arch/arm64/include/asm/virt.h

   1 /*
   2  * Copyright (C) 2012 ARM Ltd.
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef __ASM__VIRT_H
  19 #define __ASM__VIRT_H
  20
  21 #define BOOT_CPU_MODE_EL1       (0xe11)
  22 #define BOOT_CPU_MODE_EL2       (0xe12)
  23
  24 #ifndef __ASSEMBLY__
  25 #include <asm/cacheflush.h>
  26
  27 /*
  28  * __boot_cpu_mode records what mode CPUs were booted in.
  29  * A correctly-implemented bootloader must start all CPUs in the same mode:
  30  * In this case, both 32bit halves of __boot_cpu_mode will contain the
  31  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
  32  *
  33  * Should the bootloader fail to do this, the two values will be different.
  34  * This allows the kernel to flag an error when the secondaries have come up.
  35  */
  36 extern u32 __boot_cpu_mode[2];
  37
  38 void __hyp_set_vectors(phys_addr_t phys_vector_base);
  39 phys_addr_t __hyp_get_vectors(void);
  40
  41 static inline void sync_boot_mode(void)
  42 {
  43         /*
  44          * As secondaries write to __boot_cpu_mode with caches disabled, we
  45          * must flush the corresponding cache entries to ensure the visibility
  46          * of their writes.
  47          */
  48         __flush_dcache_area(__boot_cpu_mode, sizeof(__boot_cpu_mode));
  49 }
  50
  51 /* Reports the availability of HYP mode */
  52 static inline bool is_hyp_mode_available(void)
  53 {
  54         sync_boot_mode();
  55         return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
  56                 __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
  57 }
  58
  59 /* Check if the bootloader has booted CPUs in different modes */
  60 static inline bool is_hyp_mode_mismatched(void)
  61 {
  62         sync_boot_mode();
  63         return __boot_cpu_mode[0] != __boot_cpu_mode[1];
  64 }
  65
  66 #endif /* __ASSEMBLY__ */
  67
  68 #endif /* ! __ASM__VIRT_H */