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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