drm/amdkfd: Define config HSA_AMD_P2P to support peer-to-peer

Extend current kernel config requirements of amdgpu by adding config
HSA_AMD_P2P. Enabling HSA_AMD_P2P is REQUIRED to support peer-to-peer
communication between AMD GPU devices over PCIe bus
Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/Kconfig

@@ -25,3 +25,17 @@ config HSA_AMD_SVM
 	  preemptions and one based on page faults. To enable page fault
 	  based memory management on most GFXv9 GPUs, set the module
 	  parameter amdgpu.noretry=0.
+
+config HSA_AMD_P2P
+	bool "HSA kernel driver support for peer-to-peer for AMD GPU devices"
+	depends on HSA_AMD && PCI_P2PDMA && DMABUF_MOVE_NOTIFY
+	help
+	  Enable peer-to-peer (P2P) communication between AMD GPUs over
+	  the PCIe bus. This can improve performance of multi-GPU compute
+	  applications and libraries by enabling GPUs to access data directly
+	  in peer GPUs' memory without intermediate copies in system memory.
+
+	  This P2P feature is only enabled on compatible chipsets, and between
+	  GPUs with large memory BARs that expose the entire VRAM in PCIe bus
+	  address space within the physical address limits of the GPUs.
+