1 files changed, 129 insertions, 52 deletions

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 0ce5e8a0658c..9f6f74689464 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -22,6 +22,7 @@
 #include <linux/of_iommu.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
@@ -106,6 +107,7 @@ struct rk_iommu {
 };
 
 struct rk_iommudata {
+	struct device_link *link; /* runtime PM link from IOMMU to master */
 	struct rk_iommu *iommu;
 };
 
@@ -520,7 +522,11 @@ static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
 	irqreturn_t ret = IRQ_NONE;
 	int i;
 
-	WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks));
+	if (WARN_ON(!pm_runtime_get_if_in_use(iommu->dev)))
+		return 0;
+
+	if (WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks)))
+		goto out;
 
 	for (i = 0; i < iommu->num_mmu; i++) {
 		int_status = rk_iommu_read(iommu->bases[i], RK_MMU_INT_STATUS);
@@ -570,6 +576,8 @@ static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
 
 	clk_bulk_disable(iommu->num_clocks, iommu->clocks);
 
+out:
+	pm_runtime_put(iommu->dev);
 	return ret;
 }
 
@@ -611,10 +619,17 @@ static void rk_iommu_zap_iova(struct rk_iommu_domain *rk_domain,
 	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
 	list_for_each(pos, &rk_domain->iommus) {
 		struct rk_iommu *iommu;
+
 		iommu = list_entry(pos, struct rk_iommu, node);
-		WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks));
-		rk_iommu_zap_lines(iommu, iova, size);
-		clk_bulk_disable(iommu->num_clocks, iommu->clocks);
+
+		/* Only zap TLBs of IOMMUs that are powered on. */
+		if (pm_runtime_get_if_in_use(iommu->dev)) {
+			WARN_ON(clk_bulk_enable(iommu->num_clocks,
+						iommu->clocks));
+			rk_iommu_zap_lines(iommu, iova, size);
+			clk_bulk_disable(iommu->num_clocks, iommu->clocks);
+			pm_runtime_put(iommu->dev);
+		}
 	}
 	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
 }
@@ -817,22 +832,30 @@ static struct rk_iommu *rk_iommu_from_dev(struct device *dev)
 	return data ? data->iommu : NULL;
 }
 
-static int rk_iommu_attach_device(struct iommu_domain *domain,
-				  struct device *dev)
+/* Must be called with iommu powered on and attached */
+static void rk_iommu_disable(struct rk_iommu *iommu)
 {
-	struct rk_iommu *iommu;
+	int i;
+
+	/* Ignore error while disabling, just keep going */
+	WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks));
+	rk_iommu_enable_stall(iommu);
+	rk_iommu_disable_paging(iommu);
+	for (i = 0; i < iommu->num_mmu; i++) {
+		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, 0);
+		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, 0);
+	}
+	rk_iommu_disable_stall(iommu);
+	clk_bulk_disable(iommu->num_clocks, iommu->clocks);
+}
+
+/* Must be called with iommu powered on and attached */
+static int rk_iommu_enable(struct rk_iommu *iommu)
+{
+	struct iommu_domain *domain = iommu->domain;
 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
-	unsigned long flags;
 	int ret, i;
 
-	/*
-	 * Allow 'virtual devices' (e.g., drm) to attach to domain.
-	 * Such a device does not belong to an iommu group.
-	 */
-	iommu = rk_iommu_from_dev(dev);
-	if (!iommu)
-		return 0;
-
 	ret = clk_bulk_enable(iommu->num_clocks, iommu->clocks);
 	if (ret)
 		return ret;
@@ -845,8 +868,6 @@ static int rk_iommu_attach_device(struct iommu_domain *domain,
 	if (ret)
 		goto out_disable_stall;
 
-	iommu->domain = domain;
-
 	for (i = 0; i < iommu->num_mmu; i++) {
 		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR,
 			       rk_domain->dt_dma);
@@ -855,14 +876,6 @@ static int rk_iommu_attach_device(struct iommu_domain *domain,
 	}
 
 	ret = rk_iommu_enable_paging(iommu);
-	if (ret)
-		goto out_disable_stall;
-
-	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
-	list_add_tail(&iommu->node, &rk_domain->iommus);
-	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
-
-	dev_dbg(dev, "Attached to iommu domain\n");
 
 out_disable_stall:
 	rk_iommu_disable_stall(iommu);
@@ -877,31 +890,71 @@ static void rk_iommu_detach_device(struct iommu_domain *domain,
 	struct rk_iommu *iommu;
 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
 	unsigned long flags;
-	int i;
 
 	/* Allow 'virtual devices' (eg drm) to detach from domain */
 	iommu = rk_iommu_from_dev(dev);
 	if (!iommu)
 		return;
 
+	dev_dbg(dev, "Detaching from iommu domain\n");
+
+	/* iommu already detached */
+	if (iommu->domain != domain)
+		return;
+
+	iommu->domain = NULL;
+
 	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
 	list_del_init(&iommu->node);
 	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
 
-	/* Ignore error while disabling, just keep going */
-	WARN_ON(clk_bulk_enable(iommu->num_clocks, iommu->clocks));
-	rk_iommu_enable_stall(iommu);
-	rk_iommu_disable_paging(iommu);
-	for (i = 0; i < iommu->num_mmu; i++) {
-		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, 0);
-		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, 0);
+	if (pm_runtime_get_if_in_use(iommu->dev)) {
+		rk_iommu_disable(iommu);
+		pm_runtime_put(iommu->dev);
 	}
-	rk_iommu_disable_stall(iommu);
-	clk_bulk_disable(iommu->num_clocks, iommu->clocks);
+}
 
-	iommu->domain = NULL;
+static int rk_iommu_attach_device(struct iommu_domain *domain,
+		struct device *dev)
+{
+	struct rk_iommu *iommu;
+	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
+	unsigned long flags;
+	int ret;
 
-	dev_dbg(dev, "Detached from iommu domain\n");
+	/*
+	 * Allow 'virtual devices' (e.g., drm) to attach to domain.
+	 * Such a device does not belong to an iommu group.
+	 */
+	iommu = rk_iommu_from_dev(dev);
+	if (!iommu)
+		return 0;
+
+	dev_dbg(dev, "Attaching to iommu domain\n");
+
+	/* iommu already attached */
+	if (iommu->domain == domain)
+		return 0;
+
+	if (iommu->domain)
+		rk_iommu_detach_device(iommu->domain, dev);
+
+	iommu->domain = domain;
+
+	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
+	list_add_tail(&iommu->node, &rk_domain->iommus);
+	spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
+
+	if (!pm_runtime_get_if_in_use(iommu->dev))
+		return 0;
+
+	ret = rk_iommu_enable(iommu);
+	if (ret)
+		rk_iommu_detach_device(iommu->domain, dev);
+
+	pm_runtime_put(iommu->dev);
+
+	return ret;
 }
 
 static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
@@ -989,17 +1042,21 @@ static int rk_iommu_add_device(struct device *dev)
 {
 	struct iommu_group *group;
 	struct rk_iommu *iommu;
+	struct rk_iommudata *data;
 
-	iommu = rk_iommu_from_dev(dev);
-	if (!iommu)
+	data = dev->archdata.iommu;
+	if (!data)
 		return -ENODEV;
 
+	iommu = rk_iommu_from_dev(dev);
+
 	group = iommu_group_get_for_dev(dev);
 	if (IS_ERR(group))
 		return PTR_ERR(group);
 	iommu_group_put(group);
 
 	iommu_device_link(&iommu->iommu, dev);
+	data->link = device_link_add(dev, iommu->dev, DL_FLAG_PM_RUNTIME);
 
 	return 0;
 }
@@ -1007,9 +1064,11 @@ static int rk_iommu_add_device(struct device *dev)
 static void rk_iommu_remove_device(struct device *dev)
 {
 	struct rk_iommu *iommu;
+	struct rk_iommudata *data = dev->archdata.iommu;
 
 	iommu = rk_iommu_from_dev(dev);
 
+	device_link_del(data->link);
 	iommu_device_unlink(&iommu->iommu, dev);
 	iommu_group_remove_device(dev);
 }
@@ -1135,6 +1194,8 @@ static int rk_iommu_probe(struct platform_device *pdev)
 
 	bus_set_iommu(&platform_bus_type, &rk_iommu_ops);
 
+	pm_runtime_enable(dev);
+
 	return 0;
 err_remove_sysfs:
 	iommu_device_sysfs_remove(&iommu->iommu);
@@ -1145,21 +1206,36 @@ err_unprepare_clocks:
 
 static void rk_iommu_shutdown(struct platform_device *pdev)
 {
-	struct rk_iommu *iommu = platform_get_drvdata(pdev);
+	pm_runtime_force_suspend(&pdev->dev);
+}
 
-	/*
-	 * Be careful not to try to shutdown an otherwise unused
-	 * IOMMU, as it is likely not to be clocked, and accessing it
-	 * would just block. An IOMMU without a domain is likely to be
-	 * unused, so let's use this as a (weak) guard.
-	 */
-	if (iommu && iommu->domain) {
-		rk_iommu_enable_stall(iommu);
-		rk_iommu_disable_paging(iommu);
-		rk_iommu_force_reset(iommu);
-	}
+static int __maybe_unused rk_iommu_suspend(struct device *dev)
+{
+	struct rk_iommu *iommu = dev_get_drvdata(dev);
+
+	if (!iommu->domain)
+		return 0;
+
+	rk_iommu_disable(iommu);
+	return 0;
+}
+
+static int __maybe_unused rk_iommu_resume(struct device *dev)
+{
+	struct rk_iommu *iommu = dev_get_drvdata(dev);
+
+	if (!iommu->domain)
+		return 0;
+
+	return rk_iommu_enable(iommu);
 }
 
+static const struct dev_pm_ops rk_iommu_pm_ops = {
+	SET_RUNTIME_PM_OPS(rk_iommu_suspend, rk_iommu_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
 static const struct of_device_id rk_iommu_dt_ids[] = {
 	{ .compatible = "rockchip,iommu" },
 	{ /* sentinel */ }
@@ -1172,6 +1248,7 @@ static struct platform_driver rk_iommu_driver = {
 	.driver = {
 		   .name = "rk_iommu",
 		   .of_match_table = rk_iommu_dt_ids,
+		   .pm = &rk_iommu_pm_ops,
 		   .suppress_bind_attrs = true,
 	},
 };