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Date:   Tue, 2 Jul 2019 13:03:22 +0100
From:   Will Deacon <will@kernel.org>
To:     Zhangshaokun <zhangshaokun@hisilicon.com>, joro@8bytes.org
Cc:     Stephen Rothwell <sfr@canb.auug.org.au>,
        Linux Next Mailing List <linux-next@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: linux-next: Tree for Jul 2
Message-ID: <20190702120321.v3224ofd4aaxvytk@willie-the-truck>
References: <20190702195158.79aa5517@canb.auug.org.au>
 <000f56ac-2abc-bc6a-e2db-5ae38779d276@hisilicon.com>
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[+Joerg]

On Tue, Jul 02, 2019 at 06:40:45PM +0800, Zhangshaokun wrote:
> +Cc: Will Deacon
> 
> There is a compiler failure on arm64 platform, as follow:
> In file included from ./include/linux/list.h:9:0,
>                  from ./include/linux/kobject.h:19,
>                  from ./include/linux/of.h:17,
>                  from ./include/linux/irqdomain.h:35,
>                  from ./include/linux/acpi.h:13,
>                  from drivers/iommu/arm-smmu-v3.c:12:
> drivers/iommu/arm-smmu-v3.c: In function ‘arm_smmu_device_hw_probe’:
> drivers/iommu/arm-smmu-v3.c:194:40: error: ‘CONFIG_CMA_ALIGNMENT’ undeclared (first use in this function)
>  #define Q_MAX_SZ_SHIFT   (PAGE_SHIFT + CONFIG_CMA_ALIGNMENT)
>                                         ^
> It's the commit <d25f6ead162e> ("iommu/arm-smmu-v3: Increase maximum size of queues")

Thanks for the report. I've provided a fix below.

Joerg -- please can you take this on top of the SMMUv3 patches queued
for 5.3?

Cheers,

Will

--->8

From e8f9d8229e3aaa4817bfb72752e804eec97a3d8d Mon Sep 17 00:00:00 2001
From: Will Deacon <will@kernel.org>
Date: Tue, 2 Jul 2019 12:53:18 +0100
Subject: [PATCH] iommu/arm-smmu-v3: Fix compilation when CONFIG_CMA=n
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Content-Type: text/plain; charset=UTF-8
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When compiling a kernel without support for CMA, CONFIG_CMA_ALIGNMENT
is not defined which results in the following build failure:

In file included from ./include/linux/list.h:9:0
                 from ./include/linux/kobject.h:19,
                 from ./include/linux/of.h:17
                 from ./include/linux/irqdomain.h:35,
                 from ./include/linux/acpi.h:13,
                 from drivers/iommu/arm-smmu-v3.c:12:
drivers/iommu/arm-smmu-v3.c: In function ‘arm_smmu_device_hw_probe’:
drivers/iommu/arm-smmu-v3.c:194:40: error: ‘CONFIG_CMA_ALIGNMENT’ undeclared (first use in this function)
 #define Q_MAX_SZ_SHIFT   (PAGE_SHIFT + CONFIG_CMA_ALIGNMENT)

Fix the breakage by capping the maximum queue size based on MAX_ORDER
when CMA is not enabled.

Reported-by: Zhangshaokun <zhangshaokun@hisilicon.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
 drivers/iommu/arm-smmu-v3.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 57fb4e080d6b..8e73a7615bf5 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -191,7 +191,13 @@
 #define Q_BASE_RWA			(1UL << 62)
 #define Q_BASE_ADDR_MASK		GENMASK_ULL(51, 5)
 #define Q_BASE_LOG2SIZE			GENMASK(4, 0)
+
+/* Ensure DMA allocations are naturally aligned */
+#ifdef CONFIG_CMA_ALIGNMENT
 #define Q_MAX_SZ_SHIFT			(PAGE_SHIFT + CONFIG_CMA_ALIGNMENT)
+#else
+#define Q_MAX_SZ_SHIFT			(PAGE_SHIFT + MAX_ORDER - 1)
+#endif
 
 /*
  * Stream table.
-- 
2.11.0