[PATCH v3 08/25] pci: Add pci_dev_exists()

[Peter Xu <peterx@redhat.com>]

From: Alexander Gordeev <agordeev@redhat.com>

Cc: Thomas Huth <thuth@redhat.com>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
 lib/pci.c | 6 ++++++
 lib/pci.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/lib/pci.c b/lib/pci.c
index 74936f3..42f47d9 100644
--- a/lib/pci.c
+++ b/lib/pci.c
@@ -7,6 +7,12 @@
 #include "pci.h"
 #include "asm/pci.h"
 
+bool pci_dev_exists(pcidevaddr_t dev)
+{
+	return (pci_config_readw(dev, PCI_VENDOR_ID) != 0xffff &&
+		pci_config_readw(dev, PCI_DEVICE_ID) != 0xffff);
+}
+
 /* Scan bus look for a specific device. Only bus 0 scanned for now. */
 pcidevaddr_t pci_find_dev(uint16_t vendor_id, uint16_t device_id)
 {
diff --git a/lib/pci.h b/lib/pci.h
index 1c20308..1462aa2 100644
--- a/lib/pci.h
+++ b/lib/pci.h
@@ -15,6 +15,7 @@ enum {
 	PCIDEVADDR_INVALID = 0xffff,
 };
 
+extern bool pci_dev_exists(pcidevaddr_t dev);
 extern pcidevaddr_t pci_find_dev(uint16_t vendor_id, uint16_t device_id);
 
 /*
-- 
2.7.4