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