Re: [PATCH] x86/acpi: remove compress irq trick for 32bit

[Ingo Molnar <mingo@elte.hu>]

* Yinghai Lu <yinghai@kernel.org> wrote:

> 
> We already have per cpu vector for 32bit, and don't need this trick any more.
> 
> on 3 ioapic system (24 per ioapic) before patch got
> ACPI: PCI Interrupt Link [ILSB] enabled at IRQ 71
> IOAPIC[2]: Set routing entry (10-23 -> 0xa9 -> IRQ 64 Mode:1 Active:1)
> pci 0000:80:01.1: PCI INT A -> Link[ILSB] -> GSI 71 (level, low) -> IRQ 64
> ACPI: PCI Interrupt Link [LE5B] enabled at IRQ 67
> IOAPIC[2]: Set routing entry (10-19 -> 0xb1 -> IRQ 65 Mode:1 Active:1)
> pci 0000:83:00.0: PCI INT B -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 65
> ACPI: PCI Interrupt Link [LE5A] enabled at IRQ 66
> IOAPIC[2]: Set routing entry (10-18 -> 0xb9 -> IRQ 66 Mode:1 Active:1)
> pci 0000:83:00.1: PCI INT A -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
> ACPI: PCI Interrupt Link [LE5D] enabled at IRQ 65
> IOAPIC[2]: Set routing entry (10-17 -> 0xc1 -> IRQ 67 Mode:1 Active:1)
> pci 0000:84:00.0: PCI INT B -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 67
> ACPI: PCI Interrupt Link [LE5C] enabled at IRQ 64
> IOAPIC[2]: Set routing entry (10-16 -> 0xc9 -> IRQ 68 Mode:1 Active:1)
> pci 0000:84:00.1: PCI INT A -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 68
> pci 0000:87:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
> pci 0000:87:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 67
> pci 0000:88:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 68
> pci 0000:88:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 65
> pci 0000:8b:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
> pci 0000:8b:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 67
> pci 0000:8c:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 68
> pci 0000:8c:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 65
> 
> after patch will get
> ACPI: PCI Interrupt Link [ILSB] enabled at IRQ 71
> IOAPIC[2]: Set routing entry (10-23 -> 0xa9 -> IRQ 71 Mode:1 Active:1)
> pci 0000:80:01.1: PCI INT A -> Link[ILSB] -> GSI 71 (level, low) -> IRQ 71
> ACPI: PCI Interrupt Link [LE5B] enabled at IRQ 67
> IOAPIC[2]: Set routing entry (10-19 -> 0xb1 -> IRQ 67 Mode:1 Active:1)
> pci 0000:83:00.0: PCI INT B -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 67
> ACPI: PCI Interrupt Link [LE5A] enabled at IRQ 66
> IOAPIC[2]: Set routing entry (10-18 -> 0xb9 -> IRQ 66 Mode:1 Active:1)
> pci 0000:83:00.1: PCI INT A -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
> ACPI: PCI Interrupt Link [LE5D] enabled at IRQ 65
> IOAPIC[2]: Set routing entry (10-17 -> 0xc1 -> IRQ 65 Mode:1 Active:1)
> pci 0000:84:00.0: PCI INT B -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 65
> ACPI: PCI Interrupt Link [LE5C] enabled at IRQ 64
> IOAPIC[2]: Set routing entry (10-16 -> 0xc9 -> IRQ 64 Mode:1 Active:1)
> pci 0000:84:00.1: PCI INT A -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 64
> pci 0000:87:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
> pci 0000:87:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 65
> pci 0000:88:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 64
> pci 0000:88:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 67
> pci 0000:8b:00.0: PCI INT B -> Link[LE5A] -> GSI 66 (level, low) -> IRQ 66
> pci 0000:8b:00.1: PCI INT A -> Link[LE5D] -> GSI 65 (level, low) -> IRQ 65
> pci 0000:8c:00.0: PCI INT B -> Link[LE5C] -> GSI 64 (level, low) -> IRQ 64
> pci 0000:8c:00.1: PCI INT A -> Link[LE5B] -> GSI 67 (level, low) -> IRQ 67
> 
> [ Impact: make irq = gsi on 32bit system with more ioapics ]
> 
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> 
> ---
>  arch/x86/kernel/acpi/boot.c |   65 ++++----------------------------------------
>  1 file changed, 7 insertions(+), 58 deletions(-)
> 
> Index: linux-2.6/arch/x86/kernel/acpi/boot.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/kernel/acpi/boot.c
> +++ linux-2.6/arch/x86/kernel/acpi/boot.c
> @@ -1162,22 +1162,9 @@ int mp_register_gsi(struct device *dev,
>  {
>  	int ioapic;
>  	int ioapic_pin;
> -#ifdef CONFIG_X86_32
> -#define MAX_GSI_NUM	4096
> -#define IRQ_COMPRESSION_START	64
> -
> -	static int pci_irq = IRQ_COMPRESSION_START;
> -	/*
> -	 * Mapping between Global System Interrupts, which
> -	 * represent all possible interrupts, and IRQs
> -	 * assigned to actual devices.
> -	 */
> -	static int gsi_to_irq[MAX_GSI_NUM];
> -#else
>  
>  	if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
>  		return gsi;
> -#endif
>  
>  	/* Don't set up the ACPI SCI because it's already set up */
>  	if (acpi_gbl_FADT.sci_interrupt == gsi)
> @@ -1196,66 +1183,28 @@ int mp_register_gsi(struct device *dev,
>  		gsi = ioapic_renumber_irq(ioapic, gsi);
>  #endif
>  
> -	/*
> -	 * Avoid pin reprogramming.  PRTs typically include entries
> -	 * with redundant pin->gsi mappings (but unique PCI devices);
> -	 * we only program the IOAPIC on the first.
> -	 */
>  	if (ioapic_pin > MP_MAX_IOAPIC_PIN) {
>  		printk(KERN_ERR "Invalid reference to IOAPIC pin "
>  		       "%d-%d\n", mp_ioapic_routing[ioapic].apic_id,
>  		       ioapic_pin);
>  		return gsi;
>  	}
> +
> +	/*
> +	 * Avoid pin reprogramming.  PRTs typically include entries
> +	 * with redundant pin->gsi mappings (but unique PCI devices);
> +	 * we only program the IOAPIC on the first.
> +	 */
>  	if (test_bit(ioapic_pin, mp_ioapic_routing[ioapic].pin_programmed)) {
>  		pr_debug("Pin %d-%d already programmed\n",
>  			 mp_ioapic_routing[ioapic].apic_id, ioapic_pin);
> -#ifdef CONFIG_X86_32
> -		return (gsi < IRQ_COMPRESSION_START ? gsi : gsi_to_irq[gsi]);
> -#else
>  		return gsi;
> -#endif
>  	}
> -
>  	set_bit(ioapic_pin, mp_ioapic_routing[ioapic].pin_programmed);
> -#ifdef CONFIG_X86_32
> -	/*
> -	 * For GSI >= 64, use IRQ compression
> -	 */
> -	if ((gsi >= IRQ_COMPRESSION_START)
> -	    && (triggering == ACPI_LEVEL_SENSITIVE)) {
> -		/*
> -		 * For PCI devices assign IRQs in order, avoiding gaps
> -		 * due to unused I/O APIC pins.
> -		 */
> -		int irq = gsi;
> -		if (gsi < MAX_GSI_NUM) {
> -			/*
> -			 * Retain the VIA chipset work-around (gsi > 15), but
> -			 * avoid a problem where the 8254 timer (IRQ0) is setup
> -			 * via an override (so it's not on pin 0 of the ioapic),
> -			 * and at the same time, the pin 0 interrupt is a PCI
> -			 * type.  The gsi > 15 test could cause these two pins
> -			 * to be shared as IRQ0, and they are not shareable.
> -			 * So test for this condition, and if necessary, avoid
> -			 * the pin collision.
> -			 */
> -			gsi = pci_irq++;
> -			/*
> -			 * Don't assign IRQ used by ACPI SCI
> -			 */
> -			if (gsi == acpi_gbl_FADT.sci_interrupt)
> -				gsi = pci_irq++;
> -			gsi_to_irq[irq] = gsi;
> -		} else {
> -			printk(KERN_ERR "GSI %u is too high\n", gsi);
> -			return gsi;
> -		}
> -	}
> -#endif
>  	io_apic_set_pci_routing(dev, ioapic, ioapic_pin, gsi,
>  				triggering == ACPI_EDGE_SENSITIVE ? 0 : 1,
>  				polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
> +
>  	return gsi;
>  }
>  

Nice!

  Acked-by: Ingo Molnar <mingo@elte.hu>

Len, any preference about which tree should carry this?

	Ingo