[PATCH 11/11] drm/xe: Add GT TLB invalidation watermark debugfs

[Matthew Brost]

Add GT TLB invalidation watermark to debugfs for feature tuning and
disabling (less than equal to a value of 1).

Signed-off-by: Matthew Brost <matthew.brost at intel.com>
---
 drivers/gpu/drm/xe/xe_debugfs.c             | 38 +++++++++++++++++++++
 drivers/gpu/drm/xe/xe_device.c              |  3 ++
 drivers/gpu/drm/xe/xe_device_types.h        |  5 +++
 drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c |  8 ++---
 4 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
index 1011e5d281fa..dd27172197be 100644
--- a/drivers/gpu/drm/xe/xe_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_debugfs.c
@@ -173,6 +173,41 @@ static const struct file_operations wedged_mode_fops = {
 	.write = wedged_mode_set,
 };
 
+static ssize_t tlb_invalidation_watermark_show(struct file *f, char __user *ubuf,
+					       size_t size, loff_t *pos)
+{
+	struct xe_device *xe = file_inode(f)->i_private;
+	char buf[32];
+	int len = 0;
+
+	len = scnprintf(buf, sizeof(buf), "%d\n", xe->tlb_invalidation_watermark);
+
+	return simple_read_from_buffer(ubuf, size, pos, buf, len);
+}
+
+static ssize_t tlb_invalidation_watermark_set(struct file *f,
+					      const char __user *ubuf,
+					      size_t size, loff_t *pos)
+{
+	struct xe_device *xe = file_inode(f)->i_private;
+	int tlb_invalidation_watermark;
+	ssize_t ret;
+
+	ret = kstrtoint_from_user(ubuf, size, 0, &tlb_invalidation_watermark);
+	if (ret)
+		return ret;
+
+	xe->tlb_invalidation_watermark = tlb_invalidation_watermark;
+
+	return size;
+}
+
+static const struct file_operations tlb_invalidation_watermark_fops = {
+	.owner = THIS_MODULE,
+	.read = tlb_invalidation_watermark_show,
+	.write = tlb_invalidation_watermark_set,
+};
+
 void xe_debugfs_register(struct xe_device *xe)
 {
 	struct ttm_device *bdev = &xe->ttm;
@@ -193,6 +228,9 @@ void xe_debugfs_register(struct xe_device *xe)
 	debugfs_create_file("wedged_mode", 0400, root, xe,
 			    &wedged_mode_fops);
 
+	debugfs_create_file("tlb_invalidation_watermark", 0400, root, xe,
+			    &tlb_invalidation_watermark_fops);
+
 	for (mem_type = XE_PL_VRAM0; mem_type <= XE_PL_VRAM1; ++mem_type) {
 		man = ttm_manager_type(bdev, mem_type);
 
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index db513175b29e..6d5ef3563082 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -274,6 +274,9 @@ struct xe_device *xe_device_create(struct pci_dev *pdev,
 	xe->info.revid = pdev->revision;
 	xe->info.force_execlist = xe_modparam.force_execlist;
 
+#define TLB_INVALIDATION_WATERMARK_DEFAULT	16
+	xe->tlb_invalidation_watermark = TLB_INVALIDATION_WATERMARK_DEFAULT;
+
 	spin_lock_init(&xe->irq.lock);
 	spin_lock_init(&xe->clients.lock);
 
diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index f0cf9020e463..7e029493110a 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -481,6 +481,11 @@ struct xe_device {
 		int mode;
 	} wedged;
 
+	/**
+	 * @tlb_invalidation_watermark: TLB invalidation watermark to coalesce
+	 */
+	int tlb_invalidation_watermark;
+
 #ifdef TEST_VM_OPS_ERROR
 	/**
 	 * @vm_inject_error_position: inject errors at different places in VM
diff --git a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
index c7634acea938..74c2c33e043d 100644
--- a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
+++ b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
@@ -391,9 +391,6 @@ xe_gt_tlb_invalidation_coalesce_issue(struct xe_gt *gt,
 	xe_gt_assert(gt, list_empty(&coalesce->link));
 }
 
-/* Any more pending TLB invalidations start to hold in KMD */
-#define SEQNO_WATERMARK		16
-
 static int
 xe_gt_tlb_invalidation_coalesce_prep(struct xe_gt *gt,
 				     struct xe_gt_tlb_invalidation_fence *fence,
@@ -404,10 +401,13 @@ xe_gt_tlb_invalidation_coalesce_prep(struct xe_gt *gt,
 
 	lockdep_assert_held(&gt->tlb_invalidation.seqno_lock);
 
+	if (gt_to_xe(gt)->tlb_invalidation_watermark <= 1)	/* Disabled */
+		return 0;
+
 	spin_lock_irq(&gt->tlb_invalidation.pending_lock);
 
 	if (list_empty(&gt->tlb_invalidation.pending_coalesce) &&
-	    tlb_invalidation_seqno_diff(gt) < SEQNO_WATERMARK) {
+	    tlb_invalidation_seqno_diff(gt) < gt_to_xe(gt)->tlb_invalidation_watermark) {
 		ret = 0;
 		goto unlock;
 	}
-- 
2.34.1