cdx_msi.c
// SPDX-License-Identifier: GPL-2.0
/*
* AMD CDX bus driver MSI support
*
* Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
*/
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/msi.h>
#include <linux/cdx/cdx_bus.h>
#include "cdx.h"
static void cdx_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 cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);
/* We would not operate on msg here rather we wait for irq_bus_sync_unlock()
* to be called from preemptible task context.
*/
msi_desc->msg = *msg;
cdx_dev->msi_write_pending = true;
}
static void cdx_msi_write_irq_lock(struct irq_data *irq_data)
{
struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);
mutex_lock(&cdx_dev->irqchip_lock);
}
static void cdx_msi_write_irq_unlock(struct irq_data *irq_data)
{
struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data);
struct cdx_device *cdx_dev = to_cdx_device(msi_desc->dev);
struct cdx_controller *cdx = cdx_dev->cdx;
struct cdx_device_config dev_config;
if (!cdx_dev->msi_write_pending) {
mutex_unlock(&cdx_dev->irqchip_lock);
return;
}
cdx_dev->msi_write_pending = false;
mutex_unlock(&cdx_dev->irqchip_lock);
dev_config.msi.msi_index = msi_desc->msi_index;
dev_config.msi.data = msi_desc->msg.data;
dev_config.msi.addr = ((u64)(msi_desc->msg.address_hi) << 32) | msi_desc->msg.address_lo;
/*
* dev_configure() is a controller callback which can interact with
* Firmware or other entities, and can sleep, so invoke this function
* outside of the mutex held region.
*/
dev_config.type = CDX_DEV_MSI_CONF;
if (cdx->ops->dev_configure)
cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num, &dev_config);
}
int cdx_enable_msi(struct cdx_device *cdx_dev)
{
struct cdx_controller *cdx = cdx_dev->cdx;
struct cdx_device_config dev_config;
dev_config.type = CDX_DEV_MSI_ENABLE;
dev_config.msi_enable = true;
if (cdx->ops->dev_configure) {
return cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num,
&dev_config);
}
return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(cdx_enable_msi);
void cdx_disable_msi(struct cdx_device *cdx_dev)
{
struct cdx_controller *cdx = cdx_dev->cdx;
struct cdx_device_config dev_config;
dev_config.type = CDX_DEV_MSI_ENABLE;
dev_config.msi_enable = false;
if (cdx->ops->dev_configure)
cdx->ops->dev_configure(cdx, cdx_dev->bus_num, cdx_dev->dev_num, &dev_config);
}
EXPORT_SYMBOL_GPL(cdx_disable_msi);
static struct irq_chip cdx_msi_irq_chip = {
.name = "CDX-MSI",
.irq_mask = irq_chip_mask_parent,
.irq_unmask = irq_chip_unmask_parent,
.irq_eoi = irq_chip_eoi_parent,
.irq_set_affinity = msi_domain_set_affinity,
.irq_write_msi_msg = cdx_msi_write_msg,
.irq_bus_lock = cdx_msi_write_irq_lock,
.irq_bus_sync_unlock = cdx_msi_write_irq_unlock
};
/* Convert an msi_desc to a unique identifier within the domain. */
static irq_hw_number_t cdx_domain_calc_hwirq(struct cdx_device *dev,
struct msi_desc *desc)
{
return ((irq_hw_number_t)dev->msi_dev_id << 10) | desc->msi_index;
}
static void cdx_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
{
arg->desc = desc;
arg->hwirq = cdx_domain_calc_hwirq(to_cdx_device(desc->dev), desc);
}
static int cdx_msi_prepare(struct irq_domain *msi_domain,
struct device *dev,
int nvec, msi_alloc_info_t *info)
{
struct cdx_device *cdx_dev = to_cdx_device(dev);
struct device *parent = cdx_dev->cdx->dev;
struct msi_domain_info *msi_info;
u32 dev_id;
int ret;
/* Retrieve device ID from requestor ID using parent device */
ret = of_map_id(parent->of_node, cdx_dev->msi_dev_id, "msi-map", "msi-map-mask",
NULL, &dev_id);
if (ret) {
dev_err(dev, "of_map_id failed for MSI: %d\n", ret);
return ret;
}
#ifdef GENERIC_MSI_DOMAIN_OPS
/* Set the device Id to be passed to the GIC-ITS */
info->scratchpad[0].ul = dev_id;
#endif
msi_info = msi_get_domain_info(msi_domain->parent);
return msi_info->ops->msi_prepare(msi_domain->parent, dev, nvec, info);
}
static struct msi_domain_ops cdx_msi_ops = {
.msi_prepare = cdx_msi_prepare,
.set_desc = cdx_msi_set_desc
};
static struct msi_domain_info cdx_msi_domain_info = {
.ops = &cdx_msi_ops,
.chip = &cdx_msi_irq_chip,
.flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | MSI_FLAG_FREE_MSI_DESCS
};
struct irq_domain *cdx_msi_domain_init(struct device *dev)
{
struct device_node *np = dev->of_node;
struct fwnode_handle *fwnode_handle;
struct irq_domain *cdx_msi_domain;
struct device_node *parent_node;
struct irq_domain *parent;
fwnode_handle = of_node_to_fwnode(np);
parent_node = of_parse_phandle(np, "msi-map", 1);
if (!parent_node) {
dev_err(dev, "msi-map not present on cdx controller\n");
return NULL;
}
parent = irq_find_matching_fwnode(of_node_to_fwnode(parent_node), DOMAIN_BUS_NEXUS);
if (!parent || !msi_get_domain_info(parent)) {
dev_err(dev, "unable to locate ITS domain\n");
return NULL;
}
cdx_msi_domain = msi_create_irq_domain(fwnode_handle, &cdx_msi_domain_info, parent);
if (!cdx_msi_domain) {
dev_err(dev, "unable to create CDX-MSI domain\n");
return NULL;
}
dev_dbg(dev, "CDX-MSI domain created\n");
return cdx_msi_domain;
}
EXPORT_SYMBOL_NS_GPL(cdx_msi_domain_init, CDX_BUS_CONTROLLER);