--- zzzz-none-000/linux-3.10.107/arch/x86/mm/highmem_32.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/x86/mm/highmem_32.c	2021-02-04 17:41:59.000000000 +0000
@@ -1,6 +1,7 @@
 #include <linux/highmem.h>
 #include <linux/module.h>
 #include <linux/swap.h> /* for totalram_pages */
+#include <linux/bootmem.h>
 
 void *kmap(struct page *page)
 {
@@ -34,7 +35,7 @@
 	unsigned long vaddr;
 	int idx, type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 
 	if (!PageHighMem(page))
@@ -99,28 +100,20 @@
 #endif
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
-struct page *kmap_atomic_to_page(void *ptr)
-{
-	unsigned long idx, vaddr = (unsigned long)ptr;
-	pte_t *pte;
-
-	if (vaddr < FIXADDR_START)
-		return virt_to_page(ptr);
-
-	idx = virt_to_fix(vaddr);
-	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
-	return pte_page(*pte);
-}
-EXPORT_SYMBOL(kmap_atomic_to_page);
-
 void __init set_highmem_pages_init(void)
 {
 	struct zone *zone;
 	int nid;
 
+	/*
+	 * Explicitly reset zone->managed_pages because set_highmem_pages_init()
+	 * is invoked before free_all_bootmem()
+	 */
+	reset_all_zones_managed_pages();
 	for_each_zone(zone) {
 		unsigned long zone_start_pfn, zone_end_pfn;