[PATCH-for-5.1] hw/misc/aspeed_sdmc: Fix incorrect memory size

[Philippe Mathieu-Daudé]

The SDRAM Memory Controller has a 32-bit address bus, thus
supports up to 4 GiB of DRAM. There is a signed to unsigned
conversion error with the AST2600 maximum memory size:

  (uint64_t)(2048 << 20) = (uint64_t)(-2147483648)
                         = 0xffffffff40000000
                         = 16 EiB - 2 GiB

Fix by using the IEC suffixes which are usually safer, and add
a check to verify the memory is valid. This would have catched
this bug:

    Unexpected error in aspeed_sdmc_realize() at hw/misc/aspeed_sdmc.c:261:
    qemu-system-arm: Invalid RAM size 16 EiB

Fixes: 1550d72679 ("aspeed/sdmc: Add AST2600 support")
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/misc/aspeed_sdmc.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/hw/misc/aspeed_sdmc.c b/hw/misc/aspeed_sdmc.c
index 0737d8de81..76dd7e6a20 100644
--- a/hw/misc/aspeed_sdmc.c
+++ b/hw/misc/aspeed_sdmc.c
@@ -256,6 +256,12 @@ static void aspeed_sdmc_realize(DeviceState *dev, Error 
**errp)
     AspeedSDMCClass *asc = ASPEED_SDMC_GET_CLASS(s);
 
     s->max_ram_size = asc->max_ram_size;
+    if (s->max_ram_size >= 4 * GiB) {
+        char *szstr = size_to_str(s->max_ram_size);
+        error_setg(errp, "Invalid RAM size %s", szstr);
+        g_free(szstr);
+        return;
+    }
 
     memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_sdmc_ops, s,
                           TYPE_ASPEED_SDMC, 0x1000);
@@ -341,7 +347,7 @@ static void aspeed_2400_sdmc_class_init(ObjectClass *klass, 
void *data)
     AspeedSDMCClass *asc = ASPEED_SDMC_CLASS(klass);
 
     dc->desc = "ASPEED 2400 SDRAM Memory Controller";
-    asc->max_ram_size = 512 << 20;
+    asc->max_ram_size = 512 * MiB;
     asc->compute_conf = aspeed_2400_sdmc_compute_conf;
     asc->write = aspeed_2400_sdmc_write;
     asc->valid_ram_sizes = aspeed_2400_ram_sizes;
@@ -408,7 +414,7 @@ static void aspeed_2500_sdmc_class_init(ObjectClass *klass, 
void *data)
     AspeedSDMCClass *asc = ASPEED_SDMC_CLASS(klass);
 
     dc->desc = "ASPEED 2500 SDRAM Memory Controller";
-    asc->max_ram_size = 1024 << 20;
+    asc->max_ram_size = 1 * GiB;
     asc->compute_conf = aspeed_2500_sdmc_compute_conf;
     asc->write = aspeed_2500_sdmc_write;
     asc->valid_ram_sizes = aspeed_2500_ram_sizes;
@@ -485,7 +491,7 @@ static void aspeed_2600_sdmc_class_init(ObjectClass *klass, 
void *data)
     AspeedSDMCClass *asc = ASPEED_SDMC_CLASS(klass);
 
     dc->desc = "ASPEED 2600 SDRAM Memory Controller";
-    asc->max_ram_size = 2048 << 20;
+    asc->max_ram_size = 2 * GiB;
     asc->compute_conf = aspeed_2600_sdmc_compute_conf;
     asc->write = aspeed_2600_sdmc_write;
     asc->valid_ram_sizes = aspeed_2600_ram_sizes;
-- 
2.21.3