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Date: Tue, 19 Nov 2013 14:36:54 -0700
From: Stephen Warren <swarren@wwwdotorg.org>
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To: Hiroshi Doyu <hdoyu@nvidia.com>, swarren@nvidia.com, will.deacon@arm.com,
        grant.likely@linaro.org, thierry.reding@gmail.com,
        galak@codeaurora.org
CC: mark.rutland@arm.com, devicetree@vger.kernel.org,
        iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, lorenzo.pieralisi@arm.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCHv5 3/9] ARM: tegra: create a DT header defining SWGROUP
 ID
References: <1384853593-32202-1-git-send-email-hdoyu@nvidia.com> <1384853593-32202-4-git-send-email-hdoyu@nvidia.com>
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On 11/19/2013 02:33 AM, Hiroshi Doyu wrote:
> Create a header file to define the swgroup IDs used by the IOMMU(SMMU)
> binding. "swgroup" is a group of H/W clients which a Tegra SoC
> supports. This unique ID can be used to calculate MC_SMMU_<swgroup
> name>_ASID_0 register offset and MC_<swgroup name>_HOTRESET_*_0
> register bit. This will allow the same header to be used by both
> device tree files, and drivers implementing this binding, which
> guarantees that the two stay in sync. This also makes device trees
> more readable by using names instead of magic numbers. For HOTRESET
> bit shifting we need another conversion table, which will come later.

> diff --git a/include/dt-bindings/memory/tegra-swgroup.h b/include/dt-bindings/memory/tegra-swgroup.h

> +#define TEGRA_SWGROUP_PPCS2	32	/* 0xab0 */
> +
> +#define TWO_U32_OF_U64(x)	((x) & ~0UL) ((x) >> 32)
> +#define TEGRA_SWGROUP_BIT(x)	(1ULL << TEGRA_SWGROUP_##x)
> +#define TEGRA_SWGROUP_CELLS(x)	TWO_U32_OF_U64(TEGRA_SWGROUP_BIT(x))

This still doesn't actually compile in dtc:

$ cat > tmp.dts <<ENDOFHERE
/dts-v1/;

#define TEGRA_SWGROUP_PPCS2	32	/* 0xab0 */

#define TWO_U32_OF_U64(x)	((x) & ~0UL) ((x) >> 32)
#define TEGRA_SWGROUP_BIT(x)	(1ULL << TEGRA_SWGROUP_##x)
#define TEGRA_SWGROUP_CELLS(x)	TWO_U32_OF_U64(TEGRA_SWGROUP_BIT(x))

/ {
    prop = <TEGRA_SWGROUP_CELLS(PPCS2)>;
};
ENDOFHERE

$ gcc -nostdinc -undef -D__DTS__ -E -x assembler-with-cpp -o tmp.dts.i \
	tmp.dts

$ ./scripts/dtc/dtc -O dts -o tmp-compiled.dts -I dts tmp.dts.i
Error: tmp.dts:10.35-36 integer value out of range 0000000000000020 \
	(32 bits)
FATAL ERROR: Syntax error parsing input tree

The reason is that "& ~0UL" expands to "& 0xffffffffffffffff" since dtc
doesn't know about the size difference between UL and ULL. You need to
change that to "& 0xffffffff" and it works, at least in dtc.

Please test!