text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * linux/arch/sh/mm/init.c
   *
   *  Copyright (C) 1999  Niibe Yutaka
   *  Copyright (C) 2002 - 2011  Paul Mundt
   *
   *  Based on linux/arch/i386/mm/init.c:
   *   Copyright (C) 1995  Linus Torvalds
   */
  #include <linux/mm.h>
  #include <linux/swap.h>
  #include <linux/init.h>
  #include <linux/gfp.h>
  #include <linux/memblock.h>
  #include <linux/proc_fs.h>
  #include <linux/pagemap.h>
  #include <linux/percpu.h>
  #include <linux/io.h>
  #include <linux/dma-mapping.h>
  #include <linux/export.h>
  #include <asm/mmu_context.h>
  #include <asm/mmzone.h>
  #include <asm/kexec.h>
  #include <asm/tlb.h>
  #include <asm/cacheflush.h>
  #include <asm/sections.h>
  #include <asm/setup.h>
  #include <asm/cache.h>
  #include <linux/sizes.h>
  
  pgd_t swapper_pg_dir[PTRS_PER_PGD];
  
  void __init generic_mem_init(void)
  {
  	memblock_add(__MEMORY_START, __MEMORY_SIZE);
  }
  
  void __init __weak plat_mem_setup(void)
  {
  	/* Nothing to see here, move along. */
  }
  
  #ifdef CONFIG_MMU
  static pte_t *__get_pte_phys(unsigned long addr)
  {
  	pgd_t *pgd;
  	pud_t *pud;
  	pmd_t *pmd;
  
  	pgd = pgd_offset_k(addr);
  	if (pgd_none(*pgd)) {
  		pgd_ERROR(*pgd);
  		return NULL;
  	}
  
  	pud = pud_alloc(NULL, pgd, addr);
  	if (unlikely(!pud)) {
  		pud_ERROR(*pud);
  		return NULL;
  	}
  
  	pmd = pmd_alloc(NULL, pud, addr);
  	if (unlikely(!pmd)) {
  		pmd_ERROR(*pmd);
  		return NULL;
  	}
  
  	return pte_offset_kernel(pmd, addr);
  }
  
  static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
  {
  	pte_t *pte;
  
  	pte = __get_pte_phys(addr);
  	if (!pte_none(*pte)) {
  		pte_ERROR(*pte);
  		return;
  	}
  
  	set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
  	local_flush_tlb_one(get_asid(), addr);
  
  	if (pgprot_val(prot) & _PAGE_WIRED)
  		tlb_wire_entry(NULL, addr, *pte);
  }
  
  static void clear_pte_phys(unsigned long addr, pgprot_t prot)
  {
  	pte_t *pte;
  
  	pte = __get_pte_phys(addr);
  
  	if (pgprot_val(prot) & _PAGE_WIRED)
  		tlb_unwire_entry();
  
  	set_pte(pte, pfn_pte(0, __pgprot(0)));
  	local_flush_tlb_one(get_asid(), addr);
  }
  
  void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
  {
  	unsigned long address = __fix_to_virt(idx);
  
  	if (idx >= __end_of_fixed_addresses) {
  		BUG();
  		return;
  	}
  
  	set_pte_phys(address, phys, prot);
  }
  
  void __clear_fixmap(enum fixed_addresses idx, pgprot_t prot)
  {
  	unsigned long address = __fix_to_virt(idx);
  
  	if (idx >= __end_of_fixed_addresses) {
  		BUG();
  		return;
  	}
  
  	clear_pte_phys(address, prot);
  }
  
  static pmd_t * __init one_md_table_init(pud_t *pud)
  {
  	if (pud_none(*pud)) {
  		pmd_t *pmd;
  
  		pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  		if (!pmd)
  			panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
  			      __func__, PAGE_SIZE, PAGE_SIZE);
  		pud_populate(&init_mm, pud, pmd);
  		BUG_ON(pmd != pmd_offset(pud, 0));
  	}
  
  	return pmd_offset(pud, 0);
  }
  
  static pte_t * __init one_page_table_init(pmd_t *pmd)
  {
  	if (pmd_none(*pmd)) {
  		pte_t *pte;
  
  		pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  		if (!pte)
  			panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
  			      __func__, PAGE_SIZE, PAGE_SIZE);
  		pmd_populate_kernel(&init_mm, pmd, pte);
  		BUG_ON(pte != pte_offset_kernel(pmd, 0));
  	}
  
  	return pte_offset_kernel(pmd, 0);
  }
  
  static pte_t * __init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
  					    unsigned long vaddr, pte_t *lastpte)
  {
  	return pte;
  }
  
  void __init page_table_range_init(unsigned long start, unsigned long end,
  					 pgd_t *pgd_base)
  {
  	pgd_t *pgd;
  	pud_t *pud;
  	pmd_t *pmd;
  	pte_t *pte = NULL;
  	int i, j, k;
  	unsigned long vaddr;
  
  	vaddr = start;
  	i = __pgd_offset(vaddr);
  	j = __pud_offset(vaddr);
  	k = __pmd_offset(vaddr);
  	pgd = pgd_base + i;
  
  	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
  		pud = (pud_t *)pgd;
  		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
  			pmd = one_md_table_init(pud);
  #ifndef __PAGETABLE_PMD_FOLDED
  			pmd += k;
  #endif
  			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
  				pte = page_table_kmap_check(one_page_table_init(pmd),
  							    pmd, vaddr, pte);
  				vaddr += PMD_SIZE;
  			}
  			k = 0;
  		}
  		j = 0;
  	}
  }
  #endif	/* CONFIG_MMU */
  
  void __init allocate_pgdat(unsigned int nid)
  {
  	unsigned long start_pfn, end_pfn;
  
  	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
  
  #ifdef CONFIG_NEED_MULTIPLE_NODES
  	NODE_DATA(nid) = memblock_alloc_try_nid(
  				sizeof(struct pglist_data),
  				SMP_CACHE_BYTES, MEMBLOCK_LOW_LIMIT,
  				MEMBLOCK_ALLOC_ACCESSIBLE, nid);
  	if (!NODE_DATA(nid))
  		panic("Can't allocate pgdat for node %d\n", nid);
  #endif
  
  	NODE_DATA(nid)->node_start_pfn = start_pfn;
  	NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
  }
  
  static void __init do_init_bootmem(void)
  {
  	struct memblock_region *reg;
  
  	/* Add active regions with valid PFNs. */
  	for_each_memblock(memory, reg) {
  		unsigned long start_pfn, end_pfn;
  		start_pfn = memblock_region_memory_base_pfn(reg);
  		end_pfn = memblock_region_memory_end_pfn(reg);
  		__add_active_range(0, start_pfn, end_pfn);
  	}
  
  	/* All of system RAM sits in node 0 for the non-NUMA case */
  	allocate_pgdat(0);
  	node_set_online(0);
  
  	plat_mem_setup();
  
  	for_each_memblock(memory, reg) {
  		int nid = memblock_get_region_node(reg);
  
  		memory_present(nid, memblock_region_memory_base_pfn(reg),
  			memblock_region_memory_end_pfn(reg));
  	}
  	sparse_init();
  }
  
  static void __init early_reserve_mem(void)
  {
  	unsigned long start_pfn;
  	u32 zero_base = (u32)__MEMORY_START + (u32)PHYSICAL_OFFSET;
  	u32 start = zero_base + (u32)CONFIG_ZERO_PAGE_OFFSET;
  
  	/*
  	 * Partially used pages are not usable - thus
  	 * we are rounding upwards:
  	 */
  	start_pfn = PFN_UP(__pa(_end));
  
  	/*
  	 * Reserve the kernel text and Reserve the bootmem bitmap. We do
  	 * this in two steps (first step was init_bootmem()), because
  	 * this catches the (definitely buggy) case of us accidentally
  	 * initializing the bootmem allocator with an invalid RAM area.
  	 */
  	memblock_reserve(start, (PFN_PHYS(start_pfn) + PAGE_SIZE - 1) - start);
  
  	/*
  	 * Reserve physical pages below CONFIG_ZERO_PAGE_OFFSET.
  	 */
  	if (CONFIG_ZERO_PAGE_OFFSET != 0)
  		memblock_reserve(zero_base, CONFIG_ZERO_PAGE_OFFSET);
  
  	/*
  	 * Handle additional early reservations
  	 */
  	check_for_initrd();
  	reserve_crashkernel();
  }
  
  void __init paging_init(void)
  {
  	unsigned long max_zone_pfns[MAX_NR_ZONES];
  	unsigned long vaddr, end;
  
  	sh_mv.mv_mem_init();
  
  	early_reserve_mem();
  
  	/*
  	 * Once the early reservations are out of the way, give the
  	 * platforms a chance to kick out some memory.
  	 */
  	if (sh_mv.mv_mem_reserve)
  		sh_mv.mv_mem_reserve();
  
  	memblock_enforce_memory_limit(memory_limit);
  	memblock_allow_resize();
  
  	memblock_dump_all();
  
  	/*
  	 * Determine low and high memory ranges:
  	 */
  	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
  	min_low_pfn = __MEMORY_START >> PAGE_SHIFT;
  
  	nodes_clear(node_online_map);
  
  	memory_start = (unsigned long)__va(__MEMORY_START);
  	memory_end = memory_start + (memory_limit ?: memblock_phys_mem_size());
  
  	uncached_init();
  	pmb_init();
  	do_init_bootmem();
  	ioremap_fixed_init();
  
  	/* We don't need to map the kernel through the TLB, as
  	 * it is permanatly mapped using P1. So clear the
  	 * entire pgd. */
  	memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
  
  	/* Set an initial value for the MMU.TTB so we don't have to
  	 * check for a null value. */
  	set_TTB(swapper_pg_dir);
  
  	/*
  	 * Populate the relevant portions of swapper_pg_dir so that
  	 * we can use the fixmap entries without calling kmalloc.
  	 * pte's will be filled in by __set_fixmap().
  	 */
  	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
  	end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
  	page_table_range_init(vaddr, end, swapper_pg_dir);
  
  	kmap_coherent_init();
  
  	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
  	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
  	free_area_init_nodes(max_zone_pfns);
  }
  
  unsigned int mem_init_done = 0;
  
  void __init mem_init(void)
  {
  	pg_data_t *pgdat;
  
  	high_memory = NULL;
  	for_each_online_pgdat(pgdat)
  		high_memory = max_t(void *, high_memory,
  				    __va(pgdat_end_pfn(pgdat) << PAGE_SHIFT));
  
  	memblock_free_all();
  
  	/* Set this up early, so we can take care of the zero page */
  	cpu_cache_init();
  
  	/* clear the zero-page */
  	memset(empty_zero_page, 0, PAGE_SIZE);
  	__flush_wback_region(empty_zero_page, PAGE_SIZE);
  
  	vsyscall_init();
  
  	mem_init_print_info(NULL);
  	pr_info("virtual kernel memory layout:\n"
  		"    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
  #ifdef CONFIG_HIGHMEM
  		"    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
  #endif
  		"    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
  		"    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB) (cached)\n"
  #ifdef CONFIG_UNCACHED_MAPPING
  		"            : 0x%08lx - 0x%08lx   (%4ld MB) (uncached)\n"
  #endif
  		"      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
  		"      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
  		"      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
  		FIXADDR_START, FIXADDR_TOP,
  		(FIXADDR_TOP - FIXADDR_START) >> 10,
  
  #ifdef CONFIG_HIGHMEM
  		PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
  		(LAST_PKMAP*PAGE_SIZE) >> 10,
  #endif
  
  		(unsigned long)VMALLOC_START, VMALLOC_END,
  		(VMALLOC_END - VMALLOC_START) >> 20,
  
  		(unsigned long)memory_start, (unsigned long)high_memory,
  		((unsigned long)high_memory - (unsigned long)memory_start) >> 20,
  
  #ifdef CONFIG_UNCACHED_MAPPING
  		uncached_start, uncached_end, uncached_size >> 20,
  #endif
  
  		(unsigned long)&__init_begin, (unsigned long)&__init_end,
  		((unsigned long)&__init_end -
  		 (unsigned long)&__init_begin) >> 10,
  
  		(unsigned long)&_etext, (unsigned long)&_edata,
  		((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
  
  		(unsigned long)&_text, (unsigned long)&_etext,
  		((unsigned long)&_etext - (unsigned long)&_text) >> 10);
  
  	mem_init_done = 1;
  }
  
  #ifdef CONFIG_MEMORY_HOTPLUG
  int arch_add_memory(int nid, u64 start, u64 size,
  			struct mhp_restrictions *restrictions)
  {
  	unsigned long start_pfn = PFN_DOWN(start);
  	unsigned long nr_pages = size >> PAGE_SHIFT;
  	int ret;
  
  	/* We only have ZONE_NORMAL, so this is easy.. */
  	ret = __add_pages(nid, start_pfn, nr_pages, restrictions);
  	if (unlikely(ret))
  		printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
  
  	return ret;
  }
  
  #ifdef CONFIG_NUMA
  int memory_add_physaddr_to_nid(u64 addr)
  {
  	/* Node 0 for now.. */
  	return 0;
  }
  EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
  #endif
  
  void arch_remove_memory(int nid, u64 start, u64 size,
  			struct vmem_altmap *altmap)
  {
  	unsigned long start_pfn = PFN_DOWN(start);
  	unsigned long nr_pages = size >> PAGE_SHIFT;
  
  	__remove_pages(start_pfn, nr_pages, altmap);
  }
  #endif /* CONFIG_MEMORY_HOTPLUG */
  