priority (1);
  89 #endif /* _ARCH_PWR8 */
  90
  91   __ppc_set_ppr_low ();
  92   rc |= check_thread_priority (2);
  93
  94   __ppc_set_ppr_med_low ();
  95   rc |= check_thread_priority (3);
  96
  97   __ppc_set_ppr_med ();
  98   rc |= check_thread_priority (4);
  99
 100   return rc;
 101 }
 102
 103 #include <support/test-driver.c>