Re: [PATCH] RISC-V: Always define XIP_FIXUP

[Palmer Dabbelt]

On Wed, 28 Apr 2021 01:25:55 PDT (-0700), alex@xxxxxxxx wrote:
> Le 4/27/21 à 11:34 PM, Palmer Dabbelt a écrit :
> > From: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
> >
> > XIP depends on MMU, but XIP_FIXUP is defined throughout the kernel in
> > order to avoid excessive ifdefs.  This just makes sure to always define
> > XIP_FIXIP, which will fix MMU=n builds.
>
> A small typo here.

Actually two: "defined" should have been "used".  Both are fixed.

> > Fixes: 44c922572952 ("RISC-V: enable XIP")
> > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
> > ---
> >   arch/riscv/include/asm/pgtable.h | 24 ++++++++++++------------
> >   1 file changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index 2f1384e14e31..fd749351f432 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -73,18 +73,6 @@
> >   #endif
> >   #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
> >
> > -#ifdef CONFIG_XIP_KERNEL
> > -#define XIP_OFFSET		SZ_8M
> > -#define XIP_FIXUP(addr) ({							\
> > -	uintptr_t __a = (uintptr_t)(addr);					\
> > -	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
> > -		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
> > -		__a;								\
> > -	})
> > -#else
> > -#define XIP_FIXUP(addr)		(addr)
> > -#endif /* CONFIG_XIP_KERNEL */
> > -
> >   #endif
> >
> >   #ifndef __ASSEMBLY__
> > @@ -101,6 +89,18 @@
> >   #include <asm/pgtable-32.h>
> >   #endif /* CONFIG_64BIT */
> >
> > +#ifdef CONFIG_XIP_KERNEL
> > +#define XIP_OFFSET		SZ_8M
>
>
> XIP_OFFSET is used in head.S and then this breaks XIP_KERNEL. XIP_OFFSET
> must live outside the ifndef __ASSEMBLY__.

Thanks, I hadn't even seen XIP_OFFSET.  This is fixed in the v2.

Do you have an XIP config that will run on QEMU, and a way to run it?  
If so, can you post a defconfig and some instructions?  That'll make it 
easier to test on my end.

> > +#define XIP_FIXUP(addr) ({							\
> > +	uintptr_t __a = (uintptr_t)(addr);					\
> > +	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
> > +		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
> > +		__a;								\
> > +	})
> > +#else
> > +#define XIP_FIXUP(addr)		(addr)
> > +#endif /* CONFIG_XIP_KERNEL */
> > +
> >   #ifdef CONFIG_MMU
> >   /* Number of entries in the page global directory */
> >   #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
>
> Thank you for doing that!
>
> Alex