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Commit 0794bfc7 authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

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: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 7b586d71

drivers/xen/events.c

+15 −5
Original line number Diff line number Diff line
@@ -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();