diff options
Diffstat (limited to 'arch/arc/mm/init.c')
| -rw-r--r-- | arch/arc/mm/init.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c new file mode 100644 index 000000000..da543fd42 --- /dev/null +++ b/arch/arc/mm/init.c @@ -0,0 +1,201 @@ +// 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; +#endif + +#ifdef CONFIG_DISCONTIGMEM +struct pglist_data node_data[MAX_NUMNODES] __read_mostly; +EXPORT_SYMBOL(node_data); +#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 }; + + init_mm.start_code = (unsigned long)_text; + init_mm.end_code = (unsigned long)_etext; + init_mm.end_data = (unsigned long)_edata; + init_mm.brk = (unsigned long)_end; + + /* first page of system - kernel .vector starts here */ + min_low_pfn = ARCH_PFN_OFFSET; + + /* Last usable page of low mem */ + max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz); + +#ifdef CONFIG_FLATMEM + /* pfn_valid() uses this */ + max_mapnr = max_low_pfn - min_low_pfn; +#endif + + /*------------- 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 + /* + * Populate a new node with highmem + * + * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based) + * than addresses in normal ala low memory (0x8000_0000 based). + * Even with PAE, the huge peripheral space hole would waste a lot of + * mem with single mem_map[]. This warrants a mem_map per region design. + * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM. + * + * DISCONTIGMEM in turns requires multiple nodes. node 0 above is + * populated with normal memory zone while node 1 only has highmem + */ + node_set_online(1); + + 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); + kmap_init(); +#endif + + 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(); + mem_init_print_info(NULL); +} |