MIPS: mm: Drop boot_mem_map

Initialize maar by resource map and replace page_is_ram
by memblock_is_memory.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[paul.burton@mips.com:
  - Fix bad MAAR address calculations.
  - Use ALIGN() & define maar_align to make it clearer what's going on
    with address manipulations.
  - Drop the new used field from struct maar_config.
  - Rework the RAM walk to avoid iterating over the cfg array needlessly
    to find the first unused entry, then count used entries at the end.
    Instead just keep the count as we go.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: yasha.che3@gmail.com
Cc: aurelien@aurel32.net
Cc: sfr@canb.auug.org.au
Cc: fancer.lancer@gmail.com
Cc: matt.redfearn@mips.com
Cc: chenhc@lemote.com

arch/mips/mm/init.c

@@ -269,37 +269,46 @@ void __init fixrange_init(unsigned long start, unsigned long end,
 #endif
 }
 
-unsigned __weak platform_maar_init(unsigned num_pairs)
+struct maar_walk_info {
+	struct maar_config cfg[16];
+	unsigned int num_cfg;
+};
+
+static int maar_res_walk(unsigned long start_pfn, unsigned long nr_pages,
+			 void *data)
 {
-	struct maar_config cfg[BOOT_MEM_MAP_MAX];
-	unsigned i, num_configured, num_cfg = 0;
-
-	for (i = 0; i < boot_mem_map.nr_map; i++) {
-		switch (boot_mem_map.map[i].type) {
-		case BOOT_MEM_RAM:
-		case BOOT_MEM_INIT_RAM:
-			break;
-		default:
-			continue;
-		}
+	struct maar_walk_info *wi = data;
+	struct maar_config *cfg = &wi->cfg[wi->num_cfg];
+	unsigned int maar_align;
 
-		/* Round lower up */
-		cfg[num_cfg].lower = boot_mem_map.map[i].addr;
-		cfg[num_cfg].lower = (cfg[num_cfg].lower + 0xffff) & ~0xffff;
+	/* MAAR registers hold physical addresses right shifted by 4 bits */
+	maar_align = BIT(MIPS_MAAR_ADDR_SHIFT + 4);
 
-		/* Round upper down */
-		cfg[num_cfg].upper = boot_mem_map.map[i].addr +
-					boot_mem_map.map[i].size;
-		cfg[num_cfg].upper = (cfg[num_cfg].upper & ~0xffff) - 1;
+	/* Fill in the MAAR config entry */
+	cfg->lower = ALIGN(PFN_PHYS(start_pfn), maar_align);
+	cfg->upper = ALIGN_DOWN(PFN_PHYS(start_pfn + nr_pages), maar_align) - 1;
+	cfg->attrs = MIPS_MAAR_S;
 
-		cfg[num_cfg].attrs = MIPS_MAAR_S;
-		num_cfg++;
-	}
+	/* Ensure we don't overflow the cfg array */
+	if (!WARN_ON(wi->num_cfg >= ARRAY_SIZE(wi->cfg)))
+		wi->num_cfg++;
+
+	return 0;
+}
+
+
+unsigned __weak platform_maar_init(unsigned num_pairs)
+{
+	unsigned int num_configured;
+	struct maar_walk_info wi;
+
+	wi.num_cfg = 0;
+	walk_system_ram_range(0, max_pfn, &wi, maar_res_walk);
 
-	num_configured = maar_config(cfg, num_cfg, num_pairs);
-	if (num_configured < num_cfg)
-		pr_warn("Not enough MAAR pairs (%u) for all bootmem regions (%u)\n",
-			num_pairs, num_cfg);
+	num_configured = maar_config(wi.cfg, wi.num_cfg, num_pairs);
+	if (num_configured < wi.num_cfg)
+		pr_warn("Not enough MAAR pairs (%u) for all memory regions (%u)\n",
+			num_pairs, wi.num_cfg);
 
 	return num_configured;
 }
@@ -382,33 +391,6 @@ void maar_init(void)
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
-int page_is_ram(unsigned long pagenr)
-{
-	int i;
-
-	for (i = 0; i < boot_mem_map.nr_map; i++) {
-		unsigned long addr, end;
-
-		switch (boot_mem_map.map[i].type) {
-		case BOOT_MEM_RAM:
-		case BOOT_MEM_INIT_RAM:
-			break;
-		default:
-			/* not usable memory */
-			continue;
-		}
-
-		addr = PFN_UP(boot_mem_map.map[i].addr);
-		end = PFN_DOWN(boot_mem_map.map[i].addr +
-			       boot_mem_map.map[i].size);
-
-		if (pagenr >= addr && pagenr < end)
-			return 1;
-	}
-
-	return 0;
-}
-
 void __init paging_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
@@ -443,7 +425,7 @@ void __init paging_init(void)
 static struct kcore_list kcore_kseg0;
 #endif
 
-static inline void mem_init_free_highmem(void)
+static inline void __init mem_init_free_highmem(void)
 {
 #ifdef CONFIG_HIGHMEM
 	unsigned long tmp;
@@ -452,9 +434,7 @@ static inline void mem_init_free_highmem(void)
 		return;
 
 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
-		struct page *page = pfn_to_page(tmp);
-
-		if (!page_is_ram(tmp))
+		if (!memblock_is_memory(PFN_PHYS(tmp)))
 			SetPageReserved(page);
 		else
 			free_highmem_page(page);