[igt-dev] [PATCH i-g-t v7 1/3] lib/igt_device: add igt_device_get_pci_addr by fd

[Daniel Mrzyglod]

From: Michał Winiarski <michal.winiarski at intel.com>

This function get us pci address based by fd.
It allows us to make things a little bit more generic.
Also, we now require fd rather than doing guesswork when it comes to pci address.

v4: close sysfs fd

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
Acked-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>

Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
Signed-off-by: Daniel Mrzyglod <daniel.t.mrzyglod at intel.com>
---
 lib/igt_device.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_device.h |   1 +
 2 files changed, 125 insertions(+)

diff --git a/lib/igt_device.c b/lib/igt_device.c
index 9469e5de..07bb0a0d 100644
--- a/lib/igt_device.c
+++ b/lib/igt_device.c
@@ -21,11 +21,14 @@
  * IN THE SOFTWARE.
  *
  */
+#include <sys/types.h>
+#include <fcntl.h>
 
 #include <sys/stat.h>
 #include <sys/sysmacros.h>
 #include "igt.h"
 #include "igt_device.h"
+#include "igt_sysfs.h"
 
 int __igt_device_set_master(int fd)
 {
@@ -112,3 +115,124 @@ int igt_device_get_card_index(int fd)
 
 	return minor(st.st_rdev);
 }
+
+#define IGT_DEV_PATH_LEN 80
+
+static bool igt_device_is_pci(int fd)
+{
+	char path[IGT_DEV_PATH_LEN];
+	char *subsystem;
+	int sysfs;
+	int len;
+
+	sysfs = igt_sysfs_open(fd);
+	if (sysfs == -1)
+		return false;
+
+	len = readlinkat(sysfs, "device/subsystem", path, sizeof(path) - 1);
+	close(sysfs);
+	if (len == -1)
+		return false;
+	path[len] = '\0';
+
+	subsystem = strrchr(path, '/');
+	if (!subsystem)
+		return false;
+
+	return strcmp(subsystem, "/pci") == 0;
+}
+
+struct igt_pci_addr {
+	unsigned int domain;
+	unsigned int bus;
+	unsigned int device;
+	unsigned int function;
+};
+
+static int igt_device_get_pci_addr(int fd, struct igt_pci_addr *pci)
+{
+	char path[IGT_DEV_PATH_LEN];
+	char *buf;
+	int sysfs;
+	int len;
+
+	if (!igt_device_is_pci(fd))
+		return -ENODEV;
+
+	sysfs = igt_sysfs_open(fd);
+	if (sysfs == -1)
+		return -ENOENT;
+
+	len = readlinkat(sysfs, "device", path, sizeof(path) - 1);
+	close(sysfs);
+	if (len == -1)
+		return -ENOENT;
+	path[len] = '\0';
+
+	buf = strrchr(path, '/');
+	if (!buf)
+		return -ENOENT;
+
+	if (sscanf(buf, "/%4x:%2x:%2x.%2x",
+		   &pci->domain, &pci->bus,
+		   &pci->device, &pci->function) != 4) {
+		igt_warn("Unable to extract PCI device address from '%s'\n", buf);
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static struct pci_device *__igt_device_get_pci_device(int fd)
+{
+	struct igt_pci_addr pci_addr;
+	struct pci_device *pci_dev;
+
+	if (igt_device_get_pci_addr(fd, &pci_addr)) {
+		igt_warn("Unable to find device PCI address\n");
+		return NULL;
+	}
+
+	if (pci_system_init()) {
+		igt_warn("Couldn't initialize PCI system\n");
+		return NULL;
+	}
+
+	pci_dev = pci_device_find_by_slot(pci_addr.domain,
+					  pci_addr.bus,
+					  pci_addr.device,
+					  pci_addr.function);
+	if (!pci_dev) {
+		igt_warn("Couldn't find PCI device %04x:%02x:%02x:%02x\n",
+			 pci_addr.domain, pci_addr.bus,
+			 pci_addr.device, pci_addr.function);
+		return NULL;
+	}
+
+	if (pci_device_probe(pci_dev)) {
+		igt_warn("Couldn't probe PCI device\n");
+		return NULL;
+	}
+
+	return pci_dev;
+}
+
+/**
+ * igt_device_get_pci_device:
+ *
+ * @fd: the device
+ *
+ * Looks up the main graphics pci device using libpciaccess.
+ *
+ * Returns:
+ * The pci_device, skips the test on any failures.
+ */
+struct pci_device *igt_device_get_pci_device(int fd)
+{
+	struct pci_device *pci_dev;
+
+	pci_dev = __igt_device_get_pci_device(fd);
+	igt_require(pci_dev);
+
+	return pci_dev;
+}
diff --git a/lib/igt_device.h b/lib/igt_device.h
index 9d7dc2c3..278ba7a9 100644
--- a/lib/igt_device.h
+++ b/lib/igt_device.h
@@ -32,5 +32,6 @@ int __igt_device_drop_master(int fd);
 void igt_device_drop_master(int fd);
 
 int igt_device_get_card_index(int fd);
+struct pci_device *igt_device_get_pci_device(int fd);
 
 #endif /* __IGT_DEVICE_H__ */
-- 
2.21.0