1 files changed, 342 insertions, 0 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
new file mode 100644
index 00000000000..e90c5426fe1
--- /dev/null
+++ b/arch/arm64/mm/init.c
@@ -0,0 +1,342 @@
+/*
+ * 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>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/swap.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/initrd.h>
+#include <linux/gfp.h>
+#include <linux/memblock.h>
+#include <linux/sort.h>
+#include <linux/of_fdt.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-contiguous.h>
+
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/sizes.h>
+#include <asm/tlb.h>
+
+#include "mm.h"
+
+phys_addr_t memstart_addr __read_mostly = 0;
+
+#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 = (unsigned long)__va(start);
+		initrd_end = (unsigned long)__va(start + size);
+	}
+	return 0;
+}
+early_param("initrd", early_initrd);
+#endif
+
+/*
+ * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
+ * currently assumes that for memory starting above 4G, 32-bit devices will
+ * use a DMA offset.
+ */
+static phys_addr_t max_zone_dma_phys(void)
+{
+	phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
+	return min(offset + (1ULL << 32), memblock_end_of_DRAM());
+}
+
+static void __init zone_sizes_init(unsigned long min, unsigned long max)
+{
+	struct memblock_region *reg;
+	unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
+	unsigned long max_dma = min;
+
+	memset(zone_size, 0, sizeof(zone_size));
+
+	/* 4GB maximum for 32-bit only capable devices */
+	if (IS_ENABLED(CONFIG_ZONE_DMA)) {
+		max_dma = PFN_DOWN(max_zone_dma_phys());
+		zone_size[ZONE_DMA] = max_dma - min;
+	}
+	zone_size[ZONE_NORMAL] = max - max_dma;
+
+	memcpy(zhole_size, zone_size, sizeof(zhole_size));
+
+	for_each_memblock(memory, reg) {
+		unsigned long start = memblock_region_memory_base_pfn(reg);
+		unsigned long end = memblock_region_memory_end_pfn(reg);
+
+		if (start >= max)
+			continue;
+
+		if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
+			unsigned long dma_end = min(end, max_dma);
+			zhole_size[ZONE_DMA] -= dma_end - start;
+		}
+
+		if (end > max_dma) {
+			unsigned long normal_end = min(end, max);
+			unsigned long normal_start = max(start, max_dma);
+			zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
+		}
+	}
+
+	free_area_init_node(0, zone_size, min, zhole_size);
+}
+
+#ifdef CONFIG_HAVE_ARCH_PFN_VALID
+int pfn_valid(unsigned long pfn)
+{
+	return memblock_is_memory(pfn << PAGE_SHIFT);
+}
+EXPORT_SYMBOL(pfn_valid);
+#endif
+
+#ifndef CONFIG_SPARSEMEM
+static void arm64_memory_present(void)
+{
+}
+#else
+static void arm64_memory_present(void)
+{
+	struct memblock_region *reg;
+
+	for_each_memblock(memory, reg)
+		memory_present(0, memblock_region_memory_base_pfn(reg),
+			       memblock_region_memory_end_pfn(reg));
+}
+#endif
+
+void __init arm64_memblock_init(void)
+{
+	phys_addr_t dma_phys_limit = 0;
+
+	/* Register the kernel text, kernel data and initrd with memblock */
+	memblock_reserve(__pa(_text), _end - _text);
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start)
+		memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
+#endif
+
+	/*
+	 * Reserve the page tables.  These are already in use,
+	 * and can only be in node 0.
+	 */
+	memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
+	memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
+
+	early_init_fdt_scan_reserved_mem();
+
+	/* 4GB maximum for 32-bit only capable devices */
+	if (IS_ENABLED(CONFIG_ZONE_DMA))
+		dma_phys_limit = max_zone_dma_phys();
+	dma_contiguous_reserve(dma_phys_limit);
+
+	memblock_allow_resize();
+	memblock_dump_all();
+}
+
+void __init bootmem_init(void)
+{
+	unsigned long min, max;
+
+	min = PFN_UP(memblock_start_of_DRAM());
+	max = PFN_DOWN(memblock_end_of_DRAM());
+
+	/*
+	 * Sparsemem tries to allocate bootmem in memory_present(), so must be
+	 * done after the fixed reservations.
+	 */
+	arm64_memory_present();
+
+	sparse_init();
+	zone_sizes_init(min, max);
+
+	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
+	max_pfn = max_low_pfn = max;
+}
+
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
+{
+	struct page *start_pg, *end_pg;
+	unsigned long pg, pgend;
+
+	/*
+	 * Convert start_pfn/end_pfn to a struct page pointer.
+	 */
+	start_pg = pfn_to_page(start_pfn - 1) + 1;
+	end_pg = pfn_to_page(end_pfn - 1) + 1;
+
+	/*
+	 * Convert to physical addresses, and round start upwards and end
+	 * downwards.
+	 */
+	pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
+	pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
+
+	/*
+	 * If there are free pages between these, free the section of the
+	 * memmap array.
+	 */
+	if (pg < pgend)
+		free_bootmem(pg, pgend - pg);
+}
+
+/*
+ * The mem_map array can get very big. Free the unused area of the memory map.
+ */
+static void __init free_unused_memmap(void)
+{
+	unsigned long start, prev_end = 0;
+	struct memblock_region *reg;
+
+	for_each_memblock(memory, reg) {
+		start = __phys_to_pfn(reg->base);
+
+#ifdef CONFIG_SPARSEMEM
+		/*
+		 * Take care not to free memmap entries that don't exist due
+		 * to SPARSEMEM sections which aren't present.
+		 */
+		start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
+#endif
+		/*
+		 * If we had a previous bank, and there is a space between the
+		 * current bank and the previous, free it.
+		 */
+		if (prev_end && prev_end < start)
+			free_memmap(prev_end, start);
+
+		/*
+		 * Align up here since the VM subsystem insists that the
+		 * memmap entries are valid from the bank end aligned to
+		 * MAX_ORDER_NR_PAGES.
+		 */
+		prev_end = ALIGN(start + __phys_to_pfn(reg->size),
+				 MAX_ORDER_NR_PAGES);
+	}
+
+#ifdef CONFIG_SPARSEMEM
+	if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
+		free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
+#endif
+}
+#endif	/* !CONFIG_SPARSEMEM_VMEMMAP */
+
+/*
+ * mem_init() marks the free areas in the mem_map and tells us how much memory
+ * is free.  This is done after various parts of the system have claimed their
+ * memory after the kernel image.
+ */
+void __init mem_init(void)
+{
+	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
+
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+	free_unused_memmap();
+#endif
+	/* this will put all unused low memory onto the freelists */
+	free_all_bootmem();
+
+	mem_init_print_info(NULL);
+
+#define MLK(b, t) b, t, ((t) - (b)) >> 10
+#define MLM(b, t) b, t, ((t) - (b)) >> 20
+#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
+
+	pr_notice("Virtual kernel memory layout:\n"
+		  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld MB)\n"
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+		  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld MB)\n"
+#endif
+		  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
+		  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
+		  "      .init : 0x%p" " - 0x%p" "   (%6ld kB)\n"
+		  "      .text : 0x%p" " - 0x%p" "   (%6ld kB)\n"
+		  "      .data : 0x%p" " - 0x%p" "   (%6ld kB)\n",
+		  MLM(VMALLOC_START, VMALLOC_END),
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+		  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
+		      (unsigned long)virt_to_page(high_memory)),
+#endif
+		  MLM(MODULES_VADDR, MODULES_END),
+		  MLM(PAGE_OFFSET, (unsigned long)high_memory),
+
+		  MLK_ROUNDUP(__init_begin, __init_end),
+		  MLK_ROUNDUP(_text, _etext),
+		  MLK_ROUNDUP(_sdata, _edata));
+
+#undef MLK
+#undef MLM
+#undef MLK_ROUNDUP
+
+	/*
+	 * Check boundaries twice: Some fundamental inconsistencies can be
+	 * detected at build time already.
+	 */
+#ifdef CONFIG_COMPAT
+	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
+#endif
+	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
+	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
+
+	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
+		extern int sysctl_overcommit_memory;
+		/*
+		 * On a machine this small we won't get anywhere without
+		 * overcommit, so turn it on by default.
+		 */
+		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
+	}
+}
+
+void free_initmem(void)
+{
+	free_initmem_default(0);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+
+static int keep_initrd;
+
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	if (!keep_initrd)
+		free_reserved_area((void *)start, (void *)end, 0, "initrd");
+}
+
+static int __init keepinitrd_setup(char *__unused)
+{
+	keep_initrd = 1;
+	return 1;
+}
+
+__setup("keepinitrd", keepinitrd_setup);
+#endif