iommu/vt-d: fix PCI device reference leakage on error recovery path

Function dmar_parse_dev_scope() should release the PCI device reference
count gained in function dmar_parse_one_dev_scope() on error recovery,
otherwise it will cause PCI device object leakage.

This patch also introduces dmar_free_dev_scope(), which will be used
to support DMAR device hotplug.

Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index b029d1aa2d12..205ee37eed73 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -62,6 +62,9 @@ extern struct list_head dmar_drhd_units;
 
 extern int dmar_table_init(void);
 extern int dmar_dev_scope_init(void);
+extern int dmar_parse_dev_scope(void *start, void *end, int *cnt,
+                                struct pci_dev ***devices, u16 segment);
+extern void dmar_free_dev_scope(struct pci_dev ***devices, int *cnt);
 
 /* Intel IOMMU detection */
 extern int detect_intel_iommu(void);
@@ -157,8 +160,6 @@ struct dmar_atsr_unit {
 int dmar_parse_rmrr_atsr_dev(void);
 extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header);
 extern int dmar_parse_one_atsr(struct acpi_dmar_header *header);
-extern int dmar_parse_dev_scope(void *start, void *end, int *cnt,
-                                struct pci_dev ***devices, u16 segment);
 extern int intel_iommu_init(void);
 #else /* !CONFIG_INTEL_IOMMU: */
 static inline int intel_iommu_init(void) { return -ENODEV; }