|
| 1 | +// SPDX-License-Identifier: GPL-2.0 |
| 2 | +/* |
| 3 | + * AMD CDX bus driver MSI support |
| 4 | + * |
| 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 | + |
| 19 | +static 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 | + |
| 31 | +static 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 | + |
| 39 | +static 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 with |
| 60 | + * Firmware or other entities, and can sleep, so invoke this function |
| 61 | + * 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 | + |
| 68 | +int 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 | +} |
| 82 | +EXPORT_SYMBOL_GPL(cdx_enable_msi); |
| 83 | + |
| 84 | +void 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 | +} |
| 94 | +EXPORT_SYMBOL_GPL(cdx_disable_msi); |
| 95 | + |
| 96 | +static 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_unlock |
| 105 | +}; |
| 106 | + |
| 107 | +/* Convert an msi_desc to a unique identifier within the domain. */ |
| 108 | +static 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 | + |
| 114 | +static 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 | + |
| 120 | +static 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_OPS |
| 139 | + /* Set the device Id to be passed to the GIC-ITS */ |
| 140 | + info->scratchpad[0].ul = dev_id; |
| 141 | +#endif |
| 142 | + |
| 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 | + |
| 148 | +static struct msi_domain_ops cdx_msi_ops = { |
| 149 | + .msi_prepare = cdx_msi_prepare, |
| 150 | + .set_desc = cdx_msi_set_desc |
| 151 | +}; |
| 152 | + |
| 153 | +static 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_DESCS |
| 158 | +}; |
| 159 | + |
| 160 | +struct 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 | +} |
| 192 | +EXPORT_SYMBOL_NS_GPL(cdx_msi_domain_init, CDX_BUS_CONTROLLER); |
0 commit comments