On Fri, Aug 24, 2018 at 02:50:48PM +0100, Will Deacon wrote:

quoted

Sorry, I was a bit quick of the mark there. You'll need a forward
declaration for the paramater type. Here it is with a commit message,
although still untested because I haven't got round to setting up a riscv
toolchain yet.

Still doesn't work.

CC      mm/memory.o
In file included from ./arch/riscv/include/asm/pgtable.h:26:0,
                 from ./include/linux/memremap.h:7,
		 from ./include/linux/mm.h:27,
		 from arch/riscv/mm/fault.c:23:
./arch/riscv/include/asm/tlb.h: In function a??tlb_flusha??:
./arch/riscv/include/asm/tlb.h:21:18: error:
	dereferencing pointer to incomplete type a??struct mmu_gathera?? flush_tlb_mm(tlb->mm);

Problem is that struct mmu_gather is dereferenced in tlb_flush().

Guenter

quoted

Will

--->8

From adb9be33d68320edcda80d540a97a647792894d2 Mon Sep 17 00:00:00 2001
From: Will Deacon <redacted>
Date: Fri, 24 Aug 2018 14:33:48 +0100
Subject: [PATCH] riscv: tlb: Provide definition of tlb_flush() before
 including tlb.h

As of commit fd1102f0aade ("mm: mmu_notifier fix for tlb_end_vma"),
asm-generic/tlb.h now calls tlb_flush() from a static inline function,
so we need to make sure that it's declared before #including the
asm-generic header in the arch header.

Since tlb_flush() is a one-liner for riscv, we can define it before
including asm-generic/tlb.h as long as we provide a forward declaration
of struct mmu_gather.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Will Deacon <redacted>
---
 arch/riscv/include/asm/tlb.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/tlb.h b/arch/riscv/include/asm/tlb.h
index c229509288ea..a3d1380ad970 100644
--- a/arch/riscv/include/asm/tlb.h
+++ b/arch/riscv/include/asm/tlb.h

@@ -14,11 +14,13 @@
 #ifndef _ASM_RISCV_TLB_H
 #define _ASM_RISCV_TLB_H
 
-#include <asm-generic/tlb.h>
+struct mmu_gather;
 
 static inline void tlb_flush(struct mmu_gather *tlb)
 {
 	flush_tlb_mm(tlb->mm);

Bah, didn't spot the dereference so this won't work either. You basically
just need to copy what I did for arm64 in d475fac95779.

Will