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Commit 9846ff10 authored by Stefano Stabellini's avatar Stefano Stabellini Committed by Konrad Rzeszutek Wilk
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xen: support pirq_eoi_map 



The pirq_eoi_map is a bitmap offered by Xen to check which pirqs need to
be EOI'd without having to issue an hypercall every time.
We use PHYSDEVOP_pirq_eoi_gmfn_v2 to map the bitmap, then if we
succeed we use pirq_eoi_map to check whether pirqs need eoi.

Changes in v3:

- explicitly use PHYSDEVOP_pirq_eoi_gmfn_v2 rather than
PHYSDEVOP_pirq_eoi_gmfn;

- introduce pirq_check_eoi_map, a function to check if a pirq needs an
eoi using the map;

-rename pirq_needs_eoi into pirq_needs_eoi_flag;

- introduce a function pointer called pirq_needs_eoi that is going to be
set to the right implementation depending on the availability of
PHYSDEVOP_pirq_eoi_gmfn_v2.

Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 102b208e

drivers/xen/events.c

+23 −3
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include <asm/idle.h>

#include <asm/io_apic.h>

#include <asm/sync_bitops.h>

#include <asm/xen/page.h>

#include <asm/xen/pci.h>

#include <asm/xen/hypercall.h>

#include <asm/xen/hypervisor.h>
@@ -109,6 +110,8 @@ struct irq_info { 
#define PIRQ_SHAREABLE	(1 << 1)



static int *evtchn_to_irq;

static unsigned long *pirq_eoi_map;

static bool (*pirq_needs_eoi)(unsigned irq);



static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],

		      cpu_evtchn_mask);
@@ -269,10 +272,14 @@ static unsigned int cpu_from_evtchn(unsigned int evtchn) 
	return ret;

}



static bool pirq_needs_eoi(unsigned irq)

static bool pirq_check_eoi_map(unsigned irq)

{

	struct irq_info *info = info_for_irq(irq);

	return test_bit(irq, pirq_eoi_map);

}



static bool pirq_needs_eoi_flag(unsigned irq)

{

	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info->type != IRQT_PIRQ);



	return info->u.pirq.flags & PIRQ_NEEDS_EOI;
@@ -1768,7 +1775,7 @@ void xen_callback_vector(void) {} 


void __init xen_init_IRQ(void)

{

	int i;

	int i, rc;



	evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),

				    GFP_KERNEL);
@@ -1782,6 +1789,8 @@ void __init xen_init_IRQ(void) 
	for (i = 0; i < NR_EVENT_CHANNELS; i++)

		mask_evtchn(i);



	pirq_needs_eoi = pirq_needs_eoi_flag;



	if (xen_hvm_domain()) {

		xen_callback_vector();

		native_init_IRQ();
@@ -1789,8 +1798,19 @@ void __init xen_init_IRQ(void) 
		 * __acpi_register_gsi can point at the right function */

		pci_xen_hvm_init();

	} else {

		struct physdev_pirq_eoi_gmfn eoi_gmfn;



		irq_ctx_init(smp_processor_id());

		if (xen_initial_domain())

			pci_xen_initial_domain();



		pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);

		eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);

		rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);

		if (rc != 0) {

			free_page((unsigned long) pirq_eoi_map);

			pirq_eoi_map = NULL;

		} else

			pirq_needs_eoi = pirq_check_eoi_map;

	}

}

include/xen/interface/physdev.h

+21 −0
Original line number Diff line number Diff line
@@ -38,6 +38,27 @@ struct physdev_eoi { 
	uint32_t irq;

};



/*

 * Register a shared page for the hypervisor to indicate whether the guest

 * must issue PHYSDEVOP_eoi. The semantics of PHYSDEVOP_eoi change slightly

 * once the guest used this function in that the associated event channel

 * will automatically get unmasked. The page registered is used as a bit

 * array indexed by Xen's PIRQ value.

 */

#define PHYSDEVOP_pirq_eoi_gmfn_v1       17

/*

 * Register a shared page for the hypervisor to indicate whether the

 * guest must issue PHYSDEVOP_eoi. This hypercall is very similar to

 * PHYSDEVOP_pirq_eoi_gmfn_v1 but it doesn't change the semantics of

 * PHYSDEVOP_eoi. The page registered is used as a bit array indexed by

 * Xen's PIRQ value.

 */

#define PHYSDEVOP_pirq_eoi_gmfn_v2       28

struct physdev_pirq_eoi_gmfn {

    /* IN */

    unsigned long gmfn;

};



/*

 * Query the status of an IRQ line.

 * @arg == pointer to physdev_irq_status_query structure.