[PATCH v2 18/29] iommu/mediatek: Add PCIe support

[Yong Wu]

Currently the code for of_iommu_configure_dev_id is like this:

static int of_iommu_configure_dev_id(struct device_node *master_np,
                                     struct device *dev,
                                     const u32 *id)
{
       struct of_phandle_args iommu_spec = { .args_count = 1 };

       err = of_map_id(master_np, *id, "iommu-map",
                       "iommu-map-mask", &iommu_spec.np,
                       iommu_spec.args);
...
}

It supports only one id output. BUT our PCIe HW has two ID(one is for
writing, the other is for reading). I'm not sure if we should change
of_map_id to support output MAX_PHANDLE_ARGS.

Here add the solution in ourselve drivers. If it's pcie case, enable one
more bit.

Not all infra iommu support PCIe, thus add a PCIe support flag here.

Signed-off-by: Yong Wu <yong.wu at mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 45b34f4e99fb..b7a31f3a1bcf 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -21,6 +21,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
@@ -133,6 +134,7 @@
 #define MTK_IOMMU_TYPE_MM		(0x0 << 13)
 #define MTK_IOMMU_TYPE_INFRA		(0x1 << 13)
 #define MTK_IOMMU_TYPE_MASK		(0x3 << 13)
+#define IFA_IOMMU_PCIe_SUPPORT		BIT(15)
 
 #define MTK_IOMMU_HAS_FLAG(pdata, _x)	(!!(((pdata)->flags) & (_x)))
 
@@ -409,8 +411,12 @@ static int mtk_iommu_config(struct mtk_iommu_data *data, struct device *dev,
 				larb_mmu->mmu &= ~MTK_SMI_MMU_EN(portid);
 		} else if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_INFRA)) {
 			peri_mmuen_msk = BIT(portid);
-			peri_mmuen = enable ? peri_mmuen_msk : 0;
 
+			/* PCIdev has only one output id, enable the next writing bit for PCIe */
+			if (dev_is_pci(dev))
+				peri_mmuen_msk |= BIT(portid + 1);
+
+			peri_mmuen = enable ? peri_mmuen_msk : 0;
 			ret = regmap_update_bits(data->pericfg, PERICFG_IOMMU_1,
 						 peri_mmuen_msk, peri_mmuen);
 			if (ret)
@@ -996,6 +1002,15 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 		ret = component_master_add_with_match(dev, &mtk_iommu_com_ops, match);
 		if (ret)
 			goto out_bus_set_null;
+	} else if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_INFRA) &&
+		   MTK_IOMMU_HAS_FLAG(data->plat_data, IFA_IOMMU_PCIe_SUPPORT)) {
+		#ifdef CONFIG_PCI
+		if (!iommu_present(&pci_bus_type)) {
+			ret = bus_set_iommu(&pci_bus_type, &mtk_iommu_ops);
+			if (ret) /* PCIe fail don't affect platform_bus. */
+				goto out_list_del;
+		}
+		#endif
 	}
 	return ret;
 
-- 
2.18.0