[CI 39/43] drm/xe/svm: Introduce DRM_XE_SVM kernel config

[Oak Zeng]

Introduce a DRM_XE_SVM kernel config entry for
xe svm feature. xe svm feature allows share
virtual address space between CPU and GPU program.

v1: Improve commit message (Thomas)
    Avoid using #if directive (Thomas)

Cc: Matthew Brost <matthew.brost at intel.com>
Cc: Thomas Hellström <thomas.hellstrom at intel.com>
Cc: Brian Welty <brian.welty at intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
Signed-off-by: Oak Zeng <oak.zeng at intel.com>
Co-developed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
---
 drivers/gpu/drm/xe/Kconfig   | 21 +++++++++++++++++++++
 drivers/gpu/drm/xe/xe_tile.c | 11 ++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
index 7bbe46a98ff1..27d6145cefa7 100644
--- a/drivers/gpu/drm/xe/Kconfig
+++ b/drivers/gpu/drm/xe/Kconfig
@@ -84,6 +84,27 @@ config DRM_XE_FORCE_PROBE
 	  4571.
 
 	  Use "!*" to block the probe of the driver for all known devices.
+config DRM_XE_SVM
+	bool "Enable Shared Virtual Memory support in xe"
+	depends on DRM_XE
+	depends on ARCH_ENABLE_MEMORY_HOTPLUG
+	depends on ARCH_ENABLE_MEMORY_HOTREMOVE
+	depends on MEMORY_HOTPLUG
+	depends on MEMORY_HOTREMOVE
+	depends on ARCH_HAS_PTE_DEVMAP
+	depends on SPARSEMEM_VMEMMAP
+	depends on ZONE_DEVICE
+	depends on DEVICE_PRIVATE
+	depends on MMU
+	select HMM_MIRROR
+	select MMU_NOTIFIER
+	default y
+	help
+	  Choose this option if you want Shared Virtual Memory (SVM)
+	  support in xe. With SVM, virtual address space is shared
+	  between CPU and GPU. This means any virtual address such
+	  as malloc or mmap returns, variables on stack, or global
+	  memory pointers, can be used for GPU transparently.
 
 menu "drm/Xe Debugging"
 depends on DRM_XE
diff --git a/drivers/gpu/drm/xe/xe_tile.c b/drivers/gpu/drm/xe/xe_tile.c
index 5daf02f5d0be..bddd9d4f4d59 100644
--- a/drivers/gpu/drm/xe/xe_tile.c
+++ b/drivers/gpu/drm/xe/xe_tile.c
@@ -170,8 +170,13 @@ static void __init_drm_mem_region_ops(struct drm_mem_region_ops *ops)
 int xe_tile_init_noalloc(struct xe_tile *tile)
 {
 	int err;
-	struct xe_device *xe = tile_to_xe(tile);
-	struct drm_device *drm = &xe->drm;
+	struct xe_device __maybe_unused *xe;
+	struct drm_device __maybe_unused *drm;
+
+	if (IS_ENABLED(CONFIG_DRM_XE_SVM)) {
+		xe = tile_to_xe(tile);
+		drm = &xe->drm;
+	}
 
 	err = tile_ttm_mgr_init(tile);
 	if (err)
@@ -185,7 +190,7 @@ int xe_tile_init_noalloc(struct xe_tile *tile)
 
 	err = xe_tile_sysfs_init(tile);
 
-	if (xe->info.has_usm) {
+	if (IS_ENABLED(CONFIG_DRM_XE_SVM) && xe->info.has_usm) {
 		__init_drm_mem_region_ops(&tile->mem.vram.drm_mr.mr_ops);
 		drm_svm_register_mem_region(drm, &tile->mem.vram.drm_mr);
 	}
-- 
2.26.3