A few MIPS fixes for 4.20:

- Re-enable the Cavium Octeon USB driver in its defconfig after it was
     accidentally removed back in 4.14.
 
   - Have early memblock allocations be performed bottom-up to more
     closely match the behaviour we used to have with bootmem, which
     seems a safer choice since we've seen fallout from the change made
     in the 4.20 merge window.
 
   - Simplify max_low_pfn calculation in the NUMA code for the Loongson3
     & SGI IP27 platforms to both clean up the code & ensure max_low_pfn
     has been set appropriately before it is used.
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Merge tag 'mips_fixes_4.20_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS fixes from Paul Burton:
 "A few MIPS fixes for 4.20:

   - Re-enable the Cavium Octeon USB driver in its defconfig after it
     was accidentally removed back in 4.14.

   - Have early memblock allocations be performed bottom-up to more
     closely match the behaviour we used to have with bootmem, which
     seems a safer choice since we've seen fallout from the change made
     in the 4.20 merge window.

   - Simplify max_low_pfn calculation in the NUMA code for the Loongson3
     and SGI IP27 platforms to both clean up the code & ensure
     max_low_pfn has been set appropriately before it is used"

* tag 'mips_fixes_4.20_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Loongson3,SGI-IP27: Simplify max_low_pfn calculation
  MIPS: Let early memblock_alloc*() allocate memories bottom-up
  MIPS: OCTEON: cavium_octeon_defconfig: re-enable OCTEON USB driver

arch/mips/configs/cavium_octeon_defconfig

@@ -140,6 +140,7 @@ CONFIG_RTC_CLASS=y
 CONFIG_RTC_DRV_DS1307=y
 CONFIG_STAGING=y
 CONFIG_OCTEON_ETHERNET=y
+CONFIG_OCTEON_USB=y
 # CONFIG_IOMMU_SUPPORT is not set
 CONFIG_RAS=y
 CONFIG_EXT4_FS=y

arch/mips/kernel/setup.c

@@ -794,6 +794,7 @@ static void __init arch_mem_init(char **cmdline_p)
 
 	/* call board setup routine */
 	plat_mem_setup();
+	memblock_set_bottom_up(true);
 
 	/*
 	 * Make sure all kernel memory is in the maps.  The "UP" and

arch/mips/kernel/traps.c

@@ -2260,10 +2260,8 @@ void __init trap_init(void)
 		unsigned long size = 0x200 + VECTORSPACING*64;
 		phys_addr_t ebase_pa;
 
-		memblock_set_bottom_up(true);
 		ebase = (unsigned long)
 			memblock_alloc_from(size, 1 << fls(size), 0);
-		memblock_set_bottom_up(false);
 
 		/*
 		 * Try to ensure ebase resides in KSeg0 if possible.
@@ -2307,6 +2305,7 @@ void __init trap_init(void)
 	if (board_ebase_setup)
 		board_ebase_setup();
 	per_cpu_trap_init(true);
+	memblock_set_bottom_up(false);
 
 	/*
 	 * Copy the generic exception handlers to their final destination.

arch/mips/loongson64/loongson-3/numa.c

@@ -231,6 +231,8 @@ static __init void prom_meminit(void)
 			cpumask_clear(&__node_data[(node)]->cpumask);
 		}
 	}
+	max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
+
 	for (cpu = 0; cpu < loongson_sysconf.nr_cpus; cpu++) {
 		node = cpu / loongson_sysconf.cores_per_node;
 		if (node >= num_online_nodes())
@@ -248,19 +250,9 @@ static __init void prom_meminit(void)
 
 void __init paging_init(void)
 {
-	unsigned node;
 	unsigned long zones_size[MAX_NR_ZONES] = {0, };
 
 	pagetable_init();
-
-	for_each_online_node(node) {
-		unsigned long  start_pfn, end_pfn;
-
-		get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
-
-		if (end_pfn > max_low_pfn)
-			max_low_pfn = end_pfn;
-	}
 #ifdef CONFIG_ZONE_DMA32
 	zones_size[ZONE_DMA32] = MAX_DMA32_PFN;
 #endif

arch/mips/sgi-ip27/ip27-memory.c

@@ -435,6 +435,7 @@ void __init prom_meminit(void)
 
 	mlreset();
 	szmem();
+	max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
 
 	for (node = 0; node < MAX_COMPACT_NODES; node++) {
 		if (node_online(node)) {
@@ -455,18 +456,8 @@ extern void setup_zero_pages(void);
 void __init paging_init(void)
 {
 	unsigned long zones_size[MAX_NR_ZONES] = {0, };
-	unsigned node;
 
 	pagetable_init();
-
-	for_each_online_node(node) {
-		unsigned long start_pfn, end_pfn;
-
-		get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
-
-		if (end_pfn > max_low_pfn)
-			max_low_pfn = end_pfn;
-	}
 	zones_size[ZONE_NORMAL] = max_low_pfn;
 	free_area_init_nodes(zones_size);
 }