Subject: [PATCH v2 3/4] powerpc/pseries: break early in dlpar_memory_remove_by_count() loops

From: Daniel Henrique Barboza <[email-masked]>
Date: Wed, 12 May 2021 17:28:08 -0300

After marking the LMBs as reserved depending on dlpar_remove_lmb() rc,
we evaluate whether we need to add the LMBs back or if we can release
the LMB DRCs. In both cases, a for_each_drmem_lmb() loop without a break
condition is used. This means that we're going to cycle through all LMBs
of the partition even after we're done with what we were going to do.

This patch adds break conditions in both loops to avoid this. The
'lmbs_removed' variable was renamed to 'lmbs_reserved', and it's now
being decremented each time a lmb reservation is removed, indicating
that the operation we're doing (adding back LMBs or releasing DRCs) is
completed.

Signed-off-by: Daniel Henrique Barboza <[email-masked]>
---
 arch/powerpc/platforms/pseries/hotplug-memory.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index c21d9278c1ce..3c7ce5361ce3 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -402,7 +402,7 @@ static int dlpar_remove_lmb(struct drmem_lmb *lmb)
 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
 {
 	struct drmem_lmb *lmb;
-	int lmbs_removed = 0;
+	int lmbs_reserved = 0;
 	int lmbs_available = 0;
 	int rc;
 
@@ -436,12 +436,12 @@ static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
 		 */
 		drmem_mark_lmb_reserved(lmb);
 
-		lmbs_removed++;
-		if (lmbs_removed == lmbs_to_remove)
+		lmbs_reserved++;
+		if (lmbs_reserved == lmbs_to_remove)
 			break;
 	}
 
-	if (lmbs_removed != lmbs_to_remove) {
+	if (lmbs_reserved != lmbs_to_remove) {
 		pr_err("Memory hot-remove failed, adding LMB's back\n");
 
 		for_each_drmem_lmb(lmb) {
@@ -454,6 +454,10 @@ static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
 				       lmb->drc_index);
 
 			drmem_remove_lmb_reservation(lmb);
+
+			lmbs_reserved--;
+			if (lmbs_reserved == 0)
+				break;
 		}
 
 		rc = -EINVAL;
@@ -467,6 +471,10 @@ static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
 				lmb->base_addr);
 
 			drmem_remove_lmb_reservation(lmb);
+
+			lmbs_reserved--;
+			if (lmbs_reserved == 0)
+				break;
 		}
 		rc = 0;
 	}
-- 
2.31.1