Hi Andreas,

On Thu, Sep 26, 2013 at 11:36:19PM +0100, Andreas Herrmann wrote:

(Depending on DT information and module parameters) each device is put
into its own protection domain (if possible).  For configuration with
one or just a few masters per SMMU that is easy to achieve.

In case of many devices per SMMU (e.g. MMU-500 with it's distributed
translation support) isolation of each device might not be possible --
depending on number of available SMR groups and/or context banks.

Default is that device isolation is contolled per SMMU with SMMU node
property "linux,arm-smmu-isolate-devices" in a DT. If the property is
set for an SMMU node device isolation is performed.

Also introduce a module parameter:

Actually, I think I'd rather do away with the module paramater / command
line option altogether in favour of DT.

+extern struct platform_device *of_find_device_by_node(struct device_node *np);
+
+static int arm_smmu_isolate_devices(void)
+{
+	struct dma_iommu_mapping *mapping;
+	struct arm_smmu_device *smmu;
+	struct rb_node *rbn;
+	struct arm_smmu_master *master;
+	struct platform_device *pdev;
+	struct device *dev;
+	void __iomem *gr0_base;
+	u32 cr0;
+	int ret = 0;
+	size_t size;
+
+	list_for_each_entry(smmu, &arm_smmu_devices, list) {
+		if (arm_smmu_disable_isolation ||
+			(!(smmu->features & ARM_SMMU_FEAT_ISOLATE_DEVICES)
+				&& !arm_smmu_force_isolation))
+			continue;
+		rbn = rb_first(&smmu->masters);
+		while (rbn) {
+			master = container_of(rbn, struct arm_smmu_master, node);
+			pdev = of_find_device_by_node(master->of_node);
+			if (!pdev)
+				break;
+			dev = &pdev->dev;
+
+			size = (size_t) dev->coherent_dma_mask;
+			size = size ? : (unsigned long) dev->dma_mask;

Hmm, this could be *huge* with 64-bit capable DMA controllers (think LPAE).
Russell also has some pending dma mask cleanup, which might break some
assumptions here:

http://lists.infradead.org/pipermail/linux-arm-kernel/2013-September/199397.html

(namely that we're offsetting everything from zero).

Will