From: Joerg.Roedel@amd•com (Roedel, Joerg)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v5 2/2] iommu/exynos: Add iommu driver for Exynos Platforms
Date: Fri, 14 Oct 2011 16:17:14 +0200 [thread overview]
Message-ID: <20111014141714.GD2198@amd.com> (raw)
In-Reply-To: <000501cc897f$fa0204f0$ee060ed0$%cho@samsung.com>
On Thu, Oct 13, 2011 at 04:13:23AM -0400, KyongHo Cho wrote:
> +struct exynos_iommu_domain {
> + struct device *dev;
> + unsigned long *pgtable;
> + spinlock_t lock;
> + spinlock_t pgtablelock;
> +};
Can you please add comments to document what these spinlocks protect?
> +static int exynos_iommu_attach_device(struct iommu_domain *domain,
> + struct device *dev)
> +{
> + struct exynos_iommu_domain *priv = domain->priv;
> + int ret;
> +
> + spin_lock(&priv->lock);
> +
> + priv->dev = dev;
> +
> + spin_unlock(&priv->lock);
> +
> + ret = exynos_iommu_enable(domain);
> +
> + return ret;
> +}
> +
> +static void exynos_iommu_detach_device(struct iommu_domain *domain,
> + struct device *dev)
> +{
> + struct exynos_iommu_domain *priv = domain->priv;
> +
> + spin_lock(&priv->lock);
> +
> + if (priv->dev == dev) {
> + priv->dev = NULL;
> +
> + spin_unlock(&priv->lock);
> +
> + exynos_iommu_disable(domain);
> + } else {
> + spin_unlock(&priv->lock);
> + }
> +}
That looks weird. As I read this code there is a 1-1 mapping between a
device and a domain. This breaks semantics of the iommu-api where a
domain can contain multiple devices.
Joerg
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next prev parent reply other threads:[~2011-10-14 14:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-13 8:13 [PATCH v5 2/2] iommu/exynos: Add iommu driver for Exynos Platforms KyongHo Cho
2011-10-14 14:17 ` Roedel, Joerg [this message]
2011-10-15 1:55 ` KyongHo Cho
-- strict thread matches above, loose matches on Subject: below --
2011-10-12 9:25 KyongHo Cho
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