[PATCH V6] acpi: add support for extended IRQ to PCI link

[Sinan Kaya <okaya@codeaurora.org>]

The ACPI compiler uses the extended format when used interrupt numbers
are greater than 256. The extended IRQ numbers use 32 bits for storing
interrupts. The code already supports parsing extended IRQ type but is
limited by 256 due to used data structure type (u8). This patch changes
the interrupt number type to 32 bits and places an upper limit of 1020
as possible interrupt id. 1020 is the maximum interrupt ID that can be
assigned to an ARM SPI interrupt according to ARM architecture.

Additional checks have been placed to return an error when ACPI_MAX_IRQS
is exceeded.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/acpi/pci_link.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index 7c8408b..5ab83dc 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -4,6 +4,7 @@
  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
+ *  Copyright (c) 2015, The Linux Foundation. All rights reserved.
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -47,6 +48,14 @@ ACPI_MODULE_NAME("pci_link");
 #define ACPI_PCI_LINK_FILE_STATUS	"state"
 #define ACPI_PCI_LINK_MAX_POSSIBLE	16
 
+/*
+ * 1020 is the maximum interrupt ID that can be assigned to
+ * an ARM SPI interrupt according to ARM architecture.
+ */
+#define ACPI_MAX_IRQS		1020
+#define ACPI_MAX_ISA_IRQ	16
+
+
 static int acpi_pci_link_add(struct acpi_device *device,
 			     const struct acpi_device_id *not_used);
 static void acpi_pci_link_remove(struct acpi_device *device);
@@ -67,12 +76,12 @@ static struct acpi_scan_handler pci_link_handler = {
  * later even the link is disable. Instead, we just repick the active irq
  */
 struct acpi_pci_link_irq {
-	u8 active;		/* Current IRQ */
+	u32 active;		/* Current IRQ */
 	u8 triggering;		/* All IRQs */
 	u8 polarity;		/* All IRQs */
 	u8 resource_type;
 	u8 possible_count;
-	u8 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
+	u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
 	u8 initialized:1;
 	u8 reserved:7;
 };
@@ -147,6 +156,13 @@ static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
 					       p->interrupts[i]);
 					continue;
 				}
+				if (p->interrupts[i] >= ACPI_MAX_IRQS) {
+					dev_warn(&link->device->dev,
+						"Ignoring IRQ(%d) as it exceeds max(%d)\n",
+						p->interrupts[i],
+						ACPI_MAX_IRQS - 1);
+					continue;
+				}
 				link->irq.possible[i] = p->interrupts[i];
 				link->irq.possible_count++;
 			}
@@ -279,6 +295,12 @@ static int acpi_pci_link_get_current(struct acpi_pci_link *link)
 		result = -ENODEV;
 	}
 
+	if (irq >= ACPI_MAX_IRQS) {
+		dev_err(&link->device->dev,
+			"Ignoring IRQ(%d) as it exceeds max(%d)\n",
+			irq,  ACPI_MAX_IRQS - 1);
+		result = -ENODEV;
+	}
 	link->irq.active = irq;
 
 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
@@ -437,9 +459,6 @@ static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
  * enabled system.
  */
 
-#define ACPI_MAX_IRQS		256
-#define ACPI_MAX_ISA_IRQ	16
-
 #define PIRQ_PENALTY_PCI_AVAILABLE	(0)
 #define PIRQ_PENALTY_PCI_POSSIBLE	(16*16)
 #define PIRQ_PENALTY_PCI_USING		(16*16*16)
-- 
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project