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>

4 files changed, 56 insertions, 41 deletions

diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
index a06f7c1b62..dc09773b0b 100644
--- a/hw/arm/aspeed.c
+++ b/hw/arm/aspeed.c
@@ -174,27 +174,6 @@ struct AspeedMachineState {
 #define BLETCHLEY_BMC_HW_STRAP1 AST2600_EVB_HW_STRAP1
 #define BLETCHLEY_BMC_HW_STRAP2 AST2600_EVB_HW_STRAP2
 
-/*
- * The max ram region is for firmwares that scan the address space
- * with load/store to guess how much RAM the SoC has.
- */
-static uint64_t max_ram_read(void *opaque, hwaddr offset, unsigned size)
-{
-    return 0;
-}
-
-static void max_ram_write(void *opaque, hwaddr offset, uint64_t value,
-                           unsigned size)
-{
-    /* Discard writes */
-}
-
-static const MemoryRegionOps max_ram_ops = {
-    .read = max_ram_read,
-    .write = max_ram_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
-};
-
 #define AST_SMP_MAILBOX_BASE            0x1e6e2180
 #define AST_SMP_MBOX_FIELD_ENTRY        (AST_SMP_MAILBOX_BASE + 0x0)
 #define AST_SMP_MBOX_FIELD_GOSIGN       (AST_SMP_MAILBOX_BASE + 0x4)
@@ -324,20 +303,16 @@ static void aspeed_machine_init(MachineState *machine)
     AspeedMachineClass *amc = ASPEED_MACHINE_GET_CLASS(machine);
     AspeedSoCClass *sc;
     DriveInfo *drive0 = drive_get(IF_MTD, 0, 0);
-    ram_addr_t max_ram_size;
     int i;
     NICInfo *nd = &nd_table[0];
 
-    memory_region_init(&bmc->ram_container, NULL, "aspeed-ram-container",
-                       4 * GiB);
-    memory_region_add_subregion(&bmc->ram_container, 0, machine->ram);
-
     object_initialize_child(OBJECT(machine), "soc", &bmc->soc, amc->soc_name);
 
     sc = ASPEED_SOC_GET_CLASS(&bmc->soc);
 
     /*
-     * This will error out if isize is not supported by memory controller.
+     * This will error out if the RAM size is not supported by the
+     * memory controller of the SoC.
      */
     object_property_set_uint(OBJECT(&bmc->soc), "ram-size", machine->ram_size,
                              &error_fatal);
@@ -369,16 +344,6 @@ static void aspeed_machine_init(MachineState *machine)
                          amc->uart_default);
     qdev_realize(DEVICE(&bmc->soc), NULL, &error_abort);
 
-    memory_region_add_subregion(get_system_memory(),
-                                sc->memmap[ASPEED_DEV_SDRAM],
-                                &bmc->ram_container);
-
-    max_ram_size = object_property_get_uint(OBJECT(&bmc->soc), "max-ram-size",
-                                            &error_abort);
-    memory_region_init_io(&bmc->max_ram, NULL, &max_ram_ops, NULL,
-                          "max_ram", max_ram_size  - machine->ram_size);
-    memory_region_add_subregion(&bmc->ram_container, machine->ram_size, &bmc->max_ram);
-
     aspeed_board_init_flashes(&bmc->soc.fmc,
                               bmc->fmc_model ? bmc->fmc_model : amc->fmc_model,
                               amc->num_cs, 0);
diff --git a/hw/arm/aspeed_ast2600.c b/hw/arm/aspeed_ast2600.c
index b0a4199b69..bb5927c36b 100644
--- a/hw/arm/aspeed_ast2600.c
+++ b/hw/arm/aspeed_ast2600.c
@@ -197,8 +197,6 @@ static void aspeed_soc_ast2600_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);
@@ -443,6 +441,11 @@ static void aspeed_soc_ast2600_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,
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;
+}
diff --git a/include/hw/arm/aspeed_soc.h b/include/hw/arm/aspeed_soc.h
index 02a5a9ffcb..e8a104823d 100644
--- a/include/hw/arm/aspeed_soc.h
+++ b/include/hw/arm/aspeed_soc.h
@@ -50,6 +50,7 @@ struct AspeedSoCState {
     A15MPPrivState     a7mpcore;
     ARMv7MState        armv7m;
     MemoryRegion *dram_mr;
+    MemoryRegion dram_container;
     MemoryRegion sram;
     AspeedVICState vic;
     AspeedRtcState rtc;
@@ -165,5 +166,6 @@ enum {
 
 qemu_irq aspeed_soc_get_irq(AspeedSoCState *s, int dev);
 void aspeed_soc_uart_init(AspeedSoCState *s);
+bool aspeed_soc_dram_init(AspeedSoCState *s, Error **errp);
 
 #endif /* ASPEED_SOC_H */