Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Zong Li <zongbox@gmail.com>
To:     palmer@sifive.com, aou@eecs.berkeley.edu
Cc:     hch@infradead.org, zong@andestech.com,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        Vincent Chen <vincentc@andestech.com>
Subject: [PATCH v4 5/5] RISC-V: Avoid corrupting the upper 32-bit of phys_addr_t in ioremap
Date:   Wed,  3 Oct 2018 11:10:02 +0800
Message-Id: <d851bbf26416d6fe5e55a2bec3121890cc95babd.1538535528.git.zongbox@gmail.com>
In-Reply-To: <cover.1538535527.git.zongbox@gmail.com>
References: <cover.1538535527.git.zongbox@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Vincent Chen <vincentc@andestech.com>

For 32bit, the upper 32-bit of phys_addr_t will be flushed to zero
after AND with PAGE_MASK because the data type of PAGE_MASK is
unsigned long. To fix this problem, the page alignment is done by
subtracting the page offset instead of AND with PAGE_MASK.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
---
 arch/riscv/mm/ioremap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/mm/ioremap.c b/arch/riscv/mm/ioremap.c
index 70ef272..bd2f2db 100644
--- a/arch/riscv/mm/ioremap.c
+++ b/arch/riscv/mm/ioremap.c
@@ -42,7 +42,7 @@ static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size,
 
 	/* Page-align mappings */
 	offset = addr & (~PAGE_MASK);
-	addr &= PAGE_MASK;
+	addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
-- 
2.7.4