hypervisor/arch/arm/include/asm/setup_mmu.h

   1 /*
   2  * Jailhouse, a Linux-based partitioning hypervisor
   3  *
   4  * Copyright (c) ARM Limited, 2014
   5  *
   6  * Authors:
   7  *  Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  */
  12
  13 #ifndef _JAILHOUSE_ASM_SETUP_MMU_H
  14 #define _JAILHOUSE_ASM_SETUP_MMU_H
  15
  16 #include <asm/head.h>
  17 #include <asm/percpu.h>
  18
  19 #ifndef __ASSEMBLY__
  20
  21 /* Procedures used to translate addresses during the MMU setup process */
  22 typedef void* (*phys2virt_t)(unsigned long);
  23 typedef unsigned long (*virt2phys_t)(volatile const void *);
  24
  25 static void __attribute__((naked)) __attribute__((noinline))
  26 cpu_switch_el2(unsigned long phys_bootstrap, virt2phys_t virt2phys)
  27 {
  28         asm volatile(
  29                 /*
  30                  * The linux hyp stub allows to install the vectors with a
  31                  * single hvc. The vector base address is in r0
  32                  * (phys_bootstrap).
  33                  */
  34                 "hvc    #0\n\t"
  35
  36                 /*
  37                  * Now that the bootstrap vectors are installed, call setup_el2
  38                  * with the translated physical values of lr and sp as
  39                  * arguments.
  40                  */
  41                 "mov    r0, sp\n\t"
  42                 "push   {lr}\n\t"
  43                 "blx    %0\n\t"
  44                 "pop    {lr}\n\t"
  45                 "push   {r0}\n\t"
  46                 "mov    r0, lr\n\t"
  47                 "blx    %0\n\t"
  48                 "pop    {r1}\n\t"
  49                 "hvc    #0\n\t"
  50                 :
  51                 : "r" (virt2phys)
  52                 /*
  53                  * The call to virt2phys may clobber all temp registers. This
  54                  * list ensures that the compiler uses a decent register for
  55                  * hvirt2phys.
  56                  */
  57                 : "cc", "memory", "r0", "r1", "r2", "r3");
  58 }
  59
  60 static inline void  __attribute__((always_inline))
  61 cpu_switch_phys2virt(phys2virt_t phys2virt)
  62 {
  63         /* phys2virt is allowed to touch the stack */
  64         asm volatile(
  65                 "mov    r0, lr\n\t"
  66                 "blx    %0\n\t"
  67                 /* Save virt_lr */
  68                 "push   {r0}\n\t"
  69                 /* Translate phys_sp */
  70                 "mov    r0, sp\n\t"
  71                 "blx    %0\n\t"
  72                 /* Jump back to virtual addresses */
  73                 "mov    sp, r0\n\t"
  74                 "pop    {pc}\n\t"
  75                 :
  76                 : "r" (phys2virt)
  77                 : "cc", "r0", "r1", "r2", "r3", "lr", "sp");
  78 }
  79
  80 #endif /* !__ASSEMBLY__ */
  81 #endif /* _JAILHOUSE_ASM_SETUP_MMU_H */