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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2012-01-30 17:21:48 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-03-20 20:34:07 +0100
commit9846ff10af12f9e7caac696737db6c990592a74a (patch)
treef0b047fedc93c820ed63657fd5c9bb28457b69ce
parentxen/acpi-processor: Do not depend on CPU frequency scaling drivers. (diff)
downloadlinux-9846ff10af12f9e7caac696737db6c990592a74a.tar.xz
linux-9846ff10af12f9e7caac696737db6c990592a74a.zip
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: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
-rw-r--r--drivers/xen/events.c26
-rw-r--r--include/xen/interface/physdev.h21
2 files changed, 44 insertions, 3 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index e5e5812a1014..4b33acd8ed4e 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -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;
}
}
diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h
index 0c28989007fb..9ce788d8cf49 100644
--- a/include/xen/interface/physdev.h
+++ b/include/xen/interface/physdev.h
@@ -39,6 +39,27 @@ struct physdev_eoi {
};
/*
+ * 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.
*/