Re: [PATCH V5] acpi: add support for extended IRQ to PCI link

[Sinan Kaya <okaya@codeaurora.org>]

On 11/24/2015 3:10 PM, Sinan Kaya wrote:
> 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 | 27 ++++++++++++++++++++++-----
>  1 file changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index 7c8408b..8fe4e6f 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -1,6 +1,7 @@
>  /*
>   *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
>   *
> + *  Copyright (c) 2015, The Linux Foundation. All rights reserved.
>   *  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>
> @@ -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 +156,12 @@ static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
>  					       p->interrupts[i]);
>  					continue;
>  				}
> +				if (p->interrupts[i] > ACPI_MAX_IRQS) {

this should have been >=
> +					pr_warn("IRQ %d exceeds max (%d)\n",
> +						p->interrupts[i],
> +						ACPI_MAX_IRQS);
> +					continue;
> +				}
>  				link->irq.possible[i] = p->interrupts[i];
>  				link->irq.possible_count++;
>  			}
> @@ -279,6 +294,11 @@ static int acpi_pci_link_get_current(struct acpi_pci_link *link)
>  		result = -ENODEV;
>  	}
>  

this should have been >=

> +	if (irq > ACPI_MAX_IRQS) {
> +		pr_err("IRQ %d number exceed max IRQ (%d)\n", irq,
> +			ACPI_MAX_IRQS);
> +		result = -ENODEV;
> +	}
>  	link->irq.active = irq;
>  
>  	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
> @@ -437,9 +457,6 @@ 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)
> 

Bjorn,
Does this look like what you were thinking?
Sinan


-- 
Sinan Kaya
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