[Qemu-devel] [PATCH 1/4] memory: cache min/max_access_size

[Paolo Bonzini <pbonzini@redhat.com>]

This will simplify the code in the next patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/exec/memory.h |  2 ++
 memory.c              | 27 +++++++++++----------------
 2 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 480dfbf..cf63adb 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -163,6 +163,8 @@ struct MemoryRegion {
     unsigned ioeventfd_nb;
     MemoryRegionIoeventfd *ioeventfds;
     NotifierList iommu_notify;
+
+    uint8_t min_access_size, max_access_size;
 };
 
 typedef struct MemoryListener MemoryListener;
diff --git a/memory.c b/memory.c
index 28f6449..56e54aa 100644
--- a/memory.c
+++ b/memory.c
@@ -443,8 +443,6 @@ static void memory_region_write_accessor(MemoryRegion *mr,
 static void access_with_adjusted_size(hwaddr addr,
                                       uint64_t *value,
                                       unsigned size,
-                                      unsigned access_size_min,
-                                      unsigned access_size_max,
                                       void (*access)(MemoryRegion *mr,
                                                      hwaddr addr,
                                                      uint64_t *value,
@@ -457,15 +455,8 @@ static void access_with_adjusted_size(hwaddr addr,
     unsigned access_size;
     unsigned i;
 
-    if (!access_size_min) {
-        access_size_min = 1;
-    }
-    if (!access_size_max) {
-        access_size_max = 4;
-    }
-
     /* FIXME: support unaligned access? */
-    access_size = MAX(MIN(size, access_size_max), access_size_min);
+    access_size = MAX(MIN(size, mr->min_access_size), mr->min_access_size);
     access_mask = -1ULL >> (64 - access_size * 8);
     if (memory_region_big_endian(mr)) {
         for (i = 0; i < size; i += access_size) {
@@ -942,11 +933,9 @@ static uint64_t memory_region_dispatch_read1(MemoryRegion *mr,
 
     if (mr->ops->read) {
         access_with_adjusted_size(addr, &data, size,
-                                  mr->ops->impl.min_access_size,
-                                  mr->ops->impl.max_access_size,
                                   memory_region_read_accessor, mr);
     } else {
-        access_with_adjusted_size(addr, &data, size, 1, 4,
+        access_with_adjusted_size(addr, &data, size,
                                   memory_region_oldmmio_read_accessor, mr);
     }
 
@@ -982,11 +971,9 @@ static bool memory_region_dispatch_write(MemoryRegion *mr,
 
     if (mr->ops->write) {
         access_with_adjusted_size(addr, &data, size,
-                                  mr->ops->impl.min_access_size,
-                                  mr->ops->impl.max_access_size,
                                   memory_region_write_accessor, mr);
     } else {
-        access_with_adjusted_size(addr, &data, size, 1, 4,
+        access_with_adjusted_size(addr, &data, size,
                                   memory_region_oldmmio_write_accessor, mr);
     }
     return false;
@@ -1004,6 +991,14 @@ void memory_region_init_io(MemoryRegion *mr,
     mr->opaque = opaque;
     mr->terminates = true;
     mr->ram_addr = ~(ram_addr_t)0;
+
+    if (mr->ops->read) {
+        mr->min_access_size = mr->ops->impl.min_access_size ? : 1;
+        mr->max_access_size = mr->ops->impl.max_access_size ? : 4;
+    } else {
+        mr->min_access_size = 1;
+        mr->max_access_size = 4;
+    }
 }
 
 void memory_region_init_ram(MemoryRegion *mr,
-- 
1.8.4.2