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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: alex.bennee@linaro.org
Subject: [PATCH 2/2] target/sh4: Disable decode_gusa when plugins enabled
Date: Thu, 24 Aug 2023 11:12:33 -0700	[thread overview]
Message-ID: <20230824181233.1568795-3-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230824181233.1568795-1-richard.henderson@linaro.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/sh4/translate.c | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/target/sh4/translate.c b/target/sh4/translate.c
index 49c87d7a01..f2bdd1d0fc 100644
--- a/target/sh4/translate.c
+++ b/target/sh4/translate.c
@@ -1817,6 +1817,18 @@ static void decode_opc(DisasContext * ctx)
 }
 
 #ifdef CONFIG_USER_ONLY
+/*
+ * Restart with the EXCLUSIVE bit set, within a TB run via
+ * cpu_exec_step_atomic holding the exclusive lock.
+ */
+static void gen_restart_exclusive(DisasContext *ctx)
+{
+    ctx->envflags |= TB_FLAG_GUSA_EXCLUSIVE;
+    gen_save_cpu_state(ctx, false);
+    gen_helper_exclusive(cpu_env);
+    ctx->base.is_jmp = DISAS_NORETURN;
+}
+
 /* For uniprocessors, SH4 uses optimistic restartable atomic sequences.
    Upon an interrupt, a real kernel would simply notice magic values in
    the registers and reset the PC to the start of the sequence.
@@ -2150,12 +2162,7 @@ static void decode_gusa(DisasContext *ctx, CPUSH4State *env)
     qemu_log_mask(LOG_UNIMP, "Unrecognized gUSA sequence %08x-%08x\n",
                   pc, pc_end);
 
-    /* Restart with the EXCLUSIVE bit set, within a TB run via
-       cpu_exec_step_atomic holding the exclusive lock.  */
-    ctx->envflags |= TB_FLAG_GUSA_EXCLUSIVE;
-    gen_save_cpu_state(ctx, false);
-    gen_helper_exclusive(cpu_env);
-    ctx->base.is_jmp = DISAS_NORETURN;
+    gen_restart_exclusive(ctx);
 
     /* We're not executing an instruction, but we must report one for the
        purposes of accounting within the TB.  We might as well report the
@@ -2243,12 +2250,22 @@ static void sh4_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
 #ifdef CONFIG_USER_ONLY
     if (unlikely(ctx->envflags & TB_FLAG_GUSA_MASK)
         && !(ctx->envflags & TB_FLAG_GUSA_EXCLUSIVE)) {
-        /* We're in an gUSA region, and we have not already fallen
-           back on using an exclusive region.  Attempt to parse the
-           region into a single supported atomic operation.  Failure
-           is handled within the parser by raising an exception to
-           retry using an exclusive region.  */
-        decode_gusa(ctx, env);
+        /*
+         * We're in an gUSA region, and we have not already fallen
+         * back on using an exclusive region.  Attempt to parse the
+         * region into a single supported atomic operation.  Failure
+         * is handled within the parser by raising an exception to
+         * retry using an exclusive region.
+         *
+         * Parsing the region in one block conflicts with plugins,
+         * so always use exclusive mode if plugins enabled.
+         */
+        if (ctx->base.plugin_enabled) {
+            gen_restart_exclusive(ctx);
+            ctx->base.pc_next += 2;
+        } else {
+            decode_gusa(ctx, env);
+        }
         return;
     }
 #endif
-- 
2.34.1



  parent reply	other threads:[~2023-08-24 18:13 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-24 18:12 [RFC PATCH 0/2] target/sh4: Disable decode_gusa when plugins enabled Richard Henderson
2023-08-24 18:12 ` [PATCH 1/2] accel/tcg: Add plugin_enabled to DisasContextBase Richard Henderson
2023-08-24 18:12 ` Richard Henderson [this message]
2023-08-30 18:44 ` [RFC PATCH 0/2] target/sh4: Disable decode_gusa when plugins enabled Alex Bennée

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