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platform-msi: Allow creation of a MSI-based stacked irq domain 

We almost have all the needed bits requiredable to create a irq domain
on top of a MSI domain.

For this, we enable a few things:
- the virq is stored in the msi_desc
- device, msi_alloc_info and domain-specific data
  are stored in the platform_priv_data structure
- we introduce a new API for platform-msi:

  /* Create a MSI-based domain */
  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);

  /* Allocate MSIs in an MSI domain */
  int platform_msi_domain_alloc(struct irq_domain *domain,
				unsigned int virq,
				unsigned int nr_irqs);

  /* Free MSIs from an MSI domain */
  void platform_msi_domain_free(struct irq_domain *domain,
				unsigned int virq,
				unsigned int nvec);

  /* Obtain the host data passed to platform_msi_create_device_domain */
  void *platform_msi_get_host_data(struct irq_domain *domain);

platform_msi_create_device_domain() is a hybrid of irqdomain creation
and interrupt allocation, creating a domain backed by the MSIs associated
to a device. IRQs can then be allocated in that domain using
platform_msi_domain_alloc().

This now allows a wired irq to MSI bridge to be created.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
hifive-unleashed-5.1
Marc Zyngier 2015-11-23 08:26:07 +00:00
parent 2145ac9310
commit 552c494a76
2 changed files with 140 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

130
drivers/base/platform-msi.c
View File

@ -32,6 +32,9 @@
* 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;
};
@ -124,8 +127,9 @@ static void platform_msi_free_descs(struct device *dev, int base, int nvec)
}
}
static int platform_msi_alloc_descs(struct device *dev, int nvec,
struct platform_msi_priv_data *data)
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;
@ -145,6 +149,7 @@ static int platform_msi_alloc_descs(struct device *dev, int nvec,
desc->platform.msi_priv_data = data;
desc->platform.msi_index = base + i;
desc->nvec_used = 1;
desc->irq = virq ? virq + i : 0;
list_add_tail(&desc->list, dev_to_msi_list(dev));
}
@ -159,6 +164,13 @@ static int platform_msi_alloc_descs(struct device *dev, int nvec,
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
@ -225,6 +237,7 @@ platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
}
datap->write_msg = write_msi_msg;
datap->dev = dev;
return datap;
}
@ -288,3 +301,116 @@ 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_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,
of_node_to_fwnode(dev->of_node),
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;
}

12
include/linux/msi.h
View File

@ -174,6 +174,7 @@ struct msi_controller {
#include <asm/msi.h>
struct irq_domain;
struct irq_domain_ops;
struct irq_chip;
struct device_node;
struct fwnode_handle;
@ -285,6 +286,17 @@ int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
int nvec, msi_alloc_info_t *args);
int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
int virq, int nvec, msi_alloc_info_t *args);
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);
int platform_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs);
void platform_msi_domain_free(struct irq_domain *domain, unsigned int virq,
unsigned int nvec);
void *platform_msi_get_host_data(struct irq_domain *domain);
#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN