aspeed: Set the dram container at the SoC level

Currently, the Aspeed machines allocate a ram container region in
which the machine ram region is mapped. See commit ad1a9782186d
("aspeed: add a RAM memory region container"). An extra region is
mapped after ram in the ram container to catch invalid access done by
FW. That's how FW determines the size of ram. See commit ebe31c0a8ef7
("aspeed: add a max_ram_size property to the memory controller").

Let's move all the logic under the SoC where it should be. It will
also ease the work on multi SoC support.

Reviewed-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220623202123.3972977-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

1 files changed, 47 insertions, 2 deletions

diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c
index 30574d4276..3e6055ac91 100644
--- a/hw/arm/aspeed_soc.c
+++ b/hw/arm/aspeed_soc.c
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/units.h"
 #include "qapi/error.h"
 #include "hw/misc/unimp.h"
 #include "hw/arm/aspeed_soc.h"
@@ -191,8 +192,6 @@ static void aspeed_soc_init(Object *obj)
     object_initialize_child(obj, "sdmc", &s->sdmc, typename);
     object_property_add_alias(obj, "ram-size", OBJECT(&s->sdmc),
                               "ram-size");
-    object_property_add_alias(obj, "max-ram-size", OBJECT(&s->sdmc),
-                              "max-ram-size");
 
     for (i = 0; i < sc->wdts_num; i++) {
         snprintf(typename, sizeof(typename), "aspeed.wdt-%s", socname);
@@ -369,6 +368,11 @@ static void aspeed_soc_realize(DeviceState *dev, Error **errp)
                         sc->memmap[ASPEED_DEV_WDT] + i * awc->offset);
     }
 
+    /* RAM  */
+    if (!aspeed_soc_dram_init(s, errp)) {
+        return;
+    }
+
     /* Net */
     for (i = 0; i < sc->macs_num; i++) {
         object_property_set_bool(OBJECT(&s->ftgmac100[i]), "aspeed", true,
@@ -561,3 +565,44 @@ void aspeed_soc_uart_init(AspeedSoCState *s)
                        serial_hd(i), DEVICE_LITTLE_ENDIAN);
     }
 }
+
+/*
+ * SDMC should be realized first to get correct RAM size and max size
+ * values
+ */
+bool aspeed_soc_dram_init(AspeedSoCState *s, Error **errp)
+{
+    AspeedSoCClass *sc = ASPEED_SOC_GET_CLASS(s);
+    ram_addr_t ram_size, max_ram_size;
+
+    ram_size = object_property_get_uint(OBJECT(&s->sdmc), "ram-size",
+                                        &error_abort);
+    max_ram_size = object_property_get_uint(OBJECT(&s->sdmc), "max-ram-size",
+                                            &error_abort);
+
+    memory_region_init(&s->dram_container, OBJECT(s), "ram-container",
+                       max_ram_size);
+    memory_region_add_subregion(&s->dram_container, 0, s->dram_mr);
+
+    /*
+     * Add a memory region beyond the RAM region to let firmwares scan
+     * the address space with load/store and guess how much RAM the
+     * SoC has.
+     */
+    if (ram_size < max_ram_size) {
+        DeviceState *dev = qdev_new(TYPE_UNIMPLEMENTED_DEVICE);
+
+        qdev_prop_set_string(dev, "name", "ram-empty");
+        qdev_prop_set_uint64(dev, "size", max_ram_size  - ram_size);
+        if (!sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), errp)) {
+            return false;
+        }
+
+        memory_region_add_subregion_overlap(&s->dram_container, ram_size,
+                      sysbus_mmio_get_region(SYS_BUS_DEVICE(dev), 0), -1000);
+    }
+
+    memory_region_add_subregion(get_system_memory(),
+                      sc->memmap[ASPEED_DEV_SDRAM], &s->dram_container);
+    return true;
+}