Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 787e279..45c00a5 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -1,20 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Based on arch/arm/mm/init.c
  *
  * Copyright (C) 1995-2005 Russell King
  * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <linux/kernel.h>
@@ -22,7 +11,6 @@
 #include <linux/errno.h>
 #include <linux/swap.h>
 #include <linux/init.h>
-#include <linux/bootmem.h>
 #include <linux/cache.h>
 #include <linux/mman.h>
 #include <linux/nodemask.h>
@@ -49,7 +37,7 @@
 #include <asm/numa.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
-#include <asm/sizes.h>
+#include <linux/sizes.h>
 #include <asm/tlb.h>
 #include <asm/alternative.h>
 
@@ -60,26 +48,16 @@
  * that cannot be mistaken for a real physical address.
  */
 s64 memstart_addr __ro_after_init = -1;
+EXPORT_SYMBOL(memstart_addr);
+
+s64 physvirt_offset __ro_after_init;
+EXPORT_SYMBOL(physvirt_offset);
+
+struct page *vmemmap __ro_after_init;
+EXPORT_SYMBOL(vmemmap);
+
 phys_addr_t arm64_dma_phys_limit __ro_after_init;
 
-#ifdef CONFIG_BLK_DEV_INITRD
-static int __init early_initrd(char *p)
-{
-	unsigned long start, size;
-	char *endp;
-
-	start = memparse(p, &endp);
-	if (*endp == ',') {
-		size = memparse(endp + 1, NULL);
-
-		initrd_start = start;
-		initrd_end = start + size;
-	}
-	return 0;
-}
-early_param("initrd", early_initrd);
-#endif
-
 #ifdef CONFIG_KEXEC_CORE
 /*
  * reserve_crashkernel() - reserves memory for crash kernel
@@ -135,35 +113,10 @@
 	crashk_res.start = crash_base;
 	crashk_res.end = crash_base + crash_size - 1;
 }
-
-static void __init kexec_reserve_crashkres_pages(void)
-{
-#ifdef CONFIG_HIBERNATION
-	phys_addr_t addr;
-	struct page *page;
-
-	if (!crashk_res.end)
-		return;
-
-	/*
-	 * To reduce the size of hibernation image, all the pages are
-	 * marked as Reserved initially.
-	 */
-	for (addr = crashk_res.start; addr < (crashk_res.end + 1);
-			addr += PAGE_SIZE) {
-		page = phys_to_page(addr);
-		SetPageReserved(page);
-	}
-#endif
-}
 #else
 static void __init reserve_crashkernel(void)
 {
 }
-
-static void __init kexec_reserve_crashkres_pages(void)
-{
-}
 #endif /* CONFIG_KEXEC_CORE */
 
 #ifdef CONFIG_CRASH_DUMP
@@ -233,8 +186,9 @@
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES]  = {0};
 
-	if (IS_ENABLED(CONFIG_ZONE_DMA32))
-		max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys());
+#ifdef CONFIG_ZONE_DMA32
+	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys());
+#endif
 	max_zone_pfns[ZONE_NORMAL] = max;
 
 	free_area_init_nodes(max_zone_pfns);
@@ -284,35 +238,23 @@
 
 #endif /* CONFIG_NUMA */
 
-#ifdef CONFIG_HAVE_ARCH_PFN_VALID
 int pfn_valid(unsigned long pfn)
 {
 	phys_addr_t addr = pfn << PAGE_SHIFT;
 
 	if ((addr >> PAGE_SHIFT) != pfn)
 		return 0;
+
+#ifdef CONFIG_SPARSEMEM
+	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
+		return 0;
+
+	if (!valid_section(__nr_to_section(pfn_to_section_nr(pfn))))
+		return 0;
+#endif
 	return memblock_is_map_memory(addr);
 }
 EXPORT_SYMBOL(pfn_valid);
-#endif
-
-#ifndef CONFIG_SPARSEMEM
-static void __init arm64_memory_present(void)
-{
-}
-#else
-static void __init arm64_memory_present(void)
-{
-	struct memblock_region *reg;
-
-	for_each_memblock(memory, reg) {
-		int nid = memblock_get_region_node(reg);
-
-		memory_present(nid, memblock_region_memory_base_pfn(reg),
-				memblock_region_memory_end_pfn(reg));
-	}
-}
-#endif
 
 static phys_addr_t memory_limit = PHYS_ADDR_MAX;
 
@@ -365,7 +307,7 @@
 
 void __init arm64_memblock_init(void)
 {
-	const s64 linear_region_size = -(s64)PAGE_OFFSET;
+	const s64 linear_region_size = BIT(vabits_actual - 1);
 
 	/* Handle linux,usable-memory-range property */
 	fdt_enforce_memory_region();
@@ -374,18 +316,25 @@
 	memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX);
 
 	/*
-	 * Ensure that the linear region takes up exactly half of the kernel
-	 * virtual address space. This way, we can distinguish a linear address
-	 * from a kernel/module/vmalloc address by testing a single bit.
-	 */
-	BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1));
-
-	/*
 	 * Select a suitable value for the base of physical memory.
 	 */
 	memstart_addr = round_down(memblock_start_of_DRAM(),
 				   ARM64_MEMSTART_ALIGN);
 
+	physvirt_offset = PHYS_OFFSET - PAGE_OFFSET;
+
+	vmemmap = ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT));
+
+	/*
+	 * If we are running with a 52-bit kernel VA config on a system that
+	 * does not support it, we have to offset our vmemmap and physvirt_offset
+	 * s.t. we avoid the 52-bit portion of the direct linear map
+	 */
+	if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) {
+		vmemmap += (_PAGE_OFFSET(48) - _PAGE_OFFSET(52)) >> PAGE_SHIFT;
+		physvirt_offset = PHYS_OFFSET - _PAGE_OFFSET(48);
+	}
+
 	/*
 	 * Remove the memory that we will not be able to cover with the
 	 * linear mapping. Take care not to clip the kernel which may be
@@ -410,14 +359,14 @@
 		memblock_add(__pa_symbol(_text), (u64)(_end - _text));
 	}
 
-	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) {
+	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {
 		/*
 		 * Add back the memory we just removed if it results in the
 		 * initrd to become inaccessible via the linear mapping.
 		 * Otherwise, this is a no-op
 		 */
-		u64 base = initrd_start & PAGE_MASK;
-		u64 size = PAGE_ALIGN(initrd_end) - base;
+		u64 base = phys_initrd_start & PAGE_MASK;
+		u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base;
 
 		/*
 		 * We can only add back the initrd memory if we don't end up
@@ -431,7 +380,7 @@
 			 base + size > memblock_start_of_DRAM() +
 				       linear_region_size,
 			"initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) {
-			initrd_start = 0;
+			phys_initrd_size = 0;
 		} else {
 			memblock_remove(base, size); /* clear MEMBLOCK_ flags */
 			memblock_add(base, size);
@@ -450,7 +399,7 @@
 		 * memory spans, randomize the linear region as well.
 		 */
 		if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
-			range = range / ARM64_MEMSTART_ALIGN + 1;
+			range /= ARM64_MEMSTART_ALIGN;
 			memstart_addr -= ARM64_MEMSTART_ALIGN *
 					 ((range * memstart_offset_seed) >> 16);
 		}
@@ -461,15 +410,11 @@
 	 * pagetables with memblock.
 	 */
 	memblock_reserve(__pa_symbol(_text), _end - _text);
-#ifdef CONFIG_BLK_DEV_INITRD
-	if (initrd_start) {
-		memblock_reserve(initrd_start, initrd_end - initrd_start);
-
+	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {
 		/* the generic initrd code expects virtual addresses */
-		initrd_start = __phys_to_virt(initrd_start);
-		initrd_end = __phys_to_virt(initrd_end);
+		initrd_start = __phys_to_virt(phys_initrd_start);
+		initrd_end = initrd_start + phys_initrd_size;
 	}
-#endif
 
 	early_init_fdt_scan_reserved_mem();
 
@@ -486,8 +431,6 @@
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
 
 	dma_contiguous_reserve(arm64_dma_phys_limit);
-
-	memblock_allow_resize();
 }
 
 void __init bootmem_init(void)
@@ -500,13 +443,14 @@
 	early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
 
 	max_pfn = max_low_pfn = max;
+	min_low_pfn = min;
 
 	arm64_numa_init();
 	/*
 	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
 	 * done after the fixed reservations.
 	 */
-	arm64_memory_present();
+	memblocks_present();
 
 	sparse_init();
 	zone_sizes_init(min, max);
@@ -538,7 +482,7 @@
 	 * memmap array.
 	 */
 	if (pg < pgend)
-		free_bootmem(pg, pgend - pg);
+		memblock_free(pg, pgend - pg);
 }
 
 /*
@@ -595,15 +539,13 @@
 	else
 		swiotlb_force = SWIOTLB_NO_FORCE;
 
-	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
+	set_max_mapnr(max_pfn - PHYS_PFN_OFFSET);
 
 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 	free_unused_memmap();
 #endif
 	/* this will put all unused low memory onto the freelists */
-	free_all_bootmem();
-
-	kexec_reserve_crashkres_pages();
+	memblock_free_all();
 
 	mem_init_print_info(NULL);
 
@@ -612,15 +554,7 @@
 	 * detected at build time already.
 	 */
 #ifdef CONFIG_COMPAT
-	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
-#endif
-
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
-	/*
-	 * Make sure we chose the upper bound of sizeof(struct page)
-	 * correctly when sizing the VMEMMAP array.
-	 */
-	BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT));
+	BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64);
 #endif
 
 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
@@ -647,24 +581,15 @@
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
-
-static int keep_initrd __initdata;
-
 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd) {
-		free_reserved_area((void *)start, (void *)end, 0, "initrd");
-		memblock_free(__virt_to_phys(start), end - start);
-	}
-}
+	unsigned long aligned_start, aligned_end;
 
-static int __init keepinitrd_setup(char *__unused)
-{
-	keep_initrd = 1;
-	return 1;
+	aligned_start = __virt_to_phys(start) & PAGE_MASK;
+	aligned_end = PAGE_ALIGN(__virt_to_phys(end));
+	memblock_free(aligned_start, aligned_end - aligned_start);
+	free_reserved_area((void *)start, (void *)end, 0, "initrd");
 }
-
-__setup("keepinitrd", keepinitrd_setup);
 #endif
 
 /*