[PATCH v3 04/11] iommu/mediatek: Get regionid from larb/port id

[Yong Wu <yong.wu@mediatek.com>]

After commit f1ad5338a4d5 ("of: Fix "dma-ranges" handling for bus
controllers"), the dma-ranges is not allowed for dts leaf node.
but we still would like to separate to different masters
into different iova regions.

Thus we have to separate it by the HW larbid and portid. For example,
larb1/2 are in region2 and larb3 is in region3. The problem is that
some ports inside a larb are in region4 while some ports inside this
larb are in region5. Therefore I define a "iova_region_larb_msk" to help
record the information for each a port. Take a example for a larb:
 [1] = ~0: means all ports in this larb are in region1;
 [2] = BIT(3) | BIT(4): means port3/4 in this larb are region2;
 [3] = ~(BIT(3) | BIT(4)): means all the other ports except port3/4
                           in this larb are region3.

This method also avoids the users forget/abuse the iova regions.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 47 ++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index ab53edcb221f..7e2cb3b8cac8 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -8,7 +8,6 @@
 #include <linux/clk.h>
 #include <linux/component.h>
 #include <linux/device.h>
-#include <linux/dma-direct.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -212,6 +211,11 @@ struct mtk_iommu_plat_data {
 	struct {
 		unsigned int	iova_region_nr;
 		const struct mtk_iommu_iova_region	*iova_region;
+		/*
+		 * Indicate the correspondence between larbs/ports and regions.
+		 * The index is same with iova_region.
+		 */
+		const u32	(*iova_region_larb_msk)[MTK_LARB_NR_MAX];
 	};
 
 	/*
@@ -529,30 +533,33 @@ static unsigned int mtk_iommu_get_bank_id(struct device *dev,
 static int mtk_iommu_get_iova_region_id(struct device *dev,
 					const struct mtk_iommu_plat_data *plat_data)
 {
-	const struct mtk_iommu_iova_region *rgn = plat_data->iova_region;
-	const struct bus_dma_region *dma_rgn = dev->dma_range_map;
-	int i, candidate = -1;
-	dma_addr_t dma_end;
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+	unsigned int portidmsk = 0, larbid;
+	const u32 *rgn_larb_msk;
+	int i, region_id = -1;
 
-	if (!dma_rgn || plat_data->iova_region_nr == 1)
+	if (plat_data->iova_region_nr == 1)
 		return 0;
 
-	dma_end = dma_rgn->dma_start + dma_rgn->size - 1;
-	for (i = 0; i < plat_data->iova_region_nr; i++, rgn++) {
-		/* Best fit. */
-		if (dma_rgn->dma_start == rgn->iova_base &&
-		    dma_end == rgn->iova_base + rgn->size - 1)
-			return i;
-		/* ok if it is inside this region. */
-		if (dma_rgn->dma_start >= rgn->iova_base &&
-		    dma_end < rgn->iova_base + rgn->size)
-			candidate = i;
+	larbid = MTK_M4U_TO_LARB(fwspec->ids[0]);
+	for (i = 0; i < fwspec->num_ids; i++)
+		portidmsk |= BIT(MTK_M4U_TO_PORT(fwspec->ids[i]));
+
+	for (i = 0; i < plat_data->iova_region_nr; i++) {
+		rgn_larb_msk = plat_data->iova_region_larb_msk[i];
+		if (!rgn_larb_msk)
+			continue;
+
+		if  ((rgn_larb_msk[larbid] & portidmsk) == portidmsk) {
+			region_id = i;
+			break;
+		}
 	}
 
-	if (candidate >= 0)
-		return candidate;
-	dev_err(dev, "Can NOT find the iommu domain id(%pad 0x%llx).\n",
-		&dma_rgn->dma_start, dma_rgn->size);
+	if (region_id >= 0)
+		return region_id;
+	dev_err(dev, "Can NOT find the region for larb(%d-%x).\n",
+		larbid, portidmsk);
 	return -EINVAL;
 }
 
-- 
2.18.0