[PATCH 05/10] iommu/ipmmu-vmsa: Introduce features, break out alias

[Magnus Damm]

From: Magnus Damm <damm+rene...@opensource.se>

Introduce struct ipmmu_features to track various hardware
and software implementation changes inside the driver for
different kinds of IPMMU hardware. Add use_ns_alias_offset
as a first example of a feature to control if the secure
register bank offset should be used or not.

Signed-off-by: Magnus Damm <damm+rene...@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

--- 0017/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c     2016-03-18 00:29:15.860513000 +0900
@@ -33,6 +33,10 @@
 
 #define IPMMU_CTX_MAX 4
 
+struct ipmmu_features {
+       bool use_ns_alias_offset;
+};
+
 struct ipmmu_vmsa_device {
        struct device *dev;
        void __iomem *base;
@@ -45,6 +49,7 @@ struct ipmmu_vmsa_device {
 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
        struct dma_iommu_mapping *mapping;
 #endif
+       const struct ipmmu_features *features;
 };
 
 struct ipmmu_vmsa_domain {
@@ -932,13 +937,33 @@ static void ipmmu_device_reset(struct ip
                ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
 }
 
+static const struct ipmmu_features ipmmu_features_default = {
+       .use_ns_alias_offset = true,
+};
+
+static const struct of_device_id ipmmu_of_ids[] = {
+       {
+               .compatible = "renesas,ipmmu-vmsa",
+               .data = &ipmmu_features_default,
+       }, {
+               /* Terminator */
+       },
+};
+
+MODULE_DEVICE_TABLE(of, ipmmu_of_ids);
+
 static int ipmmu_probe(struct platform_device *pdev)
 {
        struct ipmmu_vmsa_device *mmu;
+       const struct of_device_id *match;
        struct resource *res;
        int irq;
        int ret;
 
+       match = of_match_node(ipmmu_of_ids, pdev->dev.of_node);
+       if (!match)
+               return -EINVAL;
+
        mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
        if (!mmu) {
                dev_err(&pdev->dev, "cannot allocate device data\n");
@@ -948,6 +973,7 @@ static int ipmmu_probe(struct platform_d
        mmu->dev = &pdev->dev;
        mmu->num_utlbs = 32;
        bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
+       mmu->features = match->data;
        dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 
        /* Map I/O memory and request IRQ. */
@@ -968,7 +994,8 @@ static int ipmmu_probe(struct platform_d
         * Offset the registers base unconditionally to point to the non-secure
         * alias space for now.
         */
-       mmu->base += IM_NS_ALIAS_OFFSET;
+       if (mmu->features->use_ns_alias_offset)
+               mmu->base += IM_NS_ALIAS_OFFSET;
 
        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
@@ -1015,11 +1042,6 @@ static int ipmmu_remove(struct platform_
        return 0;
 }
 
-static const struct of_device_id ipmmu_of_ids[] = {
-       { .compatible = "renesas,ipmmu-vmsa", },
-       { }
-};
-
 static struct platform_driver ipmmu_driver = {
        .driver = {
                .name = "ipmmu-vmsa",