[PATCH] riscv: keep 32-bit kernel to 32-bit phys_addr_t

From: Olof Johansson
Date: Mon Jan 06 2020 - 18:16:22 EST


While rv32 technically has 34-bit physical addresses, no current
platforms use it and it's likely to shake out driver bugs.

Let's keep 64-bit phys_addr_t off on 32-bit builds until one shows up,
since other work will be needed to make such a system useful anyway.

Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
---
arch/riscv/Kconfig | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index a31169b02ec06..33a20fa046e0a 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -12,8 +12,9 @@ config 32BIT

config RISCV
def_bool y
- # even on 32-bit, physical (and DMA) addresses are > 32-bits
- select PHYS_ADDR_T_64BIT
+ # While RV32 has 34-bit physical addresses, no known platform
+ # uses it, so keep it to 32-bit until one shows up to test with.
+ select PHYS_ADDR_T_64BIT if 64BIT
select OF
select OF_EARLY_FLATTREE
select OF_IRQ
--
2.20.1