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>
---
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
