diff options
Diffstat (limited to 'drivers/base/platform-msi.c')
| -rw-r--r-- | drivers/base/platform-msi.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c new file mode 100644 index 0000000000..f37ad34c80 --- /dev/null +++ b/drivers/base/platform-msi.c @@ -0,0 +1,352 @@ +// 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 = desc->dev->msi.data->platform_data->devid; + + return (devid << (32 - DEV_ID_SHIFT)) | desc->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); +} + +static void platform_msi_set_proxy_dev(msi_alloc_info_t *arg) +{ + arg->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE; +} +#else +#define platform_msi_set_desc NULL +#define platform_msi_init NULL +#define platform_msi_set_proxy_dev(x) do {} while(0) +#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); + + desc->dev->msi.data->platform_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; +} + +/** + * 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); + info->flags |= MSI_FLAG_DEV_SYSFS | MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS | + MSI_FLAG_FREE_MSI_DESCS; + + domain = msi_create_irq_domain(fwnode, info, parent); + if (domain) + irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI); + + return domain; +} +EXPORT_SYMBOL_GPL(platform_msi_create_irq_domain); + +static int 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; + int err; + + /* + * 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 -EINVAL; + + if (dev->msi.domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) { + dev_err(dev, "Incompatible msi_domain, giving up\n"); + return -EINVAL; + } + + err = msi_setup_device_data(dev); + if (err) + return err; + + /* Already initialized? */ + if (dev->msi.data->platform_data) + return -EBUSY; + + datap = kzalloc(sizeof(*datap), GFP_KERNEL); + if (!datap) + return -ENOMEM; + + datap->devid = ida_simple_get(&platform_msi_devid_ida, + 0, 1 << DEV_ID_SHIFT, GFP_KERNEL); + if (datap->devid < 0) { + err = datap->devid; + kfree(datap); + return err; + } + + datap->write_msg = write_msi_msg; + datap->dev = dev; + dev->msi.data->platform_data = datap; + return 0; +} + +static void platform_msi_free_priv_data(struct device *dev) +{ + struct platform_msi_priv_data *data = dev->msi.data->platform_data; + + dev->msi.data->platform_data = NULL; + 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) +{ + int err; + + err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); + if (err) + return err; + + err = msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1); + if (err) + platform_msi_free_priv_data(dev); + + 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) +{ + msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN); + platform_msi_free_priv_data(dev); +} +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 + * + * Return: 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; +} + +static struct lock_class_key platform_device_msi_lock_class; + +/** + * __platform_msi_create_device_domain - Create a platform-msi device domain + * + * @dev: The device generating the MSIs + * @nvec: The number of MSIs that need to be allocated + * @is_tree: flag to indicate tree hierarchy + * @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 + * + * Return: An irqdomain for @nvec interrupts on success, NULL in case of error. + * + * This is for interrupt domains which stack on a platform-msi domain + * created by platform_msi_create_irq_domain(). @dev->msi.domain points to + * that platform-msi domain which is the parent for the new domain. + */ +struct irq_domain * +__platform_msi_create_device_domain(struct device *dev, + unsigned int nvec, + bool is_tree, + 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; + + err = platform_msi_alloc_priv_data(dev, nvec, write_msi_msg); + if (err) + return NULL; + + /* + * Use a separate lock class for the MSI descriptor mutex on + * platform MSI device domains because the descriptor mutex nests + * into the domain mutex. See alloc/free below. + */ + lockdep_set_class(&dev->msi.data->mutex, &platform_device_msi_lock_class); + + data = dev->msi.data->platform_data; + data->host_data = host_data; + domain = irq_domain_create_hierarchy(dev->msi.domain, 0, + is_tree ? 0 : nvec, + dev->fwnode, ops, data); + if (!domain) + goto free_priv; + + platform_msi_set_proxy_dev(&data->arg); + 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(dev); + return NULL; +} + +/** + * platform_msi_device_domain_free - Free interrupts associated with a platform-msi + * device domain + * + * @domain: The platform-msi device domain + * @virq: The base irq from which to perform the free operation + * @nr_irqs: How many interrupts to free from @virq + */ +void platform_msi_device_domain_free(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs) +{ + struct platform_msi_priv_data *data = domain->host_data; + + msi_lock_descs(data->dev); + msi_domain_depopulate_descs(data->dev, virq, nr_irqs); + irq_domain_free_irqs_common(domain, virq, nr_irqs); + msi_free_msi_descs_range(data->dev, virq, virq + nr_irqs - 1); + msi_unlock_descs(data->dev); +} + +/** + * platform_msi_device_domain_alloc - Allocate interrupts associated with + * a platform-msi device domain + * + * @domain: The platform-msi device domain + * @virq: The base irq from which to perform the allocate operation + * @nr_irqs: How many interrupts to allocate 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_device_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs) +{ + struct platform_msi_priv_data *data = domain->host_data; + struct device *dev = data->dev; + + return msi_domain_populate_irqs(domain->parent, dev, virq, nr_irqs, &data->arg); +} |