drm/xe/userptr: replace xe_hmm with gpusvm

Goal here is cut over to gpusvm and remove xe_hmm, relying instead on
common code. The core facilities we need are get_pages(), unmap_pages()
and free_pages() for a given useptr range, plus a vm level notifier
lock, which is now provided by gpusvm.

v2:
  - Reuse the same SVM vm struct we use for full SVM, that way we can
    use the same lock (Matt B & Himal)
v3:
  - Re-use svm_init/fini for userptr.
v4:
  - Allow building xe without userptr if we are missing DRM_GPUSVM
    config. (Matt B)
  - Always make .read_only match xe_vma_read_only() for the ctx. (Dafna)
v5:
  - Fix missing conversion with CONFIG_DRM_XE_USERPTR_INVAL_INJECT
v6:
  - Convert the new user in xe_vm_madise.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Dafna Hirschfeld <dafna.hirschfeld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250828142430.615826-17-matthew.auld@intel.com

Author: matt-auld

drivers/gpu/drm/xe/Kconfig

@@ -40,12 +40,12 @@ config DRM_XE
 	select DRM_TTM
 	select DRM_TTM_HELPER
 	select DRM_EXEC
+	select DRM_GPUSVM if !UML && DEVICE_PRIVATE
 	select DRM_GPUVM
 	select DRM_SCHED
 	select MMU_NOTIFIER
 	select WANT_DEV_COREDUMP
 	select AUXILIARY_BUS
-	select HMM_MIRROR
 	select REGMAP if I2C
 	help
 	  Driver for Intel Xe2 series GPUs and later. Experimental support

drivers/gpu/drm/xe/Kconfig.debug

@@ -104,6 +104,7 @@ config DRM_XE_DEBUG_GUC
 
 config DRM_XE_USERPTR_INVAL_INJECT
        bool "Inject userptr invalidation -EINVAL errors"
+       depends on DRM_GPUSVM
        default n
        help
          Choose this option when debugging error paths that

drivers/gpu/drm/xe/Makefile

@@ -130,7 +130,6 @@ xe-y += xe_bb.o \
 	xe_tuning.o \
 	xe_uc.o \
 	xe_uc_fw.o \
-	xe_userptr.o \
 	xe_vm.o \
 	xe_vm_madvise.o \
 	xe_vram.o \
@@ -141,8 +140,8 @@ xe-y += xe_bb.o \
 	xe_wopcm.o
 
 xe-$(CONFIG_I2C)	+= xe_i2c.o
-xe-$(CONFIG_HMM_MIRROR) += xe_hmm.o
 xe-$(CONFIG_DRM_XE_GPUSVM) += xe_svm.o
+xe-$(CONFIG_DRM_GPUSVM) += xe_userptr.o
 
 # graphics hardware monitoring (HWMON) support
 xe-$(CONFIG_HWMON) += xe_hwmon.o

drivers/gpu/drm/xe/xe_exec.c

@@ -19,6 +19,7 @@
 #include "xe_ring_ops_types.h"
 #include "xe_sched_job.h"
 #include "xe_sync.h"
+#include "xe_svm.h"
 #include "xe_vm.h"
 
 /**
@@ -294,7 +295,7 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		if (err)
 			goto err_put_job;
 
-		err = down_read_interruptible(&vm->userptr.notifier_lock);
+		err = xe_svm_notifier_lock_interruptible(vm);
 		if (err)
 			goto err_put_job;
 
@@ -336,7 +337,7 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 
 err_repin:
 	if (!xe_vm_in_lr_mode(vm))
-		up_read(&vm->userptr.notifier_lock);
+		xe_svm_notifier_unlock(vm);
 err_put_job:
 	if (err)
 		xe_sched_job_put(job);