[PATCH v2 5/8] drm/xe: apply debug page-size policy to user BO creation

[Nareshkumar Gollakoti <naresh.kumar.g@intel.com>]

Apply the debug page-size allocation policy in xe_bo_create_user().

In 2M-only and 1G-only modes, set the matching BO flag when the
requested size is aligned. In mixed mode, rotate across 4K, 64K, 2M,
and 1G, and set the selected flag only when the size is aligned for
it.

Otherwise, leave the flags unchanged and use the default allocation
behavior.

This makes user BO creation follow the same debug page-size policy as
other BO allocation paths.

v2
- make sure debug page-size allocation do not
  break default/usual path(sashiko)
- add atomic accesses to avoid race for concurrent access(sashiko)
- refactored commit messages for readability

Signed-off-by: Nareshkumar Gollakoti <naresh.kumar.g@intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c | 56 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 45ff01df68e1..e1da9701c898 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -2612,6 +2612,60 @@ static struct xe_bo *xe_bo_create_novm(struct xe_device *xe, struct xe_tile *til
 	return ret ? ERR_PTR(ret) : bo;
 }
 
+static u32 get_flag_from_cur_index_in_mixed_mode(struct xe_device *xe, size_t size)
+{
+	static const u32 map[4] = {
+		0, //default mode 4K
+		XE_BO_FLAG_NEEDS_64K,
+		XE_BO_FLAG_NEEDS_2M,
+		XE_BO_FLAG_NEEDS_1G,
+	};
+	u32 idx;
+
+	idx = (atomic_inc_return(&xe->page_size_alloc_ctrl.cur_index) - 1) % 4;
+
+	if (!map[idx] && IS_ALIGNED(size, SZ_4K))
+		return 0;
+
+	if (map[idx] == XE_BO_FLAG_NEEDS_64K && IS_ALIGNED(size, SZ_64K))
+		return map[idx];
+
+	if (map[idx] == XE_BO_FLAG_NEEDS_2M && IS_ALIGNED(size, SZ_2M))
+		return map[idx];
+
+	if (map[idx] == XE_BO_FLAG_NEEDS_1G && IS_ALIGNED(size, SZ_1G))
+		return map[idx];
+
+	return 0;
+}
+
+static void xe_bo_apply_debug_page_size_policy(struct xe_device *xe,
+					       u32 *bo_flags,
+					       size_t size)
+{
+	int mode = READ_ONCE(xe->page_size_alloc_ctrl.mode);
+	u32 want = 0;
+
+	if (!xe_device_supports_multi_pagesize(xe))
+		return;
+
+	/* No action if default mode */
+	if (!mode)
+		return;
+
+	if (mode == XE_PAGE_SIZE_ALLOC_CTRL_MODE_ONLY_2M && IS_ALIGNED(size, SZ_2M))
+		want = XE_BO_FLAG_NEEDS_2M;
+	else if (mode == XE_PAGE_SIZE_ALLOC_CTRL_MODE_ONLY_1G &&
+		 IS_ALIGNED(size, SZ_1G))
+		want = XE_BO_FLAG_NEEDS_1G;
+	else if (mode == XE_PAGE_SIZE_ALLOC_CTRL_MODE_MIXED)
+		want = get_flag_from_cur_index_in_mixed_mode(xe, size);
+	else
+		return;
+
+	*bo_flags |= want;
+}
+
 /**
  * xe_bo_create_user() - Create a user BO
  * @xe: The xe device.
@@ -2635,6 +2689,8 @@ struct xe_bo *xe_bo_create_user(struct xe_device *xe,
 
 	flags |= XE_BO_FLAG_USER;
 
+	xe_bo_apply_debug_page_size_policy(xe, &flags, size);
+
 	if (vm || exec) {
 		xe_assert(xe, exec);
 		bo = __xe_bo_create_locked(xe, NULL, vm, size, 0, ~0ULL,
-- 
2.43.0