[PATCH v2 3/7] hw/arm/musicpal: Map flash using memory_region_add_subregion_aliased()

[Philippe Mathieu-Daudé]

Instead of using a device specific feature for mapping the
flash memory multiple times over a wider region, use the
generic memory_region_add_subregion_aliased() helper.

There is no change in the memory layout:

- before:

  (qemu) info mtree
  00000000fe000000-00000000ffffffff (prio 0, i/o): pflash
    00000000fe000000-00000000fe7fffff (prio 0, romd): alias pflash-alias 
@musicpal.flash 0000000000000000-00000000007fffff
    00000000fe800000-00000000feffffff (prio 0, romd): alias pflash-alias 
@musicpal.flash 0000000000000000-00000000007fffff
    00000000ff000000-00000000ff7fffff (prio 0, romd): alias pflash-alias 
@musicpal.flash 0000000000000000-00000000007fffff
    00000000ff800000-00000000ffffffff (prio 0, romd): alias pflash-alias 
@musicpal.flash 0000000000000000-00000000007fffff

- after:

  00000000fe000000-00000000ffffffff (prio 0, i/o): masked musicpal.flash [span 
of 8 MiB]
    00000000fe000000-00000000fe7fffff (prio 0, romd): alias musicpal.flash 
[#0/4] @musicpal.flash 0000000000000000-00000000007fffff
    00000000fe800000-00000000feffffff (prio 0, romd): alias musicpal.flash 
[#1/4] @musicpal.flash 0000000000000000-00000000007fffff
    00000000ff000000-00000000ff7fffff (prio 0, romd): alias musicpal.flash 
[#2/4] @musicpal.flash 0000000000000000-00000000007fffff
    00000000ff800000-00000000ffffffff (prio 0, romd): alias musicpal.flash 
[#3/4] @musicpal.flash 0000000000000000-00000000007fffff

Flatview is the same:

  (qemu) info mtree -f
  FlatView #0
   AS "memory", root: system
   AS "cpu-memory-0", root: system
   AS "emac-dma", root: system
   Root memory region: system
    00000000fe000000-00000000fe7fffff (prio 0, romd): musicpal.flash
    00000000fe800000-00000000feffffff (prio 0, romd): musicpal.flash
    00000000ff000000-00000000ff7fffff (prio 0, romd): musicpal.flash
    00000000ff800000-00000000ffffffff (prio 0, romd): musicpal.flash

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/arm/musicpal.c | 11 +++++++----
 hw/arm/Kconfig    |  1 +
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/hw/arm/musicpal.c b/hw/arm/musicpal.c
index 8b58b66f263..7d1f2f3fb3f 100644
--- a/hw/arm/musicpal.c
+++ b/hw/arm/musicpal.c
@@ -30,6 +30,7 @@
 #include "hw/irq.h"
 #include "hw/or-irq.h"
 #include "hw/audio/wm8750.h"
+#include "hw/misc/aliased_region.h"
 #include "sysemu/block-backend.h"
 #include "sysemu/runstate.h"
 #include "sysemu/dma.h"
@@ -1656,7 +1657,7 @@ static void musicpal_init(MachineState *machine)
         qdev_prop_set_uint32(dev, "num-blocks", flash_size / sector_size);
         qdev_prop_set_uint32(dev, "sector-length", sector_size);
         qdev_prop_set_uint8(dev, "width", 2); /* 16-bit */
-        qdev_prop_set_uint8(dev, "mappings", MP_FLASH_SIZE_MAX / flash_size);
+        qdev_prop_set_uint8(dev, "mappings", 0);
         qdev_prop_set_uint8(dev, "big-endian", 0);
         qdev_prop_set_uint16(dev, "id0", 0x00bf);
         qdev_prop_set_uint16(dev, "id1", 0x236d);
@@ -1667,14 +1668,16 @@ static void musicpal_init(MachineState *machine)
         qdev_prop_set_string(dev, "name", "musicpal.flash");
         sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
 
-        sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0,
-                        0x100000000ULL - MP_FLASH_SIZE_MAX);
-
         /*
          * The original U-Boot accesses the flash at 0xFE000000 instead of
          * 0xFF800000 (if there is 8 MB flash). So remap flash access if the
          * image is smaller than 32 MB.
          */
+        memory_region_add_subregion_aliased(get_system_memory(),
+                                0x100000000ULL - MP_FLASH_SIZE_MAX,
+                                MP_FLASH_SIZE_MAX,
+                                sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0),
+                                flash_size);
     }
     sysbus_create_simple(TYPE_MV88W8618_FLASHCFG, MP_FLASHCFG_BASE, NULL);
 
diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 8c37cf00da7..aa8553b3cd3 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -101,6 +101,7 @@ config MUSICPAL
     select MARVELL_88W8618
     select PTIMER
     select PFLASH_CFI02
+    select ALIASED_REGION
     select SERIAL
     select WM8750
 
-- 
2.26.3