LXR linux/arch/powerpc/platforms/powernv/opal-takeover.S

   1/*
   2 * PowerNV OPAL takeover assembly code, for use by prom_init.c
   3 *
   4 * Copyright 2011 IBM Corp.
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <asm/ppc_asm.h>
  13#include <asm/hvcall.h>
  14#include <asm/asm-offsets.h>
  15#include <asm/opal.h>
  16
  17#define H_HAL_TAKEOVER                  0x5124
  18#define H_HAL_TAKEOVER_QUERY_MAGIC      -1
  19
  20        .text
  21_GLOBAL(opal_query_takeover)
  22        mfcr    r0
  23        stw     r0,8(r1)
  24        std     r3,STK_PARAM(R3)(r1)
  25        std     r4,STK_PARAM(R4)(r1)
  26        li      r3,H_HAL_TAKEOVER
  27        li      r4,H_HAL_TAKEOVER_QUERY_MAGIC
  28        HVSC
  29        ld      r10,STK_PARAM(R3)(r1)
  30        std     r4,0(r10)
  31        ld      r10,STK_PARAM(R4)(r1)
  32        std     r5,0(r10)
  33        lwz     r0,8(r1)
  34        mtcrf   0xff,r0
  35        blr
  36
  37_GLOBAL(opal_do_takeover)
  38        mfcr    r0
  39        stw     r0,8(r1)
  40        mflr    r0
  41        std     r0,16(r1)
  42        bl      __opal_do_takeover
  43        ld      r0,16(r1)
  44        mtlr    r0
  45        lwz     r0,8(r1)
  46        mtcrf   0xff,r0
  47        blr
  48
  49__opal_do_takeover:
  50        ld      r4,0(r3)
  51        ld      r5,0x8(r3)
  52        ld      r6,0x10(r3)
  53        ld      r7,0x18(r3)
  54        ld      r8,0x20(r3)
  55        ld      r9,0x28(r3)
  56        ld      r10,0x30(r3)
  57        ld      r11,0x38(r3)
  58        li      r3,H_HAL_TAKEOVER
  59        HVSC
  60        blr
  61
  62        .globl opal_secondary_entry
  63opal_secondary_entry:
  64        mr      r31,r3
  65        mfmsr   r11
  66        li      r12,(MSR_SF | MSR_ISF)@highest
  67        sldi    r12,r12,48
  68        or      r11,r11,r12
  69        mtmsrd  r11
  70        isync
  71        mfspr   r4,SPRN_PIR
  72        std     r4,0(r3)
  731:      HMT_LOW
  74        ld      r4,8(r3)
  75        cmpli   cr0,r4,0
  76        beq     1b
  77        HMT_MEDIUM
  781:      addi    r3,r31,16
  79        bl      __opal_do_takeover
  80        b       1b
  81
  82_GLOBAL(opal_enter_rtas)
  83        mflr    r0
  84        std     r0,16(r1)
  85        stdu    r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
  86
  87        /* Because PROM is running in 32b mode, it clobbers the high order half
  88         * of all registers that it saves.  We therefore save those registers
  89         * PROM might touch to the stack.  (r0, r3-r13 are caller saved)
  90        */
  91        SAVE_GPR(2, r1)
  92        SAVE_GPR(13, r1)
  93        SAVE_8GPRS(14, r1)
  94        SAVE_10GPRS(22, r1)
  95        mfcr    r10
  96        mfmsr   r11
  97        std     r10,_CCR(r1)
  98        std     r11,_MSR(r1)
  99
 100        /* Get the PROM entrypoint */
 101        mtlr    r5
 102
 103        /* Switch MSR to 32 bits mode
 104         */
 105        li      r12,1
 106        rldicr  r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
 107        andc    r11,r11,r12
 108        li      r12,1
 109        rldicr  r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
 110        andc    r11,r11,r12
 111        mtmsrd  r11
 112        isync
 113
 114        /* Enter RTAS here... */
 115        blrl
 116
 117        /* Just make sure that r1 top 32 bits didn't get
 118         * corrupt by OF
 119         */
 120        rldicl  r1,r1,0,32
 121
 122        /* Restore the MSR (back to 64 bits) */
 123        ld      r0,_MSR(r1)
 124        MTMSRD(r0)
 125        isync
 126
 127        /* Restore other registers */
 128        REST_GPR(2, r1)
 129        REST_GPR(13, r1)
 130        REST_8GPRS(14, r1)
 131        REST_10GPRS(22, r1)
 132        ld      r4,_CCR(r1)
 133        mtcr    r4
 134
 135        addi    r1,r1,PROM_FRAME_SIZE
 136        ld      r0,16(r1)
 137        mtlr    r0
 138        blr
 139