| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * MSI framework for platform devices |
| * |
| * Copyright (C) 2015 ARM Limited, All Rights Reserved. |
| * Author: Marc Zyngier <marc.zyngier@arm.com> |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/idr.h> |
| #include <linux/irq.h> |
| #include <linux/irqdomain.h> |
| #include <linux/msi.h> |
| #include <linux/slab.h> |
| |
| #define DEV_ID_SHIFT 21 |
| #define MAX_DEV_MSIS (1 << (32 - DEV_ID_SHIFT)) |
| |
| /* |
| * Internal data structure containing a (made up, but unique) devid |
| * and the callback to write the MSI message. |
| */ |
| struct platform_msi_priv_data { |
| struct device *dev; |
| void *host_data; |
| msi_alloc_info_t arg; |
| irq_write_msi_msg_t write_msg; |
| int devid; |
| }; |
| |
| /* The devid allocator */ |
| static DEFINE_IDA(platform_msi_devid_ida); |
| |
| #ifdef GENERIC_MSI_DOMAIN_OPS |
| /* |
| * Convert an msi_desc to a globaly unique identifier (per-device |
| * devid + msi_desc position in the msi_list). |
| */ |
| static irq_hw_number_t platform_msi_calc_hwirq(struct msi_desc *desc) |
| { |
| u32 devid; |
| |
| devid = desc->platform.msi_priv_data->devid; |
| |
| return (devid << (32 - DEV_ID_SHIFT)) | desc->platform.msi_index; |
| } |
| |
| static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc) |
| { |
| arg->desc = desc; |
| arg->hwirq = platform_msi_calc_hwirq(desc); |
| } |
| |
| static int platform_msi_init(struct irq_domain *domain, |
| struct msi_domain_info *info, |
| unsigned int virq, irq_hw_number_t hwirq, |
| msi_alloc_info_t *arg) |
| { |
| return irq_domain_set_hwirq_and_chip(domain, virq, hwirq, |
| info->chip, info->chip_data); |
| } |
| #else |
| #define platform_msi_set_desc NULL |
| #define platform_msi_init NULL |
| #endif |
| |
| static void platform_msi_update_dom_ops(struct msi_domain_info *info) |
| { |
| struct msi_domain_ops *ops = info->ops; |
| |
| BUG_ON(!ops); |
| |
| if (ops->msi_init == NULL) |
| ops->msi_init = platform_msi_init; |
| if (ops->set_desc == NULL) |
| ops->set_desc = platform_msi_set_desc; |
| } |
| |
| static void platform_msi_write_msg(struct irq_data *data, struct msi_msg *msg) |
| { |
| struct msi_desc *desc = irq_data_get_msi_desc(data); |
| struct platform_msi_priv_data *priv_data; |
| |
| priv_data = desc->platform.msi_priv_data; |
| |
| priv_data->write_msg(desc, msg); |
| } |
| |
| static void platform_msi_update_chip_ops(struct msi_domain_info *info) |
| { |
| struct irq_chip *chip = info->chip; |
| |
| BUG_ON(!chip); |
| if (!chip->irq_mask) |
| chip->irq_mask = irq_chip_mask_parent; |
| if (!chip->irq_unmask) |
| chip->irq_unmask = irq_chip_unmask_parent; |
| if (!chip->irq_eoi) |
| chip->irq_eoi = irq_chip_eoi_parent; |
| if (!chip->irq_set_affinity) |
| chip->irq_set_affinity = msi_domain_set_affinity; |
| if (!chip->irq_write_msi_msg) |
| chip->irq_write_msi_msg = platform_msi_write_msg; |
| if (WARN_ON((info->flags & MSI_FLAG_LEVEL_CAPABLE) && |
| !(chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI))) |
| info->flags &= ~MSI_FLAG_LEVEL_CAPABLE; |
| } |
| |
| static void platform_msi_free_descs(struct device *dev, int base, int nvec) |
| { |
| struct msi_desc *desc, *tmp; |
| |
| list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) { |
| if (desc->platform.msi_index >= base && |
| desc->platform.msi_index < (base + nvec)) { |
| list_del(&desc->list); |
| free_msi_entry(desc); |
| } |
| } |
| } |
| |
| static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq, |
| int nvec, |
| struct platform_msi_priv_data *data) |
| |
| { |
| struct msi_desc *desc; |
| int i, base = 0; |
| |
| if (!list_empty(dev_to_msi_list(dev))) { |
| desc = list_last_entry(dev_to_msi_list(dev), |
| struct msi_desc, list); |
| base = desc->platform.msi_index + 1; |
| } |
| |
| for (i = 0; i < nvec; i++) { |
| desc = alloc_msi_entry(dev, 1, NULL); |
| if (!desc) |
| break; |
| |
| desc->platform.msi_priv_data = data; |
| desc->platform.msi_index = base + i; |
| desc->irq = virq ? virq + i : 0; |
| |
| list_add_tail(&desc->list, dev_to_msi_list(dev)); |
| } |
| |
| if (i != nvec) { |
| /* Clean up the mess */ |
| platform_msi_free_descs(dev, base, nvec); |
| |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static int platform_msi_alloc_descs(struct device *dev, int nvec, |
| struct platform_msi_priv_data *data) |
| |
| { |
| return platform_msi_alloc_descs_with_irq(dev, 0, nvec, data); |
| } |
| |
| /** |
| * platform_msi_create_irq_domain - Create a platform MSI interrupt domain |
| * @fwnode: Optional fwnode of the interrupt controller |
| * @info: MSI domain info |
| * @parent: Parent irq domain |
| * |
| * Updates the domain and chip ops and creates a platform MSI |
| * interrupt domain. |
| * |
| * Returns: |
| * A domain pointer or NULL in case of failure. |
| */ |
| struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode, |
| struct msi_domain_info *info, |
| struct irq_domain *parent) |
| { |
| struct irq_domain *domain; |
| |
| if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) |
| platform_msi_update_dom_ops(info); |
| if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) |
| platform_msi_update_chip_ops(info); |
| |
| domain = msi_create_irq_domain(fwnode, info, parent); |
| if (domain) |
| irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI); |
| |
| return domain; |
| } |
| |
| static struct platform_msi_priv_data * |
| platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec, |
| irq_write_msi_msg_t write_msi_msg) |
| { |
| struct platform_msi_priv_data *datap; |
| /* |
| * Limit the number of interrupts to 2048 per device. Should we |
| * need to bump this up, DEV_ID_SHIFT should be adjusted |
| * accordingly (which would impact the max number of MSI |
| * capable devices). |
| */ |
| if (!dev->msi_domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS) |
| return ERR_PTR(-EINVAL); |
| |
| if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) { |
| dev_err(dev, "Incompatible msi_domain, giving up\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* Already had a helping of MSI? Greed... */ |
| if (!list_empty(dev_to_msi_list(dev))) |
| return ERR_PTR(-EBUSY); |
| |
| datap = kzalloc(sizeof(*datap), GFP_KERNEL); |
| if (!datap) |
| return ERR_PTR(-ENOMEM); |
| |
| datap->devid = ida_simple_get(&platform_msi_devid_ida, |
| 0, 1 << DEV_ID_SHIFT, GFP_KERNEL); |
| if (datap->devid < 0) { |
| int err = datap->devid; |
| kfree(datap); |
| return ERR_PTR(err); |
| } |
| |
| datap->write_msg = write_msi_msg; |
| datap->dev = dev; |
| |
| return datap; |
| } |
| |
| static void platform_msi_free_priv_data(struct platform_msi_priv_data *data) |
| { |
| ida_simple_remove(&platform_msi_devid_ida, data->devid); |
| kfree(data); |
| } |
| |
| /** |
| * platform_msi_domain_alloc_irqs - Allocate MSI interrupts for @dev |
| * @dev: The device for which to allocate interrupts |
| * @nvec: The number of interrupts to allocate |
| * @write_msi_msg: Callback to write an interrupt message for @dev |
| * |
| * Returns: |
| * Zero for success, or an error code in case of failure |
| */ |
| int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec, |
| irq_write_msi_msg_t write_msi_msg) |
| { |
| struct platform_msi_priv_data *priv_data; |
| int err; |
| |
| priv_data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); |
| if (IS_ERR(priv_data)) |
| return PTR_ERR(priv_data); |
| |
| err = platform_msi_alloc_descs(dev, nvec, priv_data); |
| if (err) |
| goto out_free_priv_data; |
| |
| err = msi_domain_alloc_irqs(dev->msi_domain, dev, nvec); |
| if (err) |
| goto out_free_desc; |
| |
| return 0; |
| |
| out_free_desc: |
| platform_msi_free_descs(dev, 0, nvec); |
| out_free_priv_data: |
| platform_msi_free_priv_data(priv_data); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs); |
| |
| /** |
| * platform_msi_domain_free_irqs - Free MSI interrupts for @dev |
| * @dev: The device for which to free interrupts |
| */ |
| void platform_msi_domain_free_irqs(struct device *dev) |
| { |
| if (!list_empty(dev_to_msi_list(dev))) { |
| struct msi_desc *desc; |
| |
| desc = first_msi_entry(dev); |
| platform_msi_free_priv_data(desc->platform.msi_priv_data); |
| } |
| |
| msi_domain_free_irqs(dev->msi_domain, dev); |
| platform_msi_free_descs(dev, 0, MAX_DEV_MSIS); |
| } |
| EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs); |
| |
| /** |
| * platform_msi_get_host_data - Query the private data associated with |
| * a platform-msi domain |
| * @domain: The platform-msi domain |
| * |
| * Returns the private data provided when calling |
| * platform_msi_create_device_domain. |
| */ |
| void *platform_msi_get_host_data(struct irq_domain *domain) |
| { |
| struct platform_msi_priv_data *data = domain->host_data; |
| return data->host_data; |
| } |
| |
| /** |
| * platform_msi_create_device_domain - Create a platform-msi domain |
| * |
| * @dev: The device generating the MSIs |
| * @nvec: The number of MSIs that need to be allocated |
| * @write_msi_msg: Callback to write an interrupt message for @dev |
| * @ops: The hierarchy domain operations to use |
| * @host_data: Private data associated to this domain |
| * |
| * Returns an irqdomain for @nvec interrupts |
| */ |
| struct irq_domain * |
| platform_msi_create_device_domain(struct device *dev, |
| unsigned int nvec, |
| irq_write_msi_msg_t write_msi_msg, |
| const struct irq_domain_ops *ops, |
| void *host_data) |
| { |
| struct platform_msi_priv_data *data; |
| struct irq_domain *domain; |
| int err; |
| |
| data = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); |
| if (IS_ERR(data)) |
| return NULL; |
| |
| data->host_data = host_data; |
| domain = irq_domain_create_hierarchy(dev->msi_domain, 0, nvec, |
| dev->fwnode, ops, data); |
| if (!domain) |
| goto free_priv; |
| |
| err = msi_domain_prepare_irqs(domain->parent, dev, nvec, &data->arg); |
| if (err) |
| goto free_domain; |
| |
| return domain; |
| |
| free_domain: |
| irq_domain_remove(domain); |
| free_priv: |
| platform_msi_free_priv_data(data); |
| return NULL; |
| } |
| |
| /** |
| * platform_msi_domain_free - Free interrupts associated with a platform-msi |
| * domain |
| * |
| * @domain: The platform-msi domain |
| * @virq: The base irq from which to perform the free operation |
| * @nvec: How many interrupts to free from @virq |
| */ |
| void platform_msi_domain_free(struct irq_domain *domain, unsigned int virq, |
| unsigned int nvec) |
| { |
| struct platform_msi_priv_data *data = domain->host_data; |
| struct msi_desc *desc; |
| for_each_msi_entry(desc, data->dev) { |
| if (WARN_ON(!desc->irq || desc->nvec_used != 1)) |
| return; |
| if (!(desc->irq >= virq && desc->irq < (virq + nvec))) |
| continue; |
| |
| irq_domain_free_irqs_common(domain, desc->irq, 1); |
| } |
| } |
| |
| /** |
| * platform_msi_domain_alloc - Allocate interrupts associated with |
| * a platform-msi domain |
| * |
| * @domain: The platform-msi domain |
| * @virq: The base irq from which to perform the allocate operation |
| * @nvec: How many interrupts to free from @virq |
| * |
| * Return 0 on success, or an error code on failure. Must be called |
| * with irq_domain_mutex held (which can only be done as part of a |
| * top-level interrupt allocation). |
| */ |
| int platform_msi_domain_alloc(struct irq_domain *domain, unsigned int virq, |
| unsigned int nr_irqs) |
| { |
| struct platform_msi_priv_data *data = domain->host_data; |
| int err; |
| |
| err = platform_msi_alloc_descs_with_irq(data->dev, virq, nr_irqs, data); |
| if (err) |
| return err; |
| |
| err = msi_domain_populate_irqs(domain->parent, data->dev, |
| virq, nr_irqs, &data->arg); |
| if (err) |
| platform_msi_domain_free(domain, virq, nr_irqs); |
| |
| return err; |
| } |