[PULL 15/62] accel/tcg: Move jmp-cache `CF_PCREL` checks to caller

Richard Henderson posted 62 patches 2 years, 2 months ago
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, Riku Voipio <riku.voipio@iki.fi>, "Alex Bennée" <alex.bennee@linaro.org>, Peter Xu <peterx@redhat.com>, David Hildenbrand <david@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Peter Maydell <peter.maydell@linaro.org>, Michael Rolnik <mrolnik@gmail.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Taylor Simpson <tsimpson@quicinc.com>, Alessandro Di Federico <ale@rev.ng>, Anton Johansson <anjo@rev.ng>, Eduardo Habkost <eduardo@habkost.net>, Song Gao <gaosong@loongson.cn>, Xiaojuan Yang <yangxiaojuan@loongson.cn>, Laurent Vivier <laurent@vivier.eu>, Aurelien Jarno <aurelien@aurel32.net>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Chris Wulff <crwulff@gmail.com>, Marek Vasut <marex@denx.de>, Stafford Horne <shorne@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Weiwei Li <liweiwei@iscas.ac.cn>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>, Artyom Tarasenko <atar4qemu@gmail.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Max Filippov <jcmvbkbc@gmail.com>
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[PULL 15/62] accel/tcg: Move jmp-cache `CF_PCREL` checks to caller
Posted by Richard Henderson 2 years, 2 months ago
From: Anton Johansson via <qemu-devel@nongnu.org>

tb-jmp-cache.h contains a few small functions that only exist to hide a
CF_PCREL check, however the caller often already performs such a check.

This patch moves CF_PCREL checks from the callee to the caller, and also
removes these functions which now only hide an access of the jmp-cache.

Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230227135202.9710-12-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 accel/tcg/tb-jmp-cache.h | 36 ---------------------------
 accel/tcg/cpu-exec.c     | 54 +++++++++++++++++++++++++++++-----------
 2 files changed, 40 insertions(+), 50 deletions(-)

diff --git a/accel/tcg/tb-jmp-cache.h b/accel/tcg/tb-jmp-cache.h
index 083939b302..bee87eb840 100644
--- a/accel/tcg/tb-jmp-cache.h
+++ b/accel/tcg/tb-jmp-cache.h
@@ -25,40 +25,4 @@ struct CPUJumpCache {
     } array[TB_JMP_CACHE_SIZE];
 };
 
-static inline TranslationBlock *
-tb_jmp_cache_get_tb(CPUJumpCache *jc, uint32_t cflags, uint32_t hash)
-{
-    if (cflags & CF_PCREL) {
-        /* Use acquire to ensure current load of pc from jc. */
-        return qatomic_load_acquire(&jc->array[hash].tb);
-    } else {
-        /* Use rcu_read to ensure current load of pc from *tb. */
-        return qatomic_rcu_read(&jc->array[hash].tb);
-    }
-}
-
-static inline target_ulong
-tb_jmp_cache_get_pc(CPUJumpCache *jc, uint32_t hash, TranslationBlock *tb)
-{
-    if (tb_cflags(tb) & CF_PCREL) {
-        return jc->array[hash].pc;
-    } else {
-        return tb_pc(tb);
-    }
-}
-
-static inline void
-tb_jmp_cache_set(CPUJumpCache *jc, uint32_t hash,
-                 TranslationBlock *tb, target_ulong pc)
-{
-    if (tb_cflags(tb) & CF_PCREL) {
-        jc->array[hash].pc = pc;
-        /* Use store_release on tb to ensure pc is written first. */
-        qatomic_store_release(&jc->array[hash].tb, tb);
-    } else{
-        /* Use the pc value already stored in tb->pc. */
-        qatomic_set(&jc->array[hash].tb, tb);
-    }
-}
-
 #endif /* ACCEL_TCG_TB_JMP_CACHE_H */
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 013856f103..aa14e97958 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -254,21 +254,46 @@ static inline TranslationBlock *tb_lookup(CPUState *cpu, target_ulong pc,
 
     hash = tb_jmp_cache_hash_func(pc);
     jc = cpu->tb_jmp_cache;
-    tb = tb_jmp_cache_get_tb(jc, cflags, hash);
 
-    if (likely(tb &&
-               tb_jmp_cache_get_pc(jc, hash, tb) == pc &&
-               tb->cs_base == cs_base &&
-               tb->flags == flags &&
-               tb->trace_vcpu_dstate == *cpu->trace_dstate &&
-               tb_cflags(tb) == cflags)) {
-        return tb;
+    if (cflags & CF_PCREL) {
+        /* Use acquire to ensure current load of pc from jc. */
+        tb =  qatomic_load_acquire(&jc->array[hash].tb);
+
+        if (likely(tb &&
+                   jc->array[hash].pc == pc &&
+                   tb->cs_base == cs_base &&
+                   tb->flags == flags &&
+                   tb->trace_vcpu_dstate == *cpu->trace_dstate &&
+                   tb_cflags(tb) == cflags)) {
+            return tb;
+        }
+        tb = tb_htable_lookup(cpu, pc, cs_base, flags, cflags);
+        if (tb == NULL) {
+            return NULL;
+        }
+        jc->array[hash].pc = pc;
+        /* Use store_release on tb to ensure pc is written first. */
+        qatomic_store_release(&jc->array[hash].tb, tb);
+    } else {
+        /* Use rcu_read to ensure current load of pc from *tb. */
+        tb = qatomic_rcu_read(&jc->array[hash].tb);
+
+        if (likely(tb &&
+                   tb_pc(tb) == pc &&
+                   tb->cs_base == cs_base &&
+                   tb->flags == flags &&
+                   tb->trace_vcpu_dstate == *cpu->trace_dstate &&
+                   tb_cflags(tb) == cflags)) {
+            return tb;
+        }
+        tb = tb_htable_lookup(cpu, pc, cs_base, flags, cflags);
+        if (tb == NULL) {
+            return NULL;
+        }
+        /* Use the pc value already stored in tb->pc. */
+        qatomic_set(&jc->array[hash].tb, tb);
     }
-    tb = tb_htable_lookup(cpu, pc, cs_base, flags, cflags);
-    if (tb == NULL) {
-        return NULL;
-    }
-    tb_jmp_cache_set(jc, hash, tb, pc);
+
     return tb;
 }
 
@@ -957,7 +982,8 @@ cpu_exec_loop(CPUState *cpu, SyncClocks *sc)
                  * for the fast lookup
                  */
                 h = tb_jmp_cache_hash_func(pc);
-                tb_jmp_cache_set(cpu->tb_jmp_cache, h, tb, pc);
+                /* Use the pc value already stored in tb->pc. */
+                qatomic_set(&cpu->tb_jmp_cache->array[h].tb, tb);
             }
 
 #ifndef CONFIG_USER_ONLY
-- 
2.34.1