On Thu, Aug 09, 2018 at 03:19:51PM -0700, Palmer Dabbelt wrote:
> This would be necessary to make non-SMP builds work, but there is
> another error in the implementation of our syscall linkage that actually
> just causes sys_riscv_flush_icache to never build. I've build tested
> this on allnoconfig and allnoconfig+SMP=y, as well as defconfig like
> normal.
>
> CC: Christoph Hellwig <h...@infradead.org>
> CC: Guenter Roeck <li...@roeck-us.net>
> In-Reply-To: <20180809055830.ga17...@infradead.org>
> In-Reply-To: <20180809132612.ga31...@roeck-us.net>
> Signed-off-by: Palmer Dabbelt <pal...@sifive.com>
Tested-by: Guenter Roeck <li...@roeck-us.net>
> ---
> arch/riscv/include/asm/vdso.h | 2 --
> arch/riscv/kernel/sys_riscv.c | 12 ++++++++++--
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h
> index 541544d64c33..ec6180a4b55d 100644
> --- a/arch/riscv/include/asm/vdso.h
> +++ b/arch/riscv/include/asm/vdso.h
> @@ -38,8 +38,6 @@ struct vdso_data {
> (void __user *)((unsigned long)(base) + __vdso_##name);
> \
> })
>
> -#ifdef CONFIG_SMP
> asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
> -#endif
>
> #endif /* _ASM_RISCV_VDSO_H */
> diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
> index f7181ed8aafc..568026ccf6e8 100644
> --- a/arch/riscv/kernel/sys_riscv.c
> +++ b/arch/riscv/kernel/sys_riscv.c
> @@ -48,7 +48,6 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long,
> len,
> }
> #endif /* !CONFIG_64BIT */
>
> -#ifdef CONFIG_SMP
> /*
> * Allows the instruction cache to be flushed from userspace. Despite RISC-V
> * having a direct 'fence.i' instruction available to userspace (which we
> @@ -66,15 +65,24 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned
> long, len,
> SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
> uintptr_t, flags)
> {
> +#ifdef CONFIG_SMP
> struct mm_struct *mm = current->mm;
> bool local = (flags & SYS_RISCV_FLUSH_ICACHE_LOCAL) != 0;
> +#endif
>
> /* Check the reserved flags. */
> if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL))
> return -EINVAL;
>
> + /*
> + * Without CONFIG_SMP flush_icache_mm is a just a flush_icache_all(),
> + * which generates unused variable warnings all over this function.
> + */
> +#ifdef CONFIG_SMP
> flush_icache_mm(mm, local);
> +#else
> + flush_icache_all();
> +#endif
>
> return 0;
> }
> -#endif
> --
> 2.16.4
>
