Hi Sinan,

On Mon, Nov 30, 2015 at 06:39:01PM -0500, Sinan Kaya wrote:
> The ACPI compiler uses the extended format when used interrupt numbers
> are greater than 15. The extended IRQ is 32 bits according to the ACPI
> spec. The code supports parsing the extended interrupt numbers. However,
> due to used data structure type; the code silently truncates interrupt
> numbers greater than 256.
> 
> 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.
> 
> Signed-off-by: Sinan Kaya <ok...@codeaurora.org>
> ---
>  drivers/acpi/pci_link.c | 30 +++++++++++++++++++++++++-----
>  1 file changed, 25 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index 7c8408b..faa37cd 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -4,6 +4,7 @@
>   *  Copyright (C) 2001, 2002 Andy Grover <andrew.gro...@intel.com>
>   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenba...@intel.com>
>   *  Copyright (C) 2002       Dominik Brodowski <de...@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

Not sure whether you saw my earlier response about this:

  ACPI_MAX_IRQS is only used to size the acpi_irq_penalty[] table (and
  after your patch, to validate IRQ numbers from ACPI).  But I think
  the acpi_irq_penalty[] table is a design we've outgrown.  I *think*
  we only care about penalties for IRQs 0-15, so even a 256-entry
  table is more than we need.

  If we could make acpi_irq_penalty[] a fixed size of 16 entries or
  replace it with a linked list, I think we could get rid of
  ACPI_MAX_IRQS completely.  Then the validation checks you add below
  would be unnecessary and we could handle any interrupt number
  supplied from ACPI.

I think it would be really nice to get rid of the arbitrary maximum
interrupt ID (1020).

Bjorn

> +
> +
>  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 +295,13 @@ 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;
> +             goto end;
> +     }
>       link->irq.active = irq;
>  
>       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
> @@ -437,9 +460,6 @@ 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
> 
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