xen/acpi-processor: fix enabling interrupts on syscore_resume

syscore->resume() callback is expected to do not enable interrupts,
it generates warning like below otherwise:

[ 9386.365390] WARNING: CPU: 0 PID: 6733 at drivers/base/syscore.c:104 syscore_resume+0x9a/0xe0()
[ 9386.365403] Interrupts enabled after xen_acpi_processor_resume+0x0/0x34 [xen_acpi_processor]
...
[ 9386.365429] Call Trace:
[ 9386.365434]  [<ffffffff81667a8b>] dump_stack+0x45/0x56
[ 9386.365437]  [<ffffffff8106921d>] warn_slowpath_common+0x7d/0xa0
[ 9386.365439]  [<ffffffff8106928c>] warn_slowpath_fmt+0x4c/0x50
[ 9386.365442]  [<ffffffffa0261bb0>] ? xen_upload_processor_pm_data+0x300/0x300 [xen_acpi_processor]
[ 9386.365443]  [<ffffffff814055fa>] syscore_resume+0x9a/0xe0
[ 9386.365445]  [<ffffffff810aef42>] suspend_devices_and_enter+0x402/0x470
[ 9386.365447]  [<ffffffff810af128>] pm_suspend+0x178/0x260

On xen_acpi_processor_resume() we call various procedures, which are
non atomic and can enable interrupts. To prevent the issue introduce
separate resume notify called after we enable interrupts on resume
and before we call other drivers resume callbacks.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 624e8dc2453239ec84f1e1d3564da09c38b16581..fc6c94c0b436f53c8d49b1849096d2f7ad441fbe 100644 (file)
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -46,6 +46,20 @@ struct suspend_info {
        void (*post)(int cancelled);
 };
 
+static RAW_NOTIFIER_HEAD(xen_resume_notifier);
+
+void xen_resume_notifier_register(struct notifier_block *nb)
+{
+       raw_notifier_chain_register(&xen_resume_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(xen_resume_notifier_register);
+
+void xen_resume_notifier_unregister(struct notifier_block *nb)
+{
+       raw_notifier_chain_unregister(&xen_resume_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister);
+
 #ifdef CONFIG_HIBERNATE_CALLBACKS
 static void xen_hvm_post_suspend(int cancelled)
 {
@@ -152,6 +166,8 @@ static void do_suspend(void)
 
        err = stop_machine(xen_suspend, &si, cpumask_of(0));
 
+       raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);
+
        dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
 
        if (err) {

diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
index 7231859119f1f126ac89e606ecc7c96c1a6a55c3..82358d14ecf18a020f200aa0dc8260d9a6d1807b 100644 (file)
--- a/drivers/xen/xen-acpi-processor.c
+++ b/drivers/xen/xen-acpi-processor.c
@@ -27,10 +27,10 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/types.h>
-#include <linux/syscore_ops.h>
 #include <linux/acpi.h>
 #include <acpi/processor.h>
 #include <xen/xen.h>
+#include <xen/xen-ops.h>
 #include <xen/interface/platform.h>
 #include <asm/xen/hypercall.h>
 
@@ -495,14 +495,15 @@ static int xen_upload_processor_pm_data(void)
        return rc;
 }
 
-static void xen_acpi_processor_resume(void)
+static int xen_acpi_processor_resume(struct notifier_block *nb,
+                                    unsigned long action, void *data)
 {
        bitmap_zero(acpi_ids_done, nr_acpi_bits);
-       xen_upload_processor_pm_data();
+       return xen_upload_processor_pm_data();
 }
 
-static struct syscore_ops xap_syscore_ops = {
-       .resume = xen_acpi_processor_resume,
+struct notifier_block xen_acpi_processor_resume_nb = {
+       .notifier_call = xen_acpi_processor_resume,
 };
 
 static int __init xen_acpi_processor_init(void)
@@ -555,7 +556,7 @@ static int __init xen_acpi_processor_init(void)
        if (rc)
                goto err_unregister;
 
-       register_syscore_ops(&xap_syscore_ops);
+       xen_resume_notifier_register(&xen_acpi_processor_resume_nb);
 
        return 0;
 err_unregister:
@@ -574,7 +575,7 @@ static void __exit xen_acpi_processor_exit(void)
 {
        int i;
 
-       unregister_syscore_ops(&xap_syscore_ops);
+       xen_resume_notifier_unregister(&xen_acpi_processor_resume_nb);
        kfree(acpi_ids_done);
        kfree(acpi_id_present);
        kfree(acpi_id_cst_present);

diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index fb2ea8f26552bdc4f093aaf1cff9b6485d888b98..2cf47175b12b3504dc6ffa4f19d94b275358a194 100644 (file)
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -2,6 +2,7 @@
 #define INCLUDE_XEN_OPS_H
 
 #include <linux/percpu.h>
+#include <linux/notifier.h>
 #include <asm/xen/interface.h>
 
 DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
@@ -16,6 +17,9 @@ void xen_mm_unpin_all(void);
 void xen_timer_resume(void);
 void xen_arch_resume(void);
 
+void xen_resume_notifier_register(struct notifier_block *nb);
+void xen_resume_notifier_unregister(struct notifier_block *nb);
+
 int xen_setup_shutdown_event(void);
 
 extern unsigned long *xen_contiguous_bitmap;