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>
As we're going to have multiple paths to allocate/free the
platform-msi private data, factor this out into separate
utility functions.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
MSIs for a given device are normally all allocated in one go.
Make sure the internal code can allocate them one at a time
if required.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
With the msi_list and the msi_domain properties now being at the
generic device level, it is starting to be relatively easy to offer
a generic way of providing non-PCI MSIs.
The two major hurdles with this idea are:
- Lack of global ID that identifies a device: this is worked around by
having a global ID allocator for each device that gets enrolled in
the platform MSI subsystem
- Lack of standard way to write the message in the generating device.
This is solved by mandating driver code to provide a write_msg
callback, so that everyone can have their own square wheel
Apart from that, the API is fairly straightforward:
- platform_msi_create_irq_domain creates an MSI domain that gets
tagged with DOMAIN_BUS_PLATFORM_MSI
- platform_msi_domain_alloc_irqs allocate MSIs for a given device,
populating the msi_list
- platform_msi_domain_free_irqs does what is written on the tin
[ tglx: Created a seperate struct platform_msi_desc and added
kerneldoc entries ]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-10-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
