[PATCH 2/4] drm/amdgpu: Add xgmi speed/width related info

[Lijo Lazar]

Add APIs to initialize XGMI speed, width details and get to max
bandwidth supported. It is assumed that a device only supports same
generation of XGMI links with uniform width.

Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c | 41 ++++++++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h | 11 +++++++
 2 files changed, 52 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
index 03d909c7b14b..edef5763e2b8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
@@ -1679,3 +1679,44 @@ bool amdgpu_xgmi_same_hive(struct amdgpu_device *adev,
 		adev->gmc.xgmi.hive_id &&
 		adev->gmc.xgmi.hive_id == bo_adev->gmc.xgmi.hive_id);
 }
+
+static inline uint32_t
+__amdgpu_xgmi_get_max_bandwidth(uint8_t link_width,
+				enum amdgpu_xgmi_link_speed max_speed)
+{
+	/* Returns unidirectional bandwidth in Mbps */
+	return max_speed * 1000 * link_width;
+}
+
+/**
+ * amdgpu_xgmi_get_max_bandwidth - Get max possible bandwidth of a single XGMI
+ * link of the device in Mbps
+ * @adev: Target device.
+ *
+ * Gets the max possible bandwidth of a single XGMI link of the device in Mbps.
+ * Assumption is all links of the device have the same width and are of the
+ * same XGMI generation.
+ */
+uint32_t amdgpu_xgmi_get_max_bandwidth(struct amdgpu_device *adev)
+{
+	if (!adev->gmc.xgmi.supported)
+		return 0;
+
+	return __amdgpu_xgmi_get_max_bandwidth(adev->gmc.xgmi.max_width, adev->gmc.xgmi.max_speed);
+}
+
+void amdgpu_xgmi_init_info(struct amdgpu_device *adev)
+{
+	switch (amdgpu_ip_version(adev, XGMI_HWIP, 0)) {
+	case IP_VERSION(6, 1, 0):
+		adev->gmc.xgmi.max_speed = XGMI2_5_SPEED_GT;
+		adev->gmc.xgmi.max_width = 16;
+		break;
+	case IP_VERSION(6, 4, 0):
+		adev->gmc.xgmi.max_speed = XGMI3_SPEED_GT;
+		adev->gmc.xgmi.max_width = 16;
+		break;
+	default:
+		break;
+	}
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h
index 044c4f6be44a..384c4ddef78a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h
@@ -25,6 +25,12 @@
 #include <drm/task_barrier.h>
 #include "amdgpu_ras.h"
 
+enum amdgpu_xgmi_link_speed {
+	XGMI2_SPEED_GT = 16,
+	XGMI2_5_SPEED_GT = 25,
+	XGMI3_SPEED_GT = 32
+};
+
 struct amdgpu_hive_info {
 	struct kobject kobj;
 	uint64_t hive_id;
@@ -75,6 +81,8 @@ struct amdgpu_xgmi {
 	struct ras_common_if *ras_if;
 	bool connected_to_cpu;
 	struct amdgpu_xgmi_ras *ras;
+	enum amdgpu_xgmi_link_speed max_speed;
+	uint8_t max_width;
 };
 
 struct amdgpu_hive_info *amdgpu_get_xgmi_hive(struct amdgpu_device *adev);
@@ -102,4 +110,7 @@ int amdgpu_xgmi_request_nps_change(struct amdgpu_device *adev,
 int amdgpu_get_xgmi_link_status(struct amdgpu_device *adev,
 				int global_link_num);
 
+void amdgpu_xgmi_init_info(struct amdgpu_device *adev);
+uint32_t amdgpu_xgmi_get_max_bandwidth(struct amdgpu_device *adev);
+
 #endif
-- 
2.25.1