From b49f700668fff7565b945dce823def79bff59bb0 Mon Sep 17 00:00:00 2001
From: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Date: Mon, 30 Jan 2023 00:18:18 +0300
Subject: riscv: mm: fix regression due to update_mmu_cache change

This is a partial revert of the commit 4bd1d80efb5a ("riscv: mm: notify
remote harts about mmu cache updates"). Original commit included two
loosely related changes serving the same purpose of fixing stale TLB
entries causing user-space application crash:
- introduce deferred per-ASID TLB flush for CPUs not running the task
- switch to per-ASID TLB flush on all CPUs running the task in update_mmu_cache

According to report and discussion in [1], the second part caused a
regression on Renesas RZ/Five SoC. For now restore the old behavior
of the update_mmu_cache.

[1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/

Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates")
Reported-by: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Link: trailer, so that it can be parsed with git's trailer functionality?
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230129211818.686557-1-geomatsi@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
---
 arch/riscv/include/asm/pgtable.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/riscv')

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 2a88362dffa5..039dee5fb76e 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -415,7 +415,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
 	 */
-	flush_tlb_page(vma, address);
+	local_flush_tlb_page(address);
 }
 
 #define __HAVE_ARCH_UPDATE_MMU_TLB
-- 
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