Re: [PATCH V6 2/3] ACPI: Add support for ResourceSource/IRQ domain mapping

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Thu, Nov 10, 2016 at 10:02:35AM -0500, agustinv@codeaurora.org wrote:
> Hey Hanjun,
> 
> On 2016-11-09 21:36, Hanjun Guo wrote:
> >Hi Marc, Rafael, Lorenzo,
> >
> >Since we agreed to add a probe deferral if we failed to get irq
> >resources which mirroring the DT does (patch 1 in this patch set),
> >I think the last blocker to make things work both for Agustin and
> >me [1] is this patch, which makes the interrupt producer and consumer
> >work in ACPI, we have two different solution for one thing, we'd happy
> >to work together for one solution, could you give some suggestions
> >please?
> >
> >[1]: https://mail-archive.com/linux-kernel@vger.kernel.org/msg1257419.html
> >
> >Agustin, I have some comments below.
> >
> >On 2016/10/29 4:48, Agustin Vega-Frias wrote:
> >>This allows irqchip drivers to associate an ACPI DSDT device to
> >>an IRQ domain and provides support for using the ResourceSource
> >>in Extended IRQ Resources to find the domain and map the IRQs
> >>specified on that domain.
> >>
> >>Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
> >>---
> >> drivers/acpi/Makefile    |   1 +
> >> drivers/acpi/irqdomain.c | 119
> >>+++++++++++++++++++++++++++++++++++++++++++++++
> >
> >Could we just reuse the gsi.c and not introduce a new
> >file, probably we can change the gsi.c to irqdomain.c
> >or something similar, then reuse the code in gsi.c.
> 
> I was thinking just that after we chatted off-list.

Yes, that's a fair point.

> I might revisit and see what I come up with given that we already have
> a device argument and we could pass the IRQ source there.

I agree with the approach taken by this patch, I do not like much
passing around struct acpi_resource_source *source (in particular
the dummy struct) I do not think it is needed, I will comment on
the code.

Hopefully there is not any buggy FW out there that does use the
resource source inappropriately otherwise we will notice on x86/ia64
(ie you can't blame FW if it breaks the kernel) but I suspect the
only way to find out is by trying, the patch has to go through Rafael's
review anyway before getting there so it is fine.

Lorenzo

> Thanks
> 
> >
> >Thanks
> >Hanjun
> >
> >> drivers/acpi/resource.c  |  21 +++++----
> >> include/linux/acpi.h     |  25 ++++++++++
> >> 4 files changed, 157 insertions(+), 9 deletions(-)
> >> create mode 100644 drivers/acpi/irqdomain.c
> >>
> >>diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> >>index 9ed0878..880401b 100644
> >>--- a/drivers/acpi/Makefile
> >>+++ b/drivers/acpi/Makefile
> >>@@ -57,6 +57,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
> >> acpi-y				+= acpi_lpat.o
> >> acpi-$(CONFIG_ACPI_GENERIC_GSI) += gsi.o
> >> acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
> >>+acpi-$(CONFIG_IRQ_DOMAIN)	+= irqdomain.o
> >>
> >> # These are (potentially) separate modules
> >>
> >>diff --git a/drivers/acpi/irqdomain.c b/drivers/acpi/irqdomain.c
> >>new file mode 100644
> >>index 0000000..11d3658
> >>--- /dev/null
> >>+++ b/drivers/acpi/irqdomain.c
> >>@@ -0,0 +1,119 @@
> >>+/*
> >>+ * ACPI ResourceSource/IRQ domain mapping support
> >>+ *
> >>+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
> >>+ *
> >>+ * This program is free software; you can redistribute it
> >>and/or modify
> >>+ * it under the terms of the GNU General Public License version 2 and
> >>+ * only version 2 as published by the Free Software Foundation.
> >>+ *
> >>+ * This program is distributed in the hope that it will be useful,
> >>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> >>+ * GNU General Public License for more details.
> >>+ */
> >>+#include <linux/acpi.h>
> >>+#include <linux/irq.h>
> >>+#include <linux/irqdomain.h>
> >>+
> >>+/**
> >>+ * acpi_irq_domain_register_irq() - Register the mapping for an
> >>IRQ produced
> >>+ *                                  by the given
> >>acpi_resource_source to a
> >>+ *                                  Linux IRQ number
> >>+ * @source: IRQ source
> >>+ * @hwirq: Hardware IRQ number
> >>+ * @trigger: trigger type of the IRQ number to be mapped
> >>+ * @polarity: polarity of the IRQ to be mapped
> >>+ *
> >>+ * Returns: a valid linux IRQ number on success
> >>+ *          -ENODEV if the given acpi_resource_source cannot be found
> >>+ *          -EPROBE_DEFER if the IRQ domain has not been registered
> >>+ *          -EINVAL for all other errors
> >>+ */
> >>+int acpi_irq_domain_register_irq(const struct
> >>acpi_resource_source *source,
> >>+				 u32 hwirq, int trigger, int polarity)
> >>+{
> >>+	struct irq_fwspec fwspec;
> >>+	struct acpi_device *device;
> >>+	acpi_handle handle;
> >>+	acpi_status status;
> >>+	int ret;
> >>+
> >>+	/* An empty acpi_resource_source means it is a GSI */
> >>+	if (!source->string_length)
> >>+		return acpi_register_gsi(NULL, hwirq, trigger, polarity);
> >>+
> >>+	status = acpi_get_handle(NULL, source->string_ptr, &handle);
> >>+	if (ACPI_FAILURE(status))
> >>+		return -ENODEV;
> >>+
> >>+	device = acpi_bus_get_acpi_device(handle);
> >>+	if (!device)
> >>+		return -ENODEV;
> >>+
> >>+	if (irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY)
> >>== NULL) {
> >>+		ret = -EPROBE_DEFER;
> >>+		goto out_put_device;
> >>+	}
> >>+
> >>+	fwspec.fwnode = &device->fwnode;
> >>+	fwspec.param[0] = hwirq;
> >>+	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
> >>+	fwspec.param_count = 2;
> >>+
> >>+	ret = irq_create_fwspec_mapping(&fwspec);
> >>+
> >>+out_put_device:
> >>+	acpi_bus_put_acpi_device(device);
> >>+
> >>+	return ret;
> >>+}
> >>+EXPORT_SYMBOL_GPL(acpi_irq_domain_register_irq);
> >>+
> >>+/**
> >>+ * acpi_irq_domain_unregister_irq() - Delete the mapping for an
> >>IRQ produced
> >>+ *                                    by the given
> >>acpi_resource_source to a
> >>+ *                                    Linux IRQ number
> >>+ * @source: IRQ source
> >>+ * @hwirq: Hardware IRQ number
> >>+ *
> >>+ * Returns: 0 on success
> >>+ *          -ENODEV if the given acpi_resource_source cannot be found
> >>+ *          -EINVAL for all other errors
> >>+ */
> >>+int acpi_irq_domain_unregister_irq(const struct
> >>acpi_resource_source *source,
> >>+				   u32 hwirq)
> >>+{
> >>+	struct irq_domain *domain;
> >>+	struct acpi_device *device;
> >>+	acpi_handle handle;
> >>+	acpi_status status;
> >>+	int ret = 0;
> >>+
> >>+	if (!source->string_length) {
> >>+		acpi_unregister_gsi(hwirq);
> >>+		return 0;
> >>+	}
> >>+
> >>+	status = acpi_get_handle(NULL, source->string_ptr, &handle);
> >>+	if (ACPI_FAILURE(status))
> >>+		return -ENODEV;
> >>+
> >>+	device = acpi_bus_get_acpi_device(handle);
> >>+	if (!device)
> >>+		return -ENODEV;
> >>+
> >>+	domain = irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY);
> >>+	if (!domain) {
> >>+		ret = -EINVAL;
> >>+		goto out_put_device;
> >>+	}
> >>+
> >>+	irq_dispose_mapping(irq_find_mapping(domain, hwirq));
> >>+
> >>+out_put_device:
> >>+	acpi_bus_put_acpi_device(device);
> >>+
> >>+	return ret;
> >>+}
> >>+EXPORT_SYMBOL_GPL(acpi_irq_domain_unregister_irq);
> >>diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> >>index 4beda15..ccb6f4f 100644
> >>--- a/drivers/acpi/resource.c
> >>+++ b/drivers/acpi/resource.c
> >>@@ -381,14 +381,15 @@ 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 resource *res, u32 hwirq,
> >>+				     const struct acpi_resource_source *source,
> >> 				     u8 triggering, u8 polarity, u8 shareable,
> >> 				     bool legacy)
> >> {
> >> 	int irq, p, t;
> >>
> >>-	if (!valid_IRQ(gsi)) {
> >>-		acpi_dev_irqresource_disabled(res, gsi);
> >>+	if ((source->string_length == 0) && !valid_IRQ(hwirq)) {
> >>+		acpi_dev_irqresource_disabled(res, hwirq);
> >> 		return;
> >> 	}
> >>
> >>@@ -402,25 +403,25 @@ static void
> >>acpi_dev_get_irqresource(struct resource *res, u32 gsi,
> >> 	 * using extended IRQ descriptors we take the IRQ configuration
> >> 	 * from _CRS directly.
> >> 	 */
> >>-	if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
> >>+	if (legacy && !acpi_get_override_irq(hwirq, &t, &p)) {
> >> 		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
> >> 		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
> >>
> >> 		if (triggering != trig || polarity != pol) {
> >>-			pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
> >>-				   t ? "level" : "edge", p ? "low" : "high");
> >>+			pr_warn("ACPI: IRQ %d override to %s, %s\n", hwirq,
> >>+				t ? "level" : "edge", p ? "low" : "high");
> >> 			triggering = trig;
> >> 			polarity = pol;
> >> 		}
> >> 	}
> >>
> >> 	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
> >>-	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
> >>+	irq = acpi_irq_domain_register_irq(source, hwirq, triggering,
> >>polarity);
> >> 	if (irq >= 0) {
> >> 		res->start = irq;
> >> 		res->end = irq;
> >> 	} else {
> >>-		acpi_dev_irqresource_disabled(res, gsi);
> >>+		acpi_dev_irqresource_disabled(res, hwirq);
> >> 	}
> >> }
> >>
> >>@@ -446,6 +447,7 @@ static void acpi_dev_get_irqresource(struct
> >>resource *res, u32 gsi,
> >> bool acpi_dev_resource_interrupt(struct acpi_resource *ares,
> >>int index,
> >> 				 struct resource *res)
> >> {
> >>+	const struct acpi_resource_source dummy = { 0, 0, NULL };
> >> 	struct acpi_resource_irq *irq;
> >> 	struct acpi_resource_extended_irq *ext_irq;
> >>
> >>@@ -460,7 +462,7 @@ 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(res, irq->interrupts[index], &dummy,
> >> 					 irq->triggering, irq->polarity,
> >> 					 irq->sharable, true);
> >> 		break;
> >>@@ -471,6 +473,7 @@ bool acpi_dev_resource_interrupt(struct
> >>acpi_resource *ares, int index,
> >> 			return false;
> >> 		}
> >> 		acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
> >>+					 &ext_irq->resource_source,
> >> 					 ext_irq->triggering, ext_irq->polarity,
> >> 					 ext_irq->sharable, false);
> >> 		break;
> >>diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> >>index 40213c4..ce30a12 100644
> >>--- a/include/linux/acpi.h
> >>+++ b/include/linux/acpi.h
> >>@@ -321,6 +321,31 @@ void acpi_set_irq_model(enum
> >>acpi_irq_model_id model,
> >>  */
> >> void acpi_unregister_gsi (u32 gsi);
> >>
> >>+#ifdef CONFIG_IRQ_DOMAIN
> >>+
> >>+int acpi_irq_domain_register_irq(const struct
> >>acpi_resource_source *source,
> >>+				 u32 hwirq, int trigger, int polarity);
> >>+int acpi_irq_domain_unregister_irq(const struct
> >>acpi_resource_source *source,
> >>+				   u32 hwirq);
> >>+
> >>+#else
> >>+
> >>+static inline int acpi_irq_domain_register_irq(
> >>+	const struct acpi_resource_source *source, u32 hwirq, int trigger,
> >>+	int polarity)
> >>+{
> >>+	return acpi_register_gsi(NULL, hwirq, trigger, polarity);
> >>+}
> >>+
> >>+static inline int acpi_irq_domain_unregister_irq(
> >>+	const struct acpi_resource_source *source,  u32 hwirq)
> >>+{
> >>+	acpi_unregister_gsi(hwirq);
> >>+	return 0;
> >>+}
> >>+
> >>+#endif /* CONFIG_IRQ_DOMAIN */
> >>+
> >> struct pci_dev;
> >>
> >> int acpi_pci_irq_enable (struct pci_dev *dev);
> >>
> 
> -- 
> Qualcomm Datacenter Technologies, Inc. on behalf of the Qualcomm
> Technologies, Inc.
> Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a
> Linux Foundation Collaborative Project.