arch/riscv/mm/init.c - linux - Git at Google

 /*
  * Copyright (C) 2012 Regents of the University of California
  *
  *   This program is free software; you can redistribute it and/or
  *   modify it under the terms of the GNU General Public License
  *   as published by the Free Software Foundation, version 2.
  *
  *   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.
  */

 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/memblock.h>
 #include <linux/initrd.h>
 #include <linux/swap.h>
 #include <linux/sizes.h>
 #include <linux/of_fdt.h>

 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
 #include <asm/pgtable.h>
 #include <asm/io.h>

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

 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(min(4UL * SZ_1G,
 			(unsigned long) PFN_PHYS(max_low_pfn)));
 #endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;

 	free_area_init_nodes(max_zone_pfns);
 }

 void setup_zero_page(void)
 {
 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
 }

 void __init paging_init(void)
 {
 	setup_zero_page();
 	local_flush_tlb_all();
 	zone_sizes_init();
 }

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

 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
 	memblock_free_all();

 	mem_init_print_info(NULL);
 }

 #ifdef CONFIG_BLK_DEV_INITRD
 static void __init setup_initrd(void)
 {
 	unsigned long size;

 	if (initrd_start >= initrd_end) {
 		pr_info("initrd not found or empty");
 		goto disable;
 	}
 	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
 		pr_err("initrd extends beyond end of memory");
 		goto disable;
 	}

 	size = initrd_end - initrd_start;
 	memblock_reserve(__pa(initrd_start), size);
 	initrd_below_start_ok = 1;

 	pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
 		(void *)(initrd_start), size);
 	return;
 disable:
 	pr_cont(" - disabling initrd\n");
 	initrd_start = 0;
 	initrd_end = 0;
 }

 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
 	free_reserved_area((void *)start, (void *)end, -1, "initrd");
 }
 #endif /* CONFIG_BLK_DEV_INITRD */

 void __init setup_bootmem(void)
 {
 	struct memblock_region *reg;
 	phys_addr_t mem_size = 0;

 	/* Find the memory region containing the kernel */
 	for_each_memblock(memory, reg) {
 		phys_addr_t vmlinux_end = __pa(_end);
 		phys_addr_t end = reg->base + reg->size;

 		if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 			/*
 			 * Reserve from the start of the region to the end of
 			 * the kernel
 			 */
 			memblock_reserve(reg->base, vmlinux_end - reg->base);
 			mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);

 			/*
 			 * Remove memblock from the end of usable area to the
 			 * end of region
 			 */
 			if (reg->base + mem_size < end)
 				memblock_remove(reg->base + mem_size,
 						end - reg->base - mem_size);
 		}
 	}
 	BUG_ON(mem_size == 0);

 	set_max_mapnr(PFN_DOWN(mem_size));
 	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());

 #ifdef CONFIG_BLK_DEV_INITRD
 	setup_initrd();
 #endif /* CONFIG_BLK_DEV_INITRD */

 	early_init_fdt_reserve_self();
 	early_init_fdt_scan_reserved_mem();
 	memblock_allow_resize();
 	memblock_dump_all();

 	for_each_memblock(memory, reg) {
 		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);

 		memblock_set_node(PFN_PHYS(start_pfn),
 				  PFN_PHYS(end_pfn - start_pfn),
 				  &memblock.memory, 0);
 	}
 }

 unsigned long va_pa_offset;
 EXPORT_SYMBOL(va_pa_offset);
 unsigned long pfn_base;
 EXPORT_SYMBOL(pfn_base);

 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);

 #ifndef __PAGETABLE_PMD_FOLDED
 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
 #endif

 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;

 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 {
 	unsigned long addr = __fix_to_virt(idx);
 	pte_t *ptep;

 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);

 	ptep = &fixmap_pte[pte_index(addr)];

 	if (pgprot_val(prot)) {
 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
 	} else {
 		pte_clear(&init_mm, addr, ptep);
 		local_flush_tlb_page(addr);
 	}
 }

 /*
  * setup_vm() is called from head.S with MMU-off.
  *
  * Following requirements should be honoured for setup_vm() to work
  * correctly:
  * 1) It should use PC-relative addressing for accessing kernel symbols.
  *    To achieve this we always use GCC cmodel=medany.
  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
  *    so disable compiler instrumentation when FTRACE is enabled.
  *
  * Currently, the above requirements are honoured by using custom CFLAGS
  * for init.o in mm/Makefile.
  */

 #ifndef __riscv_cmodel_medany
 #error "setup_vm() is called from head.S before relocate so it should "
 	"not use absolute addressing."
 #endif

 asmlinkage void __init setup_vm(void)
 {
 	extern char _start;
 	uintptr_t i;
 	uintptr_t pa = (uintptr_t) &_start;
 	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);

 	va_pa_offset = PAGE_OFFSET - pa;
 	pfn_base = PFN_DOWN(pa);

 	/* Sanity check alignment and size */
 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);

 #ifndef __PAGETABLE_PMD_FOLDED
 	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 		pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 			__pgprot(_PAGE_TABLE));
 	trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);

 	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;

 		swapper_pg_dir[o] =
 			pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 				__pgprot(_PAGE_TABLE));
 	}
 	for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 		swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);

 	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 		pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd),
 				__pgprot(_PAGE_TABLE));
 	fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] =
 		pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte),
 				__pgprot(_PAGE_TABLE));
 #else
 	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 		pfn_pgd(PFN_DOWN(pa), prot);

 	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 		size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;

 		swapper_pg_dir[o] =
 			pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 	}

 	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 		pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
 				__pgprot(_PAGE_TABLE));
 #endif
 }
	/*
	* Copyright (C) 2012 Regents of the University of California
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation, version 2.
	*
	* 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.
	*/

	#include <linux/init.h>
	#include <linux/mm.h>
	#include <linux/memblock.h>
	#include <linux/initrd.h>
	#include <linux/swap.h>
	#include <linux/sizes.h>
	#include <linux/of_fdt.h>

	#include <asm/fixmap.h>
	#include <asm/tlbflush.h>
	#include <asm/sections.h>
	#include <asm/pgtable.h>
	#include <asm/io.h>

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

	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(min(4UL * SZ_1G,
	(unsigned long) PFN_PHYS(max_low_pfn)));
	#endif
	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;

	free_area_init_nodes(max_zone_pfns);
	}

	void setup_zero_page(void)
	{
	memset((void *)empty_zero_page, 0, PAGE_SIZE);
	}

	void __init paging_init(void)
	{
	setup_zero_page();
	local_flush_tlb_all();
	zone_sizes_init();
	}

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

	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
	memblock_free_all();

	mem_init_print_info(NULL);
	}

	#ifdef CONFIG_BLK_DEV_INITRD
	static void __init setup_initrd(void)
	{
	unsigned long size;

	if (initrd_start >= initrd_end) {
	pr_info("initrd not found or empty");
	goto disable;
	}
	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
	pr_err("initrd extends beyond end of memory");
	goto disable;
	}

	size = initrd_end - initrd_start;
	memblock_reserve(__pa(initrd_start), size);
	initrd_below_start_ok = 1;

	pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
	(void *)(initrd_start), size);
	return;
	disable:
	pr_cont(" - disabling initrd\n");
	initrd_start = 0;
	initrd_end = 0;
	}

	void __init free_initrd_mem(unsigned long start, unsigned long end)
	{
	free_reserved_area((void )start, (void )end, -1, "initrd");
	}
	#endif /* CONFIG_BLK_DEV_INITRD */

	void __init setup_bootmem(void)
	{
	struct memblock_region *reg;
	phys_addr_t mem_size = 0;

	/* Find the memory region containing the kernel */
	for_each_memblock(memory, reg) {
	phys_addr_t vmlinux_end = __pa(_end);
	phys_addr_t end = reg->base + reg->size;

	if (reg->base <= vmlinux_end && vmlinux_end <= end) {
	/*
	* Reserve from the start of the region to the end of
	* the kernel
	*/
	memblock_reserve(reg->base, vmlinux_end - reg->base);
	mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);

	/*
	* Remove memblock from the end of usable area to the
	* end of region
	*/
	if (reg->base + mem_size < end)
	memblock_remove(reg->base + mem_size,
	end - reg->base - mem_size);
	}
	}
	BUG_ON(mem_size == 0);

	set_max_mapnr(PFN_DOWN(mem_size));
	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());

	#ifdef CONFIG_BLK_DEV_INITRD
	setup_initrd();
	#endif /* CONFIG_BLK_DEV_INITRD */

	early_init_fdt_reserve_self();
	early_init_fdt_scan_reserved_mem();
	memblock_allow_resize();
	memblock_dump_all();

	for_each_memblock(memory, reg) {
	unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
	unsigned long end_pfn = memblock_region_memory_end_pfn(reg);

	memblock_set_node(PFN_PHYS(start_pfn),
	PFN_PHYS(end_pfn - start_pfn),
	&memblock.memory, 0);
	}
	}

	unsigned long va_pa_offset;
	EXPORT_SYMBOL(va_pa_offset);
	unsigned long pfn_base;
	EXPORT_SYMBOL(pfn_base);

	pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
	pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);

	#ifndef __PAGETABLE_PMD_FOLDED
	#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
	pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
	pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
	pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
	#endif

	pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;

	void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
	{
	unsigned long addr = __fix_to_virt(idx);
	pte_t *ptep;

	BUG_ON(idx <= FIX_HOLE \|\| idx >= __end_of_fixed_addresses);

	ptep = &fixmap_pte[pte_index(addr)];

	if (pgprot_val(prot)) {
	set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
	} else {
	pte_clear(&init_mm, addr, ptep);
	local_flush_tlb_page(addr);
	}
	}

	/*
	* setup_vm() is called from head.S with MMU-off.
	*
	* Following requirements should be honoured for setup_vm() to work
	* correctly:
	* 1) It should use PC-relative addressing for accessing kernel symbols.
	* To achieve this we always use GCC cmodel=medany.
	* 2) The compiler instrumentation for FTRACE will not work for setup_vm()
	* so disable compiler instrumentation when FTRACE is enabled.
	*
	* Currently, the above requirements are honoured by using custom CFLAGS
	* for init.o in mm/Makefile.
	*/

	#ifndef __riscv_cmodel_medany
	#error "setup_vm() is called from head.S before relocate so it should "
	"not use absolute addressing."
	#endif

	asmlinkage void __init setup_vm(void)
	{
	extern char _start;
	uintptr_t i;
	uintptr_t pa = (uintptr_t) &_start;
	pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) \| _PAGE_EXEC);

	va_pa_offset = PAGE_OFFSET - pa;
	pfn_base = PFN_DOWN(pa);

	/* Sanity check alignment and size */
	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
	BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);

	#ifndef __PAGETABLE_PMD_FOLDED
	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
	pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
	__pgprot(_PAGE_TABLE));
	trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);

	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
	size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;

	swapper_pg_dir[o] =
	pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
	__pgprot(_PAGE_TABLE));
	}
	for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
	swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);

	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
	pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd),
	__pgprot(_PAGE_TABLE));
	fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] =
	pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte),
	__pgprot(_PAGE_TABLE));
	#else
	trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
	pfn_pgd(PFN_DOWN(pa), prot);

	for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
	size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;

	swapper_pg_dir[o] =
	pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
	}

	swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
	pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
	__pgprot(_PAGE_TABLE));
	#endif
	}