diff mbox series

[for-8.0,7/7] accel/tcg: Use QEMU_IOTHREAD_LOCK_GUARD in io_readx/io_writex

Message ID 20221118091858.242569-8-richard.henderson@linaro.org
State Superseded
Headers show
Series main-loop: Introduce QEMU_IOTHREAD_LOCK_GUARD | expand

Commit Message

Richard Henderson Nov. 18, 2022, 9:18 a.m. UTC 
Narrow the scope of the lock to the actual read/write,
moving the cpu_transation_failed call outside the lock.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 accel/tcg/cputlb.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

Comments

Philippe Mathieu-Daudé Nov. 21, 2022, 11:02 a.m. UTC | #1 
On 18/11/22 10:18, Richard Henderson wrote:
> Narrow the scope of the lock to the actual read/write,
> moving the cpu_transation_failed call outside the lock.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   accel/tcg/cputlb.c | 25 ++++++++-----------------
>   1 file changed, 8 insertions(+), 17 deletions(-)

> @@ -1367,11 +1366,11 @@ static uint64_t io_readx(CPUArchState *env, CPUTLBEntryFull *full,
>           cpu_io_recompile(cpu, retaddr);
>       }
>   
> -    if (!qemu_mutex_iothread_locked()) {
> -        qemu_mutex_lock_iothread();
> -        locked = true;
> +    {
> +        QEMU_IOTHREAD_LOCK_GUARD();
> +        r = memory_region_dispatch_read(mr, mr_offset, &val, op, full->attrs);
>       }
> -    r = memory_region_dispatch_read(mr, mr_offset, &val, op, full->attrs);
> +

Example of clearer WITH_QEMU_IOTHREAD_LOCK_GUARD() macro
use suggested earlier:

         WITH_QEMU_IOTHREAD_LOCK_GUARD() {
             r = memory_region_dispatch_read(mr, mr_offset, &val,
                                             op, full->attrs);
         }

>       if (r != MEMTX_OK) {
>           hwaddr physaddr = mr_offset +
>               section->offset_within_address_space -
> @@ -1380,10 +1379,6 @@ static uint64_t io_readx(CPUArchState *env, CPUTLBEntryFull *full,
>           cpu_transaction_failed(cpu, physaddr, addr, memop_size(op), access_type,
>                                  mmu_idx, full->attrs, r, retaddr);
>       }
> -    if (locked) {
> -        qemu_mutex_unlock_iothread();
> -    }
> -
>       return val;
>   }

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff mbox series

Patch

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index 517b599c5f..d177afcad6 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -1356,7 +1356,6 @@  static uint64_t io_readx(CPUArchState *env, CPUTLBEntryFull *full,
     MemoryRegionSection *section;
     MemoryRegion *mr;
     uint64_t val;
-    bool locked = false;
     MemTxResult r;
 
     section = iotlb_to_section(cpu, full->xlat_section, full->attrs);
@@ -1367,11 +1366,11 @@  static uint64_t io_readx(CPUArchState *env, CPUTLBEntryFull *full,
         cpu_io_recompile(cpu, retaddr);
     }
 
-    if (!qemu_mutex_iothread_locked()) {
-        qemu_mutex_lock_iothread();
-        locked = true;
+    {
+        QEMU_IOTHREAD_LOCK_GUARD();
+        r = memory_region_dispatch_read(mr, mr_offset, &val, op, full->attrs);
     }
-    r = memory_region_dispatch_read(mr, mr_offset, &val, op, full->attrs);
+
     if (r != MEMTX_OK) {
         hwaddr physaddr = mr_offset +
             section->offset_within_address_space -
@@ -1380,10 +1379,6 @@  static uint64_t io_readx(CPUArchState *env, CPUTLBEntryFull *full,
         cpu_transaction_failed(cpu, physaddr, addr, memop_size(op), access_type,
                                mmu_idx, full->attrs, r, retaddr);
     }
-    if (locked) {
-        qemu_mutex_unlock_iothread();
-    }
-
     return val;
 }
 
@@ -1410,7 +1405,6 @@  static void io_writex(CPUArchState *env, CPUTLBEntryFull *full,
     hwaddr mr_offset;
     MemoryRegionSection *section;
     MemoryRegion *mr;
-    bool locked = false;
     MemTxResult r;
 
     section = iotlb_to_section(cpu, full->xlat_section, full->attrs);
@@ -1427,11 +1421,11 @@  static void io_writex(CPUArchState *env, CPUTLBEntryFull *full,
      */
     save_iotlb_data(cpu, section, mr_offset);
 
-    if (!qemu_mutex_iothread_locked()) {
-        qemu_mutex_lock_iothread();
-        locked = true;
+    {
+        QEMU_IOTHREAD_LOCK_GUARD();
+        r = memory_region_dispatch_write(mr, mr_offset, val, op, full->attrs);
     }
-    r = memory_region_dispatch_write(mr, mr_offset, val, op, full->attrs);
+
     if (r != MEMTX_OK) {
         hwaddr physaddr = mr_offset +
             section->offset_within_address_space -
@@ -1441,9 +1435,6 @@  static void io_writex(CPUArchState *env, CPUTLBEntryFull *full,
                                MMU_DATA_STORE, mmu_idx, full->attrs, r,
                                retaddr);
     }
-    if (locked) {
-        qemu_mutex_unlock_iothread();
-    }
 }
 
 static inline target_ulong tlb_read_ofs(CPUTLBEntry *entry, size_t ofs)