diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 5f3a69f6ec340106fd9dda536edfb24af961cf71..0305485edcd3ef68dd1ace7844fc0902967aa8b4 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -379,3 +379,36 @@ void __init xen_add_extra_mem(unsigned long start_pfn, unsigned long n_pfns)
memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
}
+
+#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
+int __init arch_xen_unpopulated_init(struct resource **res)
+{
+ unsigned int i;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ /* Must be set strictly before calling xen_free_unpopulated_pages(). */
+ *res = &iomem_resource;
+
+ /*
+ * Initialize with pages from the extra memory regions (see
+ * arch/x86/xen/setup.c).
+ */
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+ unsigned int j;
+
+ for (j = 0; j < xen_extra_mem[i].n_pfns; j++) {
+ struct page *pg =
+ pfn_to_page(xen_extra_mem[i].start_pfn + j);
+
+ xen_free_unpopulated_pages(1, &pg);
+ }
+
+ /* Zero so region is not also added to the balloon driver. */
+ xen_extra_mem[i].n_pfns = 0;
+ }
+
+ return 0;
+}
+#endif
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 9bdc3b656b2c49ac1bc1323b3e6ec4bf0ec418af..99918beccd80cf6c5fe5871a950b2beaf4b21710 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -555,7 +555,6 @@ int xen_alloc_p2m_entry(unsigned long pfn)
/* Separately check the mid mfn level */
unsigned long missing_mfn;
unsigned long mid_mfn_mfn;
- unsigned long old_mfn;
mid_mfn = alloc_p2m_page();
if (!mid_mfn)
@@ -565,12 +564,12 @@ int xen_alloc_p2m_entry(unsigned long pfn)
missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
mid_mfn_mfn = virt_to_mfn(mid_mfn);
- old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
- if (old_mfn != missing_mfn) {
- free_p2m_page(mid_mfn);
- mid_mfn = mfn_to_virt(old_mfn);
- } else {
+ /* try_cmpxchg() updates missing_mfn on failure. */
+ if (try_cmpxchg(top_mfn_p, &missing_mfn, mid_mfn_mfn)) {
p2m_top_mfn_p[topidx] = mid_mfn;
+ } else {
+ free_p2m_page(mid_mfn);
+ mid_mfn = mfn_to_virt(missing_mfn);
}
}
} else {
diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile
index 0c75321108151d12df8c946fbadee5c1e1779e76..b0d69602214e6c447cfbd9900dccee4900256562 100644
--- a/drivers/xen/xenbus/Makefile
+++ b/drivers/xen/xenbus/Makefile
@@ -1,15 +1,13 @@
# SPDX-License-Identifier: GPL-2.0
obj-y += xenbus.o
-obj-y += xenbus_dev_frontend.o
-xenbus-objs =
-xenbus-objs += xenbus_client.o
-xenbus-objs += xenbus_comms.o
-xenbus-objs += xenbus_xs.o
-xenbus-objs += xenbus_probe.o
+xenbus-y := xenbus_client.o
+xenbus-y += xenbus_comms.o
+xenbus-y += xenbus_xs.o
+xenbus-y += xenbus_probe.o
-xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o
-xenbus-objs += $(xenbus-be-objs-y)
+xenbus-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o
+obj-y += xenbus_dev_frontend.o
obj-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o
obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 3205e5d724c8cf849f6476f598ace14350d3464c..1a9ded0cddcb0f324f038f7f536dab7d0ee46a66 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -65,13 +65,17 @@
#include "xenbus.h"
-static int xs_init_irq;
+static int xs_init_irq = -1;
int xen_store_evtchn;
EXPORT_SYMBOL_GPL(xen_store_evtchn);
struct xenstore_domain_interface *xen_store_interface;
EXPORT_SYMBOL_GPL(xen_store_interface);
+#define XS_INTERFACE_READY \
+ ((xen_store_interface != NULL) && \
+ (xen_store_interface->connection == XENSTORE_CONNECTED))
+
enum xenstore_init xen_store_domain_type;
EXPORT_SYMBOL_GPL(xen_store_domain_type);
@@ -751,19 +755,19 @@ static void xenbus_probe(void)
{
xenstored_ready = 1;
- if (!xen_store_interface) {
+ if (!xen_store_interface)
xen_store_interface = memremap(xen_store_gfn << XEN_PAGE_SHIFT,
XEN_PAGE_SIZE, MEMREMAP_WB);
- /*
- * Now it is safe to free the IRQ used for xenstore late
- * initialization. No need to unbind: it is about to be
- * bound again from xb_init_comms. Note that calling
- * unbind_from_irqhandler now would result in xen_evtchn_close()
- * being called and the event channel not being enabled again
- * afterwards, resulting in missed event notifications.
- */
+ /*
+ * Now it is safe to free the IRQ used for xenstore late
+ * initialization. No need to unbind: it is about to be
+ * bound again from xb_init_comms. Note that calling
+ * unbind_from_irqhandler now would result in xen_evtchn_close()
+ * being called and the event channel not being enabled again
+ * afterwards, resulting in missed event notifications.
+ */
+ if (xs_init_irq >= 0)
free_irq(xs_init_irq, &xb_waitq);
- }
/*
* In the HVM case, xenbus_init() deferred its call to
@@ -822,7 +826,7 @@ static int __init xenbus_probe_initcall(void)
if (xen_store_domain_type == XS_PV ||
(xen_store_domain_type == XS_HVM &&
!xs_hvm_defer_init_for_callback() &&
- xen_store_interface != NULL))
+ XS_INTERFACE_READY))
xenbus_probe();
/*
@@ -831,7 +835,7 @@ static int __init xenbus_probe_initcall(void)
* started, then probe. It will be triggered when communication
* starts happening, by waiting on xb_waitq.
*/
- if (xen_store_domain_type == XS_LOCAL || xen_store_interface == NULL) {
+ if (xen_store_domain_type == XS_LOCAL || !XS_INTERFACE_READY) {
struct task_struct *probe_task;
probe_task = kthread_run(xenbus_probe_thread, NULL,
@@ -1014,6 +1018,12 @@ static int __init xenbus_init(void)
xen_store_interface =
memremap(xen_store_gfn << XEN_PAGE_SHIFT,
XEN_PAGE_SIZE, MEMREMAP_WB);
+ if (!xen_store_interface) {
+ pr_err("%s: cannot map HVM_PARAM_STORE_PFN=%llx\n",
+ __func__, v);
+ err = -EINVAL;
+ goto out_error;
+ }
if (xen_store_interface->connection != XENSTORE_CONNECTED)
wait = true;
}