Re: [PATCH v3 11/14] ACPI: irq: introduce interrupt producer

From: Hanjun Guo
Date: Wed Nov 02 2016 - 17:09:52 EST

Hi Agustin,

Sorry for the late reply, on travailing for now.

On 10/29/2016 03:32 AM, agustinv@xxxxxxxxxxxxxx wrote:
Hey Hanjun,

On 2016-10-25 11:09, Hanjun Guo wrote:
From: Hanjun Guo <hanjun.guo@xxxxxxxxxx>

In ACPI 6.1 spec, section 19.6.62, Interrupt Resource Descriptor Macro,

Interrupt (ResourceUsage, EdgeLevel, ActiveLevel, Shared,
ResourceSourceIndex, ResourceSource, DescriptorName)
{ InterruptList } => Buffer

For the arguement ResourceUsage and DescriptorName, which means:

ResourceUsage describes whether the device consumes the specified
interrupt ( ResourceConsumer ) or produces it for use by a child
device ( ResourceProducer ).
If nothing is specified, then ResourceConsumer is assumed.

DescriptorName evaluates to a name string which refers to the
entire resource descriptor.

So it can be used for devices connecting to a specific interrupt
prodcucer instead of the main interrupt controller in MADT. In the
real world, we have irqchip such as mbi-gen which connecting to
a group of wired interrupts and then issue msi to the ITS, devices
connecting to such interrupt controller fit this scope.

For now the irq for ACPI only pointer to the main interrupt
controller's irqdomain, for devices not connecting to those
irqdomains, which need to present its irq parent, we can use
following ASL code to represent it:

Interrupt(ResourceConsumer,..., "\_SB.IRQP") {12,14,....}

then we can parse the interrupt producer with the full
path name "\_SB.IRQP".

In order to do that, we introduce a pointer interrupt_producer
in struct acpi_device, and fill it when scanning irq resources
for acpi device if it specifies the interrupt producer.

But for now when parsing the resources for acpi devices, we don't
pass the acpi device for acpi_walk_resoures() in drivers/acpi/resource.c,
so introduce a adev in struct res_proc_context to pass it as a context
to scan the interrupt resources, then finally pass to acpi_register_gsi()
to find its interrupt producer to get the virq from diffrent domains.

With steps above ready, rework acpi_register_gsi() to get other
interrupt producer if devices not connecting to main interrupt
controller.

Since we often pass NULL to acpi_register_gsi() and there is no interrupt
producer for devices connect to gicd on ARM or io-apic on X86, so it will
use the default irqdomain for those deivces and no functional changes to
those devices.

Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Agustin Vega-Frias <agustinv@xxxxxxxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
---
drivers/acpi/gsi.c | 10 ++++--
drivers/acpi/resource.c | 85
++++++++++++++++++++++++++++++++++---------------
include/acpi/acpi_bus.h | 1 +
3 files changed, 68 insertions(+), 28 deletions(-)

diff --git a/drivers/acpi/gsi.c b/drivers/acpi/gsi.c
index ee9e0f2..29ee547 100644
--- a/drivers/acpi/gsi.c
+++ b/drivers/acpi/gsi.c
@@ -55,13 +55,19 @@ int acpi_register_gsi(struct device *dev, u32 gsi,
int trigger,
int polarity)
{
struct irq_fwspec fwspec;
+ struct acpi_device *adev = dev ? to_acpi_device(dev) : NULL;

- if (WARN_ON(!acpi_gsi_domain_id)) {
+ if (adev && &adev->fwnode && adev->interrupt_producer)
+ /* devices in DSDT connecting to spefic interrupt producer */
+ fwspec.fwnode = adev->interrupt_producer;
+ else if (acpi_gsi_domain_id)
+ /* devices connecting to gicd in default */
+ fwspec.fwnode = acpi_gsi_domain_id;
+ else {
pr_warn("GSI: No registered irqchip, giving up\n");
return -EINVAL;
}

- fwspec.fwnode = acpi_gsi_domain_id;
fwspec.param[0] = gsi;
fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
fwspec.param_count = 2;
diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 56241eb..f1371cf 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -381,7 +381,7 @@ static void acpi_dev_irqresource_disabled(struct
resource *res, u32 gsi)
res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED |
IORESOURCE_UNSET;
}

-static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
+static void acpi_dev_get_irqresource(struct acpi_device *adev, struct
resource *res, u32 gsi,
u8 triggering, u8 polarity, u8 shareable,
bool legacy)
{
@@ -415,7 +415,7 @@ static void acpi_dev_get_irqresource(struct
resource *res, u32 gsi,
}

res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
- irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
+ irq = acpi_register_gsi(&adev->dev, gsi, triggering, polarity);
if (irq >= 0) {
res->start = irq;
res->end = irq;
@@ -424,27 +424,9 @@ static void acpi_dev_get_irqresource(struct
resource *res, u32 gsi,
}
}

-/**
- * acpi_dev_resource_interrupt - Extract ACPI interrupt resource
information.
- * @ares: Input ACPI resource object.
- * @index: Index into the array of GSIs represented by the resource.
- * @res: Output generic resource object.
- *
- * Check if the given ACPI resource object represents an interrupt
resource
- * and @index does not exceed the resource's interrupt count (true is
returned
- * in that case regardless of the results of the other checks)). If
that's the
- * case, register the GSI corresponding to @index from the array of
interrupts
- * represented by the resource and populate the generic resource
object pointed
- * to by @res accordingly. If the registration of the GSI is not
successful,
- * IORESOURCE_DISABLED will be set it that object's flags.
- *
- * Return:
- * 1) false with res->flags setting to zero: not the expected
resource type
- * 2) false with IORESOURCE_DISABLED in res->flags: valid unassigned
resource
- * 3) true: valid assigned resource
- */
-bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
- struct resource *res)
+static bool __acpi_dev_resource_interrupt(struct acpi_device *adev,
+ struct acpi_resource *ares, int index,
+ struct resource *res)
{
struct acpi_resource_irq *irq;
struct acpi_resource_extended_irq *ext_irq;
@@ -460,7 +442,7 @@ bool acpi_dev_resource_interrupt(struct
acpi_resource *ares, int index,
acpi_dev_irqresource_disabled(res, 0);
return false;
}
- acpi_dev_get_irqresource(res, irq->interrupts[index],
+ acpi_dev_get_irqresource(adev, res, irq->interrupts[index],
irq->triggering, irq->polarity,
irq->sharable, true);
break;
@@ -470,7 +452,31 @@ bool acpi_dev_resource_interrupt(struct
acpi_resource *ares, int index,
acpi_dev_irqresource_disabled(res, 0);
return false;
}
- acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
+
+ /*
+ * It's a interrupt consumer device and connecting to specfic
+ * interrupt controller. For now, we only support connecting
+ * interrupts to one irq controller for a single device
+ */
+ if (ext_irq->producer_consumer == ACPI_CONSUMER
+ && ext_irq->resource_source.string_length != 0
+ && !adev->interrupt_producer) {
+ acpi_status status;
+ acpi_handle handle;
+ struct acpi_device *device;
+
+ status = acpi_get_handle(NULL,
ext_irq->resource_source.string_ptr, &handle);
+ if (ACPI_FAILURE(status))
+ return false;
+
+ device = acpi_bus_get_acpi_device(handle);
+ if (!device)
+ return false;
+
+ adev->interrupt_producer = &device->fwnode;

You are missing an 'acpi_bus_put_acpi_device(device)' call here.

good catch!


Besides that, this approach will not work in the case where a device
wants to consume interrupts from multiple controllers since you are
forcing adev->interrupt_producer to be the first resource_source
found.

Yes, you are right, and it's in the comment of the code, we
can fix that to add some extra code.


That's the reason I was advocating dynamic lookup (see [1]).

I am about to submit V6 of my series where I also address the probe
ordering issues by enabling re-initialization of platform_device
resources when the resource was marked disabled due to the domain
nor being there during ACPI bus scan.

I will take a deep look for your v6 patch set, probably we can
work together to get things down.

Thanks
Hanjun