1 files changed, 276 insertions, 0 deletions
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 000000000000..3a8258ff4426
--- /dev/null
+++ b/drivers/staging/fsl-mc/bus/mc-msi.c
@@ -0,0 +1,276 @@
+/*
+ * Freescale Management Complex (MC) bus driver MSI support
+ *
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ * Author: German Rivera <German.Rivera@freescale.com>
+ *
+ * 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/of_irq.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->fsl_mc.msi_index;
+}
+
+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;
+
+	/*
+	 * set_desc should not be set by the caller
+	 */
+	if (WARN_ON(ops->set_desc))
+		return;
+
+	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;
+
+	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 {
+		/*
+		 * IRQ is for for a child device of mc_bus_dev
+		 */
+		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->fsl_mc.msi_index];
+
+	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;
+
+	/*
+	 * irq_write_msi_msg should not be set by the caller
+	 */
+	if (WARN_ON(chip->irq_write_msi_msg))
+		return;
+
+	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 *mc_platform_dev,
+			   struct irq_domain **mc_msi_domain)
+{
+	struct irq_domain *msi_domain;
+	struct device_node *mc_of_node = mc_platform_dev->of_node;
+
+	msi_domain = of_msi_get_domain(mc_platform_dev, mc_of_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->fsl_mc.msi_index = 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);
+}