On Fri, 24 Aug 2018 06:50:48 PDT (-0700), Will Deacon wrote:

On Fri, Aug 24, 2018 at 02:34:27PM +0100, Will Deacon wrote:

quoted

On Fri, Aug 24, 2018 at 06:24:19AM -0700, Guenter Roeck wrote:

quoted

On Fri, Aug 24, 2018 at 02:10:27PM +0100, Will Deacon wrote:

quoted

On Fri, Aug 24, 2018 at 06:07:22AM -0700, Guenter Roeck wrote:

quoted

On Thu, Aug 23, 2018 at 06:47:09PM +1000, Nicholas Piggin wrote:

quoted

The generic tlb_end_vma does not call invalidate_range mmu notifier,
and it resets resets the mmu_gather range, which means the notifier
won't be called on part of the range in case of an unmap that spans
multiple vmas.

ARM64 seems to be the only arch I could see that has notifiers and
uses the generic tlb_end_vma. I have not actually tested it.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Will Deacon <redacted>

This patch breaks riscv builds in mainline.

Looks very similar to the breakage we hit on arm64. diff below should fix
it.

Unfortunately it doesn't.

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:19:18: error: dereferencing pointer to incomplete type a??struct mmu_gathera??
  flush_tlb_mm(tlb->mm);
                  ^

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.

FWIW, Arnd built them last time he updated the cross tools so you should be 
able to get GCC 8.1.0 for RISC-V from there.  I use this make.cross script that 
I stole from the Intel 0-day robot

    https://github.com/palmer-dabbelt/home/blob/master/.local/src/local-scripts/make.cross.bash

If I'm reading it correctly the tools come from here

    http://cdn.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/x86_64-gcc-8.1.0-nolibc-riscv64-linux.tar.gz

I use the make.cross script as it makes it super easy to test my 
across-the-tree patches on other people's ports.

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