[PATCH v5 03/10] hw/arm/ast27x0: Add DRAM alias for SSP SDRAM remap

[Jamin Lin <jamin_lin@aspeedtech.com>]

This commit adds two MemoryRegion aliases to support PSP access to
SSP SDRAM through shared memory remapping.

The SSP exposes two DRAM aliases:
  - remap1 maps PSP DRAM at 0x400000000 to SSP SDRAM offset 0x5880000
  - remap2 maps PSP DRAM at 0x42C000000 to SSP SDRAM offset 0x0

These mappings follow the default SCU register configuration used by
the ASPEED SDK firmware, which defines the memory window mapping
between PSP and the SSP.

Set SSP CPUID 4.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
---
 include/hw/misc/aspeed_scu.h |  4 ++++
 hw/arm/aspeed_ast27x0-fc.c   |  2 ++
 hw/arm/aspeed_ast27x0-ssp.c  |  6 ++++++
 hw/arm/aspeed_ast27x0.c      |  4 ++++
 hw/misc/aspeed_scu.c         | 32 ++++++++++++++++++++++++++++++++
 5 files changed, 48 insertions(+)

diff --git a/include/hw/misc/aspeed_scu.h b/include/hw/misc/aspeed_scu.h
index 904549465f..ae49f6ab9a 100644
--- a/include/hw/misc/aspeed_scu.h
+++ b/include/hw/misc/aspeed_scu.h
@@ -44,6 +44,10 @@ struct AspeedSCUState {
 
 struct Aspeed2700SCUState {
     AspeedSCUState parent_obj;
+
+    MemoryRegion dram_remap_alias[3];
+    MemoryRegion *dram;
+    int ssp_cpuid;
 };
 
 #define AST2400_A1_SILICON_REV   0x02010303U
diff --git a/hw/arm/aspeed_ast27x0-fc.c b/hw/arm/aspeed_ast27x0-fc.c
index 058cea42ed..ce245118af 100644
--- a/hw/arm/aspeed_ast27x0-fc.c
+++ b/hw/arm/aspeed_ast27x0-fc.c
@@ -102,6 +102,8 @@ static bool ast2700fc_ca35_init(MachineState *machine, Error **errp)
                             sc->uarts_num, serial_hd(1));
     aspeed_soc_uart_set_chr(soc->uart, ASPEED_DEV_UART7, sc->uarts_base,
                             sc->uarts_num, serial_hd(2));
+    object_property_set_int(OBJECT(&s->ca35), "ssp-cpuid", 4,
+                            &error_abort);
     if (!qdev_realize(DEVICE(&s->ca35), NULL, errp)) {
         return false;
     }
diff --git a/hw/arm/aspeed_ast27x0-ssp.c b/hw/arm/aspeed_ast27x0-ssp.c
index 9c984d23cd..778876a60e 100644
--- a/hw/arm/aspeed_ast27x0-ssp.c
+++ b/hw/arm/aspeed_ast27x0-ssp.c
@@ -232,6 +232,12 @@ static void aspeed_soc_ast27x0ssp_realize(DeviceState *dev_soc, Error **errp)
     memory_region_add_subregion(s->memory, sc->memmap[ASPEED_DEV_SCUIO],
                                 &a->scuio_alias);
 
+    /* SDRAM remap alias used by PSP to access SSP SDRAM */
+    memory_region_add_subregion(&s->sdram, 0, &a->scu->dram_remap_alias[1]);
+    memory_region_add_subregion(&s->sdram,
+            memory_region_size(&a->scu->dram_remap_alias[1]),
+            &a->scu->dram_remap_alias[0]);
+
     /* INTC */
     if (!sysbus_realize(SYS_BUS_DEVICE(&a->intc[0]), errp)) {
         return;
diff --git a/hw/arm/aspeed_ast27x0.c b/hw/arm/aspeed_ast27x0.c
index dd6dd0377c..10d3e35a9b 100644
--- a/hw/arm/aspeed_ast27x0.c
+++ b/hw/arm/aspeed_ast27x0.c
@@ -442,6 +442,8 @@ static void aspeed_soc_ast2700_init(Object *obj)
                               "hw-strap1");
     object_property_add_alias(obj, "hw-prot-key", OBJECT(&a->scu),
                               "hw-prot-key");
+    object_property_add_alias(obj, "ssp-cpuid", OBJECT(&a->scu),
+                              "ssp-cpuid");
 
     object_initialize_child(obj, "scuio", &s->scuio, TYPE_ASPEED_2700_SCUIO);
     qdev_prop_set_uint32(DEVICE(&s->scuio), "silicon-rev",
@@ -808,6 +810,8 @@ static void aspeed_soc_ast2700_realize(DeviceState *dev, Error **errp)
                                 sc->memmap[ASPEED_DEV_VBOOTROM], &s->vbootrom);
 
     /* SCU */
+    object_property_set_link(OBJECT(&a->scu), "dram", OBJECT(s->dram_mr),
+                             &error_abort);
     if (!sysbus_realize(SYS_BUS_DEVICE(&a->scu), errp)) {
         return;
     }
diff --git a/hw/misc/aspeed_scu.c b/hw/misc/aspeed_scu.c
index ca93c3699d..cc0aa3234a 100644
--- a/hw/misc/aspeed_scu.c
+++ b/hw/misc/aspeed_scu.c
@@ -20,6 +20,7 @@
 #include "qemu/guest-random.h"
 #include "qemu/module.h"
 #include "trace.h"
+#include "qemu/units.h"
 
 #define TO_REG(offset) ((offset) >> 2)
 
@@ -932,9 +933,39 @@ static void aspeed_ast2700_scu_reset_hold(Object *obj, ResetType type)
 
 static void aspeed_2700_scu_realize(DeviceState *dev, Error **errp)
 {
+    Aspeed2700SCUState *a = ASPEED_2700_SCU(dev);
+
     aspeed_scu_realize(dev, errp);
+
+    if (a->ssp_cpuid > 0) {
+        if (!a->dram) {
+            error_setg(errp, TYPE_ASPEED_2700_SCU ": 'dram' link not set");
+            return;
+        }
+        /*
+         * The SSP coprocessor uses two memory aliases (remap1 and remap2)
+         * to access shared memory regions in the PSP DRAM:
+         *
+         * - remap1 maps PSP DRAM at 0x400000000 (size: 0x1A77E000) to
+         *   SSP SDRAM offset 0x5880000
+         * - remap2 maps PSP DRAM at 0x42C000000 (size: 0x05880000) to
+         *   SSP SDRAM offset 0x0
+         */
+        memory_region_init_alias(&a->dram_remap_alias[0], OBJECT(a),
+                                 "ssp.dram.remap1", a->dram,
+                                 0, 0x1a77e000);
+        memory_region_init_alias(&a->dram_remap_alias[1], OBJECT(a),
+                                 "ssp.dram.remap2", a->dram,
+                                 0x2c000000, 0x05880000);
+    }
 }
 
+static const Property aspeed_2700_scu_properties[] = {
+    DEFINE_PROP_INT32("ssp-cpuid", Aspeed2700SCUState, ssp_cpuid, -1),
+    DEFINE_PROP_LINK("dram", Aspeed2700SCUState, dram, TYPE_MEMORY_REGION,
+                     MemoryRegion *),
+};
+
 static void aspeed_2700_scu_class_init(ObjectClass *klass, const void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -944,6 +975,7 @@ static void aspeed_2700_scu_class_init(ObjectClass *klass, const void *data)
     dc->desc = "ASPEED 2700 System Control Unit";
     dc->realize = aspeed_2700_scu_realize;
     rc->phases.hold = aspeed_ast2700_scu_reset_hold;
+    device_class_set_props(dc, aspeed_2700_scu_properties);
     asc->resets = ast2700_a0_resets;
     asc->calc_hpll = aspeed_2600_scu_calc_hpll;
     asc->get_apb = aspeed_2700_scu_get_apb_freq;
-- 
2.43.0