LXR qemu/target/ppc/cpu.c

   1/*
   2 *  PowerPC CPU routines for qemu.
   3 *
   4 * Copyright (c) 2017 Nikunj A Dadhania, IBM Corporation.
   5 *
   6 * This library is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU Lesser General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2.1 of the License, or (at your option) any later version.
  10 *
  11 * This library is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * Lesser General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU Lesser General Public
  17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20#include "qemu/osdep.h"
  21#include "cpu.h"
  22#include "cpu-models.h"
  23#include "cpu-qom.h"
  24#include "exec/log.h"
  25#include "fpu/softfloat-helpers.h"
  26#include "mmu-hash64.h"
  27#include "helper_regs.h"
  28#include "sysemu/tcg.h"
  29
  30target_ulong cpu_read_xer(const CPUPPCState *env)
  31{
  32    if (is_isa300(env)) {
  33        return env->xer | (env->so << XER_SO) |
  34            (env->ov << XER_OV) | (env->ca << XER_CA) |
  35            (env->ov32 << XER_OV32) | (env->ca32 << XER_CA32);
  36    }
  37
  38    return env->xer | (env->so << XER_SO) | (env->ov << XER_OV) |
  39        (env->ca << XER_CA);
  40}
  41
  42void cpu_write_xer(CPUPPCState *env, target_ulong xer)
  43{
  44    env->so = (xer >> XER_SO) & 1;
  45    env->ov = (xer >> XER_OV) & 1;
  46    env->ca = (xer >> XER_CA) & 1;
  47    /* write all the flags, while reading back check of isa300 */
  48    env->ov32 = (xer >> XER_OV32) & 1;
  49    env->ca32 = (xer >> XER_CA32) & 1;
  50    env->xer = xer & ~((1ul << XER_SO) |
  51                       (1ul << XER_OV) | (1ul << XER_CA) |
  52                       (1ul << XER_OV32) | (1ul << XER_CA32));
  53}
  54
  55void ppc_store_vscr(CPUPPCState *env, uint32_t vscr)
  56{
  57    env->vscr = vscr & ~(1u << VSCR_SAT);
  58    /* Which bit we set is completely arbitrary, but clear the rest.  */
  59    env->vscr_sat.u64[0] = vscr & (1u << VSCR_SAT);
  60    env->vscr_sat.u64[1] = 0;
  61    set_flush_to_zero((vscr >> VSCR_NJ) & 1, &env->vec_status);
  62}
  63
  64uint32_t ppc_get_vscr(CPUPPCState *env)
  65{
  66    uint32_t sat = (env->vscr_sat.u64[0] | env->vscr_sat.u64[1]) != 0;
  67    return env->vscr | (sat << VSCR_SAT);
  68}
  69
  70/* GDBstub can read and write MSR... */
  71void ppc_store_msr(CPUPPCState *env, target_ulong value)
  72{
  73    hreg_store_msr(env, value, 0);
  74}
  75
  76void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val)
  77{
  78    PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
  79    CPUPPCState *env = &cpu->env;
  80
  81    env->spr[SPR_LPCR] = val & pcc->lpcr_mask;
  82    /* The gtse bit affects hflags */
  83    hreg_compute_hflags(env);
  84}
  85
  86static inline void fpscr_set_rounding_mode(CPUPPCState *env)
  87{
  88    int rnd_type;
  89
  90    /* Set rounding mode */
  91    switch (fpscr_rn) {
  92    case 0:
  93        /* Best approximation (round to nearest) */
  94        rnd_type = float_round_nearest_even;
  95        break;
  96    case 1:
  97        /* Smaller magnitude (round toward zero) */
  98        rnd_type = float_round_to_zero;
  99        break;
 100    case 2:
 101        /* Round toward +infinite */
 102        rnd_type = float_round_up;
 103        break;
 104    default:
 105    case 3:
 106        /* Round toward -infinite */
 107        rnd_type = float_round_down;
 108        break;
 109    }
 110    set_float_rounding_mode(rnd_type, &env->fp_status);
 111}
 112
 113void ppc_store_fpscr(CPUPPCState *env, target_ulong val)
 114{
 115    val &= ~(FP_VX | FP_FEX);
 116    if (val & FPSCR_IX) {
 117        val |= FP_VX;
 118    }
 119    if ((val >> FPSCR_XX) & (val >> FPSCR_XE) & 0x1f) {
 120        val |= FP_FEX;
 121    }
 122    env->fpscr = val;
 123    if (tcg_enabled()) {
 124        fpscr_set_rounding_mode(env);
 125    }
 126}
 127