Patchwork [PATCHv7,09/12] iommu/tegra: smmu: get swgroups from DT "iommus="

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Submitter Hiroshi Doyu
Date Dec. 12, 2013, 7:57 a.m.
Message ID <1386835033-4701-10-git-send-email-hdoyu@nvidia.com>
Download mbox | patch
Permalink /patch/300553/
State Superseded, archived
Headers show

Comments

Hiroshi Doyu - Dec. 12, 2013, 7:57 a.m.
This provides the info about which swgroups a device belongs to. This
info is passed from DT. This is necessary for the unified SMMU driver
among Tegra SoCs since each has different H/W accelerators.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
---
v6:
- Explained "#iommu-cells" in the binding document.
- Fixed old "nvidia,memory-clients" with 'iommus" in the binding
  document.
- Move smmu_of_get_swgroups() here from the previous patch not to break
  git bisecting.

v5:
"iommu=" in a device DT is used instead of "mmu-masters" in an iommu
DT. This is "iommu=" version of:

  [PATCHv4 5/7] iommu/tegra: smmu: Support "mmu-masters" binding

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
---
 .../bindings/iommu/nvidia,tegra30-smmu.txt         |  30 ++++-
 drivers/iommu/tegra-smmu.c                         | 135 ++++++++++++++++++---
 2 files changed, 145 insertions(+), 20 deletions(-)
Stephen Warren - Dec. 16, 2013, 7:09 p.m.
On 12/12/2013 12:57 AM, Hiroshi Doyu wrote:
> This provides the info about which swgroups a device belongs to. This
> info is passed from DT. This is necessary for the unified SMMU driver
> among Tegra SoCs since each has different H/W accelerators.

> diff --git a/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt b/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt

> -Required properties:
> +Required properties in the IOMMU node:
...
> +- iommus: phandle to an iommu device which a device is
> +  attached to and indicates which swgroups a device belongs to(SWGROUP ID).
> +  SWGROUP ID is from 0 to 63, and a device can belong to multiple SWGROUPS.

Shouldn't that property have been deleted from the "Required properties
in the IOMMU node" section, when it got move to the "Required properties
in device nodes affected by the IOMMU" section?

> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c

> +static int smmu_of_get_swgroups(struct device *dev, unsigned long *swgroups)

> +	of_property_for_each_phandle_with_args(dev->of_node, "iommus",
> +					       "#iommu-cells", 0, args, cur, end) {
> +		if (args.np != smmu_handle->dev->of_node)
> +			continue;
> +
> +		BUG_ON(args.args_count != 2);

Wouldn't it be better to WARN() and prevent the IOMMU from affecting
that given client device, i.e. simply return some error?

> @@ -719,21 +812,16 @@ static int smmu_iommu_attach_dev(struct iommu_domain *domain,

> -	client->dev = dev;
> -	client->as = as;
> -	map = (unsigned long *)dev->platform_data;
> -	if (!map)
> -		return -EINVAL;

OK good, so this does get deleted. Ignore my comment re: this on an
earlier patch then.
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Patch

diff --git a/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt b/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt
index 89fb543..fd53f54 100644
--- a/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/nvidia,tegra30-smmu.txt
@@ -1,6 +1,6 @@ 
 NVIDIA Tegra 30 IOMMU H/W, SMMU (System Memory Management Unit)
 
-Required properties:
+Required properties in the IOMMU node:
 - compatible : "nvidia,tegra30-smmu"
 - reg : Should contain 3 register banks(address and length) for each
   of the SMMU register blocks.
@@ -8,9 +8,23 @@  Required properties:
 - nvidia,#asids : # of ASIDs
 - dma-window : IOVA start address and length.
 - nvidia,ahb : phandle to the ahb bus connected to SMMU.
+- iommus: phandle to an iommu device which a device is
+  attached to and indicates which swgroups a device belongs to(SWGROUP ID).
+  SWGROUP ID is from 0 to 63, and a device can belong to multiple SWGROUPS.
+- #iommu-cells. Should be 2. In client IOMMU specifiers, the two cells
+  represent a 64-bit bitmask of SWGROUP IDs under which the device
+  initiates transactions. The least significant word is first. See
+  <dt-bindings/memory/tegra-swgroup.h> for a list of valid values.
+
+Required properties in device nodes affected by the IOMMU:
+- iommus: A list of phandle plus specifier pairs for each IOMMU that
+  affects master transactions initiated by the device. The number of
+  cells in each specifier is defined by the #iommu-cells property in
+  the IOMMU node referred to by the phandle. The meaning of the
+  specifier cells is defined by the referenced IOMMU's binding.
 
 Example:
-	smmu {
+	smmu: iommu {
 		compatible = "nvidia,tegra30-smmu";
 		reg = <0x7000f010 0x02c
 		       0x7000f1f0 0x010
@@ -18,4 +32,16 @@  Example:
 		nvidia,#asids = <4>;		/* # of ASIDs */
 		dma-window = <0 0x40000000>;	/* IOVA start & length */
 		nvidia,ahb = <&ahb>;
+		#iommu-cells = <2>;
 	};
+
+	host1x {
+		compatible = "nvidia,tegra30-host1x", "simple-bus";
+		iommus = <&smmu TEGRA_SWGROUP_CELLS(HC)>;
+		....
+		gr3d {
+			compatible = "nvidia,tegra30-gr3d";
+			iommus = <&smmu TEGRA_SWGROUP_CELLS(NV)
+					TEGRA_SWGROUP_CELLS(NV2)>;
+			....
+		};
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 6ab977a..fd4479a 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -190,6 +190,8 @@  enum {
  * Per client for address space
  */
 struct smmu_client {
+	struct device_node	*of_node;
+	struct rb_node		node;
 	struct device		*dev;
 	struct list_head	list;
 	struct smmu_as		*as;
@@ -233,6 +235,7 @@  struct smmu_device {
 	spinlock_t	lock;
 	char		*name;
 	struct device	*dev;
+	struct rb_root	clients;
 	struct page *avp_vector_page;	/* dummy page shared by all AS's */
 
 	/*
@@ -310,6 +313,96 @@  static inline void smmu_write(struct smmu_device *smmu, u32 val, size_t offs)
  */
 #define FLUSH_SMMU_REGS(smmu)	smmu_read(smmu, SMMU_CONFIG)
 
+static struct smmu_client *find_smmu_client(struct smmu_device *smmu,
+					    struct device_node *dev_node)
+{
+	struct rb_node *node = smmu->clients.rb_node;
+
+	while (node) {
+		struct smmu_client *client;
+
+		client = container_of(node, struct smmu_client, node);
+		if (dev_node < client->of_node)
+			node = node->rb_left;
+		else if (dev_node > client->of_node)
+			node = node->rb_right;
+		else
+			return client;
+	}
+
+	return NULL;
+}
+
+static int insert_smmu_client(struct smmu_device *smmu,
+			      struct smmu_client *client)
+{
+	struct rb_node **new, *parent;
+
+	new = &smmu->clients.rb_node;
+	parent = NULL;
+	while (*new) {
+		struct smmu_client *this;
+		this = container_of(*new, struct smmu_client, node);
+
+		parent = *new;
+		if (client->of_node < this->of_node)
+			new = &((*new)->rb_left);
+		else if (client->of_node > this->of_node)
+			new = &((*new)->rb_right);
+		else
+			return -EEXIST;
+	}
+
+	rb_link_node(&client->node, parent, new);
+	rb_insert_color(&client->node, &smmu->clients);
+	return 0;
+}
+
+static int register_smmu_client(struct smmu_device *smmu,
+				struct device *dev, unsigned long *swgroups)
+{
+	struct smmu_client *client;
+
+	client = find_smmu_client(smmu, dev->of_node);
+	if (client) {
+		dev_err(dev,
+			"rejecting multiple registrations for client device %s\n",
+			dev->of_node->full_name);
+		return -EBUSY;
+	}
+
+	client = devm_kzalloc(smmu->dev, sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return -ENOMEM;
+
+	client->dev = dev;
+	client->of_node = dev->of_node;
+	memcpy(client->hwgrp, swgroups, sizeof(u64));
+	return insert_smmu_client(smmu, client);
+}
+
+static int smmu_of_get_swgroups(struct device *dev, unsigned long *swgroups)
+{
+	struct of_phandle_args args;
+	const __be32 *cur, *end;
+
+	of_property_for_each_phandle_with_args(dev->of_node, "iommus",
+					       "#iommu-cells", 0, args, cur, end) {
+		if (args.np != smmu_handle->dev->of_node)
+			continue;
+
+		BUG_ON(args.args_count != 2);
+
+		memcpy(swgroups, args.args, sizeof(u64));
+		pr_debug("swgroups=%08lx %08lx ops=%p %s\n",
+			 swgroups[0], swgroups[1],
+			 dev->bus->iommu_ops, dev_name(dev));
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
 static int __smmu_client_set_hwgrp(struct smmu_client *c,
 				   unsigned long *map, int on)
 {
@@ -719,21 +812,16 @@  static int smmu_iommu_attach_dev(struct iommu_domain *domain,
 	struct smmu_as *as = domain->priv;
 	struct smmu_device *smmu = as->smmu;
 	struct smmu_client *client, *c;
-	unsigned long *map;
 	int err;
 
-	client = devm_kzalloc(smmu->dev, sizeof(*c), GFP_KERNEL);
+	client = find_smmu_client(smmu, dev->of_node);
 	if (!client)
 		return -ENOMEM;
-	client->dev = dev;
-	client->as = as;
-	map = (unsigned long *)dev->platform_data;
-	if (!map)
-		return -EINVAL;
 
-	err = smmu_client_enable_hwgrp(client, map);
+	client->as = as;
+	err = smmu_client_enable_hwgrp(client, client->hwgrp);
 	if (err)
-		goto err_hwgrp;
+		return -EINVAL;
 
 	spin_lock(&as->client_lock);
 	list_for_each_entry(c, &as->client, list) {
@@ -751,7 +839,7 @@  static int smmu_iommu_attach_dev(struct iommu_domain *domain,
 	 * Reserve "page zero" for AVP vectors using a common dummy
 	 * page.
 	 */
-	if (test_bit(TEGRA_SWGROUP_AVPC, map)) {
+	if (test_bit(TEGRA_SWGROUP_AVPC, client->hwgrp)) {
 		struct page *page;
 
 		page = as->smmu->avp_vector_page;
@@ -766,8 +854,6 @@  static int smmu_iommu_attach_dev(struct iommu_domain *domain,
 err_client:
 	smmu_client_disable_hwgrp(client);
 	spin_unlock(&as->client_lock);
-err_hwgrp:
-	devm_kfree(smmu->dev, client);
 	return err;
 }
 
@@ -784,7 +870,6 @@  static void smmu_iommu_detach_dev(struct iommu_domain *domain,
 		if (c->dev == dev) {
 			smmu_client_disable_hwgrp(c);
 			list_del(&c->list);
-			devm_kfree(smmu->dev, c);
 			c->as = NULL;
 			dev_dbg(smmu->dev,
 				"%s is detached\n", dev_name(c->dev));
@@ -888,10 +973,23 @@  enum {
 
 static int smmu_iommu_bound_driver(struct device *dev)
 {
-	int err = -EPROBE_DEFER;
-	u32 swgroups = dev->platform_data;
+	int err;
+	unsigned long swgroups[2];
 	struct dma_iommu_mapping *map = NULL;
 
+	err = smmu_of_get_swgroups(dev, swgroups);
+	if (err)
+		return -ENODEV;
+
+	if (!find_smmu_client(smmu_handle, dev->of_node)) {
+		err = register_smmu_client(smmu_handle, dev, swgroups);
+		if (err) {
+			dev_err(dev, "failed to add client %s\n",
+				dev_name(dev));
+			return -EINVAL;
+		}
+	}
+
 	if (test_bit(TEGRA_SWGROUP_PPCS, swgroups))
 		map = smmu_handle->map[SYSTEM_PROTECTED];
 	else
@@ -900,10 +998,10 @@  static int smmu_iommu_bound_driver(struct device *dev)
 	if (map)
 		err = arm_iommu_attach_device(dev, map);
 	else
-		return -EPROBE_DEFER;
+		return -ENODEV;
 
-	pr_debug("swgroups=%08lx map=%p err=%d %s\n",
-		 swgroups, map, err, dev_name(dev));
+	pr_debug("swgroups=%08lx %08lx map=%p err=%d %s\n",
+		 swgroups[0], swgroups[1], map, err, dev_name(dev));
 	return err;
 }
 
@@ -1156,6 +1254,7 @@  static int tegra_smmu_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	smmu->clients = RB_ROOT;
 	smmu->map = (struct dma_iommu_mapping **)(smmu->as + asids);
 	smmu->nregs = pdev->num_resources;
 	smmu->regs = devm_kzalloc(dev, 2 * smmu->nregs * sizeof(*smmu->regs),