diff options
Diffstat (limited to 'drivers/cdx/cdx_msi.c')
| -rw-r--r-- | drivers/cdx/cdx_msi.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c new file mode 100644 index 0000000000..e55f1716cf --- /dev/null +++ b/drivers/cdx/cdx_msi.c @@ -0,0 +1,192 @@ +// 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); |