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target/alpha: Simplify call_pal implementation

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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
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5
linux-user/alpha/cpu_loop.c
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 */

1
target/alpha/helper.h
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)

6
target/alpha/sys_helper.c
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) {

21
target/alpha/translate.c
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
? 0x2000 + (palcode - 0x80) * 64
: 0x1000 + palcode * 64);
tcg_gen_movi_i64(cpu_pc, entry);
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);
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