diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/powerpc/powerpc64/arch-pkey.h')
-rw-r--r-- | sysdeps/unix/sysv/linux/powerpc/powerpc64/arch-pkey.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/arch-pkey.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/arch-pkey.h new file mode 100644 index 0000000000..623b073d5a --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/arch-pkey.h @@ -0,0 +1,55 @@ +/* Helper functions for manipulating memory protection keys, for powerpc64. + Copyright (C) 2017-2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _ARCH_PKEY_H +#define _ARCH_PKEY_H + +/* Read and write access bits in the AMR register. Needs to be + translated from and to PKEY_DISABLE_* flags. */ +#define PKEY_AMR_READ 1UL +#define PKEY_AMR_WRITE 2UL + +/* Return the value of the AMR register. */ +static inline unsigned long int +pkey_read (void) +{ + unsigned long int result; + __asm__ volatile ("mfspr %0, 13" : "=r" (result)); + return result; +} + +/* Overwrite the AMR register with VALUE. */ +static inline void +pkey_write (unsigned long int value) +{ + __asm__ volatile ("mtspr 13, %0" : : "r" (value)); +} + +/* Number of the largest supported key. This depends on the width of + the AMR register. */ +#define PKEY_MAX (sizeof (unsigned long int) * 8 / 2 - 1) +_Static_assert (PKEY_MAX == 15 || PKEY_MAX == 31, "PKEY_MAX value"); + +/* Translate key number into AMR index position. */ +static inline int +pkey_index (int key) +{ + return 2 * (PKEY_MAX - key); +} + +#endif /* _ARCH_PKEY_H */ |