target/alpha: Simplify call_pal implementation

Since 288a5fe980, we don't link translation blocks
directly to palcode entry points.  If we load palbr
from env instead of encoding the constant, we avoid
all need for tb_flush().

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson
2025-09-05 18:43:30 +02:00
parent dae1e0df49
commit 521c9e1b1a
4 changed files with 6 additions and 27 deletions

View File

@ -94,11 +94,6 @@ void cpu_loop(CPUAlphaState *env)
break;
case 0x86:
/* IMB */
/* ??? We can probably elide the code using page_unprotect
that is checking for self-modifying code. Instead we
could simply call tb_flush here. Until we work out the
changes required to turn off the extra write protection,
this can be a no-op. */
break;
case 0x9E:
/* RDUNIQUE */

View File

@ -90,7 +90,6 @@ DEF_HELPER_FLAGS_2(ieee_input_s, TCG_CALL_NO_WG, void, env, i64)
#if !defined (CONFIG_USER_ONLY)
DEF_HELPER_FLAGS_1(tbia, TCG_CALL_NO_RWG, void, env)
DEF_HELPER_FLAGS_2(tbis, TCG_CALL_NO_RWG, void, env, i64)
DEF_HELPER_FLAGS_1(tb_flush, TCG_CALL_NO_RWG, void, env)
DEF_HELPER_1(halt, void, i64)

View File

@ -20,7 +20,6 @@
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/cputlb.h"
#include "exec/tb-flush.h"
#include "exec/helper-proto.h"
#include "system/runstate.h"
#include "system/system.h"
@ -38,11 +37,6 @@ void helper_tbis(CPUAlphaState *env, uint64_t p)
tlb_flush_page(env_cpu(env), p);
}
void helper_tb_flush(CPUAlphaState *env)
{
tb_flush(env_cpu(env));
}
void helper_halt(uint64_t restart)
{
if (restart) {

View File

@ -48,8 +48,6 @@ struct DisasContext {
#ifdef CONFIG_USER_ONLY
MemOp unalign;
#else
uint64_t palbr;
#endif
uint32_t tbflags;
int mem_idx;
@ -1155,7 +1153,6 @@ static DisasJumpType gen_call_pal(DisasContext *ctx, int palcode)
#else
{
TCGv tmp = tcg_temp_new();
uint64_t entry;
gen_pc_disp(ctx, tmp, 0);
if (ctx->tbflags & ENV_FLAG_PAL_MODE) {
@ -1165,12 +1162,11 @@ static DisasJumpType gen_call_pal(DisasContext *ctx, int palcode)
}
tcg_gen_st_i64(tmp, tcg_env, offsetof(CPUAlphaState, exc_addr));
entry = ctx->palbr;
entry += (palcode & 0x80
tcg_gen_ld_i64(cpu_pc, tcg_env, offsetof(CPUAlphaState, palbr));
tcg_gen_addi_i64(cpu_pc, cpu_pc,
palcode & 0x80
? 0x2000 + (palcode - 0x80) * 64
: 0x1000 + palcode * 64);
tcg_gen_movi_i64(cpu_pc, entry);
return DISAS_PC_UPDATED;
}
#endif
@ -1292,11 +1288,7 @@ static DisasJumpType gen_mtpr(DisasContext *ctx, TCGv vb, int regno)
case 7:
/* PALBR */
tcg_gen_st_i64(vb, tcg_env, offsetof(CPUAlphaState, palbr));
/* Changing the PAL base register implies un-chaining all of the TBs
that ended with a CALL_PAL. Since the base register usually only
changes during boot, flushing everything works well. */
gen_helper_tb_flush(tcg_env);
return DISAS_PC_STALE;
break;
case 32 ... 39:
/* Accessing the "non-shadow" general registers. */
@ -2874,7 +2866,6 @@ static void alpha_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cpu)
ctx->ir = cpu_std_ir;
ctx->unalign = (ctx->tbflags & TB_FLAG_UNALIGN ? MO_UNALN : MO_ALIGN);
#else
ctx->palbr = env->palbr;
ctx->ir = (ctx->tbflags & ENV_FLAG_PAL_MODE ? cpu_pal_ir : cpu_std_ir);
#endif