[PATCH v2] riscv: enable multi-range memory layout

[Fei Wu]

In order to enable PCIe passthrough on qemu riscv, the physical memory
range between 3GB and 4GB is reserved. Therefore if guest has 4GB ram,
two ranges are created as [2G, 3G) and [4G, 7G), currently u-boot sets
ram_top to 4G - 1 if the gd->ram_top is above 4G in
board_get_usable_ram_top(), but that address is not backed by ram. This
patch selects the lowest range instead.

Signed-off-by: Fei Wu <fei2.wu at intel.com>
---
 arch/riscv/cpu/generic/dram.c        | 2 +-
 configs/qemu-riscv64_defconfig       | 2 +-
 configs/qemu-riscv64_smode_defconfig | 2 +-
 configs/qemu-riscv64_spl_defconfig   | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/cpu/generic/dram.c b/arch/riscv/cpu/generic/dram.c
index 44e11bd56c..fb53a57b4e 100644
--- a/arch/riscv/cpu/generic/dram.c
+++ b/arch/riscv/cpu/generic/dram.c
@@ -13,7 +13,7 @@ DECLARE_GLOBAL_DATA_PTR;
 
 int dram_init(void)
 {
-	return fdtdec_setup_mem_size_base();
+	return fdtdec_setup_mem_size_base_lowest();
 }
 
 int dram_init_banksize(void)
diff --git a/configs/qemu-riscv64_defconfig b/configs/qemu-riscv64_defconfig
index 9a8bbef192..aa55317d26 100644
--- a/configs/qemu-riscv64_defconfig
+++ b/configs/qemu-riscv64_defconfig
@@ -1,6 +1,6 @@
 CONFIG_RISCV=y
 CONFIG_SYS_MALLOC_LEN=0x800000
-CONFIG_NR_DRAM_BANKS=1
+CONFIG_NR_DRAM_BANKS=2
 CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
 CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x80200000
 CONFIG_ENV_SIZE=0x20000
diff --git a/configs/qemu-riscv64_smode_defconfig b/configs/qemu-riscv64_smode_defconfig
index 1d0f021ade..de08a49dab 100644
--- a/configs/qemu-riscv64_smode_defconfig
+++ b/configs/qemu-riscv64_smode_defconfig
@@ -1,6 +1,6 @@
 CONFIG_RISCV=y
 CONFIG_SYS_MALLOC_LEN=0x800000
-CONFIG_NR_DRAM_BANKS=1
+CONFIG_NR_DRAM_BANKS=2
 CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
 CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x80200000
 CONFIG_ENV_SIZE=0x20000
diff --git a/configs/qemu-riscv64_spl_defconfig b/configs/qemu-riscv64_spl_defconfig
index bb10145e6e..66dc2a1dd9 100644
--- a/configs/qemu-riscv64_spl_defconfig
+++ b/configs/qemu-riscv64_spl_defconfig
@@ -1,6 +1,6 @@
 CONFIG_RISCV=y
 CONFIG_SYS_MALLOC_LEN=0x800000
-CONFIG_NR_DRAM_BANKS=1
+CONFIG_NR_DRAM_BANKS=2
 CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y
 CONFIG_CUSTOM_SYS_INIT_SP_ADDR=0x80200000
 CONFIG_ENV_SIZE=0x20000
-- 
2.34.1