Hi Hanjun,

On 2017-01-17 07:47, Hanjun Guo wrote:

On 2016/12/15 6:10, Agustin Vega-Frias wrote:

quoted

ACPI extended IRQ resources may contain a ResourceSource to specify
an alternate interrupt controller. Introduce acpi_irq_get and use it
to implement ResourceSource/IRQ domain mapping.

The new API is similar to of_irq_get and allows re-initialization
of a platform resource from the ACPI extended IRQ resource, and
provides proper behavior for probe deferral when the domain is not
yet present when called.

Signed-off-by: Agustin Vega-Frias <redacted>
---
 drivers/acpi/Makefile         |   2 +-
 drivers/acpi/{gsi.c => irq.c} | 182 
++++++++++++++++++++++++++++++++++++++++++
 drivers/base/platform.c       |   9 ++-
 include/linux/acpi.h          |  10 +++
 4 files changed, 201 insertions(+), 2 deletions(-)
 rename drivers/acpi/{gsi.c => irq.c} (32%)

[...]

quoted

+/**
+ * acpi_irq_parse_one_cb - Handle the given resource
+ * @ares: resource to handle
+ * @context: context for the walk, contains the lookup index and 
references
+ *           to the flags and fwspec where the result is returned
+ *
+ * This is called by acpi_walk_resources passing each resource 
returned by
+ * the _CRS method. We only inspect IRQ resources. Since IRQ 
resources
+ * might contain multiple interrupts we check if the index is within 
this
+ * one's interrupt array, otherwise we subtract the current resource 
IRQ
+ * count from the lookup index to prepare for the next resource.
+ * Once a match is found we call acpi_irq_parse_one_match to populate
+ * the result and end the walk by returning AE_CTRL_TERMINATE.
+ *
+ * Return AE_OK if the walk should continue, AE_CTRL_TERMINATE if a 
matching
+ * IRQ resource was found.
+ */
+static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
+					 void *context)
+{
+	struct acpi_irq_parse_one_ctx *ctx = context;
+	struct acpi_resource_irq *irq;
+	struct acpi_resource_extended_irq *eirq;
+	struct fwnode_handle *fwnode;
+
+	switch (ares->type) {
+	case ACPI_RESOURCE_TYPE_IRQ:
+		irq = &ares->data.irq;
+		if (ctx->index >= irq->interrupt_count) {
+			ctx->index -= irq->interrupt_count;
+			return AE_OK;
+		}
+		fwnode = acpi_gsi_domain_id;
+		acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
+					 irq->triggering, irq->polarity,
+					 irq->sharable, ctx);
+		return AE_CTRL_TERMINATE;
+	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+		eirq = &ares->data.extended_irq;

If it's an interrupt producer, I think we don't need to map the 
interrupts in
any irqdomain, and return AE_CTRL_TERMINATE here.

        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
                eirq = &ares->data.extended_irq;
+         if (eirq->producer_consumer == ACPI_PRODUCER)
+                 return AE_CTRL_TERMINATE;
                if (ctx->index >= eirq->interrupt_count) {

Agreed. I'll add the check. However, we need to return AE_OK, not
AE_CTRL_TERMINATE, since that terminates the walk and there might
be other resources to check after this one.

Thanks,
Agustin

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