iommu/core: Convert iommu_found to iommu_present

With per-bus iommu_ops the iommu_found function needs to
work on a bus_type too. This patch adds a bus_type parameter
to that function and converts all call-places.
The function is also renamed to iommu_present because the
function now checks if an iommu is present for a given bus
and does not check for a global iommu anymore.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/ia64/kvm/kvm-ia64.c

@@ -33,6 +33,7 @@
 #include <linux/uaccess.h>
 #include <linux/iommu.h>
 #include <linux/intel-iommu.h>
+#include <linux/pci.h>
 
 #include <asm/pgtable.h>
 #include <asm/gcc_intrin.h>
@@ -204,7 +205,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 		r = KVM_COALESCED_MMIO_PAGE_OFFSET;
 		break;
 	case KVM_CAP_IOMMU:
-		r = iommu_found();
+		r = iommu_present(&pci_bus_type);
 		break;
 	default:
 		r = 0;

arch/x86/kvm/x86.c

@@ -44,6 +44,7 @@
 #include <linux/perf_event.h>
 #include <linux/uaccess.h>
 #include <linux/hash.h>
+#include <linux/pci.h>
 #include <trace/events/kvm.h>
 
 #define CREATE_TRACE_POINTS
@@ -2095,7 +2096,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 		r = 0;
 		break;
 	case KVM_CAP_IOMMU:
-		r = iommu_found();
+		r = iommu_present(&pci_bus_type);
 		break;
 	case KVM_CAP_MCE:
 		r = KVM_MAX_MCE_BANKS;

drivers/iommu/iommu.c

@@ -66,11 +66,14 @@ int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops)
 }
 EXPORT_SYMBOL_GPL(bus_set_iommu);
 
-bool iommu_found(void)
+bool iommu_present(struct bus_type *bus)
 {
-	return iommu_ops != NULL;
+	if (bus->iommu_ops != NULL)
+		return true;
+	else
+		return iommu_ops != NULL;
 }
-EXPORT_SYMBOL_GPL(iommu_found);
+EXPORT_SYMBOL_GPL(iommu_present);
 
 struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
 {

include/linux/iommu.h

@@ -56,7 +56,7 @@ struct iommu_ops {
 
 extern void register_iommu(struct iommu_ops *ops);
 extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops);
-extern bool iommu_found(void);
+extern bool iommu_present(struct bus_type *bus);
 extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
 extern void iommu_domain_free(struct iommu_domain *domain);
 extern int iommu_attach_device(struct iommu_domain *domain,
@@ -76,7 +76,7 @@ extern int iommu_domain_has_cap(struct iommu_domain *domain,
 
 struct iommu_ops {};
 
-static inline bool iommu_found(void)
+static inline bool iommu_present(struct bus_type *bus)
 {
 	return false;
 }

virt/kvm/iommu.c

@@ -228,7 +228,7 @@ int kvm_iommu_map_guest(struct kvm *kvm)
 {
 	int r;
 
-	if (!iommu_found()) {
+	if (!iommu_present(&pci_bus_type)) {
 		printk(KERN_ERR "%s: iommu not found\n", __func__);
 		return -ENODEV;
 	}