LXR linux/arch/powerpc/platforms/cell/spufs/spu_restore

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * crt0_r.S: Entry function for SPU-side context restore.
   4 *
   5 * Copyright (C) 2005 IBM
   6 *
   7 * Entry and exit function for SPU-side of the context restore
   8 * sequence.  Sets up an initial stack frame, then branches to
   9 * 'main'.  On return, restores all 128 registers from the LSCSA
  10 * and exits.
  11 */
  12
  13#include <asm/spu_csa.h>
  14
  15.data
  16.align 7
  17.globl regs_spill
  18regs_spill:
  19.space SIZEOF_SPU_SPILL_REGS, 0x0
  20
  21.text
  22.global _start
  23_start:
  24        /* Initialize the stack pointer to point to 16368
  25         * (16kb-16). The back chain pointer is initialized
  26         * to NULL.
  27         */
  28        il      $0, 0
  29        il      $SP, 16368
  30        stqd    $0, 0($SP)
  31
  32        /* Allocate a minimum stack frame for the called main.
  33         * This is needed so that main has a place to save the
  34         * link register when it calls another function.
  35         */
  36        stqd    $SP, -160($SP)
  37        ai      $SP, $SP, -160
  38
  39        /* Call the program's main function. */
  40        brsl    $0, main
  41
  42.global exit
  43.global _exit
  44exit:
  45_exit:
  46        /* SPU Context Restore, Step 5: Restore the remaining 112 GPRs. */
  47        ila     $3, regs_spill + 256
  48restore_regs:
  49        lqr     $4, restore_reg_insts
  50restore_reg_loop:
  51        ai      $4, $4, 4
  52        .balignl 16, 0x40200000
  53restore_reg_insts:       /* must be quad-word aligned. */
  54        lqd     $16, 0($3)
  55        lqd     $17, 16($3)
  56        lqd     $18, 32($3)
  57        lqd     $19, 48($3)
  58        andi    $5, $4, 0x7F
  59        stqr    $4, restore_reg_insts
  60        ai      $3, $3, 64
  61        brnz    $5, restore_reg_loop
  62
  63        /* SPU Context Restore Step 17: Restore the first 16 GPRs. */
  64        lqa $0, regs_spill + 0
  65        lqa $1, regs_spill + 16
  66        lqa $2, regs_spill + 32
  67        lqa $3, regs_spill + 48
  68        lqa $4, regs_spill + 64
  69        lqa $5, regs_spill + 80
  70        lqa $6, regs_spill + 96
  71        lqa $7, regs_spill + 112
  72        lqa $8, regs_spill + 128
  73        lqa $9, regs_spill + 144
  74        lqa $10, regs_spill + 160
  75        lqa $11, regs_spill + 176
  76        lqa $12, regs_spill + 192
  77        lqa $13, regs_spill + 208
  78        lqa $14, regs_spill + 224
  79        lqa $15, regs_spill + 240
  80
  81        /* Under normal circumstances, the 'exit' function
  82         * terminates with 'stop SPU_RESTORE_COMPLETE',
  83         * indicating that the SPU-side restore code has
  84         * completed.
  85         *
  86         * However it is possible that instructions immediately
  87         * following the 'stop 0x3ffc' have been modified at run
  88         * time so as to recreate the exact SPU_Status settings
  89         * from the application, e.g. illegal instruciton, halt,
  90         * etc.
  91         */
  92.global exit_fini
  93.global _exit_fini
  94exit_fini:
  95_exit_fini:
  96        stop    SPU_RESTORE_COMPLETE
  97        stop    0
  98        stop    0
  99        stop    0
 100
 101        /* Pad the size of this crt0.o to be multiple of 16 bytes. */
 102.balignl 16, 0x0
 103