drm/amdgpu: Add use_xgmi_p2p module parameter

This parameter controls xGMI p2p communication, which is enabled by
default. However, it can be disabled by setting it to 0. In case xGMI
p2p is disabled in a dGPU, PCIe p2p interface will be used instead.
This parameter is ignored in GPUs that do not support xGMI
p2p configuration.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Acked-by: Luben Tuikov <luben.tuikov@amd.com>
Acked-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index bbe9950bf4db6eca3fc3c2b9ad3b61fef648c753..d990ebfd2afc8a9036ac85be5e803c8bf28dbb55 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -211,6 +211,7 @@ extern int amdgpu_mes;
 extern int amdgpu_noretry;
 extern int amdgpu_force_asic_type;
 extern int amdgpu_smartshift_bias;
+extern int amdgpu_use_xgmi_p2p;
 #ifdef CONFIG_HSA_AMD
 extern int sched_policy;
 extern bool debug_evictions;

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index e18356fff7104a63dbb6e2f27e00825f1b9031c0..312d15d5df95800d94faa413701552162fb9cf5a 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -176,6 +176,7 @@ int amdgpu_tmz = -1; /* auto */
 int amdgpu_reset_method = -1; /* auto */
 int amdgpu_num_kcq = -1;
 int amdgpu_smartshift_bias;
+int amdgpu_use_xgmi_p2p = 1;
 
 static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
 
@@ -651,6 +652,13 @@ MODULE_PARM_DESC(force_asic_type,
        "A non negative value used to specify the asic type for all supported GPUs");
 module_param_named(force_asic_type, amdgpu_force_asic_type, int, 0444);
 
+/**
+ * DOC: use_xgmi_p2p (int)
+ * Enables/disables XGMI P2P interface (0 = disable, 1 = enable).
+ */
+MODULE_PARM_DESC(use_xgmi_p2p,
+       "Enable XGMI P2P interface (0 = disable; 1 = enable (default))");
+module_param_named(use_xgmi_p2p, amdgpu_use_xgmi_p2p, int, 0444);
 
 
 #ifdef CONFIG_HSA_AMD

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h
index 0afca51c3c0c939249ac728398546e4d8b4bcb12..095921851fb5759bda7625b66be98705ef53e13d 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.h
@@ -66,7 +66,8 @@ uint64_t amdgpu_xgmi_get_relative_phy_addr(struct amdgpu_device *adev,
 static inline bool amdgpu_xgmi_same_hive(struct amdgpu_device *adev,
                struct amdgpu_device *bo_adev)
 {
-       return (adev != bo_adev &&
+       return (amdgpu_use_xgmi_p2p &&
+               adev != bo_adev &&
                adev->gmc.xgmi.hive_id &&
                adev->gmc.xgmi.hive_id == bo_adev->gmc.xgmi.hive_id);
 }