[PATCH 1/2] MIPS: jazz: always allow little-endian builds

From: Arnd Bergmann
Date: Fri Jan 22 2021 - 06:11:15 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

The kernel test robot keeps reporting the same bug when it
shows up in new files after random unrelated patches:

In file included from arch/mips/include/uapi/asm/byteorder.h:13,
from arch/mips/include/asm/bitops.h:20,
from include/linux/bitops.h:26,
from include/linux/kernel.h:12,
from include/linux/clk.h:13,
from drivers/base/regmap/regmap-mmio.c:7:
include/linux/byteorder/big_endian.h:8:2: warning: #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN [-Wcpp]
8 | #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN
| ^~~~~~~
drivers/base/regmap/regmap-mmio.c: In function 'regmap_mmio_gen_context':
>> drivers/base/regmap/regmap-mmio.c:274:2: error: duplicate case value
274 | case REGMAP_ENDIAN_NATIVE:
| ^~~~
drivers/base/regmap/regmap-mmio.c:246:2: note: previously used here
246 | case REGMAP_ENDIAN_NATIVE:

The problem is that some randconfig builds end up on the MIPS jazz
platform with neither CONFIG_CPU_BIG_ENDIAN nor CONFIG_CPU_LITTLE_ENDIAN
because no specific machine is selected. As it turns out, all jazz
machines support little-endian kernels, so this can simply be allowed
globally.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
The configuration used by lkp here showed two other unrelated bugs,
one of which I'm addressing in another patch. The one I'm not
addressing is that 32-bit JAZZ with hugepages and 4K pages triggers
BUILD_BUG_ON(IS_ENABLED(CONFIG_32BIT) && (_PFN_SHIFT > PAGE_SHIFT)).
---
arch/mips/Kconfig | 1 +
arch/mips/jazz/Kconfig | 3 ---
2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2000bb2b0220..e6bd1eee70f2 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -406,6 +406,7 @@ config MACH_JAZZ
select SYS_SUPPORTS_32BIT_KERNEL
select SYS_SUPPORTS_64BIT_KERNEL
select SYS_SUPPORTS_100HZ
+ select SYS_SUPPORTS_LITTLE_ENDIAN
help
This a family of machines based on the MIPS R4030 chipset which was
used by several vendors to build RISC/os and Windows NT workstations.
diff --git a/arch/mips/jazz/Kconfig b/arch/mips/jazz/Kconfig
index 06838f80a5d7..42932ca98db9 100644
--- a/arch/mips/jazz/Kconfig
+++ b/arch/mips/jazz/Kconfig
@@ -3,7 +3,6 @@ config ACER_PICA_61
bool "Support for Acer PICA 1 chipset"
depends on MACH_JAZZ
select DMA_NONCOHERENT
- select SYS_SUPPORTS_LITTLE_ENDIAN
help
This is a machine with a R4400 133/150 MHz CPU. To compile a Linux
kernel that runs on these, say Y here. For details about Linux on
@@ -15,7 +14,6 @@ config MIPS_MAGNUM_4000
depends on MACH_JAZZ
select DMA_NONCOHERENT
select SYS_SUPPORTS_BIG_ENDIAN
- select SYS_SUPPORTS_LITTLE_ENDIAN
help
This is a machine with a R4000 100 MHz CPU. To compile a Linux
kernel that runs on these, say Y here. For details about Linux on
@@ -26,7 +24,6 @@ config OLIVETTI_M700
bool "Support for Olivetti M700-10"
depends on MACH_JAZZ
select DMA_NONCOHERENT
- select SYS_SUPPORTS_LITTLE_ENDIAN
help
This is a machine with a R4000 100 MHz CPU. To compile a Linux
kernel that runs on these, say Y here. For details about Linux on
--
2.29.2