memory: Change MemoryRegion priorities from unsigned to signed

When memory regions overlap, priority can be used to specify
which of them takes priority. By making the priority values signed
rather than unsigned, we make it more convenient to implement
a situation where one "background" region should appear only
where no other region exists: rather than having to explicitly
specify a high priority for all the other regions, we can let them take
the default (zero) priority and specify a negative priority for the
background region.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
index b84cd4a16f75975af9624ce08b80b3ee7b1f07ba..146f50aa157ac5047c30664adeb4673b74ca907f 100644 (file)
--- a/hw/core/sysbus.c
+++ b/hw/core/sysbus.c
@@ -49,7 +49,7 @@ void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq irq)
 }
 
 static void sysbus_mmio_map_common(SysBusDevice *dev, int n, hwaddr addr,
-                                   bool may_overlap, unsigned priority)
+                                   bool may_overlap, int priority)
 {
     assert(n >= 0 && n < dev->num_mmio);
 
@@ -81,7 +81,7 @@ void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr)
 }
 
 void sysbus_mmio_map_overlap(SysBusDevice *dev, int n, hwaddr addr,
-                             unsigned priority)
+                             int priority)
 {
     sysbus_mmio_map_common(dev, n, addr, true, priority);
 }

diff --git a/include/exec/memory.h b/include/exec/memory.h
index ebe0d24182cabbe01ee75e603765556e52883fb0..480dfbf9dadf31cdca8521dd34aabcbe75656cf6 100644 (file)
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -153,7 +153,7 @@ struct MemoryRegion {
     bool flush_coalesced_mmio;
     MemoryRegion *alias;
     hwaddr alias_offset;
-    unsigned priority;
+    int priority;
     bool may_overlap;
     QTAILQ_HEAD(subregions, MemoryRegion) subregions;
     QTAILQ_ENTRY(MemoryRegion) subregions_link;
@@ -779,7 +779,7 @@ void memory_region_add_subregion(MemoryRegion *mr,
 void memory_region_add_subregion_overlap(MemoryRegion *mr,
                                          hwaddr offset,
                                          MemoryRegion *subregion,
-                                         unsigned priority);
+                                         int priority);
 
 /**
  * memory_region_get_ram_addr: Get the ram address associated with a memory

diff --git a/include/hw/sysbus.h b/include/hw/sysbus.h
index bb50a877ccf56764c78d5c717451c51f64bf0ff7..f5aaa05ee3b55814e117ad8ad949f8db747bca2d 100644 (file)
--- a/include/hw/sysbus.h
+++ b/include/hw/sysbus.h
@@ -68,7 +68,7 @@ void sysbus_init_ioports(SysBusDevice *dev, pio_addr_t ioport, pio_addr_t size);
 void sysbus_connect_irq(SysBusDevice *dev, int n, qemu_irq irq);
 void sysbus_mmio_map(SysBusDevice *dev, int n, hwaddr addr);
 void sysbus_mmio_map_overlap(SysBusDevice *dev, int n, hwaddr addr,
-                             unsigned priority);
+                             int priority);
 void sysbus_add_io(SysBusDevice *dev, hwaddr addr,
                    MemoryRegion *mem);
 void sysbus_del_io(SysBusDevice *dev, MemoryRegion *mem);

diff --git a/memory.c b/memory.c
index 5a10fd0bde229f8d1a7cea5a7158259131cdd16d..f49d31ae72f42501ea3ee27ed6fc125e5d4b2539 100644 (file)
--- a/memory.c
+++ b/memory.c
@@ -1473,7 +1473,7 @@ void memory_region_add_subregion(MemoryRegion *mr,
 void memory_region_add_subregion_overlap(MemoryRegion *mr,
                                          hwaddr offset,
                                          MemoryRegion *subregion,
-                                         unsigned priority)
+                                         int priority)
 {
     subregion->may_overlap = true;
     subregion->priority = priority;
@@ -1506,7 +1506,7 @@ void memory_region_set_enabled(MemoryRegion *mr, bool enabled)
 void memory_region_set_address(MemoryRegion *mr, hwaddr addr)
 {
     MemoryRegion *parent = mr->parent;
-    unsigned priority = mr->priority;
+    int priority = mr->priority;
     bool may_overlap = mr->may_overlap;
 
     if (addr == mr->addr || !parent) {