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author | Marc Zyngier <marc.zyngier@arm.com> | 2015-11-23 08:26:07 +0000 |
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committer | Marc Zyngier <marc.zyngier@arm.com> | 2015-12-16 15:29:44 +0000 |
commit | 552c494a7666c7fe490f179db1f52239a41fe734 (patch) | |
tree | 816a72e91dfe110f585fb5aeba604713a0b46d52 /drivers/base/platform-msi.c | |
parent | 2145ac9310b60c1c11294b7bea10fe154009be1d (diff) | |
download | lwn-552c494a7666c7fe490f179db1f52239a41fe734.tar.gz lwn-552c494a7666c7fe490f179db1f52239a41fe734.zip |
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>
Diffstat (limited to 'drivers/base/platform-msi.c')
-rw-r--r-- | drivers/base/platform-msi.c | 130 |
1 files changed, 128 insertions, 2 deletions
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c index 44b8c0d816fe..a203896f204f 100644 --- a/drivers/base/platform-msi.c +++ b/drivers/base/platform-msi.c @@ -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; +} |