On 15/11/11 13:14, Jan Beulich wrote:
> Rather than going through all IO-APICs and calling io_apic_eoi_vector()
> for the vector in question, just use eoi_IO_APIC_irq().
>
> This in turn allows to eliminate quite a bit of other code.
>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Tested-and-acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> (tested
via backport to xen-4.1.x)
> --- a/xen/arch/x86/io_apic.c
> +++ b/xen/arch/x86/io_apic.c
> @@ -69,10 +69,6 @@ int __read_mostly nr_ioapics;
>
> #define ioapic_has_eoi_reg(apic) (mp_ioapics[(apic)].mpc_apicver >= 0x20)
>
> -#define io_apic_eoi_vector(apic, vector) io_apic_eoi((apic), (vector), -1)
> -#define io_apic_eoi_pin(apic, pin) io_apic_eoi((apic), -1, (pin))
> -
> -
> /*
> * This is performance-critical, we want to do it O(1)
> *
> @@ -213,21 +209,18 @@ static void ioapic_write_entry(
> spin_unlock_irqrestore(&ioapic_lock, flags);
> }
>
> -/* EOI an IO-APIC entry. One of vector or pin may be -1, indicating that
> - * it should be worked out using the other. This function expect that the
> - * ioapic_lock is taken, and interrupts are disabled (or there is a good
> reason
> - * not to), and that if both pin and vector are passed, that they refer to
> the
> +/* EOI an IO-APIC entry. Vector may be -1, indicating that it should be
> + * worked out using the pin. This function expects that the ioapic_lock is
> + * being held, and interrupts are disabled (or there is a good reason not
> + * to), and that if both pin and vector are passed, that they refer to the
> * same redirection entry in the IO-APIC. */
> static void __io_apic_eoi(unsigned int apic, unsigned int vector, unsigned
> int pin)
> {
> - /* Ensure some useful information is passed in */
> - BUG_ON( (vector == -1 && pin == -1) );
> -
> /* Prefer the use of the EOI register if available */
> if ( ioapic_has_eoi_reg(apic) )
> {
> /* If vector is unknown, read it from the IO-APIC */
> - if ( vector == -1 )
> + if ( vector == IRQ_VECTOR_UNASSIGNED )
> vector = __ioapic_read_entry(apic, pin, TRUE).vector;
>
> *(IO_APIC_BASE(apic)+16) = vector;
> @@ -239,42 +232,6 @@ static void __io_apic_eoi(unsigned int a
> struct IO_APIC_route_entry entry;
> bool_t need_to_unmask = 0;
>
> - /* If pin is unknown, search for it */
> - if ( pin == -1 )
> - {
> - unsigned int p;
> - for ( p = 0; p < nr_ioapic_entries[apic]; ++p )
> - {
> - entry = __ioapic_read_entry(apic, p, TRUE);
> - if ( entry.vector == vector )
> - {
> - pin = p;
> - /* break; */
> -
> - /* Here should be a break out of the loop, but at the
> - * Xen code doesn't actually prevent multiple IO-APIC
> - * entries being assigned the same vector, so EOI all
> - * pins which have the correct vector.
> - *
> - * Remove the following code when the above assertion
> - * is fulfilled. */
> - __io_apic_eoi(apic, vector, p);
> - }
> - }
> -
> - /* If search fails, nothing to do */
> -
> - /* if ( pin == -1 ) */
> -
> - /* Because the loop wasn't broken out of (see comment above),
> - * all relevant pins have been EOI, so we can always return.
> - *
> - * Re-instate the if statement above when the Xen logic has been
> - * fixed.*/
> -
> - return;
> - }
> -
> entry = __ioapic_read_entry(apic, pin, TRUE);
>
> if ( ! entry.mask )
> @@ -301,17 +258,6 @@ static void __io_apic_eoi(unsigned int a
> }
> }
>
> -/* EOI an IO-APIC entry. One of vector or pin may be -1, indicating that
> - * it should be worked out using the other. This function disables
> interrupts
> - * and takes the ioapic_lock */
> -static void io_apic_eoi(unsigned int apic, unsigned int vector, unsigned int
> pin)
> -{
> - unsigned int flags;
> - spin_lock_irqsave(&ioapic_lock, flags);
> - __io_apic_eoi(apic, vector, pin);
> - spin_unlock_irqrestore(&ioapic_lock, flags);
> -}
> -
> /*
> * Saves all the IO-APIC RTE's
> */
> @@ -1693,11 +1639,7 @@ static void end_level_ioapic_irq(struct
>
> /* Manually EOI the old vector if we are moving to the new */
> if ( vector && i != vector )
> - {
> - int ioapic;
> - for (ioapic = 0; ioapic < nr_ioapics; ioapic++)
> - io_apic_eoi_vector(ioapic, i);
> - }
> + eoi_IO_APIC_irq(desc);
>
> v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
>
>
>
--
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com
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