[PATCH 2/3] amd/amdkfd: Unmap range from GPUs based on granularity

[Philip Yang]

Align unmap range start and last address to granularity boundary.
Skip unmap if range is already unmapped from GPUs.

This also solve the rocgdb CWSR migration related issue.

Signed-off-by: Philip Yang <Philip.Yang at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 35 ++++++++++++++++++++++++----
 1 file changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 626e0dd4ec79..ac65bf25c685 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2004,6 +2004,26 @@ static void svm_range_restore_work(struct work_struct *work)
 	mmput(mm);
 }
 
+static unsigned long
+svm_range_align_start(struct svm_range *prange, unsigned long start)
+{
+	unsigned long start_align;
+
+	start_align = ALIGN_DOWN(start, 1UL << prange->granularity);
+	start_align = max_t(unsigned long, start_align, prange->start);
+	return start_align;
+}
+
+static unsigned long
+svm_range_align_last(struct svm_range *prange, unsigned long last)
+{
+	unsigned long last_align;
+
+	last_align = ALIGN(last, 1UL << prange->granularity) - 1;
+	last_align = min_t(unsigned long, last_align, prange->last);
+	return last_align;
+}
+
 /**
  * svm_range_evict - evict svm range
  * @prange: svm range structure
@@ -2078,6 +2098,12 @@ svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
 		unsigned long s, l;
 		uint32_t trigger;
 
+		if (!svm_range_partial_mapped(prange, start, last)) {
+			pr_debug("svms 0x%p [0x%lx 0x%lx] unmapped already\n",
+				prange->svms, start, last);
+			return 0;
+		}
+
 		if (event == MMU_NOTIFY_MIGRATE)
 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY_MIGRATE;
 		else
@@ -2085,16 +2111,17 @@ svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
 
 		pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
 			 prange->svms, start, last);
+
 		list_for_each_entry(pchild, &prange->child_list, child_list) {
 			mutex_lock_nested(&pchild->lock, 1);
-			s = max(start, pchild->start);
-			l = min(last, pchild->last);
+			s = svm_range_align_start(pchild, start);
+			l = svm_range_align_last(pchild, last);
 			if (l >= s)
 				svm_range_unmap_from_gpus(pchild, s, l, trigger);
 			mutex_unlock(&pchild->lock);
 		}
-		s = max(start, prange->start);
-		l = min(last, prange->last);
+		s = svm_range_align_start(prange, start);
+		l = svm_range_align_last(prange, last);
 		if (l >= s)
 			svm_range_unmap_from_gpus(prange, s, l, trigger);
 	}
-- 
2.35.1