Re: [RFC PATCH] mips: BCM63XX: select CPU_SUPPORTS_32BIT_KERNEL

[Florian Fainelli]

On 11/5/2021 7:58 PM, Randy Dunlap wrote:
> Several header files need info on CONFIG_32BIT or CONFIG_64BIT,
> but kconfig symbol BCM63XX does not provide that info. This leads
> to many build errors, e.g.:
>
>     arch/mips/include/asm/page.h:196:13: error: use of undeclared identifier 'CAC_BASE'
>             return x - PAGE_OFFSET + PHYS_OFFSET;
>     arch/mips/include/asm/mach-generic/spaces.h:91:23: note: expanded from macro 'PAGE_OFFSET'
>     #define PAGE_OFFSET             (CAC_BASE + PHYS_OFFSET)
>     arch/mips/include/asm/io.h:134:28: error: use of undeclared identifier 'CAC_BASE'
>             return (void *)(address + PAGE_OFFSET - PHYS_OFFSET);
>     arch/mips/include/asm/mach-generic/spaces.h:91:23: note: expanded from macro 'PAGE_OFFSET'
>     #define PAGE_OFFSET             (CAC_BASE + PHYS_OFFSET)
>
> arch/mips/include/asm/uaccess.h:82:10: error: use of undeclared identifier '__UA_LIMIT'
>             return (__UA_LIMIT & (addr | (addr + size) | __ua_size(size))) == 0;
>
>
> Fixes: e7300d04bd08 ("MIPS: BCM63xx: Add support for the Broadcom BCM63xx family of SOCs.")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Cc: bcm-kernel-feedback-list@xxxxxxxxxxxx
> Cc: linux-mips@xxxxxxxxxxxxxxx
> Cc: Paul Burton <paulburton@xxxxxxxxxx>
> Cc: Maxime Bizon <mbizon@xxxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> ---
> Note: I did see a bunch of build errors like this one:
> ../arch/mips/kernel/r4k_fpu.S:217: Error: opcode not supported on this processor: mips1 (mips1) `ldc1 $f24,192($4)'
> but I'm hoping/guessing that this is due to not having a proper compiler
> for the BCM63xx target.
>
>   arch/mips/Kconfig |    1 +
>   1 file changed, 1 insertion(+)
>
> --- linux-next-20211105.orig/arch/mips/Kconfig
> +++ linux-next-20211105/arch/mips/Kconfig
> @@ -329,6 +329,7 @@ config BCM63XX
>   	select SYNC_R4K
>   	select DMA_NONCOHERENT
>   	select IRQ_MIPS_CPU
> +	select CPU_SUPPORTS_32BIT_KERNEL

That's one option, the other could be to add:

        select SYS_HAS_CPU_BMIPS32_3300
        select SYS_HAS_CPU_BMIPS4350
        select SYS_HAS_CPU_BMIPS4380

Which would ensure that CPU_SUPPORTS_32BIT_KERNEL is selected AFAICT. 
Can you try that? What config file did you use to produce that build 
error BTW?
--
Florian