OpenCloudOS-Kernel/arch/arc/mm/init.c

202 lines
5.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#ifdef CONFIG_BLK_DEV_INITRD
#include <linux/initrd.h>
#endif
#include <linux/of_fdt.h>
#include <linux/swap.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/arcregs.h>
pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
EXPORT_SYMBOL(empty_zero_page);
static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
static unsigned long low_mem_sz;
#ifdef CONFIG_HIGHMEM
static unsigned long min_high_pfn, max_high_pfn;
static phys_addr_t high_mem_start;
static phys_addr_t high_mem_sz;
unsigned long arch_pfn_offset;
EXPORT_SYMBOL(arch_pfn_offset);
#endif
long __init arc_get_mem_sz(void)
{
return low_mem_sz;
}
/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
static int __init setup_mem_sz(char *str)
{
low_mem_sz = memparse(str, NULL) & PAGE_MASK;
/* early console might not be setup yet - it will show up later */
pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
return 0;
}
early_param("mem", setup_mem_sz);
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
int in_use = 0;
if (!low_mem_sz) {
if (base != low_mem_start)
panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
low_mem_sz = size;
in_use = 1;
memblock_add_node(base, size, 0);
} else {
#ifdef CONFIG_HIGHMEM
high_mem_start = base;
high_mem_sz = size;
in_use = 1;
memblock_add_node(base, size, 1);
memblock_reserve(base, size);
#endif
}
pr_info("Memory @ %llx [%lldM] %s\n",
base, TO_MB(size), !in_use ? "Not used":"");
}
bool arch_has_descending_max_zone_pfns(void)
{
return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
}
/*
* First memory setup routine called from setup_arch()
* 1. setup swapper's mm @init_mm
* 2. Count the pages we have and setup bootmem allocator
* 3. zone setup
*/
void __init setup_arch_memory(void)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
setup_initial_init_mm(_text, _etext, _edata, _end);
/* first page of system - kernel .vector starts here */
min_low_pfn = virt_to_pfn(CONFIG_LINUX_RAM_BASE);
/* Last usable page of low mem */
max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
/*------------- bootmem allocator setup -----------------------*/
/*
* seed the bootmem allocator after any DT memory node parsing or
* "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
*
* Only low mem is added, otherwise we have crashes when allocating
* mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
* avail memory, ending in highmem with a > 32-bit address. However
* it then tries to memset it with a truncaed 32-bit handle, causing
* the crash
*/
memblock_reserve(CONFIG_LINUX_LINK_BASE,
__pa(_end) - CONFIG_LINUX_LINK_BASE);
#ifdef CONFIG_BLK_DEV_INITRD
if (phys_initrd_size) {
memblock_reserve(phys_initrd_start, phys_initrd_size);
initrd_start = (unsigned long)__va(phys_initrd_start);
initrd_end = initrd_start + phys_initrd_size;
}
#endif
early_init_fdt_reserve_self();
early_init_fdt_scan_reserved_mem();
memblock_dump_all();
/*----------------- node/zones setup --------------------------*/
max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
/*
* On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
* than addresses in normal aka low memory (0x8000_0000 based).
* Even with PAE, the huge peripheral space hole would waste a lot of
* mem with single contiguous mem_map[].
* Thus when HIGHMEM on ARC is enabled the memory map corresponding
* to the hole is freed and ARC specific version of pfn_valid()
* handles the hole in the memory map.
*/
min_high_pfn = PFN_DOWN(high_mem_start);
max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
/*
* max_high_pfn should be ok here for both HIGHMEM and HIGHMEM+PAE.
* For HIGHMEM without PAE max_high_pfn should be less than
* min_low_pfn to guarantee that these two regions don't overlap.
* For PAE case highmem is greater than lowmem, so it is natural
* to use max_high_pfn.
*
* In both cases, holes should be handled by pfn_valid().
*/
max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn;
high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
arch_pfn_offset = min(min_low_pfn, min_high_pfn);
kmap_init();
#else /* CONFIG_HIGHMEM */
/* pfn_valid() uses this when FLATMEM=y and HIGHMEM=n */
max_mapnr = max_low_pfn - min_low_pfn;
#endif /* CONFIG_HIGHMEM */
free_area_init(max_zone_pfn);
}
static void __init highmem_init(void)
{
#ifdef CONFIG_HIGHMEM
unsigned long tmp;
memblock_free(high_mem_start, high_mem_sz);
for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
free_highmem_page(pfn_to_page(tmp));
#endif
}
/*
* mem_init - initializes memory
*
* Frees up bootmem
* Calculates and displays memory available/used
*/
void __init mem_init(void)
{
memblock_free_all();
highmem_init();
}
#ifdef CONFIG_HIGHMEM
int pfn_valid(unsigned long pfn)
{
return (pfn >= min_high_pfn && pfn <= max_high_pfn) ||
(pfn >= min_low_pfn && pfn <= max_low_pfn);
}
EXPORT_SYMBOL(pfn_valid);
#endif