[PATCH V8 2/3] ACPI: Retry IRQ conversion if it failed previously

Agustin Vega-Frias
2016-11-29T22:58:00Z

This allows probe deferral to work properly when a dependent device
fails to get a valid IRQ because the IRQ domain was not registered
at the time the resources were added to the platform_device.

Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
---
drivers/acpi/irq.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/base/platform.c | 9 ++-
include/linux/acpi.h | 9 +++
3 files changed, 161 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
index e82eb6e..9279168 100644
--- a/drivers/acpi/irq.c
+++ b/drivers/acpi/irq.c
@@ -158,6 +158,150 @@ void acpi_unregister_gsi(u32 gsi)
EXPORT_SYMBOL_GPL(acpi_unregister_gsi);

/**
+ * Context for the resource walk used to lookup IRQ resources.
+ */
+struct acpi_irq_parse_one_ctx {
+ int rc;
+ unsigned int index;
+ unsigned long *res_flags;
+ struct irq_fwspec *fwspec;
+};
+
+/**
+ * acpi_irq_parse_one_match - Handle a matching IRQ resource
+ */
+static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
+ u32 hwirq, u8 triggering,
+ u8 polarity, u8 shareable,
+ struct acpi_irq_parse_one_ctx *ctx)
+{
+ ctx->rc = 0;
+ *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
+ ctx->fwspec->fwnode = fwnode;
+ ctx->fwspec->param[0] = hwirq;
+ ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
+ ctx->fwspec->param_count = 2;
+}
+
+/**
+ * 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 (ctx->index >= eirq->interrupt_count) {
+ ctx->index -= eirq->interrupt_count;
+ return AE_OK;
+ }
+ fwnode = acpi_get_irq_source_fwhandle(&eirq->resource_source);
+ acpi_irq_parse_one_match(fwnode, eirq->interrupts[ctx->index],
+ eirq->triggering, eirq->polarity,
+ eirq->sharable, ctx);
+ return AE_CTRL_TERMINATE;
+ }
+
+ return AE_OK;
+}
+
+/**
+ * acpi_irq_parse_one - Resolve an interrupt for a device
+ * @handle: the device whose interrupt is to be resolved
+ * @index: index of the interrupt to resolve
+ * @fwspec: structure irq_fwspec filled by this function
+ * @flags: resource flags filled by this function
+ *
+ * This function resolves an interrupt for a device by walking its CRS resources
+ * to find the appropriate ACPI IRQ resource and populating the given structure
+ * which can be used to retrieve a Linux IRQ number.
+ *
+ * Returns the result stored in ctx.rc by the callback, or -EINVAL if the given
+ * index is out of range.
+ */
+static int acpi_irq_parse_one(acpi_handle handle, unsigned int index,
+ struct irq_fwspec *fwspec, unsigned long *flags)
+{
+ struct acpi_irq_parse_one_ctx ctx = { -EINVAL, index, flags, fwspec };
+ acpi_status status;
+
+ status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+ acpi_irq_parse_one_cb, &ctx);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+ return ctx.rc;
+}
+
+/**
+ * acpi_irq_get - Look for the ACPI IRQ resource with the given index and
+ * use it to initialize the given Linux IRQ resource.
+ * @handle ACPI device handle
+ * @index ACPI IRQ resource index to lookup
+ * @res Linux IRQ resource to initialize
+ *
+ * Return: 0 on success
+ * -EINVAL if an error occurs
+ * -EPROBE_DEFER if the IRQ lookup/conversion failed
+ */
+int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
+{
+ int rc;
+ struct irq_fwspec fwspec;
+ struct irq_domain *domain;
+ unsigned long flags;
+
+ rc = acpi_irq_parse_one(handle, index, &fwspec, &flags);
+ if (rc)
+ return rc;
+
+ domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
+ if (!domain)
+ return -EPROBE_DEFER;
+
+ rc = irq_create_fwspec_mapping(&fwspec);
+ if (rc <= 0)
+ return -EINVAL;
+
+ res->start = rc;
+ res->end = rc;
+ res->flags = flags;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_irq_get);
+
+/**
* acpi_set_irq_model - Setup the GSI irqdomain information
* @model: the value assigned to acpi_irq_model
* @fwnode: the irq_domain identifier for mapping and looking up
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index c4af003..61423d2 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -102,6 +102,14 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
}

r = platform_get_resource(dev, IORESOURCE_IRQ, num);
+ if (r && r->flags & IORESOURCE_DISABLED && ACPI_COMPANION(&dev->dev)) {
+ int ret;
+
+ ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
+ if (ret)
+ return ret;
+ }
+
/*
* The resources may pass trigger flags to the irqs that need
* to be set up. It so happens that the trigger flags for
@@ -1450,4 +1458,3 @@ void __init early_platform_cleanup(void)
memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
}
}
-
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 154e576..6919bfd 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -327,6 +327,7 @@ struct fwnode_handle *
int acpi_register_irq(struct fwnode_handle *source, u32 hwirq, int trigger,
int polarity);
void acpi_unregister_irq(struct fwnode_handle *source, u32 hwirq);
+int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res);
#else
#define acpi_get_irq_source_fwhandle(source) (NULL)
static inline int acpi_register_irq(struct fwnode_handle *source, u32 hwirq,
@@ -785,6 +786,14 @@ static inline int acpi_reconfig_notifier_unregister(struct notifier_block *nb)

#endif /* !CONFIG_ACPI */

+#ifndef CONFIG_ACPI_GENERIC_GSI
+static inline int acpi_irq_get(acpi_handle handle, unsigned int index,
+ struct resource *res)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_ACPI_GENERIC_GSI */
+
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
int acpi_ioapic_add(acpi_handle root);
#else
--
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