video: rockchip: mpp: fix share iommu issue for rk3528 on Arch32

Issue:
1. On arm32 platform iommu use the mapping->domain, while use the
   group->domain on arm64 platform.
2. __iommu_attach_group use group->default to judge whether new device
   in kernel 5.10 branch, while use group->domain in kernel 6.1 branch.
   For this change, when two devices share the iommu, the first device
   attach success, while the second device failed in kernel 6.1 branch.

Method:
1. Set driver_managed_dma=true to ensure that during the IOMMU probe
phase,
   even if attach group failed, the mapping will not be released.
2. After the IOMMU probe succeeds, record info->domain=mapping->domain
and
   detach it, ensuring that group->domain is set to NULL. This prevents
the
   next device which sharing the IOMMU, not return -EBUSY when attach
the
   group.
3. Before hardware running, the shared IOMMU should check whether the
   device has been switched. If so, it needs to attach the current
   device's info->domain.
4. When removing a shared IOMMU, it must also ensure that group->domain
   corresponds to the current device.

Change-Id: If0fec01a0bcf9c49850129bfa5ac28484fece9a2
Signed-off-by: Ding Wei <leo.ding@rock-chips.com>

drivers/video/rockchip/mpp/mpp_common.c

@@ -2239,7 +2239,10 @@ int mpp_dev_probe(struct mpp_dev *mpp,
 	if (IS_ERR(mpp->iommu_info)) {
 		dev_err(dev, "failed to attach iommu\n");
 		mpp->iommu_info = NULL;
+	} else {
+		mpp->iommu_info->queue = mpp->queue;
 	}
+
 	if (mpp->hw_ops->init) {
 		ret = mpp->hw_ops->init(mpp);
 		if (ret)

drivers/video/rockchip/mpp/mpp_common.h

@@ -507,6 +507,9 @@ struct mpp_taskqueue {
 	u32 core_id_max;
 	u32 core_count;
 	unsigned long dev_active_flags;
+
+	/* for devices which share iommu, record last attach device */
+	struct mpp_iommu_info *last_iommu_info;
 };
 
 struct mpp_reset_group {
@@ -547,6 +550,9 @@ struct mpp_service {
 	/* global timing record flag */
 	u32 timing_en;
 	u32 load_interval;
+
+	/* bit mask for iommu shared */
+	u32 iommu_shared_mask;
 };
 
 /*

drivers/video/rockchip/mpp/mpp_iommu.c

@@ -17,6 +17,7 @@
 #include <linux/kref.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
 
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 #include <asm/dma-iommu.h>
@@ -451,9 +452,19 @@ int mpp_iommu_detach(struct mpp_iommu_info *info)
 
 int mpp_iommu_attach(struct mpp_iommu_info *info)
 {
+	struct mpp_iommu_info *last_info;
+
 	if (!info)
 		return 0;
 
+	/* if device changed, detach last first */
+	last_info = info->queue->last_iommu_info;
+	if (info->shared && last_info && last_info->shared
+	    && (info->dev != last_info->dev)) {
+		iommu_detach_group(last_info->domain, last_info->group);
+	}
+	info->queue->last_iommu_info = info;
+
 	if (info->domain == iommu_get_domain_for_dev(info->dev))
 		return 0;
 
@@ -561,6 +572,15 @@ mpp_iommu_probe(struct device *dev)
 	info->irq = platform_get_irq(pdev, 0);
 	info->got_irq = (info->irq < 0) ? false : true;
 
+	/* get shared flag, if true detach */
+	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
+		struct platform_driver *drv = to_platform_driver(dev->driver);
+
+		info->shared = drv->driver_managed_dma;
+		if (info->shared)
+			iommu_detach_group(info->domain, info->group);
+	}
+
 	return info;
 
 err_put_group:
@@ -578,6 +598,10 @@ int mpp_iommu_remove(struct mpp_iommu_info *info)
 	if (!info)
 		return 0;
 
+	/* if iommu shared, ensure current device's domain, then remove correctly */
+	if (info->shared)
+		mpp_iommu_attach(info);
+
 	iommu_group_put(info->group);
 	platform_device_put(info->pdev);
 

drivers/video/rockchip/mpp/mpp_iommu.h

@@ -102,6 +102,9 @@ struct mpp_iommu_info {
 
 	int irq;
 	int got_irq;
+	/* flag for mark iommu whether shared */
+	bool shared;
+	struct mpp_taskqueue *queue;
 };
 
 struct mpp_dma_session *

drivers/video/rockchip/mpp/mpp_service.c

@@ -100,6 +100,9 @@ static int mpp_add_driver(struct mpp_service *srv,
 		     &srv->grf_infos[type],
 		     grf_name);
 
+	if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
+		driver->driver_managed_dma = (srv->iommu_shared_mask & BIT(type)) ? true : false;
+
 	ret = platform_driver_register(driver);
 	if (ret)
 		return ret;
@@ -444,6 +447,9 @@ static int mpp_service_probe(struct platform_device *pdev)
 		}
 	}
 
+	of_property_read_u32(np, "rockchip,iommu-shared-mask",
+			     &srv->iommu_shared_mask);
+
 	ret = mpp_register_service(srv, MPP_SERVICE_NAME);
 	if (ret) {
 		dev_err(dev, "register %s device\n", MPP_SERVICE_NAME);