iommu: qti: Track iommu domains

Add a new module to track iommu domains, including those which
may not currently be active. Supports multiple types of smmu
drivers.

Change-Id: Iacb98d823db8a87a2cf0868c467914847351950b
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
[isaacm@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>

drivers/iommu/Kconfig

@@ -399,6 +399,14 @@ config SPAPR_TCE_IOMMU
 	  Enables bits of IOMMU API required by VFIO. The iommu_ops
 	  is not implemented as it is not necessary for VFIO.
 
+config QTI_IOMMU_SUPPORT
+	tristate "Support for QTI iommu drivers"
+	help
+	  The QTI GPU device may switch between multiple iommu domains,
+	  depending on usecase. This introduces a need to track all such
+	  domains in a non-driver specific manner.
+	  If in doubt say N.
+
 # ARM IOMMU support
 config ARM_SMMU
 	tristate "ARM Ltd. System MMU (SMMU) Support"
@@ -406,6 +414,7 @@ config ARM_SMMU
 	select IOMMU_API
 	select IOMMU_IO_PGTABLE_LPAE
 	select ARM_DMA_USE_IOMMU if ARM
+	select QTI_IOMMU_SUPPORT
 	help
 	  Support for implementations of the ARM System MMU architecture
 	  versions 1 and 2.

drivers/iommu/Makefile

@@ -36,6 +36,7 @@ obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
 obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
 obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
 obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
+obj-$(CONFIG_QTI_IOMMU_SUPPORT) += iommu-logger.o
 obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o
 obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
 obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o

drivers/iommu/arm-smmu.c

@@ -51,6 +51,7 @@
 
 #include <linux/qcom_scm.h>
 #include "arm-smmu.h"
+#include "iommu-logger.h"
 
 #define CREATE_TRACE_POINTS
 #include "arm-smmu-trace.h"
@@ -1872,17 +1873,24 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 	struct msm_io_pgtable_info *pgtbl_info = &smmu_domain->pgtbl_info;
 	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 	unsigned long quirks = 0;
+	struct iommu_group *group;
 
 	mutex_lock(&smmu_domain->init_mutex);
 	if (smmu_domain->smmu)
 		goto out_unlock;
 
+	group = iommu_group_get(dev);
+	ret = iommu_logger_register(&smmu_domain->logger, domain, group);
+	iommu_group_put(group);
+	if (ret)
+		goto out_unlock;
+
 	if (domain->type == IOMMU_DOMAIN_DMA) {
 		ret = arm_smmu_setup_default_domain(dev, domain);
 		if (ret) {
 			dev_err(dev, "%s: default domain setup failed\n",
 				__func__);
-			goto out_unlock;
+			goto out_logger;
 		}
 	}
 
@@ -1939,7 +1947,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 
 	if (cfg->fmt == ARM_SMMU_CTX_FMT_NONE) {
 		ret = -EINVAL;
-		goto out_unlock;
+		goto out_logger;
 	}
 
 	switch (smmu_domain->stage) {
@@ -1987,7 +1995,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 		break;
 	default:
 		ret = -EINVAL;
-		goto out_unlock;
+		goto out_logger;
 	}
 
 #ifdef CONFIG_IOMMU_IO_PGTABLE_FAST
@@ -2001,7 +2009,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 
 	ret = arm_smmu_alloc_cb(domain, smmu, dev);
 	if (ret < 0)
-		goto out_unlock;
+		goto out_logger;
 
 	cfg->cbndx = ret;
 
@@ -2071,6 +2079,8 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 out_clear_smmu:
 	arm_smmu_destroy_domain_context(domain);
 	smmu_domain->smmu = NULL;
+out_logger:
+	iommu_logger_unregister(smmu_domain->logger);
 out_unlock:
 	mutex_unlock(&smmu_domain->init_mutex);
 	return ret;
@@ -2186,6 +2196,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
 	 */
 	arm_smmu_put_dma_cookie(domain);
 	arm_smmu_destroy_domain_context(domain);
+	iommu_logger_unregister(smmu_domain->logger);
 	kfree(smmu_domain);
 }
 

drivers/iommu/arm-smmu.h

@@ -433,6 +433,7 @@ struct arm_smmu_domain {
 	struct list_head		secure_pool_list;
 	/* nonsecure pool protected by pgtbl_lock */
 	struct list_head		nonsecure_pool;
+	struct iommu_debug_attachment	*logger;
 	struct msm_iommu_domain		domain;
 };
 

drivers/iommu/iommu-logger.c

@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/iommu.h>
+#include <linux/slab.h>
+
+#include "iommu-logger.h"
+
+static DEFINE_MUTEX(iommu_debug_attachments_lock);
+static LIST_HEAD(iommu_debug_attachments);
+
+/*
+ * Each group may have more than one domain; but each domain may
+ * only have one group.
+ * Used by debug tools to display the name of the device(s) associated
+ * with a particular domain.
+ */
+struct iommu_debug_attachment {
+	struct iommu_domain *domain;
+	struct iommu_group *group;
+	struct list_head list;
+};
+
+static struct iommu_debug_attachment *iommu_logger_init(
+						struct iommu_domain *domain,
+						struct iommu_group *group)
+{
+	struct iommu_debug_attachment *logger;
+
+	logger = kzalloc(sizeof(*logger), GFP_KERNEL);
+	if (!logger)
+		return NULL;
+
+	INIT_LIST_HEAD(&logger->list);
+	logger->domain = domain;
+	logger->group = group;
+
+	return logger;
+}
+
+int iommu_logger_register(struct iommu_debug_attachment **logger_out,
+			  struct iommu_domain *domain,
+			  struct iommu_group *group)
+{
+	struct iommu_debug_attachment *logger;
+
+	if (!logger_out)
+		return -EINVAL;
+
+	logger = iommu_logger_init(domain, group);
+	if (!logger)
+		return -ENOMEM;
+
+	mutex_lock(&iommu_debug_attachments_lock);
+	list_add(&logger->list, &iommu_debug_attachments);
+	mutex_unlock(&iommu_debug_attachments_lock);
+
+	*logger_out = logger;
+	return 0;
+}
+EXPORT_SYMBOL(iommu_logger_register);
+
+void iommu_logger_unregister(struct iommu_debug_attachment *logger)
+{
+	if (!logger)
+		return;
+
+	mutex_lock(&iommu_debug_attachments_lock);
+	list_del(&logger->list);
+	mutex_unlock(&iommu_debug_attachments_lock);
+	kfree(logger);
+}
+EXPORT_SYMBOL(iommu_logger_unregister);
+
+MODULE_DESCRIPTION("QTI IOMMU SUPPORT");
+MODULE_LICENSE("GPL v2");

drivers/iommu/iommu-logger.h

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2020, The Linux Foundation. All rights reserved. */
+
+#ifndef __LINUX_QTI_IOMMU_LOGGER_H
+#define __LINUX_QTI_IOMMU_LOGGER_H
+
+struct iommu_debug_attachment;
+
+#if IS_ENABLED(CONFIG_QTI_IOMMU_SUPPORT)
+
+int iommu_logger_register(struct iommu_debug_attachment **a,
+			  struct iommu_domain *domain,
+			  struct iommu_group *group);
+void iommu_logger_unregister(struct iommu_debug_attachment *a);
+#else
+static inline int iommu_logger_register(struct iommu_debug_attachment **a,
+					struct iommu_domain *domain,
+					struct iommu_group *group)
+{
+	return 0;
+}
+
+static inline void iommu_logger_unregister(struct iommu_debug_attachment *a) {}
+#endif /* CONFIG_QTI_IOMMU_LOGGER */
+#endif /* __LINUX_QTI_IOMMU_LOGGER_H */