LXR linux/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 */
  36extern u32 __boot_cpu_mode[2];
  37
  38void __hyp_set_vectors(phys_addr_t phys_vector_base);
  39phys_addr_t __hyp_get_vectors(void);
  40
  41static 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 */
  52static 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 */
  60static 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 */
  69