fsl-mc-msi.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Freescale Management Complex (MC) bus driver MSI support
  4 *
  5 * Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
  6 * Author: German Rivera <German.Rivera@freescale.com>
  7 *
  8 */
  9
 10#include <linux/of_irq.h>
 11#include <linux/irq.h>
 12#include <linux/irqdomain.h>
 13#include <linux/msi.h>
 14#include <linux/acpi_iort.h>
 15
 16#include "fsl-mc-private.h"
 17
 18#ifdef GENERIC_MSI_DOMAIN_OPS
 19/*
 20 * Generate a unique ID identifying the interrupt (only used within the MSI
 21 * irqdomain.  Combine the icid with the interrupt index.
 22 */
 23static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev,
 24						struct msi_desc *desc)
 25{
 26	/*
 27	 * Make the base hwirq value for ICID*10000 so it is readable
 28	 * as a decimal value in /proc/interrupts.
 29	 */
 30	return (irq_hw_number_t)(desc->msi_index + (dev->icid * 10000));
 31}
 32
 33static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg,
 34				struct msi_desc *desc)
 35{
 36	arg->desc = desc;
 37	arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev),
 38					      desc);
 39}
 40#else
 41#define fsl_mc_msi_set_desc NULL
 42#endif
 43
 44static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info)
 45{
 46	struct msi_domain_ops *ops = info->ops;
 47
 48	if (!ops)
 49		return;
 50
 51	/*
 52	 * set_desc should not be set by the caller
 53	 */
 54	if (!ops->set_desc)
 55		ops->set_desc = fsl_mc_msi_set_desc;
 56}
 57
 58static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev,
 59				   struct fsl_mc_device_irq *mc_dev_irq,
 60				   struct msi_desc *msi_desc)
 61{
 62	int error;
 63	struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev;
 64	struct dprc_irq_cfg irq_cfg;
 65
 66	/*
 67	 * msi_desc->msg.address is 0x0 when this function is invoked in
 68	 * the free_irq() code path. In this case, for the MC, we don't
 69	 * really need to "unprogram" the MSI, so we just return.
 70	 */
 71	if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0)
 72		return;
 73
 74	if (!owner_mc_dev)
 75		return;
 76
 77	irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) |
 78			msi_desc->msg.address_lo;
 79	irq_cfg.val = msi_desc->msg.data;
 80	irq_cfg.irq_num = msi_desc->irq;
 81
 82	if (owner_mc_dev == mc_bus_dev) {
 83		/*
 84		 * IRQ is for the mc_bus_dev's DPRC itself
 85		 */
 86		error = dprc_set_irq(mc_bus_dev->mc_io,
 87				     MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
 88				     mc_bus_dev->mc_handle,
 89				     mc_dev_irq->dev_irq_index,
 90				     &irq_cfg);
 91		if (error < 0) {
 92			dev_err(&owner_mc_dev->dev,
 93				"dprc_set_irq() failed: %d\n", error);
 94		}
 95	} else {
 96		/*
 97		 * IRQ is for for a child device of mc_bus_dev
 98		 */
 99		error = dprc_set_obj_irq(mc_bus_dev->mc_io,
100					 MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI,
101					 mc_bus_dev->mc_handle,
102					 owner_mc_dev->obj_desc.type,
103					 owner_mc_dev->obj_desc.id,
104					 mc_dev_irq->dev_irq_index,
105					 &irq_cfg);
106		if (error < 0) {
107			dev_err(&owner_mc_dev->dev,
108				"dprc_obj_set_irq() failed: %d\n", error);
109		}
110	}
111}
112
113/*
114 * NOTE: This function is invoked with interrupts disabled
115 */
116static void fsl_mc_msi_write_msg(struct irq_data *irq_data,
117				 struct msi_msg *msg)
118{
119	struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
120	struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev);
121	struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);
122	struct fsl_mc_device_irq *mc_dev_irq =
123		&mc_bus->irq_resources[msi_desc->msi_index];
124
125	msi_desc->msg = *msg;
126
127	/*
128	 * Program the MSI (paddr, value) pair in the device:
129	 */
130	__fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq, msi_desc);
131}
132
133static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info)
134{
135	struct irq_chip *chip = info->chip;
136
137	if (!chip)
138		return;
139
140	/*
141	 * irq_write_msi_msg should not be set by the caller
142	 */
143	if (!chip->irq_write_msi_msg)
144		chip->irq_write_msi_msg = fsl_mc_msi_write_msg;
145}
146
147/**
148 * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain
149 * @fwnode:	Optional firmware node of the interrupt controller
150 * @info:	MSI domain info
151 * @parent:	Parent irq domain
152 *
153 * Updates the domain and chip ops and creates a fsl-mc MSI
154 * interrupt domain.
155 *
156 * Returns:
157 * A domain pointer or NULL in case of failure.
158 */
159struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode,
160						struct msi_domain_info *info,
161						struct irq_domain *parent)
162{
163	struct irq_domain *domain;
164
165	if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE)))
166		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
167	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
168		fsl_mc_msi_update_dom_ops(info);
169	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
170		fsl_mc_msi_update_chip_ops(info);
171	info->flags |= MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS;
172
173	domain = msi_create_irq_domain(fwnode, info, parent);
174	if (domain)
175		irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI);
176
177	return domain;
178}
179
180struct irq_domain *fsl_mc_find_msi_domain(struct device *dev)
181{
182	struct device *root_dprc_dev;
183	struct device *bus_dev;
184	struct irq_domain *msi_domain;
185	struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
186
187	fsl_mc_get_root_dprc(dev, &root_dprc_dev);
188	bus_dev = root_dprc_dev->parent;
189
190	if (bus_dev->of_node) {
191		msi_domain = of_msi_map_get_device_domain(dev,
192						  mc_dev->icid,
193						  DOMAIN_BUS_FSL_MC_MSI);
194
195		/*
196		 * if the msi-map property is missing assume that all the
197		 * child containers inherit the domain from the parent
198		 */
199		if (!msi_domain)
200
201			msi_domain = of_msi_get_domain(bus_dev,
202						bus_dev->of_node,
203						DOMAIN_BUS_FSL_MC_MSI);
204	} else {
205		msi_domain = iort_get_device_domain(dev, mc_dev->icid,
206						    DOMAIN_BUS_FSL_MC_MSI);
207	}
208
209	return msi_domain;
210}
211
212int fsl_mc_msi_domain_alloc_irqs(struct device *dev,  unsigned int irq_count)
213{
214	int error = msi_setup_device_data(dev);
215
216	if (error)
217		return error;
218
219	/*
220	 * NOTE: Calling this function will trigger the invocation of the
221	 * its_fsl_mc_msi_prepare() callback
222	 */
223	error = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, irq_count - 1);
224
225	if (error)
226		dev_err(dev, "Failed to allocate IRQs\n");
227	return error;
228}
229
230void fsl_mc_msi_domain_free_irqs(struct device *dev)
231{
232	msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
233}