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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-24 08:23:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-24 08:23:45 -0700
commit836ee4874e201a5907f9658fb2bf3527dd952d30 (patch)
tree34a9e521bbba61d127794278e7b14d96797273f4 /drivers/acpi/gsi.c
parentfb65d872d7a8dc629837a49513911d0281577bfd (diff)
parent7676fa70feb2f3bcdd4b854a553a57d8ef8505aa (diff)
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull initial ACPI support for arm64 from Will Deacon: "This series introduces preliminary ACPI 5.1 support to the arm64 kernel using the "hardware reduced" profile. We don't support any peripherals yet, so it's fairly limited in scope: - MEMORY init (UEFI) - ACPI discovery (RSDP via UEFI) - CPU init (FADT) - GIC init (MADT) - SMP boot (MADT + PSCI) - ACPI Kconfig options (dependent on EXPERT) ACPI for arm64 has been in development for a while now and hardware has been available that can boot with either FDT or ACPI tables. This has been made possible by both changes to the ACPI spec to cater for ARM-based machines (known as "hardware-reduced" in ACPI parlance) but also a Linaro-driven effort to get this supported on top of the Linux kernel. This pull request is the result of that work. These changes allow us to initialise the CPUs, interrupt controller, and timers via ACPI tables, with memory information and cmdline coming from EFI. We don't support a hybrid ACPI/FDT scheme. Of course, there is still plenty of work to do (a serial console would be nice!) but I expect that to happen on a per-driver basis after this core series has been merged. Anyway, the diff stat here is fairly horrible, but splitting this up and merging it via all the different subsystems would have been extremely painful. Instead, we've got all the relevant Acks in place and I've not seen anything other than trivial (Kconfig) conflicts in -next (for completeness, I've included my resolution below). Nearly half of the insertions fall under Documentation/. So, we'll see how this goes. Right now, it all depends on EXPERT and I fully expect people to use FDT by default for the immediate future" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits) ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface() ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface ARM64: kernel: acpi: honour acpi=force command line parameter ARM64: kernel: acpi: refactor ACPI tables init and checks ARM64: kernel: psci: let ACPI probe PSCI version ARM64: kernel: psci: factor out probe function ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed ARM64 / ACPI: additions of ACPI documentation for arm64 Documentation: ACPI for ARM64 ARM64 / ACPI: Enable ARM64 in Kconfig XEN / ACPI: Make XEN ACPI depend on X86 ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64 clocksource / arch_timer: Parse GTDT to initialize arch timer irqchip: Add GICv2 specific ACPI boot support ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi ACPI / processor: Make it possible to get CPU hardware ID via GICC ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID ARM64 / ACPI: Parse MADT for SMP initialization ...
Diffstat (limited to 'drivers/acpi/gsi.c')
-rw-r--r--drivers/acpi/gsi.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/acpi/gsi.c b/drivers/acpi/gsi.c
new file mode 100644
index 000000000000..38208f2d0e69
--- /dev/null
+++ b/drivers/acpi/gsi.c
@@ -0,0 +1,105 @@
+/*
+ * ACPI GSI IRQ layer
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+
+enum acpi_irq_model_id acpi_irq_model;
+
+static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity)
+{
+ switch (polarity) {
+ case ACPI_ACTIVE_LOW:
+ return trigger == ACPI_EDGE_SENSITIVE ?
+ IRQ_TYPE_EDGE_FALLING :
+ IRQ_TYPE_LEVEL_LOW;
+ case ACPI_ACTIVE_HIGH:
+ return trigger == ACPI_EDGE_SENSITIVE ?
+ IRQ_TYPE_EDGE_RISING :
+ IRQ_TYPE_LEVEL_HIGH;
+ case ACPI_ACTIVE_BOTH:
+ if (trigger == ACPI_EDGE_SENSITIVE)
+ return IRQ_TYPE_EDGE_BOTH;
+ default:
+ return IRQ_TYPE_NONE;
+ }
+}
+
+/**
+ * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
+ * @gsi: GSI IRQ number to map
+ * @irq: pointer where linux IRQ number is stored
+ *
+ * irq location updated with irq value [>0 on success, 0 on failure]
+ *
+ * Returns: linux IRQ number on success (>0)
+ * -EINVAL on failure
+ */
+int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
+{
+ /*
+ * Only default domain is supported at present, always find
+ * the mapping corresponding to default domain by passing NULL
+ * as irq_domain parameter
+ */
+ *irq = irq_find_mapping(NULL, gsi);
+ /*
+ * *irq == 0 means no mapping, that should
+ * be reported as a failure
+ */
+ return (*irq > 0) ? *irq : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
+
+/**
+ * acpi_register_gsi() - Map a GSI to a linux IRQ number
+ * @dev: device for which IRQ has to be mapped
+ * @gsi: GSI IRQ number
+ * @trigger: trigger type of the GSI number to be mapped
+ * @polarity: polarity of the GSI to be mapped
+ *
+ * Returns: a valid linux IRQ number on success
+ * -EINVAL on failure
+ */
+int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
+ int polarity)
+{
+ unsigned int irq;
+ unsigned int irq_type = acpi_gsi_get_irq_type(trigger, polarity);
+
+ /*
+ * There is no way at present to look-up the IRQ domain on ACPI,
+ * hence always create mapping referring to the default domain
+ * by passing NULL as irq_domain parameter
+ */
+ irq = irq_create_mapping(NULL, gsi);
+ if (!irq)
+ return -EINVAL;
+
+ /* Set irq type if specified and different than the current one */
+ if (irq_type != IRQ_TYPE_NONE &&
+ irq_type != irq_get_trigger_type(irq))
+ irq_set_irq_type(irq, irq_type);
+ return irq;
+}
+EXPORT_SYMBOL_GPL(acpi_register_gsi);
+
+/**
+ * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
+ * @gsi: GSI IRQ number
+ */
+void acpi_unregister_gsi(u32 gsi)
+{
+ int irq = irq_find_mapping(NULL, gsi);
+
+ irq_dispose_mapping(irq);
+}
+EXPORT_SYMBOL_GPL(acpi_unregister_gsi);