[RFC PATCH-for-6.1 05/10] hw/arm/digic: 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-system-arm -M canon-a1100 -S -monitor stdio
  QEMU 5.2.90 monitor - type 'help' for more information
  (qemu) info mtree
  address-space: memory
    0000000000000000-ffffffffffffffff (prio 0, i/o): system
      0000000000000000-0000000003ffffff (prio 0, ram): ram
      00000000c0210000-00000000c02100ff (prio 0, i/o): digic-timer
      00000000c0210100-00000000c02101ff (prio 0, i/o): digic-timer
      00000000c0210200-00000000c02102ff (prio 0, i/o): digic-timer
      00000000c0800000-00000000c0800017 (prio 0, i/o): digic-uart
      00000000f8000000-00000000ffffffff (prio 0, i/o): pflash
        00000000f8000000-00000000f83fffff (prio 0, romd): alias pflash-alias 
@pflash 0000000000000000-00000000003fffff
        00000000f8400000-00000000f87fffff (prio 0, romd): alias pflash-alias 
@pflash 0000000000000000-00000000003fffff
        00000000f8800000-00000000f8bfffff (prio 0, romd): alias pflash-alias 
@pflash 0000000000000000-00000000003fffff
        ...
        00000000ff400000-00000000ff7fffff (prio 0, romd): alias pflash-alias 
@pflash 0000000000000000-00000000003fffff
        00000000ff800000-00000000ffbfffff (prio 0, romd): alias pflash-alias 
@pflash 0000000000000000-00000000003fffff
        00000000ffc00000-00000000ffffffff (prio 0, romd): alias pflash-alias 
@pflash 0000000000000000-00000000003fffff

* after:

  (qemu) info mtree
  address-space: memory
    0000000000000000-ffffffffffffffff (prio 0, i/o): system
      0000000000000000-0000000003ffffff (prio 0, ram): ram
      00000000c0210000-00000000c02100ff (prio 0, i/o): digic-timer
      00000000c0210100-00000000c02101ff (prio 0, i/o): digic-timer
      00000000c0210200-00000000c02102ff (prio 0, i/o): digic-timer
      00000000c0800000-00000000c0800017 (prio 0, i/o): digic-uart
      00000000f8000000-00000000ffffffff (prio 0, i/o): masked pflash [span of 4 
MiB]
        00000000f8000000-00000000f83fffff (prio 0, romd): alias pflash [#0/32] 
@pflash 0000000000000000-00000000003fffff
        00000000f8400000-00000000f87fffff (prio 0, romd): alias pflash [#1/32] 
@pflash 0000000000000000-00000000003fffff
        00000000f8800000-00000000f8bfffff (prio 0, romd): alias pflash [#2/32] 
@pflash 0000000000000000-00000000003fffff
        ...
        00000000ff400000-00000000ff7fffff (prio 0, romd): alias pflash [#29/32] 
@pflash 0000000000000000-00000000003fffff
        00000000ff800000-00000000ffbfffff (prio 0, romd): alias pflash [#30/32] 
@pflash 0000000000000000-00000000003fffff
        00000000ffc00000-00000000ffffffff (prio 0, romd): alias pflash [#31/32] 
@pflash 0000000000000000-00000000003fffff

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/arm/digic_boards.c | 8 +++++---
 hw/arm/Kconfig        | 1 +
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/hw/arm/digic_boards.c b/hw/arm/digic_boards.c
index fc4a671b2e1..293402b1240 100644
--- a/hw/arm/digic_boards.c
+++ b/hw/arm/digic_boards.c
@@ -128,8 +128,7 @@ static void digic4_add_k8p3215uqb_rom(DigicState *s, hwaddr 
addr,
                          FLASH_K8P3215UQB_SIZE / FLASH_K8P3215UQB_SECTOR_SIZE);
     qdev_prop_set_uint32(dev, "sector-length", FLASH_K8P3215UQB_SECTOR_SIZE);
     qdev_prop_set_uint8(dev, "width", 4); /* 32-bit */
-    qdev_prop_set_uint8(dev, "mappings",
-                        DIGIC4_ROM_MAX_SIZE / FLASH_K8P3215UQB_SIZE);
+    qdev_prop_set_uint8(dev, "mappings", 0);
     qdev_prop_set_uint8(dev, "big-endian", 0);
     qdev_prop_set_uint16(dev, "id0", 0x00ec);
     qdev_prop_set_uint16(dev, "id1", 0x007e);
@@ -140,7 +139,10 @@ static void digic4_add_k8p3215uqb_rom(DigicState *s, 
hwaddr addr,
     qdev_prop_set_string(dev, "name", "pflash");
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
 
-    sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
+    memory_region_add_subregion_aliased(get_system_memory(),
+                            addr, DIGIC4_ROM_MAX_SIZE,
+                            sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0),
+                            FLASH_K8P3215UQB_SIZE);
 
     digic_load_rom(s, addr, FLASH_K8P3215UQB_SIZE, filename);
 }
diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index aa8553b3cd3..1a7b9724d6c 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -42,6 +42,7 @@ config DIGIC
     bool
     select PTIMER
     select PFLASH_CFI02
+    select ALIASED_REGION
 
 config EXYNOS4
     bool
-- 
2.26.2