arch/powerpc/kvm/book3s_rmhandlers.S

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright SUSE Linux Products GmbH 2009
  16  *
  17  * Authors: Alexander Graf <agraf@suse.de>
  18  */
  19
  20 #include <asm/ppc_asm.h>
  21 #include <asm/kvm_asm.h>
  22 #include <asm/reg.h>
  23 #include <asm/mmu.h>
  24 #include <asm/page.h>
  25 #include <asm/asm-offsets.h>
  26
  27 #ifdef CONFIG_PPC_BOOK3S_64
  28 #include <asm/exception-64s.h>
  29 #endif
  30
  31 /*****************************************************************************
  32  *                                                                           *
  33  *        Real Mode handlers that need to be in low physical memory          *
  34  *                                                                           *
  35  ****************************************************************************/
  36
  37 #if defined(CONFIG_PPC_BOOK3S_64)
  38
  39 #ifdef PPC64_ELF_ABI_v2
  40 #define FUNC(name)              name
  41 #else
  42 #define FUNC(name)              GLUE(.,name)
  43 #endif
  44
  45 #elif defined(CONFIG_PPC_BOOK3S_32)
  46
  47 #define FUNC(name)              name
  48
  49 #define RFI_TO_KERNEL   RFI
  50 #define RFI_TO_GUEST    RFI
  51
  52 .macro INTERRUPT_TRAMPOLINE intno
  53
  54 .global kvmppc_trampoline_\intno
  55 kvmppc_trampoline_\intno:
  56
  57         mtspr   SPRN_SPRG_SCRATCH0, r13         /* Save r13 */
  58
  59         /*
  60          * First thing to do is to find out if we're coming
  61          * from a KVM guest or a Linux process.
  62          *
  63          * To distinguish, we check a magic byte in the PACA/current
  64          */
  65         mfspr   r13, SPRN_SPRG_THREAD
  66         lwz     r13, THREAD_KVM_SVCPU(r13)
  67         /* PPC32 can have a NULL pointer - let's check for that */
  68         mtspr   SPRN_SPRG_SCRATCH1, r12         /* Save r12 */
  69         mfcr    r12
  70         cmpwi   r13, 0
  71         bne     1f
  72 2:      mtcr    r12
  73         mfspr   r12, SPRN_SPRG_SCRATCH1
  74         mfspr   r13, SPRN_SPRG_SCRATCH0         /* r13 = original r13 */
  75         b       kvmppc_resume_\intno            /* Get back original handler */
  76
  77 1:      tophys(r13, r13)
  78         stw     r12, HSTATE_SCRATCH1(r13)
  79         mfspr   r12, SPRN_SPRG_SCRATCH1
  80         stw     r12, HSTATE_SCRATCH0(r13)
  81         lbz     r12, HSTATE_IN_GUEST(r13)
  82         cmpwi   r12, KVM_GUEST_MODE_NONE
  83         bne     ..kvmppc_handler_hasmagic_\intno
  84         /* No KVM guest? Then jump back to the Linux handler! */
  85         lwz     r12, HSTATE_SCRATCH1(r13)
  86         b       2b
  87
  88         /* Now we know we're handling a KVM guest */
  89 ..kvmppc_handler_hasmagic_\intno:
  90
  91         /* Should we just skip the faulting instruction? */
  92         cmpwi   r12, KVM_GUEST_MODE_SKIP
  93         beq     kvmppc_handler_skip_ins
  94
  95         /* Let's store which interrupt we're handling */
  96         li      r12, \intno
  97
  98         /* Jump into the SLB exit code that goes to the highmem handler */
  99         b       kvmppc_handler_trampoline_exit
 100
 101 .endm
 102
 103 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_SYSTEM_RESET
 104 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_MACHINE_CHECK
 105 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_DATA_STORAGE
 106 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_INST_STORAGE
 107 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_EXTERNAL
 108 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_ALIGNMENT
 109 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_PROGRAM
 110 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_FP_UNAVAIL
 111 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_DECREMENTER
 112 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_SYSCALL
 113 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_TRACE
 114 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_PERFMON
 115 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_ALTIVEC
 116
 117 /*
 118  * Bring us back to the faulting code, but skip the
 119  * faulting instruction.
 120  *
 121  * This is a generic exit path from the interrupt
 122  * trampolines above.
 123  *
 124  * Input Registers:
 125  *
 126  * R12            = free
 127  * R13            = Shadow VCPU (PACA)
 128  * HSTATE.SCRATCH0 = guest R12
 129  * HSTATE.SCRATCH1 = guest CR
 130  * SPRG_SCRATCH0  = guest R13
 131  *
 132  */
 133 kvmppc_handler_skip_ins:
 134
 135         /* Patch the IP to the next instruction */
 136         mfsrr0  r12
 137         addi    r12, r12, 4
 138         mtsrr0  r12
 139
 140         /* Clean up all state */
 141         lwz     r12, HSTATE_SCRATCH1(r13)
 142         mtcr    r12
 143         PPC_LL  r12, HSTATE_SCRATCH0(r13)
 144         GET_SCRATCH0(r13)
 145
 146         /* And get back into the code */
 147         RFI_TO_KERNEL
 148 #endif
 149
 150 /*
 151  * Call kvmppc_handler_trampoline_enter in real mode
 152  *
 153  * On entry, r4 contains the guest shadow MSR
 154  * MSR.EE has to be 0 when calling this function
 155  */
 156 _GLOBAL_TOC(kvmppc_entry_trampoline)
 157         mfmsr   r5
 158         LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
 159         toreal(r7)
 160
 161         li      r6, MSR_IR | MSR_DR
 162         andc    r6, r5, r6      /* Clear DR and IR in MSR value */
 163         /*
 164          * Set EE in HOST_MSR so that it's enabled when we get into our
 165          * C exit handler function.
 166          */
 167         ori     r5, r5, MSR_EE
 168         mtsrr0  r7
 169         mtsrr1  r6
 170         RFI_TO_KERNEL
 171
 172 #include "book3s_segment.S"