[PATCH 00/10] iommu/ipmmu-vmsa: Initial r8a7795 support

[PATCH 00/10] iommu/ipmmu-vmsa: Initial r8a7795 support

[Magnus Damm]

iommu/ipmmu-vmsa: Initial r8a7795 support

[PATCH 01/10] iommu/ipmmu-vmsa: Make use of IOMMU_OF_DECLARE()
[PATCH 02/10] iommu/ipmmu-vmsa: Enable multi context support
[PATCH 03/10] iommu/ipmmu-vmsa: Teach xlate() to skip disabled iommus
[PATCH 04/10] iommu/ipmmu-vmsa: IPMMU device is 64-bit bus master
[PATCH 05/10] iommu/ipmmu-vmsa: Introduce features, break out alias
[PATCH 06/10] iommu/ipmmu-vmsa: Add optional root device feature
[PATCH 07/10] iommu/ipmmu-vmsa: Write IMCTR twice
[PATCH 08/10] iommu/ipmmu-vmsa: Make IMBUSCTR setup optional
[PATCH 09/10] iommu/ipmmu-vmsa: Allow two bit SL0
[PATCH 10/10] iommu/ipmmu-vmsa: Hook up r8a7795 DT matching code

This series contains slightly more mature r8a7795 support for the
IPMMU driver compared to the earlier series posted as:

[PATCH/RFC 00/10] iommu/ipmmu-vmsa: Experimental r8a7795 support

The DT binding for r8a7795 has been accepted for upstream merge
and this series implements support following such format:

d4e42e7 iommu/ipmmu-vmsa: Add r8a7795 DT binding

The r8a7795 IPMMU is almost register compatible with earlier devices
like r8a7790-r8a7794, however some bitfields have been shifted
slightly. On a grander scale topology has been added and interrupts
have been reworked. So now there are several "cache" IPMMU units
without interrupt that somehow communicate with IPMMU-MM that
is the only instance that supports interrupts. The code refers to
IPMMU-MM as a "root" device and the other ones as leaf nodes.

To make this more interesting the IPMMU driver needs to be shared
between 32-bit ARM for r8a7790-r8a7794 and 64-bit ARM for r8a7795.
In practice this means that two separate implementations are needed
inside the driver to attach to the rather different architecture
specific code.

CONFIG_IOMMU_DMA=y is needed on 64-bit ARM while on 32-bit ARM
the arch specific dma-mapping code is hooked up rather directly.
During init 64-bit ARM IPMMU support is relying on IOMMU_OF_DECLARE().

The code is known to build on 32-bit and 64-bit ARM and x86_64.
Tested on 32-bit ARM and 64-bit ARM with addtional DT integration
changes.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 Developed on top of next-20160315 and:
 [PATCH v2 00/04] iommu/ipmmu-vmsa: IPMMU multi-arch update V2
 [PATCH 00/04] iommu/ipmmu-vmsa: IPMMU CONFIG_IOMMU_DMA update

 drivers/iommu/ipmmu-vmsa.c |  231 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 191 insertions(+), 40 deletions(-)

[PATCH 01/10] iommu/ipmmu-vmsa: Make use of IOMMU_OF_DECLARE()

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Hook up IOMMU_OF_DECLARE() support in case CONFIG_IOMMU_DMA
is enabled. The only current supported case for 32-bit ARM
is disabled, however for 64-bit ARM this is required.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

--- 0014/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:12:22.950513000 +0900
@@ -19,6 +19,7 @@
 #include <linux/iommu.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_iommu.h>
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
@@ -1016,18 +1017,22 @@ static struct platform_driver ipmmu_driv
 
 static int __init ipmmu_init(void)
 {
-	const struct iommu_ops *ops;
+	static bool setup_done;
 	int ret;
 
+	if (setup_done)
+		return 0;
+
 	ret = platform_driver_register(&ipmmu_driver);
 	if (ret < 0)
 		return ret;
 
-	ops = IS_ENABLED(CONFIG_IOMMU_DMA) ? &ipmmu_ops_dma : &ipmmu_ops;
-
+#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
 	if (!iommu_present(&platform_bus_type))
-		bus_set_iommu(&platform_bus_type, ops);
+		bus_set_iommu(&platform_bus_type, &ipmmu_ops);
+#endif
 
+	setup_done = true;
 	return 0;
 }
 
@@ -1039,6 +1044,24 @@ static void __exit ipmmu_exit(void)
 subsys_initcall(ipmmu_init);
 module_exit(ipmmu_exit);
 
+#ifdef CONFIG_IOMMU_DMA
+static int __init ipmmu_vmsa_iommu_of_setup(struct device_node *np)
+{
+	static const struct iommu_ops *ops = &ipmmu_ops_dma;
+
+	ipmmu_init();
+
+	of_iommu_set_ops(np, (struct iommu_ops *)ops);
+	if (!iommu_present(&platform_bus_type))
+		bus_set_iommu(&platform_bus_type, ops);
+
+	return 0;
+}
+
+IOMMU_OF_DECLARE(ipmmu_vmsa_iommu_of, "renesas,ipmmu-vmsa",
+		 ipmmu_vmsa_iommu_of_setup);
+#endif
+
 MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 MODULE_LICENSE("GPL v2");

[PATCH 02/10] iommu/ipmmu-vmsa: Enable multi context support

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Add support for up to 4 contexts. Each context is mapped
to one domain. One domain is associated with each device,
however one or more uTLBs for a single device are kept
in the same domain.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- 0015/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:15:49.180513000 +0900
@@ -31,7 +31,7 @@
 
 #include "io-pgtable.h"
 
-#define IPMMU_CTX_MAX 1
+#define IPMMU_CTX_MAX 4
 
 struct ipmmu_vmsa_device {
 	struct device *dev;
@@ -536,6 +536,13 @@ static int ipmmu_attach_device(struct io
 		/* The domain hasn't been used yet, initialize it. */
 		domain->mmu = mmu;
 		ret = ipmmu_domain_init_context(domain);
+		if (ret < 0) {
+			dev_err(dev, "Unable to initialize IPMMU context\n");
+			domain->mmu = NULL;
+		} else {
+			dev_info(dev, "Using IPMMU context %u\n",
+				 domain->context_id);
+		}
 	} else if (domain->mmu != mmu) {
 		/*
 		 * Something is wrong, we can't attach two devices using
@@ -915,7 +922,7 @@ static void ipmmu_device_reset(struct ip
 	unsigned int i;
 
 	/* Disable all contexts. */
-	for (i = 0; i < 4; ++i)
+	for (i = 0; i < IPMMU_CTX_MAX; ++i)
 		ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
 }
 

[PATCH 03/10] iommu/ipmmu-vmsa: Teach xlate() to skip disabled iommus

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Right now the ->xlate() call gets invoked even though
the iommu device has status = "disabled" in DT, so
make sure we skip over disabled devices.

In my mind it would make sense to have this at some
shared level, but I guess some users may want to
configure the iommu regardless of DT state.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- 0017/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:16:51.200513000 +0900
@@ -890,7 +890,13 @@ static struct iommu_group *ipmmu_device_
 static int ipmmu_of_xlate_dma(struct device *dev,
 			      struct of_phandle_args *spec)
 {
-	/* dummy callback to satisfy of_iommu_configure() */
+	/* If the IPMMU device is disabled in DT then return error
+	 * to make sure the of_iommu code does not install ops
+	 * even though the iommu device is disabled
+	 */
+	if (!of_device_is_available(spec->np))
+		return -ENODEV;
+
 	return 0;
 }
 #endif

[PATCH 04/10] iommu/ipmmu-vmsa: IPMMU device is 64-bit bus master

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

The r8a7795 IPMMU supports 64-bit bus mastering and
coherency for page tables.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |    1 +
 1 file changed, 1 insertion(+)

--- 0020/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:22:09.830513000 +0900
@@ -948,6 +948,7 @@ static int ipmmu_probe(struct platform_d
 	mmu->dev = &pdev->dev;
 	mmu->num_utlbs = 32;
 	bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
+	dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 
 	/* Map I/O memory and request IRQ. */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

[PATCH 05/10] iommu/ipmmu-vmsa: Introduce features, break out alias

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Introduce struct ipmmu_features to track various hardware
and software implementation changes inside the driver for
different kinds of IPMMU hardware. Add use_ns_alias_offset
as a first example of a feature to control if the secure
register bank offset should be used or not.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

--- 0017/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:29:15.860513000 +0900
@@ -33,6 +33,10 @@
 
 #define IPMMU_CTX_MAX 4
 
+struct ipmmu_features {
+	bool use_ns_alias_offset;
+};
+
 struct ipmmu_vmsa_device {
 	struct device *dev;
 	void __iomem *base;
@@ -45,6 +49,7 @@ struct ipmmu_vmsa_device {
 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
 	struct dma_iommu_mapping *mapping;
 #endif
+	const struct ipmmu_features *features;
 };
 
 struct ipmmu_vmsa_domain {
@@ -932,13 +937,33 @@ static void ipmmu_device_reset(struct ip
 		ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
 }
 
+static const struct ipmmu_features ipmmu_features_default = {
+	.use_ns_alias_offset = true,
+};
+
+static const struct of_device_id ipmmu_of_ids[] = {
+	{
+		.compatible = "renesas,ipmmu-vmsa",
+		.data = &ipmmu_features_default,
+	}, {
+		/* Terminator */
+	},
+};
+
+MODULE_DEVICE_TABLE(of, ipmmu_of_ids);
+
 static int ipmmu_probe(struct platform_device *pdev)
 {
 	struct ipmmu_vmsa_device *mmu;
+	const struct of_device_id *match;
 	struct resource *res;
 	int irq;
 	int ret;
 
+	match = of_match_node(ipmmu_of_ids, pdev->dev.of_node);
+	if (!match)
+		return -EINVAL;
+
 	mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
 	if (!mmu) {
 		dev_err(&pdev->dev, "cannot allocate device data\n");
@@ -948,6 +973,7 @@ static int ipmmu_probe(struct platform_d
 	mmu->dev = &pdev->dev;
 	mmu->num_utlbs = 32;
 	bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
+	mmu->features = match->data;
 	dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 
 	/* Map I/O memory and request IRQ. */
@@ -968,7 +994,8 @@ static int ipmmu_probe(struct platform_d
 	 * Offset the registers base unconditionally to point to the non-secure
 	 * alias space for now.
 	 */
-	mmu->base += IM_NS_ALIAS_OFFSET;
+	if (mmu->features->use_ns_alias_offset)
+		mmu->base += IM_NS_ALIAS_OFFSET;
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
@@ -1015,11 +1042,6 @@ static int ipmmu_remove(struct platform_
 	return 0;
 }
 
-static const struct of_device_id ipmmu_of_ids[] = {
-	{ .compatible = "renesas,ipmmu-vmsa", },
-	{ }
-};
-
 static struct platform_driver ipmmu_driver = {
 	.driver = {
 		.name = "ipmmu-vmsa",

[PATCH 06/10] iommu/ipmmu-vmsa: Add optional root device feature

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Add root device handling to the IPMMU driver by
allowing certain DT compat strings to enable
has_cache_leaf_nodes that in turn will support
both root devices with interrupts and leaf devices
that face the actual IPMMU consumer devices.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   92 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 73 insertions(+), 19 deletions(-)

--- 0019/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:30:22.270513000 +0900
@@ -35,6 +35,7 @@
 
 struct ipmmu_features {
 	bool use_ns_alias_offset;
+	bool has_cache_leaf_nodes;
 };
 
 struct ipmmu_vmsa_device {
@@ -50,10 +51,12 @@ struct ipmmu_vmsa_device {
 	struct dma_iommu_mapping *mapping;
 #endif
 	const struct ipmmu_features *features;
+	bool is_leaf;
 };
 
 struct ipmmu_vmsa_domain {
 	struct ipmmu_vmsa_device *mmu;
+	struct ipmmu_vmsa_device *root;
 	struct iommu_domain io_domain;
 
 	struct io_pgtable_cfg cfg;
@@ -198,6 +201,36 @@ static struct ipmmu_vmsa_domain *to_vmsa
 #define IMUASID_ASID0_SHIFT		0
 
 /* -----------------------------------------------------------------------------
+ * Root device handling
+ */
+
+static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
+{
+	if (mmu->features->has_cache_leaf_nodes)
+		return mmu->is_leaf ? false : true;
+	else
+		return true; /* older IPMMU hardware treated as single root */
+}
+
+static struct ipmmu_vmsa_device *ipmmu_find_root(struct ipmmu_vmsa_device *leaf)
+{
+	struct ipmmu_vmsa_device *mmu = NULL;
+
+	if (ipmmu_is_root(leaf))
+		return leaf;
+
+	spin_lock(&ipmmu_devices_lock);
+
+	list_for_each_entry(mmu, &ipmmu_devices, list) {
+		if (ipmmu_is_root(mmu))
+			break;
+	}
+
+	spin_unlock(&ipmmu_devices_lock);
+	return mmu;
+}
+
+/* -----------------------------------------------------------------------------
  * Read/Write Access
  */
 
@@ -214,13 +247,13 @@ static void ipmmu_write(struct ipmmu_vms
 
 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_domain *domain, unsigned int reg)
 {
-	return ipmmu_read(domain->mmu, domain->context_id * IM_CTX_SIZE + reg);
+	return ipmmu_read(domain->root, domain->context_id * IM_CTX_SIZE + reg);
 }
 
 static void ipmmu_ctx_write(struct ipmmu_vmsa_domain *domain, unsigned int reg,
 			    u32 data)
 {
-	ipmmu_write(domain->mmu, domain->context_id * IM_CTX_SIZE + reg, data);
+	ipmmu_write(domain->root, domain->context_id * IM_CTX_SIZE + reg, data);
 }
 
 /* -----------------------------------------------------------------------------
@@ -334,7 +367,7 @@ static int ipmmu_domain_init_context(str
 	 * TODO: Add support for coherent walk through CCI with DVM and remove
 	 * cache handling. For now, delegate it to the io-pgtable code.
 	 */
-	domain->cfg.iommu_dev = domain->mmu->dev;
+	domain->cfg.iommu_dev = domain->root->dev;
 
 	domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
 					   domain);
@@ -344,15 +377,15 @@ static int ipmmu_domain_init_context(str
 	/*
 	 * Find an unused context.
 	 */
-	ret = find_first_zero_bit(domain->mmu->ctx, IPMMU_CTX_MAX);
+	ret = find_first_zero_bit(domain->root->ctx, IPMMU_CTX_MAX);
 	if (ret == IPMMU_CTX_MAX) {
 		free_io_pgtable_ops(domain->iop);
 		return -EBUSY;
 	}
 
 	domain->context_id = ret;
-	domain->mmu->domains[ret] = domain;
-	set_bit(ret, domain->mmu->ctx);
+	domain->root->domains[ret] = domain;
+	set_bit(ret, domain->root->ctx);
 
 	/* TTBR0 */
 	ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
@@ -396,7 +429,7 @@ static int ipmmu_domain_init_context(str
 
 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 {
-	clear_bit(domain->context_id, domain->mmu->ctx);
+	clear_bit(domain->context_id, domain->root->ctx);
 
 	/*
 	 * Disable the context. Flush the TLB as required when modifying the
@@ -524,7 +557,7 @@ static int ipmmu_attach_device(struct io
 			       struct device *dev)
 {
 	struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
-	struct ipmmu_vmsa_device *mmu = archdata->mmu;
+	struct ipmmu_vmsa_device *root, *mmu = archdata->mmu;
 	struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
 	unsigned long flags;
 	unsigned int i;
@@ -535,15 +568,23 @@ static int ipmmu_attach_device(struct io
 		return -ENXIO;
 	}
 
+	root = ipmmu_find_root(archdata->mmu);
+	if (!root) {
+		dev_err(dev, "Unable to locate root IPMMU\n");
+		return -EAGAIN;
+	}
+
 	spin_lock_irqsave(&domain->lock, flags);
 
 	if (!domain->mmu) {
 		/* The domain hasn't been used yet, initialize it. */
 		domain->mmu = mmu;
+		domain->root = root;
 		ret = ipmmu_domain_init_context(domain);
 		if (ret < 0) {
 			dev_err(dev, "Unable to initialize IPMMU context\n");
 			domain->mmu = NULL;
+			domain->root = NULL;
 		} else {
 			dev_info(dev, "Using IPMMU context %u\n",
 				 domain->context_id);
@@ -939,6 +980,7 @@ static void ipmmu_device_reset(struct ip
 
 static const struct ipmmu_features ipmmu_features_default = {
 	.use_ns_alias_offset = true,
+	.has_cache_leaf_nodes = false,
 };
 
 static const struct of_device_id ipmmu_of_ids[] = {
@@ -998,19 +1040,31 @@ static int ipmmu_probe(struct platform_d
 		mmu->base += IM_NS_ALIAS_OFFSET;
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		dev_err(&pdev->dev, "no IRQ found\n");
-		return irq;
-	}
 
-	ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
-			       dev_name(&pdev->dev), mmu);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
-		return ret;
-	}
+	/*
+	 * Determine if this IPMMU instance is a leaf device by checking
+	 * if the renesas,ipmmu-main property exists or not.
+	 */
+	if (mmu->features->has_cache_leaf_nodes &&
+	    of_find_property(pdev->dev.of_node, "renesas,ipmmu-main", NULL))
+		mmu->is_leaf = true;
+
+	/* Root devices have mandatory IRQs */
+	if (ipmmu_is_root(mmu)) {
+		if (irq < 0) {
+			dev_err(&pdev->dev, "no IRQ found\n");
+			return irq;
+		}
+
+		ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
+				       dev_name(&pdev->dev), mmu);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
+			return ret;
+		}
 
-	ipmmu_device_reset(mmu);
+		ipmmu_device_reset(mmu);
+	}
 
 	/*
 	 * We can't create the ARM mapping here as it requires the bus to have

[PATCH 07/10] iommu/ipmmu-vmsa: Write IMCTR twice

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Write IMCTR both in the root device and the leaf node.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

--- 0021/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:31:24.250513000 +0900
@@ -256,6 +256,16 @@ static void ipmmu_ctx_write(struct ipmmu
 	ipmmu_write(domain->root, domain->context_id * IM_CTX_SIZE + reg, data);
 }
 
+static void ipmmu_ctx_write2(struct ipmmu_vmsa_domain *domain, unsigned int reg,
+			     u32 data)
+{
+	if (domain->mmu != domain->root)
+		ipmmu_write(domain->mmu,
+			    domain->context_id * IM_CTX_SIZE + reg, data);
+
+	ipmmu_write(domain->root, domain->context_id * IM_CTX_SIZE + reg, data);
+}
+
 /* -----------------------------------------------------------------------------
  * TLB and microTLB Management
  */
@@ -282,7 +292,7 @@ static void ipmmu_tlb_invalidate(struct
 
 	reg = ipmmu_ctx_read(domain, IMCTR);
 	reg |= IMCTR_FLUSH;
-	ipmmu_ctx_write(domain, IMCTR, reg);
+	ipmmu_ctx_write2(domain, IMCTR, reg);
 
 	ipmmu_tlb_sync(domain);
 }
@@ -422,7 +432,8 @@ static int ipmmu_domain_init_context(str
 	 * software management as we have no use for it. Flush the TLB as
 	 * required when modifying the context registers.
 	 */
-	ipmmu_ctx_write(domain, IMCTR, IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
+	ipmmu_ctx_write2(domain, IMCTR,
+			 IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
 
 	return 0;
 }
@@ -437,7 +448,7 @@ static void ipmmu_domain_destroy_context
 	 *
 	 * TODO: Is TLB flush really needed ?
 	 */
-	ipmmu_ctx_write(domain, IMCTR, IMCTR_FLUSH);
+	ipmmu_ctx_write2(domain, IMCTR, IMCTR_FLUSH);
 	ipmmu_tlb_sync(domain);
 }
 

[PATCH 08/10] iommu/ipmmu-vmsa: Make IMBUSCTR setup optional

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Allow certain DT compat strings to opt-out of setting up
IMBUSCR. The default case is unchanged.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- 0023/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:32:45.550513000 +0900
@@ -36,6 +36,7 @@
 struct ipmmu_features {
 	bool use_ns_alias_offset;
 	bool has_cache_leaf_nodes;
+	bool setup_imbuscr;
 };
 
 struct ipmmu_vmsa_device {
@@ -415,10 +416,10 @@ static int ipmmu_domain_init_context(str
 	ipmmu_ctx_write(domain, IMMAIR0, domain->cfg.arm_lpae_s1_cfg.mair[0]);
 
 	/* IMBUSCR */
-	ipmmu_ctx_write(domain, IMBUSCR,
-			ipmmu_ctx_read(domain, IMBUSCR) &
-			~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
-
+	if (domain->root->features->setup_imbuscr)
+		ipmmu_ctx_write(domain, IMBUSCR,
+				ipmmu_ctx_read(domain, IMBUSCR) &
+				~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
 	/*
 	 * IMSTR
 	 * Clear all interrupt flags.
@@ -992,6 +993,7 @@ static void ipmmu_device_reset(struct ip
 static const struct ipmmu_features ipmmu_features_default = {
 	.use_ns_alias_offset = true,
 	.has_cache_leaf_nodes = false,
+	.setup_imbuscr = true,
 };
 
 static const struct of_device_id ipmmu_of_ids[] = {

[PATCH 09/10] iommu/ipmmu-vmsa: Allow two bit SL0

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Introduce support for two bit SL0 bitfield in IMTTBCR
by using a separate feature flag.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

--- 0025/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:33:36.500513000 +0900
@@ -37,6 +37,7 @@ struct ipmmu_features {
 	bool use_ns_alias_offset;
 	bool has_cache_leaf_nodes;
 	bool setup_imbuscr;
+	bool twobit_imttbcr_sl0;
 };
 
 struct ipmmu_vmsa_device {
@@ -141,6 +142,10 @@ static struct ipmmu_vmsa_domain *to_vmsa
 #define IMTTBCR_TSZ0_MASK		(7 << 0)
 #define IMTTBCR_TSZ0_SHIFT		O
 
+#define IMTTBCR_SL0_TWOBIT_LVL_3	(0 << 6)
+#define IMTTBCR_SL0_TWOBIT_LVL_2	(1 << 6)
+#define IMTTBCR_SL0_TWOBIT_LVL_1	(2 << 6)
+
 #define IMBUSCR				0x000c
 #define IMBUSCR_DVM			(1 << 2)
 #define IMBUSCR_BUSSEL_SYS		(0 << 0)
@@ -356,6 +361,7 @@ static struct iommu_gather_ops ipmmu_gat
 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 {
 	u64 ttbr;
+	u32 tmp;
 	int ret;
 
 	/*
@@ -408,9 +414,15 @@ static int ipmmu_domain_init_context(str
 	 * We use long descriptors with inner-shareable WBWA tables and allocate
 	 * the whole 32-bit VA space to TTBR0.
 	 */
+
+	if (domain->root->features->twobit_imttbcr_sl0)
+		tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
+	else
+		tmp = IMTTBCR_SL0_LVL_1;
+
 	ipmmu_ctx_write(domain, IMTTBCR, IMTTBCR_EAE |
 			IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
-			IMTTBCR_IRGN0_WB_WA | IMTTBCR_SL0_LVL_1);
+			IMTTBCR_IRGN0_WB_WA | tmp);
 
 	/* MAIR0 */
 	ipmmu_ctx_write(domain, IMMAIR0, domain->cfg.arm_lpae_s1_cfg.mair[0]);
@@ -994,6 +1006,7 @@ static const struct ipmmu_features ipmmu
 	.use_ns_alias_offset = true,
 	.has_cache_leaf_nodes = false,
 	.setup_imbuscr = true,
+	.twobit_imttbcr_sl0 = false,
 };
 
 static const struct of_device_id ipmmu_of_ids[] = {

[PATCH 10/10] iommu/ipmmu-vmsa: Hook up r8a7795 DT matching code

[Magnus Damm]

From: Magnus Damm <damm+renesas@opensource.se>

Tie in r8a7795 features and update the IOMMU_OF_DECLARE
compat string to hook up the updated compat string.

TODO:
 - Go over init order once more
 - Consider counting number of IPMMU devices from ->xlate()
 - Experiment with delaying call to bus_set_iommu()
 - Poke around with IPMMU-MP1 and the associated dma-controller
 - 64-bit bus mastering and coherency may need per-device enablement

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 drivers/iommu/ipmmu-vmsa.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- 0027/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-18 00:34:36.510513000 +0900
@@ -1009,11 +1009,21 @@ static const struct ipmmu_features ipmmu
 	.twobit_imttbcr_sl0 = false,
 };
 
+static const struct ipmmu_features ipmmu_features_r8a7795 = {
+	.use_ns_alias_offset = false,
+	.has_cache_leaf_nodes = true,
+	.setup_imbuscr = false,
+	.twobit_imttbcr_sl0 = true,
+};
+
 static const struct of_device_id ipmmu_of_ids[] = {
 	{
 		.compatible = "renesas,ipmmu-vmsa",
 		.data = &ipmmu_features_default,
 	}, {
+		.compatible = "renesas,ipmmu-r8a7795",
+		.data = &ipmmu_features_r8a7795,
+	}, {
 		/* Terminator */
 	},
 };
@@ -1176,6 +1186,8 @@ static int __init ipmmu_vmsa_iommu_of_se
 
 IOMMU_OF_DECLARE(ipmmu_vmsa_iommu_of, "renesas,ipmmu-vmsa",
 		 ipmmu_vmsa_iommu_of_setup);
+IOMMU_OF_DECLARE(ipmmu_r8a7795_iommu_of, "renesas,ipmmu-r8a7795",
+		 ipmmu_vmsa_iommu_of_setup);
 #endif
 
 MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");

Re: [PATCH 03/10] iommu/ipmmu-vmsa: Teach xlate() to skip disabled iommus

[Geert Uytterhoeven]

On Thu, Mar 17, 2016 at 5:29 PM, Magnus Damm <magnus.damm@gmail.com> wrote:
> From: Magnus Damm <damm+renesas@opensource.se>
>
> Right now the ->xlate() call gets invoked even though
> the iommu device has status = "disabled" in DT, so
> make sure we skip over disabled devices.
>
> In my mind it would make sense to have this at some
> shared level, but I guess some users may want to
> configure the iommu regardless of DT state.
>
> Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
> ---
>
>  drivers/iommu/ipmmu-vmsa.c |    8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> --- 0017/drivers/iommu/ipmmu-vmsa.c
> +++ work/drivers/iommu/ipmmu-vmsa.c     2016-03-18 00:16:51.200513000 +0900
> @@ -890,7 +890,13 @@ static struct iommu_group *ipmmu_device_
>  static int ipmmu_of_xlate_dma(struct device *dev,
>                               struct of_phandle_args *spec)
>  {
> -       /* dummy callback to satisfy of_iommu_configure() */
> +       /* If the IPMMU device is disabled in DT then return error
> +        * to make sure the of_iommu code does not install ops
> +        * even though the iommu device is disabled
> +        */
> +       if (!of_device_is_available(spec->np))
> +               return -ENODEV;
> +
>         return 0;

I think this should be handled in drivers/iommu/of_iommu.c:of_iommu_init()
instead, cfr. commit 3e5dd6f6e690048d ("clk: Ignore disabled DT clock
providers").

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds