linux-kernel - [PATCH] csky: syscache: Fixup duplicate cache flush

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Date:   Tue,  4 May 2021 07:14:48 +0000
From:   guoren@...nel.org
To:     guoren@...nel.org, arnd@...db.de
Cc:     linux-kernel@...r.kernel.org, linux-csky@...r.kernel.org,
        linux-arch@...r.kernel.org, Guo Ren <guoren@...ux.alibaba.com>,
        Randy Dunlap <rdunlap@...radead.org>
Subject: [PATCH] csky: syscache: Fixup duplicate cache flush

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

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")
Signed-off-by: Guo Ren <guoren@...ux.alibaba.com>
Cc: Randy Dunlap <rdunlap@...radead.org>
Cc: Arnd Bergmann <arnd@...db.de>
---
 arch/csky/mm/syscache.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/csky/mm/syscache.c b/arch/csky/mm/syscache.c
index 4e51d63..a7b53b0 100644
--- a/arch/csky/mm/syscache.c
+++ b/arch/csky/mm/syscache.c
@@ -12,15 +12,18 @@ 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)
+			fallthrough;
+		else
+			break;
+	case ICACHE:
+		flush_icache_mm_range(current->mm,
+				(unsigned long)addr,
+				(unsigned long)addr + bytes);
 		break;
 	default:
 		return -EINVAL;
-- 
2.7.4