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1// SPDX-License-Identifier: GPL-2.02/*3 * AMD CDX bus driver MSI support4 *5 * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.6 */7 8#include <linux/of.h>9#include <linux/of_device.h>10#include <linux/of_address.h>11#include <linux/of_irq.h>12#include <linux/irq.h>13#include <linux/irqdomain.h>14#include <linux/msi.h>15#include <linux/cdx/cdx_bus.h>16 17#include "cdx.h"18 19static void cdx_msi_write_msg(struct irq_data *irq_data, struct msi_msg *msg)20{21 struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);22 struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);23 24 /* We would not operate on msg here rather we wait for irq_bus_sync_unlock()25 * to be called from preemptible task context.26 */27 msi_desc->msg = *msg;28 cdx_dev->msi_write_pending = true;29}30 31static void cdx_msi_write_irq_lock(struct irq_data *irq_data)32{33 struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);34 struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);35 36 mutex_lock(&cdx_dev->irqchip_lock);37}38 39static void cdx_msi_write_irq_unlock(struct irq_data *irq_data)40{41 struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);42 struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);43 struct cdx_controller *cdx = cdx_dev->cdx;44 struct cdx_device_config dev_config;45 46 if (!cdx_dev->msi_write_pending) {47 mutex_unlock(&cdx_dev->irqchip_lock);48 return;49 }50 51 cdx_dev->msi_write_pending = false;52 mutex_unlock(&cdx_dev->irqchip_lock);53 54 dev_config.msi.msi_index = msi_desc->msi_index;55 dev_config.msi.data = msi_desc->msg.data;56 dev_config.msi.addr = ((u64)(msi_desc->msg.address_hi) << 32) | msi_desc->msg.address_lo;57 58 /*59 * dev_configure() is a controller callback which can interact with60 * Firmware or other entities, and can sleep, so invoke this function61 * outside of the mutex held region.62 */63 dev_config.type = CDX_DEV_MSI_CONF;64 if (cdx->ops->dev_configure)65 cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num, &dev_config);66}67 68int cdx_enable_msi(struct cdx_device *cdx_dev)69{70 struct cdx_controller *cdx = cdx_dev->cdx;71 struct cdx_device_config dev_config;72 73 dev_config.type = CDX_DEV_MSI_ENABLE;74 dev_config.msi_enable = true;75 if (cdx->ops->dev_configure) {76 return cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num,77 &dev_config);78 }79 80 return -EOPNOTSUPP;81}82EXPORT_SYMBOL_GPL(cdx_enable_msi);83 84void cdx_disable_msi(struct cdx_device *cdx_dev)85{86 struct cdx_controller *cdx = cdx_dev->cdx;87 struct cdx_device_config dev_config;88 89 dev_config.type = CDX_DEV_MSI_ENABLE;90 dev_config.msi_enable = false;91 if (cdx->ops->dev_configure)92 cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num, &dev_config);93}94EXPORT_SYMBOL_GPL(cdx_disable_msi);95 96static struct irq_chip cdx_msi_irq_chip = {97 .name = "CDX-MSI",98 .irq_mask = irq_chip_mask_parent,99 .irq_unmask = irq_chip_unmask_parent,100 .irq_eoi = irq_chip_eoi_parent,101 .irq_set_affinity = msi_domain_set_affinity,102 .irq_write_msi_msg = cdx_msi_write_msg,103 .irq_bus_lock = cdx_msi_write_irq_lock,104 .irq_bus_sync_unlock = cdx_msi_write_irq_unlock105};106 107/* Convert an msi_desc to a unique identifier within the domain. */108static irq_hw_number_t cdx_domain_calc_hwirq(struct cdx_device *dev,109 struct msi_desc *desc)110{111 return ((irq_hw_number_t)dev->msi_dev_id << 10) | desc->msi_index;112}113 114static void cdx_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)115{116 arg->desc = desc;117 arg->hwirq = cdx_domain_calc_hwirq(to_cdx_device(desc->dev), desc);118}119 120static int cdx_msi_prepare(struct irq_domain *msi_domain,121 struct device *dev,122 int nvec, msi_alloc_info_t *info)123{124 struct cdx_device *cdx_dev = to_cdx_device(dev);125 struct device *parent = cdx_dev->cdx->dev;126 struct msi_domain_info *msi_info;127 u32 dev_id;128 int ret;129 130 /* Retrieve device ID from requestor ID using parent device */131 ret = of_map_id(parent->of_node, cdx_dev->msi_dev_id, "msi-map", "msi-map-mask",132 NULL, &dev_id);133 if (ret) {134 dev_err(dev, "of_map_id failed for MSI: %d\n", ret);135 return ret;136 }137 138#ifdef GENERIC_MSI_DOMAIN_OPS139 /* Set the device Id to be passed to the GIC-ITS */140 info->scratchpad[0].ul = dev_id;141#endif142 143 msi_info = msi_get_domain_info(msi_domain->parent);144 145 return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);146}147 148static struct msi_domain_ops cdx_msi_ops = {149 .msi_prepare = cdx_msi_prepare,150 .set_desc = cdx_msi_set_desc151};152 153static struct msi_domain_info cdx_msi_domain_info = {154 .ops = &cdx_msi_ops,155 .chip = &cdx_msi_irq_chip,156 .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |157 MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS158};159 160struct irq_domain *cdx_msi_domain_init(struct device *dev)161{162 struct device_node *np = dev->of_node;163 struct fwnode_handle *fwnode_handle;164 struct irq_domain *cdx_msi_domain;165 struct device_node *parent_node;166 struct irq_domain *parent;167 168 fwnode_handle = of_node_to_fwnode(np);169 170 parent_node = of_parse_phandle(np, "msi-map", 1);171 if (!parent_node) {172 dev_err(dev, "msi-map not present on cdx controller\n");173 return NULL;174 }175 176 parent = irq_find_matching_fwnode(of_node_to_fwnode(parent_node), DOMAIN_BUS_NEXUS);177 if (!parent || !msi_get_domain_info(parent)) {178 dev_err(dev, "unable to locate ITS domain\n");179 return NULL;180 }181 182 cdx_msi_domain = msi_create_irq_domain(fwnode_handle, &cdx_msi_domain_info, parent);183 if (!cdx_msi_domain) {184 dev_err(dev, "unable to create CDX-MSI domain\n");185 return NULL;186 }187 188 dev_dbg(dev, "CDX-MSI domain created\n");189 190 return cdx_msi_domain;191}192EXPORT_SYMBOL_NS_GPL(cdx_msi_domain_init, CDX_BUS_CONTROLLER);193