Subject: [PATCH v2 03/17] arm, xtensa: simplify initialization of high memory pages

From: Mike Rapoport <[email-masked]>
Date: Sun, 2 Aug 2020 19:35:47 +0300

From: Mike Rapoport <[email-masked]>

The function free_highpages() in both arm and xtensa essentially open-code
for_each_free_mem_range() loop to detect high memory pages that were not
reserved and that should be initialized and passed to the buddy allocator.

Replace open-coded implementation of for_each_free_mem_range() with usage
of memblock API to simplify the code.

Signed-off-by: Mike Rapoport <[email-masked]>
Reviewed-by: Max Filippov <[email-masked]>		# xtensa
Tested-by: Max Filippov <[email-masked]>		# xtensa
---
 arch/arm/mm/init.c    | 48 +++++++------------------------------
 arch/xtensa/mm/init.c | 55 ++++++++-----------------------------------
 2 files changed, 18 insertions(+), 85 deletions(-)

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 01e18e43b174..626af348eb8f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -352,61 +352,29 @@ static void __init free_unused_memmap(void)
 #endif
 }
 
-#ifdef CONFIG_HIGHMEM
-static inline void free_area_high(unsigned long pfn, unsigned long end)
-{
-	for (; pfn < end; pfn++)
-		free_highmem_page(pfn_to_page(pfn));
-}
-#endif
-
 static void __init free_highpages(void)
 {
 #ifdef CONFIG_HIGHMEM
 	unsigned long max_low = max_low_pfn;
-	struct memblock_region *mem, *res;
+	phys_addr_t range_start, range_end;
+	u64 i;
 
 	/* set highmem page free */
-	for_each_memblock(memory, mem) {
-		unsigned long start = memblock_region_memory_base_pfn(mem);
-		unsigned long end = memblock_region_memory_end_pfn(mem);
+	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
+				&range_start, &range_end, NULL) {
+		unsigned long start = PHYS_PFN(range_start);
+		unsigned long end = PHYS_PFN(range_end);
 
 		/* Ignore complete lowmem entries */
 		if (end <= max_low)
 			continue;
 
-		if (memblock_is_nomap(mem))
-			continue;
-
 		/* Truncate partial highmem entries */
 		if (start < max_low)
 			start = max_low;
 
-		/* Find and exclude any reserved regions */
-		for_each_memblock(reserved, res) {
-			unsigned long res_start, res_end;
-
-			res_start = memblock_region_reserved_base_pfn(res);
-			res_end = memblock_region_reserved_end_pfn(res);
-
-			if (res_end < start)
-				continue;
-			if (res_start < start)
-				res_start = start;
-			if (res_start > end)
-				res_start = end;
-			if (res_end > end)
-				res_end = end;
-			if (res_start != start)
-				free_area_high(start, res_start);
-			start = res_end;
-			if (start == end)
-				break;
-		}
-
-		/* And now free anything which remains */
-		if (start < end)
-			free_area_high(start, end);
+		for (; start < end; start++)
+			free_highmem_page(pfn_to_page(start));
 	}
 #endif
 }
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index a05b306cf371..ad9d59d93f39 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -79,67 +79,32 @@ void __init zones_init(void)
 	free_area_init(max_zone_pfn);
 }
 
-#ifdef CONFIG_HIGHMEM
-static void __init free_area_high(unsigned long pfn, unsigned long end)
-{
-	for (; pfn < end; pfn++)
-		free_highmem_page(pfn_to_page(pfn));
-}
-
 static void __init free_highpages(void)
 {
+#ifdef CONFIG_HIGHMEM
 	unsigned long max_low = max_low_pfn;
-	struct memblock_region *mem, *res;
+	phys_addr_t range_start, range_end;
+	u64 i;
 
-	reset_all_zones_managed_pages();
 	/* set highmem page free */
-	for_each_memblock(memory, mem) {
-		unsigned long start = memblock_region_memory_base_pfn(mem);
-		unsigned long end = memblock_region_memory_end_pfn(mem);
+	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
+				&range_start, &range_end, NULL) {
+		unsigned long start = PHYS_PFN(range_start);
+		unsigned long end = PHYS_PFN(range_end);
 
 		/* Ignore complete lowmem entries */
 		if (end <= max_low)
 			continue;
 
-		if (memblock_is_nomap(mem))
-			continue;
-
 		/* Truncate partial highmem entries */
 		if (start < max_low)
 			start = max_low;
 
-		/* Find and exclude any reserved regions */
-		for_each_memblock(reserved, res) {
-			unsigned long res_start, res_end;
-
-			res_start = memblock_region_reserved_base_pfn(res);
-			res_end = memblock_region_reserved_end_pfn(res);
-
-			if (res_end < start)
-				continue;
-			if (res_start < start)
-				res_start = start;
-			if (res_start > end)
-				res_start = end;
-			if (res_end > end)
-				res_end = end;
-			if (res_start != start)
-				free_area_high(start, res_start);
-			start = res_end;
-			if (start == end)
-				break;
-		}
-
-		/* And now free anything which remains */
-		if (start < end)
-			free_area_high(start, end);
+		for (; start < end; start++)
+			free_highmem_page(pfn_to_page(start));
 	}
-}
-#else
-static void __init free_highpages(void)
-{
-}
 #endif
+}
 
 /*
  * Initialize memory pages.
-- 
2.26.2