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From:   Florian Fainelli <f.fainelli@gmail.com>
To:     linux-arm-kernel@lists.infradead.org
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Russell King <linux@armlinux.org.uk>,
        Nicolas Pitre <nico@fluxnic.net>,
        Catalin Marinas <catalin.marinas@arm.com>,
        linux-kernel@vger.kernel.org (open list),
        linus.walleij@linaro.org, Rob Herring <robh+dt@kernel.org>,
        Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH 1/2] ARM: Fix off by one in checking DMA zone size
Date:   Thu, 24 Mar 2022 10:54:16 -0700
Message-Id: <20220324175417.1014562-2-f.fainelli@gmail.com>
In-Reply-To: <20220324175417.1014562-1-f.fainelli@gmail.com>
References: <20220324175417.1014562-1-f.fainelli@gmail.com>
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The maximum DMA address is PAGE_OFFSET + arm_dma_zone_size - 1, fix this
by doing the appropriate subtraction.

Fixes: 650320181a08 ("ARM: change ARM_DMA_ZONE_SIZE into a variable")
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 arch/arm/include/asm/dma.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/dma.h b/arch/arm/include/asm/dma.h
index a81dda65c576..f244ee68e814 100644
--- a/arch/arm/include/asm/dma.h
+++ b/arch/arm/include/asm/dma.h
@@ -11,7 +11,7 @@
 #define MAX_DMA_ADDRESS	({ \
 	extern phys_addr_t arm_dma_zone_size; \
 	arm_dma_zone_size && arm_dma_zone_size < (0x10000000 - PAGE_OFFSET) ? \
-		(PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; })
+		(PAGE_OFFSET + arm_dma_zone_size - 1) : 0xffffffffUL; })
 #endif
 
 #ifdef CONFIG_ISA_DMA_API
-- 
2.25.1