arm64: MMU initialisation

This patch contains the initialisation of the memory blocks, MMU
attributes and the memory map. Only five memory types are defined:
Device nGnRnE (equivalent to Strongly Ordered), Device nGnRE (classic
Device memory), Device GRE, Normal Non-cacheable and Normal Cacheable.
Cache policies are supported via the memory attributes register
(MAIR_EL1) and only affect the Normal Cacheable mappings.

This patch also adds the SPARSEMEM_VMEMMAP initialisation.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 437 insertions, 0 deletions

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
new file mode 100644
index 000000000000..5f719ba949bc
--- /dev/null
+++ b/arch/arm64/mm/init.c
@@ -0,0 +1,437 @@
+/*
+ * 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 <asm/prom.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/sizes.h>
+#include <asm/tlb.h>
+
+#include "mm.h"
+
+static unsigned long phys_initrd_start __initdata = 0;
+static unsigned long phys_initrd_size __initdata = 0;
+
+phys_addr_t memstart_addr __read_mostly = 0;
+
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+					    unsigned long end)
+{
+	phys_initrd_start = start;
+	phys_initrd_size = end - start;
+}
+
+static int __init early_initrd(char *p)
+{
+	unsigned long start, size;
+	char *endp;
+
+	start = memparse(p, &endp);
+	if (*endp == ',') {
+		size = memparse(endp + 1, NULL);
+
+		phys_initrd_start = start;
+		phys_initrd_size = size;
+	}
+	return 0;
+}
+early_param("initrd", early_initrd);
+
+#define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)
+
+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_dma32 = min;
+
+	memset(zone_size, 0, sizeof(zone_size));
+
+#ifdef CONFIG_ZONE_DMA32
+	/* 4GB maximum for 32-bit only capable devices */
+	max_dma32 = min(max, MAX_DMA32_PFN);
+	zone_size[ZONE_DMA32] = max_dma32 - min;
+#endif
+	zone_size[ZONE_NORMAL] = max - max_dma32;
+
+	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;
+#ifdef CONFIG_ZONE_DMA32
+		if (start < max_dma32) {
+			unsigned long dma_end = min(end, max_dma32);
+			zhole_size[ZONE_DMA32] -= dma_end - start;
+		}
+#endif
+		if (end > max_dma32) {
+			unsigned long normal_end = min(end, max);
+			unsigned long normal_start = max(start, max_dma32);
+			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)
+{
+	u64 *reserve_map, base, size;
+
+	/* Register the kernel text, kernel data and initrd with memblock */
+	memblock_reserve(__pa(_text), _end - _text);
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (phys_initrd_size) {
+		memblock_reserve(phys_initrd_start, phys_initrd_size);
+
+		/* Now convert initrd to virtual addresses */
+		initrd_start = __phys_to_virt(phys_initrd_start);
+		initrd_end = initrd_start + phys_initrd_size;
+	}
+#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);
+
+	/* Reserve the dtb region */
+	memblock_reserve(virt_to_phys(initial_boot_params),
+			 be32_to_cpu(initial_boot_params->totalsize));
+
+	/*
+	 * Process the reserve map.  This will probably overlap the initrd
+	 * and dtb locations which are already reserved, but overlapping
+	 * doesn't hurt anything
+	 */
+	reserve_map = ((void*)initial_boot_params) +
+			be32_to_cpu(initial_boot_params->off_mem_rsvmap);
+	while (1) {
+		base = be64_to_cpup(reserve_map++);
+		size = be64_to_cpup(reserve_map++);
+		if (!size)
+			break;
+		memblock_reserve(base, size);
+	}
+
+	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;
+}
+
+static inline int free_area(unsigned long pfn, unsigned long end, char *s)
+{
+	unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);
+
+	for (; pfn < end; pfn++) {
+		struct page *page = pfn_to_page(pfn);
+		ClearPageReserved(page);
+		init_page_count(page);
+		__free_page(page);
+		pages++;
+	}
+
+	if (size && s)
+		pr_info("Freeing %s memory: %dK\n", s, size);
+
+	return pages;
+}
+
+/*
+ * Poison init memory with an undefined instruction (0x0).
+ */
+static inline void poison_init_mem(void *s, size_t count)
+{
+	memset(s, 0, count);
+}
+
+#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)
+{
+	unsigned long reserved_pages, free_pages;
+	struct memblock_region *reg;
+
+#if CONFIG_SWIOTLB
+	extern void __init arm64_swiotlb_init(size_t max_size);
+	arm64_swiotlb_init(max_pfn << (PAGE_SHIFT - 1));
+#endif
+
+	max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
+
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+	/* this will put all unused low memory onto the freelists */
+	free_unused_memmap();
+#endif
+
+	totalram_pages += free_all_bootmem();
+
+	reserved_pages = free_pages = 0;
+
+	for_each_memblock(memory, reg) {
+		unsigned int pfn1, pfn2;
+		struct page *page, *end;
+
+		pfn1 = __phys_to_pfn(reg->base);
+		pfn2 = pfn1 + __phys_to_pfn(reg->size);
+
+		page = pfn_to_page(pfn1);
+		end  = pfn_to_page(pfn2 - 1) + 1;
+
+		do {
+			if (PageReserved(page))
+				reserved_pages++;
+			else if (!page_count(page))
+				free_pages++;
+			page++;
+		} while (page < end);
+	}
+
+	/*
+	 * Since our memory may not be contiguous, calculate the real number
+	 * of pages we have in this system.
+	 */
+	pr_info("Memory:");
+	num_physpages = 0;
+	for_each_memblock(memory, reg) {
+		unsigned long pages = memblock_region_memory_end_pfn(reg) -
+			memblock_region_memory_base_pfn(reg);
+		num_physpages += pages;
+		printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
+	}
+	printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
+
+	pr_notice("Memory: %luk/%luk available, %luk reserved\n",
+		  nr_free_pages() << (PAGE_SHIFT-10),
+		  free_pages << (PAGE_SHIFT-10),
+		  reserved_pages << (PAGE_SHIFT-10));
+
+#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 && 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)
+{
+	poison_init_mem(__init_begin, __init_end - __init_begin);
+	totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
+				    __phys_to_pfn(__pa(__init_end)),
+				    "init");
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+
+static int keep_initrd;
+
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	if (!keep_initrd) {
+		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
+		totalram_pages += free_area(__phys_to_pfn(__pa(start)),
+					    __phys_to_pfn(__pa(end)),
+					    "initrd");
+	}
+}
+
+static int __init keepinitrd_setup(char *__unused)
+{
+	keep_initrd = 1;
+	return 1;
+}
+
+__setup("keepinitrd", keepinitrd_setup);
+#endif