path: root/arch/riscv/mm/init.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
 * Copyright (C) 2020 FORTH-ICS/CARV
 *  Nick Kossifidis <mick@ics.forth.gr>
 */

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/swap.h>
#include <linux/swiotlb.h>
#include <linux/sizes.h>
#include <linux/of_fdt.h>
#include <linux/of_reserved_mem.h>
#include <linux/libfdt.h>
#include <linux/set_memory.h>
#include <linux/dma-map-ops.h>
#include <linux/crash_dump.h>
#include <linux/hugetlb.h>

#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/soc.h>
#include <asm/io.h>
#include <asm/ptdump.h>
#include <asm/numa.h>

#include "../kernel/head.h"

struct kernel_mapping kernel_map __ro_after_init;
EXPORT_SYMBOL(kernel_map);
#ifdef CONFIG_XIP_KERNEL
#define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
#endif

#ifdef CONFIG_64BIT
u64 satp_mode = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_48 : SATP_MODE_39;
#else
u64 satp_mode = SATP_MODE_32;
#endif
EXPORT_SYMBOL(satp_mode);

bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
EXPORT_SYMBOL(pgtable_l4_enabled);

phys_addr_t phys_ram_base __ro_after_init;
EXPORT_SYMBOL(phys_ram_base);

unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
							__page_aligned_bss;
EXPORT_SYMBOL(empty_zero_page);

extern char _start[];
#define DTB_EARLY_BASE_VA      PGDIR_SIZE
void *_dtb_early_va __initdata;
uintptr_t _dtb_early_pa __initdata;

static phys_addr_t dma32_phys_limit __initdata;

static void __init zone_sizes_init(void)
{
	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };

#ifdef CONFIG_ZONE_DMA32
	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
#endif
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;

	free_area_init(max_zone_pfns);
}

#if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
static inline void print_mlk(char *name, unsigned long b, unsigned long t)
{
	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
		  (((t) - (b)) >> 10));
}

static inline void print_mlm(char *name, unsigned long b, unsigned long t)
{
	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
		  (((t) - (b)) >> 20));
}

static void __init print_vm_layout(void)
{
	pr_notice("Virtual kernel memory layout:\n");
	print_mlk("fixmap", (unsigned long)FIXADDR_START,
		  (unsigned long)FIXADDR_TOP);
	print_mlm("pci io", (unsigned long)PCI_IO_START,
		  (unsigned long)PCI_IO_END);
	print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
		  (unsigned long)VMEMMAP_END);
	print_mlm("vmalloc", (unsigned long)VMALLOC_START,
		  (unsigned long)VMALLOC_END);
	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
		  (unsigned long)high_memory);
	if (IS_ENABLED(CONFIG_64BIT)) {
#ifdef CONFIG_KASAN
		print_mlm("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
#endif

		print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR,
			  (unsigned long)ADDRESS_SPACE_END);
	}
}
#else
static void print_vm_layout(void) { }
#endif /* CONFIG_DEBUG_VM */

void __init mem_init(void)
{
#ifdef CONFIG_FLATMEM
	BUG_ON(!mem_map);
#endif /* CONFIG_FLATMEM */

#ifdef CONFIG_SWIOTLB
	if (swiotlb_force == SWIOTLB_FORCE ||
	    max_pfn > PFN_DOWN(dma32_phys_limit))
		swiotlb_init(1);
	else
		swiotlb_force = SWIOTLB_NO_FORCE;
#endif
	memblock_free_all();

	print_vm_layout();
}

/* Limit the memory size via mem. */
static phys_addr_t memory_limit;

static int __init early_mem(char *p)
{
	u64 size;

	if (!p)
		return 1;

	size = memparse(p, &p) & PAGE_MASK;
	memory_limit = min_t(u64, size, memory_limit);

	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);

	return 0;
}
early_param("mem", early_mem);

static void __init setup_bootmem(void)
{
	phys_addr_t vmlinux_end = __pa_symbol(&_end);
	phys_addr_t max_mapped_addr;
	phys_addr_t phys_ram_end, vmlinux_start;

	if (IS_ENABLED(CONFIG_XIP_KERNEL))
		vmlinux_start = __pa_symbol(&_sdata);
	else
		vmlinux_start = __pa_symbol(&_start);

	memblock_enforce_memory_limit(memory_limit);

	/*
	 * Make sure we align the reservation on PMD_SIZE since we will
	 * map the kernel in the linear mapping as read-only: we do not want
	 * any allocation to happen between _end and the next pmd aligned page.
	 */
	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
	/*
	 * Reserve from the start of the kernel to the end of the kernel
	 */
	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);

	phys_ram_end = memblock_end_of_DRAM();
	if (!IS_ENABLED(CONFIG_XIP_KERNEL))
		phys_ram_base = memblock_start_of_DRAM();
	/*
	 * memblock allocator is not aware of the fact that last 4K bytes of
	 * the addressable memory can not be mapped because of IS_ERR_VALUE
	 * macro. Make sure that last 4k bytes are not usable by memblock
	 * if end of dram is equal to maximum addressable memory.  For 64-bit
	 * kernel, this problem can't happen here as the end of the virtual