[PATCH 02/10] staging: fsl-mc: Added generic MSI support for FSL-MC devices

From: J. German Rivera
Date: Mon Oct 26 2015 - 12:05:09 EST


Created an MSI domain for the fsl-mc bus-- including functions
to create a domain, find a domain, alloc/free domain irqs, and
bus specific overrides for domain and irq_chip ops.

Signed-off-by: J. German Rivera <German.Rivera@xxxxxxxxxxxxx>
---
drivers/staging/fsl-mc/bus/Kconfig | 1 +
drivers/staging/fsl-mc/bus/Makefile | 1 +
drivers/staging/fsl-mc/bus/mc-msi.c | 278 ++++++++++++++++++++++++++++
drivers/staging/fsl-mc/include/mc-private.h | 17 ++
drivers/staging/fsl-mc/include/mc.h | 17 ++
5 files changed, 314 insertions(+)
create mode 100644 drivers/staging/fsl-mc/bus/mc-msi.c

diff --git a/drivers/staging/fsl-mc/bus/Kconfig b/drivers/staging/fsl-mc/bus/Kconfig
index 0d779d9..c498ac6 100644
--- a/drivers/staging/fsl-mc/bus/Kconfig
+++ b/drivers/staging/fsl-mc/bus/Kconfig
@@ -9,6 +9,7 @@
config FSL_MC_BUS
tristate "Freescale Management Complex (MC) bus driver"
depends on OF && ARM64
+ select GENERIC_MSI_IRQ_DOMAIN
help
Driver to enable the bus infrastructure for the Freescale
QorIQ Management Complex (fsl-mc). The fsl-mc is a hardware
diff --git a/drivers/staging/fsl-mc/bus/Makefile b/drivers/staging/fsl-mc/bus/Makefile
index 25433a9..a5f2ba4 100644
--- a/drivers/staging/fsl-mc/bus/Makefile
+++ b/drivers/staging/fsl-mc/bus/Makefile
@@ -13,5 +13,6 @@ mc-bus-driver-objs := mc-bus.o \
dpmng.o \
dprc-driver.o \
mc-allocator.o \
+ mc-msi.o \
dpmcp.o \
dpbp.o
diff --git a/drivers/staging/fsl-mc/bus/mc-msi.c b/drivers/staging/fsl-mc/bus/mc-msi.c
new file mode 100644
index 0000000..dfe8016
--- /dev/null
+++ b/drivers/staging/fsl-mc/bus/mc-msi.c
@@ -0,0 +1,278 @@
+/*
+ * Freescale Management Complex (MC) bus driver MSI support
+ *
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ * Author: German Rivera <German.Rivera@xxxxxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include "../include/mc-private.h"
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/msi.h>
+#include "../include/mc-sys.h"
+#include "dprc-cmd.h"
+
+static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg,
+ struct msi_desc *desc)
+{
+ arg->desc = desc;
+ arg->hwirq = (irq_hw_number_t)desc->msi_attrib.entry_nr;
+}
+
+static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info)
+{
+ struct msi_domain_ops *ops = info->ops;
+
+ if (WARN_ON(!ops))
+ return;
+
+ if (!ops->set_desc)
+ ops->set_desc = fsl_mc_msi_set_desc;
+}
+
+static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
+ struct fsl_mc_device_irq *mc_dev_irq)
+{
+ int error;
+ struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
+ struct msi_desc *msi_desc = mc_dev_irq->msi_desc;
+ struct dprc_irq_cfg irq_cfg;
+
+ /*
+ * msi_desc->msg.address is 0x0 when this function is invoked in
+ * the free_irq() code path. In this case, for the MC, we don't
+ * really need to "unprogram" the MSI, so we just return.
+ */
+ if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0)
+ return;
+
+ if (WARN_ON(!owner_mc_dev))
+ return;
+
+ irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) |
+ msi_desc->msg.address_lo;
+ irq_cfg.val = msi_desc->msg.data;
+ irq_cfg.user_irq_id = msi_desc->irq;
+
+ /*
+ * DPRCs and other objects use different commands to set up IRQs,
+ * so we have to differentiate them here.
+ */
+ if (owner_mc_dev == mc_bus_dev) {
+ /*
+ * IRQ is for the mc_bus_dev's DPRC itself
+ */
+ error = dprc_set_irq(mc_bus_dev->mc_io,
+ MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
+ mc_bus_dev->mc_handle,
+ mc_dev_irq->dev_irq_index,
+ &irq_cfg);
+ if (error < 0) {
+ dev_err(&owner_mc_dev->dev,
+ "dprc_set_irq() failed: %d\n", error);
+ }
+ } else {
+ error = dprc_set_obj_irq(mc_bus_dev->mc_io,
+ MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
+ mc_bus_dev->mc_handle,
+ owner_mc_dev->obj_desc.type,
+ owner_mc_dev->obj_desc.id,
+ mc_dev_irq->dev_irq_index,
+ &irq_cfg);
+ if (error < 0) {
+ dev_err(&owner_mc_dev->dev,
+ "dprc_obj_set_irq() failed: %d\n", error);
+ }
+ }
+}
+
+/*
+ * NOTE: This function is invoked with interrupts disabled
+ */
+static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
+ struct msi_msg *msg)
+{
+ struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
+ struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
+ struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
+ struct fsl_mc_device_irq *mc_dev_irq =
+ &mc_bus->irq_resources[msi_desc->msi_attrib.entry_nr];
+
+ WARN_ON(mc_dev_irq->msi_desc != msi_desc);
+ msi_desc->msg = *msg;
+
+ /*
+ * Program the MSI (paddr, value) pair in the device:
+ */
+ __fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq);
+}
+
+static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
+{
+ struct irq_chip *chip = info->chip;
+
+ if (WARN_ON((!chip)))
+ return;
+
+ if (!chip->irq_write_msi_msg)
+ chip->irq_write_msi_msg = fsl_mc_msi_write_msg;
+}
+
+/**
+ * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain
+ * @np: Optional device-tree node of the interrupt controller
+ * @info: MSI domain info
+ * @parent: Parent irq domain
+ *
+ * Updates the domain and chip ops and creates a fsl-mc MSI
+ * interrupt domain.
+ *
+ * Returns:
+ * A domain pointer or NULL in case of failure.
+ */
+struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
+ struct msi_domain_info *info,
+ struct irq_domain *parent)
+{
+ struct irq_domain *domain;
+
+ if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
+ fsl_mc_msi_update_dom_ops(info);
+ if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
+ fsl_mc_msi_update_chip_ops(info);
+
+ domain = msi_create_irq_domain(fwnode, info, parent);
+ if (domain)
+ domain->bus_token = DOMAIN_BUS_FSL_MC_MSI;
+
+ return domain;
+}
+
+int fsl_mc_find_msi_domain(struct device_node *mc_of_node,
+ struct irq_domain **mc_msi_domain)
+{
+ struct device_node *msi_parent_node;
+ struct irq_domain *msi_domain;
+
+ msi_parent_node = of_parse_phandle(mc_of_node, "msi-parent", 0);
+ if (!msi_parent_node) {
+ pr_err("msi-parent phandle missing for %s\n",
+ mc_of_node->full_name);
+ return -ENOENT;
+ }
+
+ /*
+ * Look up the fsl-mc MSI domain:
+ */
+ msi_domain = irq_find_matching_host(msi_parent_node,
+ DOMAIN_BUS_FSL_MC_MSI);
+ if (!msi_domain) {
+ pr_err("Unable to find fsl-mc MSI domain for %s\n",
+ mc_of_node->full_name);
+
+ return -ENOENT;
+ }
+
+ *mc_msi_domain = msi_domain;
+ return 0;
+}
+
+static void fsl_mc_msi_free_descs(struct device *dev)
+{
+ struct msi_desc *desc, *tmp;
+
+ list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {
+ list_del(&desc->list);
+ free_msi_entry(desc);
+ }
+}
+
+static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
+
+{
+ unsigned int i;
+ int error;
+ struct msi_desc *msi_desc;
+
+ for (i = 0; i < irq_count; i++) {
+ msi_desc = alloc_msi_entry(dev);
+ if (!msi_desc) {
+ dev_err(dev, "Failed to allocate msi entry\n");
+ error = -ENOMEM;
+ goto cleanup_msi_descs;
+ }
+
+ msi_desc->msi_attrib.is_msix = 1;
+ msi_desc->msi_attrib.is_64 = 1;
+ msi_desc->msi_attrib.entry_nr = i;
+ msi_desc->nvec_used = 1;
+ INIT_LIST_HEAD(&msi_desc->list);
+ list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
+ }
+
+ return 0;
+
+cleanup_msi_descs:
+ fsl_mc_msi_free_descs(dev);
+ return error;
+}
+
+int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
+ unsigned int irq_count)
+{
+ struct irq_domain *msi_domain;
+ int error;
+
+ if (WARN_ON(!list_empty(dev_to_msi_list(dev))))
+ return -EINVAL;
+
+ error = fsl_mc_msi_alloc_descs(dev, irq_count);
+ if (error < 0)
+ return error;
+
+ msi_domain = dev_get_msi_domain(dev);
+ if (WARN_ON(!msi_domain)) {
+ error = -EINVAL;
+ goto cleanup_msi_descs;
+ }
+
+ /*
+ * NOTE: Calling this function will trigger the invocation of the
+ * its_fsl_mc_msi_prepare() callback
+ */
+ error = msi_domain_alloc_irqs(msi_domain, dev, irq_count);
+
+ if (error) {
+ dev_err(dev, "Failed to allocate IRQs\n");
+ goto cleanup_msi_descs;
+ }
+
+ return 0;
+
+cleanup_msi_descs:
+ fsl_mc_msi_free_descs(dev);
+ return error;
+}
+
+void fsl_mc_msi_domain_free_irqs(struct device *dev)
+{
+ struct irq_domain *msi_domain;
+
+ msi_domain = dev_get_msi_domain(dev);
+ if (WARN_ON(!msi_domain))
+ return;
+
+ msi_domain_free_irqs(msi_domain, dev);
+
+ if (WARN_ON(list_empty(dev_to_msi_list(dev))))
+ return;
+
+ fsl_mc_msi_free_descs(dev);
+}
diff --git a/drivers/staging/fsl-mc/include/mc-private.h b/drivers/staging/fsl-mc/include/mc-private.h
index 2c4cc79..3dabd003 100644
--- a/drivers/staging/fsl-mc/include/mc-private.h
+++ b/drivers/staging/fsl-mc/include/mc-private.h
@@ -26,6 +26,9 @@
strcmp(_obj_type, "dpmcp") == 0 || \
strcmp(_obj_type, "dpcon") == 0)

+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
@@ -79,11 +82,13 @@ struct fsl_mc_resource_pool {
* @resource_pools: array of resource pools (one pool per resource type)
* for this MC bus. These resources represent allocatable entities
* from the physical DPRC.
+ * @irq_resources: Pointer to array of IRQ objects for the IRQ pool
* @scan_mutex: Serializes bus scanning
*/
struct fsl_mc_bus {
struct fsl_mc_device mc_dev;
struct fsl_mc_resource_pool resource_pools[FSL_MC_NUM_POOL_TYPES];
+ struct fsl_mc_device_irq *irq_resources;
struct mutex scan_mutex; /* serializes bus scanning */
};

@@ -116,4 +121,16 @@ int __must_check fsl_mc_resource_allocate(struct fsl_mc_bus *mc_bus,

void fsl_mc_resource_free(struct fsl_mc_resource *resource);

+struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
+ struct msi_domain_info *info,
+ struct irq_domain *parent);
+
+int fsl_mc_find_msi_domain(struct device_node *mc_of_node,
+ struct irq_domain **mc_msi_domain);
+
+int fsl_mc_msi_domain_alloc_irqs(struct device *dev,
+ unsigned int irq_count);
+
+void fsl_mc_msi_domain_free_irqs(struct device *dev);
+
#endif /* _FSL_MC_PRIVATE_H_ */
diff --git a/drivers/staging/fsl-mc/include/mc.h b/drivers/staging/fsl-mc/include/mc.h
index a933291..1c1d6ae 100644
--- a/drivers/staging/fsl-mc/include/mc.h
+++ b/drivers/staging/fsl-mc/include/mc.h
@@ -104,6 +104,23 @@ struct fsl_mc_resource {
};

/**
+ * struct fsl_mc_device_irq - MC object device message-based interrupt
+ * @msi_desc: pointer to MSI descriptor allocated by fsl_mc_msi_alloc_descs()
+ * @mc_dev: MC object device that owns this interrupt
+ * @dev_irq_index: device-relative IRQ index
+ * @resource: MC generic resource associated with the interrupt
+ */
+struct fsl_mc_device_irq {
+ struct msi_desc *msi_desc;
+ struct fsl_mc_device *mc_dev;
+ u8 dev_irq_index;
+ struct fsl_mc_resource resource;
+};
+
+#define to_fsl_mc_irq(_mc_resource) \
+ container_of(_mc_resource, struct fsl_mc_device_irq, resource)
+
+/**
* Bit masks for a MC object device (struct fsl_mc_device) flags
*/
#define FSL_MC_IS_DPRC 0x0001
--
2.3.3

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