Merge tag 'riscv-for-v5.2/fixes-rc6' of git://git.kernel.org/pub/scm/linux/kernel...

[thirdparty/linux.git] / arch / riscv / mm / fault.c

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index cec8be9e2d6aca1049945fc0a4200f0ef36071b0..3e2708c626a854884358ced1e6f60bbd1e5f5fa6 100644 (file)
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
  *  Lennox Wu <lennox.wu@sunplusct.com>
  *  Chen Liqin <liqin.chen@sunplusct.com>
  * Copyright (C) 2012 Regents of the University of California
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.,
  */
 
 
@@ -29,6 +16,7 @@
 
 #include <asm/pgalloc.h>
 #include <asm/ptrace.h>
+#include <asm/tlbflush.h>
 
 /*
  * This routine handles page faults.  It determines the address and the
@@ -278,6 +266,18 @@ vmalloc_fault:
                pte_k = pte_offset_kernel(pmd_k, addr);
                if (!pte_present(*pte_k))
                        goto no_context;
+
+               /*
+                * The kernel assumes that TLBs don't cache invalid
+                * entries, but in RISC-V, SFENCE.VMA specifies an
+                * ordering constraint, not a cache flush; it is
+                * necessary even after writing invalid entries.
+                * Relying on flush_tlb_fix_spurious_fault would
+                * suffice, but the extra traps reduce
+                * performance. So, eagerly SFENCE.VMA.
+                */
+               local_flush_tlb_page(addr);
+
                return;
        }
 }