Re: [tip:x86/irq] x86, acpi/irq: Handle isa irqs that are not identitymapped to gsi's.

[Yinghai]

On 05/04/2010 07:10 PM, tip-bot for Eric W. Biederman wrote:
> Commit-ID:  988856ee1623bd37e384105f7bb2b7fe44c009f6
> Gitweb:     http://git.kernel.org/tip/988856ee1623bd37e384105f7bb2b7fe44c009f6
> Author:     Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
> AuthorDate: Tue, 30 Mar 2010 01:07:15 -0700
> Committer:  H. Peter Anvin <hpa@xxxxxxxxx>
> CommitDate: Tue, 4 May 2010 13:35:17 -0700
> 
> x86, acpi/irq: Handle isa irqs that are not identity mapped to gsi's.
> 
> ACPI irq source overrides are allowed for the 16 isa irqs and are
> allowed to map any gsi to any isa irq.  A few motherboards have been
> seen to take advantage of this and put the isa irqs on the 2nd or
> 3rd ioapic.  This causes some problems, most notably the fact
> that we can not use any gsi < 16.
> 
> To correct this move the gsis that are not isa irqs and have
> a gsi number < 16 into the linux irq space just past gsi_end.
> This is what the es7000 platform is doing today.  Moving only the
> low 16 gsis above the rest of the gsi's only penalizes weird
> platforms, leaving sane acpi implementations with a 1-1 mapping
> of gsis and irqs.
> 
> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
> LKML-Reference: <1269936436-7039-14-git-send-email-ebiederm@xxxxxxxxxxxx>
> Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
> ---
>  arch/x86/kernel/acpi/boot.c    |   57 +++++++++++++++++++++++++++++++++++++---
>  arch/x86/kernel/apic/io_apic.c |    8 ++++-
>  2 files changed, 59 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 07a63ce..325fbba 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -94,6 +94,53 @@ enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PIC;
>  
>  
>  /*
> + * ISA irqs by default are the first 16 gsis but can be
> + * any gsi as specified by an interrupt source override.
> + */
> +static u32 isa_irq_to_gsi[NR_IRQS_LEGACY] __read_mostly = {
> +	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
> +};
> +
> +static unsigned int gsi_to_irq(unsigned int gsi)
> +{
> +	unsigned int irq = gsi + NR_IRQS_LEGACY;
> +	unsigned int i;
> +
> +	for (i = 0; i < NR_IRQS_LEGACY; i++) {
> +		if (isa_irq_to_gsi[i] == gsi) {
> +			return i;
> +		}
> +	}
> +
> +	/* Provide an identity mapping of gsi == irq
> +	 * except on truly weird platforms that have
> +	 * non isa irqs in the first 16 gsis.
> +	 */
> +	if (gsi >= NR_IRQS_LEGACY)
> +		irq = gsi;
> +	else
> +		irq = gsi_end + 1 + gsi;
> +
> +	return irq;
> +}
> +
> +static u32 irq_to_gsi(int irq)
> +{
> +	unsigned int gsi;
> +
> +	if (irq < NR_IRQS_LEGACY)
> +		gsi = isa_irq_to_gsi[irq];
> +	else if (irq <= gsi_end)
> +		gsi = irq;
> +	else if (irq <= (gsi_end + NR_IRQS_LEGACY))
> +		gsi = irq - gsi_end;

here should be
	gsi = irq - gsi_end - 1;

> +	else
> +		gsi = 0xffffffff;
> +
> +	return gsi;
> +}
> +
> +/*
>   * Temporarily use the virtual area starting from FIX_IO_APIC_BASE_END,
>   * to map the target physical address. The problem is that set_fixmap()
>   * provides a single page, and it is possible that the page is not
> @@ -449,7 +496,7 @@ void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)
>  
>  int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
>  {
> -	*irq = gsi;
> +	*irq = gsi_to_irq(gsi);
>  
>  #ifdef CONFIG_X86_IO_APIC
>  	if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
> @@ -463,7 +510,7 @@ int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
>  {
>  	if (isa_irq >= 16)
>  		return -1;
> -	*gsi = isa_irq;
> +	*gsi = irq_to_gsi(isa_irq);
>  	return 0;
>  }
>  
> @@ -491,7 +538,7 @@ int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
>  		plat_gsi = mp_register_gsi(dev, gsi, trigger, polarity);
>  	}
>  #endif
> -	irq = plat_gsi;
> +	irq = gsi_to_irq(plat_gsi);
>  
>  	return irq;
>  }
> @@ -933,6 +980,8 @@ void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, u32 gsi)
>  	mp_irq.dstirq = pin;	/* INTIN# */
>  
>  	save_mp_irq(&mp_irq);
> +
> +	isa_irq_to_gsi[bus_irq] = gsi;
>  }
>  
>  void __init mp_config_acpi_legacy_irqs(void)
> @@ -1086,7 +1135,7 @@ int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
>  	set_io_apic_irq_attr(&irq_attr, ioapic, ioapic_pin,
>  			     trigger == ACPI_EDGE_SENSITIVE ? 0 : 1,
>  			     polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
> -	io_apic_set_pci_routing(dev, gsi, &irq_attr);
> +	io_apic_set_pci_routing(dev, gsi_to_irq(gsi), &irq_attr);
>  
>  	return gsi;
>  }
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index 9f3f6ca..594827c 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -1037,7 +1037,11 @@ static int pin_2_irq(int idx, int apic, int pin)
>                   */
>  		if (ioapic_renumber_irq)
>  			gsi = ioapic_renumber_irq(apic, gsi);
> -		irq = gsi;
> +
> +		if (gsi >= NR_IRQS_LEGACY)
> +			irq = gsi;
> +		else
> +			irq = gsi_end + 1 + gsi;
>  	}
>  
>  #ifdef CONFIG_X86_32
> @@ -3852,7 +3856,7 @@ void __init probe_nr_irqs_gsi(void)
>  {
>  	int nr;
>  
> -	nr = gsi_end + 1;
> +	nr = gsi_end + 1 + NR_IRQS_LEGACY;
>  	if (nr > nr_irqs_gsi)
>  		nr_irqs_gsi = nr;

can you use legacy_irq->nr_legacy_irqs instead of NR_IRQS_LEGACY ?

YH
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