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 /*
  22  * The arm64 hcall implementation uses x0 to specify the hcall
  23  * number. A value less than HVC_STUB_HCALL_NR indicates a special
  24  * hcall, such as set vector. Any other value is handled in a
  25  * hypervisor specific way.
  26  *
  27  * The hypercall is allowed to clobber any of the caller-saved
  28  * registers (x0-x18), so it is advisable to use it through the
  29  * indirection of a function call (as implemented in hyp-stub.S).
  30  */
  31
  32 /*
  33  * HVC_SET_VECTORS - Set the value of the vbar_el2 register.
  34  *
  35  * @x1: Physical address of the new vector table.
  36  */
  37 #define HVC_SET_VECTORS 0
  38
  39 /*
  40  * HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine.
  41  */
  42 #define HVC_SOFT_RESTART 1
  43
  44 /*
  45  * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
  46  */
  47 #define HVC_RESET_VECTORS 2
  48
  49 /* Max number of HYP stub hypercalls */
  50 #define HVC_STUB_HCALL_NR 3
  51
  52 /* Error returned when an invalid stub number is passed into x0 */
  53 #define HVC_STUB_ERR    0xbadca11
  54
  55 #define BOOT_CPU_MODE_EL1       (0xe11)
  56 #define BOOT_CPU_MODE_EL2       (0xe12)
  57
  58 #ifndef __ASSEMBLY__
  59
  60 #include <asm/ptrace.h>
  61 #include <asm/sections.h>
  62 #include <asm/sysreg.h>
  63 #include <asm/cpufeature.h>
  64
  65 /*
  66  * __boot_cpu_mode records what mode CPUs were booted in.
  67  * A correctly-implemented bootloader must start all CPUs in the same mode:
  68  * In this case, both 32bit halves of __boot_cpu_mode will contain the
  69  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
  70  *
  71  * Should the bootloader fail to do this, the two values will be different.
  72  * This allows the kernel to flag an error when the secondaries have come up.
  73  */
  74 extern u32 __boot_cpu_mode[2];
  75
  76 void __hyp_set_vectors(phys_addr_t phys_vector_base);
  77 void __hyp_reset_vectors(void);
  78
  79 /* Reports the availability of HYP mode */
  80 static inline bool is_hyp_mode_available(void)
  81 {
  82         return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
  83                 __boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
  84 }
  85
  86 /* Check if the bootloader has booted CPUs in different modes */
  87 static inline bool is_hyp_mode_mismatched(void)
  88 {
  89         return __boot_cpu_mode[0] != __boot_cpu_mode[1];
  90 }
  91
  92 static inline bool is_kernel_in_hyp_mode(void)
  93 {
  94         return read_sysreg(CurrentEL) == CurrentEL_EL2;
  95 }
  96
  97 static inline bool has_vhe(void)
  98 {
  99         if (cpus_have_const_cap(ARM64_HAS_VIRT_HOST_EXTN))
 100                 return true;
 101
 102         return false;
 103 }
 104
 105 #endif /* __ASSEMBLY__ */
 106
 107 #endif /* ! __ASM__VIRT_H */