xen: refactor suspend pre/post hooks

New architectures currently have to provide implementations of 5 different
functions: xen_arch_pre_suspend(), xen_arch_post_suspend(),
xen_arch_hvm_post_suspend(), xen_mm_pin_all(), and xen_mm_unpin_all().

Refactor the suspend code to only require xen_arch_pre_suspend() and
xen_arch_post_suspend().
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

arch/x86/xen/suspend.c

@@ -12,8 +12,10 @@
 #include "xen-ops.h"
 #include "mmu.h"
 
-void xen_arch_pre_suspend(void)
+static void xen_pv_pre_suspend(void)
 {
+	xen_mm_pin_all();
+
 	xen_start_info->store_mfn = mfn_to_pfn(xen_start_info->store_mfn);
 	xen_start_info->console.domU.mfn =
 		mfn_to_pfn(xen_start_info->console.domU.mfn);
@@ -26,7 +28,7 @@ void xen_arch_pre_suspend(void)
 		BUG();
 }
 
-void xen_arch_hvm_post_suspend(int suspend_cancelled)
+static void xen_hvm_post_suspend(int suspend_cancelled)
 {
 #ifdef CONFIG_XEN_PVHVM
 	int cpu;
@@ -41,7 +43,7 @@ void xen_arch_hvm_post_suspend(int suspend_cancelled)
 #endif
 }
 
-void xen_arch_post_suspend(int suspend_cancelled)
+static void xen_pv_post_suspend(int suspend_cancelled)
 {
 	xen_build_mfn_list_list();
 
@@ -60,6 +62,21 @@ void xen_arch_post_suspend(int suspend_cancelled)
 		xen_vcpu_restore();
 	}
 
+	xen_mm_unpin_all();
+}
+
+void xen_arch_pre_suspend(void)
+{
+    if (xen_pv_domain())
+        xen_pv_pre_suspend();
+}
+
+void xen_arch_post_suspend(int cancelled)
+{
+    if (xen_pv_domain())
+        xen_pv_post_suspend(cancelled);
+    else
+        xen_hvm_post_suspend(cancelled);
 }
 
 static void xen_vcpu_notify_restore(void *data)

arch/x86/xen/xen-ops.h

@@ -31,6 +31,8 @@ void xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
 void xen_reserve_top(void);
 extern unsigned long xen_max_p2m_pfn;
 
+void xen_mm_pin_all(void);
+void xen_mm_unpin_all(void);
 void xen_set_pat(u64);
 
 char * __init xen_memory_setup(void);

drivers/xen/manage.c

@@ -41,9 +41,6 @@ static enum shutdown_state shutting_down = SHUTDOWN_INVALID;
 
 struct suspend_info {
 	int cancelled;
-	unsigned long arg; /* extra hypercall argument */
-	void (*pre)(void);
-	void (*post)(int cancelled);
 };
 
 static RAW_NOTIFIER_HEAD(xen_resume_notifier);
@@ -61,26 +58,6 @@ void xen_resume_notifier_unregister(struct notifier_block *nb)
 EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister);
 
 #ifdef CONFIG_HIBERNATE_CALLBACKS
-static void xen_hvm_post_suspend(int cancelled)
-{
-	xen_arch_hvm_post_suspend(cancelled);
-	gnttab_resume();
-}
-
-static void xen_pre_suspend(void)
-{
-	xen_mm_pin_all();
-	gnttab_suspend();
-	xen_arch_pre_suspend();
-}
-
-static void xen_post_suspend(int cancelled)
-{
-	xen_arch_post_suspend(cancelled);
-	gnttab_resume();
-	xen_mm_unpin_all();
-}
-
 static int xen_suspend(void *data)
 {
 	struct suspend_info *si = data;
@@ -94,18 +71,20 @@ static int xen_suspend(void *data)
 		return err;
 	}
 
-	if (si->pre)
-		si->pre();
+	gnttab_suspend();
+	xen_arch_pre_suspend();
 
 	/*
 	 * This hypercall returns 1 if suspend was cancelled
 	 * or the domain was merely checkpointed, and 0 if it
 	 * is resuming in a new domain.
 	 */
-	si->cancelled = HYPERVISOR_suspend(si->arg);
+	si->cancelled = HYPERVISOR_suspend(xen_pv_domain()
+                                           ? virt_to_mfn(xen_start_info)
+                                           : 0);
 
-	if (si->post)
-		si->post(si->cancelled);
+	xen_arch_post_suspend(si->cancelled);
+	gnttab_resume();
 
 	if (!si->cancelled) {
 		xen_irq_resume();
@@ -154,16 +133,6 @@ static void do_suspend(void)
 
 	si.cancelled = 1;
 
-	if (xen_hvm_domain()) {
-		si.arg = 0UL;
-		si.pre = NULL;
-		si.post = &xen_hvm_post_suspend;
-	} else {
-		si.arg = virt_to_mfn(xen_start_info);
-		si.pre = &xen_pre_suspend;
-		si.post = &xen_post_suspend;
-	}
-
 	err = stop_machine(xen_suspend, &si, cpumask_of(0));
 
 	raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);

include/xen/xen-ops.h

@@ -9,10 +9,6 @@ DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
 
 void xen_arch_pre_suspend(void);
 void xen_arch_post_suspend(int suspend_cancelled);
-void xen_arch_hvm_post_suspend(int suspend_cancelled);
-
-void xen_mm_pin_all(void);
-void xen_mm_unpin_all(void);
 
 void xen_timer_resume(void);
 void xen_arch_resume(void);