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Re: [Qemu-devel] [PATCH v5 05/19] tcg-runtime: add lookup_tb_ptr helper
From: |
Alex Bennée |
Subject: |
Re: [Qemu-devel] [PATCH v5 05/19] tcg-runtime: add lookup_tb_ptr helper |
Date: |
Fri, 28 Apr 2017 11:29:14 +0100 |
User-agent: |
mu4e 0.9.19; emacs 25.2.17 |
Richard Henderson <address@hidden> writes:
> From: "Emilio G. Cota" <address@hidden>
>
> This paves the way for upcoming work.
>
> Reviewed-by: Richard Henderson <address@hidden>
> Reviewed-by: Alex Bennée <address@hidden>
> Signed-off-by: Emilio G. Cota <address@hidden>
> Message-Id: <address@hidden>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
> tcg-runtime.c | 24 ++++++++++++++++++++++++
> tcg/tcg-runtime.h | 2 ++
> tcg/tcg.h | 1 +
> 3 files changed, 27 insertions(+)
>
> diff --git a/tcg-runtime.c b/tcg-runtime.c
> index 4c60c96..8a24bdd 100644
> --- a/tcg-runtime.c
> +++ b/tcg-runtime.c
> @@ -27,6 +27,7 @@
> #include "exec/helper-proto.h"
> #include "exec/cpu_ldst.h"
> #include "exec/exec-all.h"
> +#include "exec/tb-hash.h"
>
> /* 32-bit helpers */
>
> @@ -141,6 +142,29 @@ uint64_t HELPER(ctpop_i64)(uint64_t arg)
> return ctpop64(arg);
> }
>
> +void *HELPER(lookup_tb_ptr)(CPUArchState *env, target_ulong addr)
> +{
> + CPUState *cpu = ENV_GET_CPU(env);
> + TranslationBlock *tb;
> + target_ulong cs_base, pc;
> + uint32_t flags;
> +
> + tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)]);
> + if (likely(tb)) {
> + cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
> + if (likely(tb->pc == addr && tb->cs_base == cs_base &&
> + tb->flags == flags)) {
> + return tb->tc_ptr;
> + }
> + tb = tb_htable_lookup(cpu, pc, cs_base, flags);
> + if (likely(tb)) {
> + atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(addr)], tb);
> + return tb->tc_ptr;
> + }
> + }
> + return tcg_ctx.code_gen_epilogue;
Minor comments: I did notice is given we rely on the backends to set this up
in later patches if it is worth adding an assert (or tcg_debug_assert?)
to catch this early if a new backend doesn't set this up?
> +}
> +
> void HELPER(exit_atomic)(CPUArchState *env)
> {
> cpu_loop_exit_atomic(ENV_GET_CPU(env), GETPC());
> diff --git a/tcg/tcg-runtime.h b/tcg/tcg-runtime.h
> index 114ea6f..c41d38a 100644
> --- a/tcg/tcg-runtime.h
> +++ b/tcg/tcg-runtime.h
> @@ -24,6 +24,8 @@ DEF_HELPER_FLAGS_1(clrsb_i64, TCG_CALL_NO_RWG_SE, i64, i64)
> DEF_HELPER_FLAGS_1(ctpop_i32, TCG_CALL_NO_RWG_SE, i32, i32)
> DEF_HELPER_FLAGS_1(ctpop_i64, TCG_CALL_NO_RWG_SE, i64, i64)
>
> +DEF_HELPER_FLAGS_2(lookup_tb_ptr, TCG_CALL_NO_WG_SE, ptr, env, tl)
> +
> DEF_HELPER_FLAGS_1(exit_atomic, TCG_CALL_NO_WG, noreturn, env)
>
> #ifdef CONFIG_SOFTMMU
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 6c216bb..5ec48d1 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -699,6 +699,7 @@ struct TCGContext {
> extension that allows arithmetic on void*. */
> int code_gen_max_blocks;
> void *code_gen_prologue;
> + void *code_gen_epilogue;
> void *code_gen_buffer;
> size_t code_gen_buffer_size;
> void *code_gen_ptr;
--
Alex Bennée
[Qemu-devel] [PATCH v5 06/19] tcg: introduce goto_ptr opcode, Richard Henderson, 2017/04/27
[Qemu-devel] [PATCH v5 10/19] target/i386: introduce gen_jr helper to generate lookup_and_goto_ptr, Richard Henderson, 2017/04/27