mirror of https://gitee.com/openkylin/qemu.git
target/hppa: Implement a pause instruction
This is an extension to the base ISA, but we can use this in the kernel idle loop to reduce the host cpu time consumed. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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@ -2826,9 +2826,45 @@ static DisasJumpType trans_ds(DisasContext *ctx, uint32_t insn,
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return nullify_end(ctx, DISAS_NEXT);
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}
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#ifndef CONFIG_USER_ONLY
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/* These are QEMU extensions and are nops in the real architecture:
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*
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* or %r10,%r10,%r10 -- idle loop; wait for interrupt
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* or %r31,%r31,%r31 -- death loop; offline cpu
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* currently implemented as idle.
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*/
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static DisasJumpType trans_pause(DisasContext *ctx, uint32_t insn,
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const DisasInsn *di)
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{
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TCGv_i32 tmp;
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/* No need to check for supervisor, as userland can only pause
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until the next timer interrupt. */
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nullify_over(ctx);
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/* Advance the instruction queue. */
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copy_iaoq_entry(cpu_iaoq_f, ctx->iaoq_b, cpu_iaoq_b);
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copy_iaoq_entry(cpu_iaoq_b, ctx->iaoq_n, ctx->iaoq_n_var);
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nullify_set(ctx, 0);
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/* Tell the qemu main loop to halt until this cpu has work. */
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tmp = tcg_const_i32(1);
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tcg_gen_st_i32(tmp, cpu_env, -offsetof(HPPACPU, env) +
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offsetof(CPUState, halted));
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tcg_temp_free_i32(tmp);
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gen_excp_1(EXCP_HALTED);
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return nullify_end(ctx, DISAS_NORETURN);
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}
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#endif
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static const DisasInsn table_arith_log[] = {
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{ 0x08000240u, 0xfc00ffffu, trans_nop }, /* or x,y,0 */
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{ 0x08000240u, 0xffe0ffe0u, trans_copy }, /* or x,0,t */
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#ifndef CONFIG_USER_ONLY
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{ 0x094a024au, 0xffffffffu, trans_pause }, /* or r10,r10,r10 */
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{ 0x0bff025fu, 0xffffffffu, trans_pause }, /* or r31,r31,r31 */
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#endif
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{ 0x08000000u, 0xfc000fe0u, trans_log, .f.ttt = tcg_gen_andc_reg },
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{ 0x08000200u, 0xfc000fe0u, trans_log, .f.ttt = tcg_gen_and_reg },
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{ 0x08000240u, 0xfc000fe0u, trans_log, .f.ttt = tcg_gen_or_reg },
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