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// 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->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);
}
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;
}
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 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_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)
{
return platform_msi_alloc_descs_with_irq(dev, 0, nvec);
}
/**
* 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;
domain = msi_create_irq_domain(fwnode, info, parent);
if (domain)
irq_domain_update_bus_token(domain, DOMAIN_BUS_PLATFORM_MSI);
return 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 = platform_msi_alloc_descs(dev, nvec);
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(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(dev->msi.domain, dev);
platform_msi_free_descs(dev, 0, MAX_DEV_MSIS);
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;
}
/**
* __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;
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
* @nvec: How many interrupts to free from @virq
*/
void platform_msi_device_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, *tmp;
for_each_msi_entry_safe(desc, tmp, 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);
list_del(&desc->list);
free_msi_entry(desc);
}
}
/**
* 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 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_device_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);
if (err)
return err;
err = msi_domain_populate_irqs(domain->parent, data->dev,
virq, nr_irqs, &data->arg);
if (err)
platform_msi_device_domain_free(domain, virq, nr_irqs);
return err;
}
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