PCI / Intel IOMMU: Use syscore_ops instead of sysdev class and sysdev

The Intel IOMMU subsystem uses a sysdev class and a sysdev for
executing iommu_suspend() after interrupts have been turned off
on the boot CPU (during system suspend) and for executing
iommu_resume() before turning on interrupts on the boot CPU
(during system resume).  However, since both of these functions
ignore their arguments, the entire mechanism may be replaced with a
struct syscore_ops object which is simpler.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 9 insertions, 29 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 4789f8e8bf7a..a4115f1afe1f 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -36,7 +36,7 @@
 #include <linux/iova.h>
 #include <linux/iommu.h>
 #include <linux/intel-iommu.h>
-#include <linux/sysdev.h>
+#include <linux/syscore_ops.h>
 #include <linux/tboot.h>
 #include <linux/dmi.h>
 #include <asm/cacheflush.h>
@@ -3135,7 +3135,7 @@ static void iommu_flush_all(void)
         }
 }
 
-static int iommu_suspend(struct sys_device *dev, pm_message_t state)
+static int iommu_suspend(void)
 {
         struct dmar_drhd_unit *drhd;
         struct intel_iommu *iommu = NULL;
@@ -3175,7 +3175,7 @@ nomem:
         return -ENOMEM;
 }
 
-static int iommu_resume(struct sys_device *dev)
+static void iommu_resume(void)
 {
         struct dmar_drhd_unit *drhd;
         struct intel_iommu *iommu = NULL;
@@ -3183,7 +3183,7 @@ static int iommu_resume(struct sys_device *dev)
 
         if (init_iommu_hw()) {
                 WARN(1, "IOMMU setup failed, DMAR can not resume!\n");
-                return -EIO;
+                return;
         }
 
         for_each_active_iommu(iommu, drhd) {
@@ -3204,40 +3204,20 @@ static int iommu_resume(struct sys_device *dev)
 
         for_each_active_iommu(iommu, drhd)
                 kfree(iommu->iommu_state);
-
-        return 0;
 }
 
-static struct sysdev_class iommu_sysclass = {
-        .name           = "iommu",
+static struct syscore_ops iommu_syscore_ops = {
         .resume         = iommu_resume,
         .suspend        = iommu_suspend,
 };
 
-static struct sys_device device_iommu = {
-        .cls    = &iommu_sysclass,
-};
-
-static int __init init_iommu_sysfs(void)
+static void __init init_iommu_pm_ops(void)
 {
-        int error;
-
-        error = sysdev_class_register(&iommu_sysclass);
-        if (error)
-                return error;
-
-        error = sysdev_register(&device_iommu);
-        if (error)
-                sysdev_class_unregister(&iommu_sysclass);
-
-        return error;
+        register_syscore_ops(&iommu_syscore_ops);
 }
 
 #else
-static int __init init_iommu_sysfs(void)
-{
-        return 0;
-}
+static inline int init_iommu_pm_ops(void) { }
 #endif  /* CONFIG_PM */
 
 /*
@@ -3320,7 +3300,7 @@ int __init intel_iommu_init(void)
 #endif
         dma_ops = &intel_dma_ops;
 
-        init_iommu_sysfs();
+        init_iommu_pm_ops();
 
         register_iommu(&intel_iommu_ops);