xen: identity map gsi->irqs

Impact: preserve compat with native

Reserve the lower irq range for use for hardware interrupts so we
can identity-map them.

[v2: Rebased on top tip/irq/core]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Konrad Rzeszutek Wilk 2010-10-18 10:41:08 -04:00
parent 7b586d7185
commit 0794bfc743

View File

@ -33,6 +33,7 @@
#include <asm/ptrace.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/io_apic.h>
#include <asm/sync_bitops.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
@ -46,9 +47,6 @@
#include <xen/interface/hvm/hvm_op.h>
#include <xen/interface/hvm/params.h>
/* Leave low irqs free for identity mapping */
#define LEGACY_IRQS 16
/*
* This lock protects updates to the following mapping and reference-count
* arrays. The lock does not need to be acquired to read the mapping tables.
@ -351,6 +349,17 @@ static void unmask_evtchn(int port)
put_cpu();
}
static int get_nr_hw_irqs(void)
{
int ret = 1;
#ifdef CONFIG_X86_IO_APIC
ret = get_nr_irqs_gsi();
#endif
return ret;
}
static int find_unbound_irq(void)
{
struct irq_data *data;
@ -382,8 +391,8 @@ static int find_unbound_irq(void)
static bool identity_mapped_irq(unsigned irq)
{
/* only identity map legacy irqs */
return irq < LEGACY_IRQS;
/* identity map all the hardware irqs */
return irq < get_nr_hw_irqs();
}
static void pirq_unmask_notify(int irq)
@ -552,6 +561,7 @@ int xen_allocate_pirq(unsigned gsi)
if (identity_mapped_irq(gsi)) {
irq = gsi;
irq_to_desc_alloc_node(irq, 0);
dynamic_irq_init(irq);
} else
irq = find_unbound_irq();