From 55548a86ebde2b3691b6a84baef1b02933408994 Mon Sep 17 00:00:00 2001
From: Bharata B Rao <bharata@linux.ibm.com>
Date: Mon, 27 Jul 2020 15:27:04 +0530
Subject: [PATCH] powerpc/mm: Limit resize_hpt_for_hotplug() call to hash
 guests only

References: bsc#1177030 ltc#187588
Patch-mainline: v5.9-rc1
Git-commit: 55548a86ebde2b3691b6a84baef1b02933408994

During memory hotplug and unplug, resize_hpt_for_hotplug() gets called
for both hash and radix guests but it should be called only for hash
guests. Though the call does nothing in the radix guest case, it is
cleaner to push this call into hash specific memory hotplug routines.

Reported-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200727095704.1432916-1-bharata@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/include/asm/sparsemem.h  | 6 ------
 arch/powerpc/mm/hash_utils_64.c | 8 +++++++-
 arch/powerpc/mm/mem.c                 | 5 -----
 3 files changed, 7 insertions(+), 12 deletions(-)

--- a/arch/powerpc/include/asm/sparsemem.h
+++ b/arch/powerpc/include/asm/sparsemem.h
@@ -26,12 +26,6 @@
 extern int create_section_mapping(unsigned long start, unsigned long end);
 extern int remove_section_mapping(unsigned long start, unsigned long end);
 
-#ifdef CONFIG_PPC_BOOK3S_64
-extern void resize_hpt_for_hotplug(unsigned long new_mem_size);
-#else
-static inline void resize_hpt_for_hotplug(unsigned long new_mem_size) { }
-#endif
-
 #ifdef CONFIG_NUMA
 extern int hot_add_scn_to_nid(unsigned long scn_addr);
 #else
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -778,7 +778,7 @@ static unsigned long __init htab_get_tab
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-void resize_hpt_for_hotplug(unsigned long new_mem_size)
+static void resize_hpt_for_hotplug(unsigned long new_mem_size)
 {
 	unsigned target_hpt_shift;
 
@@ -809,9 +809,13 @@ void resize_hpt_for_hotplug(unsigned lon
 
 int hash__create_section_mapping(unsigned long start, unsigned long end)
 {
-	int rc = htab_bolt_mapping(start, end, __pa(start),
-				   pgprot_val(PAGE_KERNEL), mmu_linear_psize,
-				   mmu_kernel_ssize);
+	int rc;
+
+	resize_hpt_for_hotplug(memblock_phys_mem_size());
+
+	rc = htab_bolt_mapping(start, end, __pa(start),
+			       pgprot_val(PAGE_KERNEL), mmu_linear_psize,
+			       mmu_kernel_ssize);
 
 	if (rc < 0) {
 		int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
@@ -826,6 +830,9 @@ int hash__remove_section_mapping(unsigne
 	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
 				     mmu_kernel_ssize);
 	WARN_ON(rc < 0);
+
+	resize_hpt_for_hotplug(memblock_phys_mem_size());
+
 	return rc;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -120,8 +120,6 @@ int __meminit arch_add_memory(int nid, u
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	int rc;
 
-	resize_hpt_for_hotplug(memblock_phys_mem_size());
-
 	start = (unsigned long)__va(start);
 	rc = create_section_mapping(start, start + size);
 	if (rc) {
@@ -163,8 +161,6 @@ int __meminit arch_remove_memory(u64 sta
 	 */
 	vm_unmap_aliases();
 
-	resize_hpt_for_hotplug(memblock_phys_mem_size());
-
 	return ret;
 }
 #endif