releases/5.10.50/csky-syscache-fixup-duplicate-cache-flush.patch

From 539994d82a72968ace4dc15d235a8dc901f3d239 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Tue, 4 May 2021 14:08:44 +0800
Subject: csky: syscache: Fixup duplicate cache flush

From: Guo Ren <guoren@linux.alibaba.com>

[ Upstream commit 6ea42c84f33368eb3fe1ec1bff8d7cb1a5c7b07a ]

The current csky logic of sys_cacheflush is wrong, it'll cause
icache flush call dcache flush again. Now fixup it with a
conditional "break & fallthrough".

Fixes: 997153b9a75c ("csky: Add flush_icache_mm to defer flush icache all")
Fixes: 0679d29d3e23 ("csky: fix syscache.c fallthrough warning")
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Co-Developed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/csky/mm/syscache.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/csky/mm/syscache.c b/arch/csky/mm/syscache.c
index 4e51d63850c4..cd847ad62c7e 100644
--- a/arch/csky/mm/syscache.c
+++ b/arch/csky/mm/syscache.c
@@ -12,15 +12,17 @@ SYSCALL_DEFINE3(cacheflush,
 		int, cache)
 {
 	switch (cache) {
-	case ICACHE:
 	case BCACHE:
-		flush_icache_mm_range(current->mm,
-				(unsigned long)addr,
-				(unsigned long)addr + bytes);
-		fallthrough;
 	case DCACHE:
 		dcache_wb_range((unsigned long)addr,
 				(unsigned long)addr + bytes);
+		if (cache != BCACHE)
+			break;
+		fallthrough;
+	case ICACHE:
+		flush_icache_mm_range(current->mm,
+				(unsigned long)addr,
+				(unsigned long)addr + bytes);
 		break;
 	default:
 		return -EINVAL;
-- 
2.30.2