1 files changed, 65 insertions, 64 deletions

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 0920c969c466..ce4e939a7f07 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -14,7 +14,6 @@
 #include <linux/module.h>
 #include <linux/highmem.h>
 #include <asm/page.h>
-#include <asm/pgalloc.h>
 #include <asm/sections.h>
 #include <asm/arcregs.h>
 
@@ -27,13 +26,10 @@ static unsigned long low_mem_sz;
 
 #ifdef CONFIG_HIGHMEM
 static unsigned long min_high_pfn, max_high_pfn;
-static u64 high_mem_start;
-static u64 high_mem_sz;
-#endif
-
-#ifdef CONFIG_DISCONTIGMEM
-struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
-EXPORT_SYMBOL(node_data);
+static phys_addr_t high_mem_start;
+static phys_addr_t high_mem_sz;
+unsigned long arch_pfn_offset;
+EXPORT_SYMBOL(arch_pfn_offset);
 #endif
 
 long __init arc_get_mem_sz(void)
@@ -63,11 +59,14 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 
 		low_mem_sz = size;
 		in_use = 1;
+		memblock_add_node(base, size, 0, MEMBLOCK_NONE);
 	} else {
 #ifdef CONFIG_HIGHMEM
 		high_mem_start = base;
 		high_mem_sz = size;
 		in_use = 1;
+		memblock_add_node(base, size, 1, MEMBLOCK_NONE);
+		memblock_reserve(base, size);
 #endif
 	}
 
@@ -75,6 +74,11 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 		base, TO_MB(size), !in_use ? "Not used":"");
 }
 
+bool arch_has_descending_max_zone_pfns(void)
+{
+	return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
+}
+
 /*
  * First memory setup routine called from setup_arch()
  * 1. setup swapper's mm @init_mm
@@ -83,25 +87,16 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  */
 void __init setup_arch_memory(void)
 {
-	unsigned long zones_size[MAX_NR_ZONES];
-	unsigned long zones_holes[MAX_NR_ZONES];
+	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
 
-	init_mm.start_code = (unsigned long)_text;
-	init_mm.end_code = (unsigned long)_etext;
-	init_mm.end_data = (unsigned long)_edata;
-	init_mm.brk = (unsigned long)_end;
+	setup_initial_init_mm(_text, _etext, _edata, _end);
 
 	/* first page of system - kernel .vector starts here */
-	min_low_pfn = ARCH_PFN_OFFSET;
+	min_low_pfn = virt_to_pfn(CONFIG_LINUX_RAM_BASE);
 
 	/* Last usable page of low mem */
 	max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 
-#ifdef CONFIG_FLATMEM
-	/* pfn_valid() uses this */
-	max_mapnr = max_low_pfn - min_low_pfn;
-#endif
-
 	/*------------- bootmem allocator setup -----------------------*/
 
 	/*
@@ -115,7 +110,6 @@ void __init setup_arch_memory(void)
 	 * the crash
 	 */
 
-	memblock_add_node(low_mem_start, low_mem_sz, 0);
 	memblock_reserve(CONFIG_LINUX_LINK_BASE,
 			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
 
@@ -133,54 +127,55 @@ void __init setup_arch_memory(void)
 	memblock_dump_all();
 
 	/*----------------- node/zones setup --------------------------*/
-	memset(zones_size, 0, sizeof(zones_size));
-	memset(zones_holes, 0, sizeof(zones_holes));
-
-	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
-	zones_holes[ZONE_NORMAL] = 0;
-
-	/*
-	 * We can't use the helper free_area_init(zones[]) because it uses
-	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
-	 * when our kernel doesn't start at PAGE_OFFSET, i.e.
-	 * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
-	 */
-	free_area_init_node(0,			/* node-id */
-			    zones_size,		/* num pages per zone */
-			    min_low_pfn,	/* first pfn of node */
-			    zones_holes);	/* holes */
+	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
 
 #ifdef CONFIG_HIGHMEM
 	/*
-	 * Populate a new node with highmem
-	 *
 	 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
-	 * than addresses in normal ala low memory (0x8000_0000 based).
+	 * than addresses in normal aka low memory (0x8000_0000 based).
 	 * Even with PAE, the huge peripheral space hole would waste a lot of
-	 * mem with single mem_map[]. This warrants a mem_map per region design.
-	 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
-	 *
-	 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
-	 * populated with normal memory zone while node 1 only has highmem
+	 * mem with single contiguous mem_map[].
+	 * Thus when HIGHMEM on ARC is enabled the memory map corresponding
+	 * to the hole is freed and ARC specific version of pfn_valid()
+	 * handles the hole in the memory map.
 	 */
-	node_set_online(1);
 
 	min_high_pfn = PFN_DOWN(high_mem_start);
 	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 
-	zones_size[ZONE_NORMAL] = 0;
-	zones_holes[ZONE_NORMAL] = 0;
-
-	zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
-	zones_holes[ZONE_HIGHMEM] = 0;
-
-	free_area_init_node(1,			/* node-id */
-			    zones_size,		/* num pages per zone */
-			    min_high_pfn,	/* first pfn of node */
-			    zones_holes);	/* holes */
+	/*
+	 * max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE.
+	 * For HIGHMEM without PAE max_high_pfn should be less than
+	 * min_low_pfn to guarantee that these two regions don't overlap.
+	 * For PAE case highmem is greater than lowmem, so it is natural
+	 * to use max_high_pfn.
+	 *
+	 * In both cases, holes should be handled by pfn_valid().
+	 */
+	max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;
 
 	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
+
+	arch_pfn_offset = min(min_low_pfn, min_high_pfn);
 	kmap_init();
+
+#else /* CONFIG_HIGHMEM */
+	/* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */
+	max_mapnr = max_low_pfn - min_low_pfn;
+
+#endif /* CONFIG_HIGHMEM */
+
+	free_area_init(max_zone_pfn);
+}
+
+static void __init highmem_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+	unsigned long tmp;
+
+	memblock_phys_free(high_mem_start, high_mem_sz);
+	for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
+		free_highmem_page(pfn_to_page(tmp));
 #endif
 }
 
@@ -192,14 +187,20 @@ void __init setup_arch_memory(void)
  */
 void __init mem_init(void)
 {
-#ifdef CONFIG_HIGHMEM
-	unsigned long tmp;
+	memblock_free_all();
+	highmem_init();
 
-	reset_all_zones_managed_pages();
-	for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
-		free_highmem_page(pfn_to_page(tmp));
-#endif
+	BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE);
+	BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE);
+	BUILD_BUG_ON((PTRS_PER_PMD * sizeof(pmd_t)) > PAGE_SIZE);
+	BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE);
+}
 
-	memblock_free_all();
-	mem_init_print_info(NULL);
+#ifdef CONFIG_HIGHMEM
+int pfn_valid(unsigned long pfn)
+{
+	return (pfn >= min_high_pfn && pfn <= max_high_pfn) ||
+		(pfn >= min_low_pfn && pfn <= max_low_pfn);
 }
+EXPORT_SYMBOL(pfn_valid);
+#endif