[igt-dev] [PATCH i-g-t v5 2/5] lib/igt_device: add igt_device_map_pci_bar_region

[Daniel Mrzyglod]

This function use sysfs to map particular mmio region.
fd of opened device point us for specific pci device.

Signed-off-by: Daniel Mrzyglod <daniel.t.mrzyglod at intel.com>
---
 lib/igt_device.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_device.h |  1 +
 2 files changed, 45 insertions(+)

diff --git a/lib/igt_device.c b/lib/igt_device.c
index 88f35cad..b456b936 100644
--- a/lib/igt_device.c
+++ b/lib/igt_device.c
@@ -227,3 +227,47 @@ struct pci_device *igt_device_get_pci_device(int fd)
 
 	return pci_dev;
 }
+
+/**
+ * igt_device_map_pci_bar_region:
+ *
+ * @fd: the device
+ * @mmio_bar: bar to be mapped
+ * @mmio_size: bar size
+ *
+ * Returns:
+ * The pointer for mmapped bar
+ */
+void *igt_device_map_pci_bar_region(int fd, int  mmio_bar, int mmio_size)
+{
+	struct igt_pci_addr pci_addr;
+	char *filepath = NULL;
+	char *pci_string = NULL;
+	int newfd;
+	void *igt_mmio;
+
+	if (igt_device_get_pci_addr(fd, &pci_addr)) {
+		igt_warn("Unable to find device PCI address\n");
+		return NULL;
+	}
+
+	asprintf(&pci_string, "%.4x:%.2x:%.2x.%.1x",
+		 pci_addr.domain, pci_addr.bus, pci_addr.device,
+		 pci_addr.function);
+
+
+	asprintf(&filepath, "/sys/devices/pci%.4x:%.2x/%s/resource%.1x",
+			pci_addr.domain, pci_addr.bus, pci_string, mmio_bar);
+
+	newfd = open(filepath, O_RDWR | O_SYNC);
+	igt_mmio = mmap(0, mmio_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+			newfd, 0);
+	free(filepath);
+	close(newfd);
+	igt_warn_on_f(igt_mmio == MAP_FAILED,
+		      "Couldn't map MMIO region %s BAR %d\n",
+		      pci_string, mmio_bar);
+	free(pci_string);
+
+	return igt_mmio;
+}
diff --git a/lib/igt_device.h b/lib/igt_device.h
index 278ba7a9..c4188e96 100644
--- a/lib/igt_device.h
+++ b/lib/igt_device.h
@@ -33,5 +33,6 @@ 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);
+void *igt_device_map_pci_bar_region(int fd, int  mmio_bar, int mmio_size);
 
 #endif /* __IGT_DEVICE_H__ */
-- 
2.20.1