[PATCH v2 05/11] staging: fsl-mc: Extended MC bus allocator to include IRQs

[J. German Rivera]

All the IRQs for DPAA2 objects in the same DPRC must use
the ICID of that DPRC, as their device Id in the GIC-ITS.
Thus, all these IRQs must share the same ITT table in the GIC.
As a result, a pool of IRQs with the same device Id must be
preallocated per DPRC (fsl-mc bus instance). So, the fsl-mc
bus object allocator is extended to also provide services
to allocate IRQs to DPAA2 devices, from their parent fsl-mc bus
IRQ pool.

Signed-off-by: J. German Rivera <German.Rivera@xxxxxxxxxxxxx>
---
Changes in v2: none

 drivers/staging/fsl-mc/bus/mc-allocator.c   | 199 ++++++++++++++++++++++++++++
 drivers/staging/fsl-mc/include/mc-private.h |  15 +++
 drivers/staging/fsl-mc/include/mc.h         |   9 ++
 3 files changed, 223 insertions(+)

diff --git a/drivers/staging/fsl-mc/bus/mc-allocator.c b/drivers/staging/fsl-mc/bus/mc-allocator.c
index 88d1857..c5fa628 100644
--- a/drivers/staging/fsl-mc/bus/mc-allocator.c
+++ b/drivers/staging/fsl-mc/bus/mc-allocator.c
@@ -15,6 +15,7 @@
 #include "../include/dpcon-cmd.h"
 #include "dpmcp-cmd.h"
 #include "dpmcp.h"
+#include <linux/msi.h>

 /**
  * fsl_mc_resource_pool_add_device - add allocatable device to a resource
@@ -160,6 +161,7 @@ static const char *const fsl_mc_pool_type_strings[] = {
 	[FSL_MC_POOL_DPMCP] = "dpmcp",
 	[FSL_MC_POOL_DPBP] = "dpbp",
 	[FSL_MC_POOL_DPCON] = "dpcon",
+	[FSL_MC_POOL_IRQ] = "irq",
 };

 static int __must_check object_type_to_pool_type(const char *object_type,
@@ -465,6 +467,203 @@ void fsl_mc_object_free(struct fsl_mc_device *mc_adev)
 }
 EXPORT_SYMBOL_GPL(fsl_mc_object_free);

+/*
+ * Initialize the interrupt pool associated with a MC bus.
+ * It allocates a block of IRQs from the GIC-ITS
+ */
+int fsl_mc_populate_irq_pool(struct fsl_mc_bus *mc_bus,
+			     unsigned int irq_count)
+{
+	unsigned int i;
+	struct msi_desc *msi_desc;
+	struct fsl_mc_device_irq *irq_resources;
+	struct fsl_mc_device_irq *mc_dev_irq;
+	int error;
+	struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
+	struct fsl_mc_resource_pool *res_pool =
+			&mc_bus->resource_pools[FSL_MC_POOL_IRQ];
+
+	if (WARN_ON(irq_count == 0 ||
+		    irq_count > FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS))
+		return -EINVAL;
+
+	error = fsl_mc_msi_domain_alloc_irqs(&mc_bus_dev->dev, irq_count);
+	if (error < 0)
+		return error;
+
+	irq_resources = devm_kzalloc(&mc_bus_dev->dev,
+				     sizeof(*irq_resources) * irq_count,
+				     GFP_KERNEL);
+	if (!irq_resources) {
+		error = -ENOMEM;
+		goto cleanup_msi_irqs;
+	}
+
+	for (i = 0; i < irq_count; i++) {
+		mc_dev_irq = &irq_resources[i];
+
+		/*
+		 * NOTE: This mc_dev_irq's MSI addr/value pair will be set
+		 * by the fsl_mc_msi_write_msg() callback
+		 */
+		mc_dev_irq->resource.type = res_pool->type;
+		mc_dev_irq->resource.data = mc_dev_irq;
+		mc_dev_irq->resource.parent_pool = res_pool;
+		INIT_LIST_HEAD(&mc_dev_irq->resource.node);
+		list_add_tail(&mc_dev_irq->resource.node, &res_pool->free_list);
+	}
+
+	for_each_msi_entry(msi_desc, &mc_bus_dev->dev) {
+		mc_dev_irq = &irq_resources[msi_desc->fsl_mc.msi_index];
+		mc_dev_irq->msi_desc = msi_desc;
+		mc_dev_irq->resource.id = msi_desc->irq;
+	}
+
+	res_pool->max_count = irq_count;
+	res_pool->free_count = irq_count;
+	mc_bus->irq_resources = irq_resources;
+	return 0;
+
+cleanup_msi_irqs:
+	fsl_mc_msi_domain_free_irqs(&mc_bus_dev->dev);
+	return error;
+}
+EXPORT_SYMBOL_GPL(fsl_mc_populate_irq_pool);
+
+/**
+ * Teardown the interrupt pool associated with an MC bus.
+ * It frees the IRQs that were allocated to the pool, back to the GIC-ITS.
+ */
+void fsl_mc_cleanup_irq_pool(struct fsl_mc_bus *mc_bus)
+{
+	struct fsl_mc_device *mc_bus_dev = &mc_bus->mc_dev;
+	struct fsl_mc_resource_pool *res_pool =
+			&mc_bus->resource_pools[FSL_MC_POOL_IRQ];
+
+	if (WARN_ON(!mc_bus->irq_resources))
+		return;
+
+	if (WARN_ON(res_pool->max_count == 0))
+		return;
+
+	if (WARN_ON(res_pool->free_count != res_pool->max_count))
+		return;
+
+	INIT_LIST_HEAD(&res_pool->free_list);
+	res_pool->max_count = 0;
+	res_pool->free_count = 0;
+	mc_bus->irq_resources = NULL;
+	fsl_mc_msi_domain_free_irqs(&mc_bus_dev->dev);
+}
+EXPORT_SYMBOL_GPL(fsl_mc_cleanup_irq_pool);
+
+/**
+ * It allocates the IRQs required by a given MC object device. The
+ * IRQs are allocated from the interrupt pool associated with the
+ * MC bus that contains the device, if the device is not a DPRC device.
+ * Otherwise, the IRQs are allocated from the interrupt pool associated
+ * with the MC bus that represents the DPRC device itself.
+ */
+int __must_check fsl_mc_allocate_irqs(struct fsl_mc_device *mc_dev)
+{
+	int i;
+	int irq_count;
+	int res_allocated_count = 0;
+	int error = -EINVAL;
+	struct fsl_mc_device_irq **irqs = NULL;
+	struct fsl_mc_bus *mc_bus;
+	struct fsl_mc_resource_pool *res_pool;
+
+	if (WARN_ON(mc_dev->irqs))
+		return -EINVAL;
+
+	irq_count = mc_dev->obj_desc.irq_count;
+	if (WARN_ON(irq_count == 0))
+		return -EINVAL;
+
+	if (strcmp(mc_dev->obj_desc.type, "dprc") == 0)
+		mc_bus = to_fsl_mc_bus(mc_dev);
+	else
+		mc_bus = to_fsl_mc_bus(to_fsl_mc_device(mc_dev->dev.parent));
+
+	if (WARN_ON(!mc_bus->irq_resources))
+		return -EINVAL;
+
+	res_pool = &mc_bus->resource_pools[FSL_MC_POOL_IRQ];
+	if (res_pool->free_count < irq_count) {
+		dev_err(&mc_dev->dev,
+			"Not able to allocate %u irqs for device\n", irq_count);
+		return -ENOSPC;
+	}
+
+	irqs = devm_kzalloc(&mc_dev->dev, irq_count * sizeof(irqs[0]),
+			    GFP_KERNEL);
+	if (!irqs)
+		return -ENOMEM;
+
+	for (i = 0; i < irq_count; i++) {
+		struct fsl_mc_resource *resource;
+
+		error = fsl_mc_resource_allocate(mc_bus, FSL_MC_POOL_IRQ,
+						 &resource);
+		if (error < 0)
+			goto error_resource_alloc;
+
+		irqs[i] = to_fsl_mc_irq(resource);
+		res_allocated_count++;
+
+		WARN_ON(irqs[i]->mc_dev);
+		irqs[i]->mc_dev = mc_dev;
+		irqs[i]->dev_irq_index = i;
+	}
+
+	mc_dev->irqs = irqs;
+	return 0;
+
+error_resource_alloc:
+	for (i = 0; i < res_allocated_count; i++) {
+		irqs[i]->mc_dev = NULL;
+		fsl_mc_resource_free(&irqs[i]->resource);
+	}
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(fsl_mc_allocate_irqs);
+
+/*
+ * It frees the IRQs that were allocated for a MC object device, by
+ * returning them to the corresponding interrupt pool.
+ */
+void fsl_mc_free_irqs(struct fsl_mc_device *mc_dev)
+{
+	int i;
+	int irq_count;
+	struct fsl_mc_bus *mc_bus;
+	struct fsl_mc_device_irq **irqs = mc_dev->irqs;
+
+	if (WARN_ON(!irqs))
+		return;
+
+	irq_count = mc_dev->obj_desc.irq_count;
+
+	if (strcmp(mc_dev->obj_desc.type, "dprc") == 0)
+		mc_bus = to_fsl_mc_bus(mc_dev);
+	else
+		mc_bus = to_fsl_mc_bus(to_fsl_mc_device(mc_dev->dev.parent));
+
+	if (WARN_ON(!mc_bus->irq_resources))
+		return;
+
+	for (i = 0; i < irq_count; i++) {
+		WARN_ON(!irqs[i]->mc_dev);
+		irqs[i]->mc_dev = NULL;
+		fsl_mc_resource_free(&irqs[i]->resource);
+	}
+
+	mc_dev->irqs = NULL;
+}
+EXPORT_SYMBOL_GPL(fsl_mc_free_irqs);
+
 /**
  * fsl_mc_allocator_probe - callback invoked when an allocatable device is
  * being added to the system
diff --git a/drivers/staging/fsl-mc/include/mc-private.h b/drivers/staging/fsl-mc/include/mc-private.h
index f2504bc..97295f0 100644
--- a/drivers/staging/fsl-mc/include/mc-private.h
+++ b/drivers/staging/fsl-mc/include/mc-private.h
@@ -30,6 +30,16 @@ struct irq_domain;
 struct msi_domain_info;

 /**
+ * Maximum number of total IRQs that can be pre-allocated for an MC bus'
+ * IRQ pool
+ */
+#define FSL_MC_IRQ_POOL_MAX_TOTAL_IRQS	256
+
+struct device_node;
+struct irq_domain;
+struct msi_domain_info;
+
+/**
  * struct fsl_mc - Private data of a "fsl,qoriq-mc" platform device
  * @root_mc_bus_dev: MC object device representing the root DPRC
  * @num_translation_ranges: number of entries in addr_translation_ranges
@@ -137,4 +147,9 @@ int __init its_fsl_mc_msi_init(void);

 void its_fsl_mc_msi_cleanup(void);

+int fsl_mc_populate_irq_pool(struct fsl_mc_bus *mc_bus,
+			     unsigned int irq_count);
+
+void fsl_mc_cleanup_irq_pool(struct fsl_mc_bus *mc_bus);
+
 #endif /* _FSL_MC_PRIVATE_H_ */
diff --git a/drivers/staging/fsl-mc/include/mc.h b/drivers/staging/fsl-mc/include/mc.h
index 1c1d6ae..ac7c1ce 100644
--- a/drivers/staging/fsl-mc/include/mc.h
+++ b/drivers/staging/fsl-mc/include/mc.h
@@ -14,12 +14,14 @@
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
 #include <linux/list.h>
+#include <linux/interrupt.h>
 #include "../include/dprc.h"

 #define FSL_MC_VENDOR_FREESCALE	0x1957

 struct fsl_mc_device;
 struct fsl_mc_io;
+struct fsl_mc_bus;

 /**
  * struct fsl_mc_driver - MC object device driver object
@@ -75,6 +77,7 @@ enum fsl_mc_pool_type {
 	FSL_MC_POOL_DPMCP = 0x0,    /* corresponds to "dpmcp" in the MC */
 	FSL_MC_POOL_DPBP,	    /* corresponds to "dpbp" in the MC */
 	FSL_MC_POOL_DPCON,	    /* corresponds to "dpcon" in the MC */
+	FSL_MC_POOL_IRQ,

 	/*
 	 * NOTE: New resource pool types must be added before this entry
@@ -141,6 +144,7 @@ struct fsl_mc_device_irq {
  * NULL if none.
  * @obj_desc: MC description of the DPAA device
  * @regions: pointer to array of MMIO region entries
+ * @irqs: pointer to array of pointers to interrupts allocated to this device
  * @resource: generic resource associated with this MC object device, if any.
  *
  * Generic device object for MC object devices that are "attached" to a
@@ -172,6 +176,7 @@ struct fsl_mc_device {
 	struct fsl_mc_io *mc_io;
 	struct dprc_obj_desc obj_desc;
 	struct resource *regions;
+	struct fsl_mc_device_irq **irqs;
 	struct fsl_mc_resource *resource;
 };

@@ -215,6 +220,10 @@ int __must_check fsl_mc_object_allocate(struct fsl_mc_device *mc_dev,

 void fsl_mc_object_free(struct fsl_mc_device *mc_adev);

+int __must_check fsl_mc_allocate_irqs(struct fsl_mc_device *mc_dev);
+
+void fsl_mc_free_irqs(struct fsl_mc_device *mc_dev);
+
 extern struct bus_type fsl_mc_bus_type;

 #endif /* _FSL_MC_H_ */
--
2.3.3

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