linux/linux-5.4.31/arch/riscv/mm/init.c

469 lines
12 KiB
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.
*/
#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 <linux/libfdt.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include "../kernel/head.h"
unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
__page_aligned_bss;
EXPORT_SYMBOL(empty_zero_page);
extern char _start[];
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 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;
}
#endif /* CONFIG_BLK_DEV_INITRD */
static phys_addr_t dtb_early_pa __initdata;
void __init setup_bootmem(void)
{
struct memblock_region *reg;
phys_addr_t mem_size = 0;
phys_addr_t vmlinux_end = __pa(&_end);
phys_addr_t vmlinux_start = __pa(&_start);
/* Find the memory region containing the kernel */
for_each_memblock(memory, reg) {
phys_addr_t end = reg->base + reg->size;
if (reg->base <= vmlinux_start && vmlinux_end <= end) {
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);
/* Reserve from the start of the kernel to the end of the kernel */
memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
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 */
/*
* Avoid using early_init_fdt_reserve_self() since __pa() does
* not work for DTB pointers that are fixmap addresses
*/
memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
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);
void *dtb_early_va;
pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
static bool mmu_enabled;
#define MAX_EARLY_MAPPING_SIZE SZ_128M
pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
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);
}
}
static pte_t *__init get_pte_virt(phys_addr_t pa)
{
if (mmu_enabled) {
clear_fixmap(FIX_PTE);
return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
} else {
return (pte_t *)((uintptr_t)pa);
}
}
static phys_addr_t __init alloc_pte(uintptr_t va)
{
/*
* We only create PMD or PGD early mappings so we
* should never reach here with MMU disabled.
*/
BUG_ON(!mmu_enabled);
return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
}
static void __init create_pte_mapping(pte_t *ptep,
uintptr_t va, phys_addr_t pa,
phys_addr_t sz, pgprot_t prot)
{
uintptr_t pte_index = pte_index(va);
BUG_ON(sz != PAGE_SIZE);
if (pte_none(ptep[pte_index]))
ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
}
#ifndef __PAGETABLE_PMD_FOLDED
pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
#if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
#define NUM_EARLY_PMDS 1UL
#else
#define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
#endif
pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
static pmd_t *__init get_pmd_virt(phys_addr_t pa)
{
if (mmu_enabled) {
clear_fixmap(FIX_PMD);
return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
} else {
return (pmd_t *)((uintptr_t)pa);
}
}
static phys_addr_t __init alloc_pmd(uintptr_t va)
{
uintptr_t pmd_num;
if (mmu_enabled)
return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
BUG_ON(pmd_num >= NUM_EARLY_PMDS);
return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
}
static void __init create_pmd_mapping(pmd_t *pmdp,
uintptr_t va, phys_addr_t pa,
phys_addr_t sz, pgprot_t prot)
{
pte_t *ptep;
phys_addr_t pte_phys;
uintptr_t pmd_index = pmd_index(va);
if (sz == PMD_SIZE) {
if (pmd_none(pmdp[pmd_index]))
pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
return;
}
if (pmd_none(pmdp[pmd_index])) {
pte_phys = alloc_pte(va);
pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
ptep = get_pte_virt(pte_phys);
memset(ptep, 0, PAGE_SIZE);
} else {
pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
ptep = get_pte_virt(pte_phys);
}
create_pte_mapping(ptep, va, pa, sz, prot);
}
#define pgd_next_t pmd_t
#define alloc_pgd_next(__va) alloc_pmd(__va)
#define get_pgd_next_virt(__pa) get_pmd_virt(__pa)
#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
#define PTE_PARENT_SIZE PMD_SIZE
#define fixmap_pgd_next fixmap_pmd
#else
#define pgd_next_t pte_t
#define alloc_pgd_next(__va) alloc_pte(__va)
#define get_pgd_next_virt(__pa) get_pte_virt(__pa)
#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
#define PTE_PARENT_SIZE PGDIR_SIZE
#define fixmap_pgd_next fixmap_pte
#endif
static void __init create_pgd_mapping(pgd_t *pgdp,
uintptr_t va, phys_addr_t pa,
phys_addr_t sz, pgprot_t prot)
{
pgd_next_t *nextp;
phys_addr_t next_phys;
uintptr_t pgd_index = pgd_index(va);
if (sz == PGDIR_SIZE) {
if (pgd_val(pgdp[pgd_index]) == 0)
pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
return;
}
if (pgd_val(pgdp[pgd_index]) == 0) {
next_phys = alloc_pgd_next(va);
pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
nextp = get_pgd_next_virt(next_phys);
memset(nextp, 0, PAGE_SIZE);
} else {
next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
nextp = get_pgd_next_virt(next_phys);
}
create_pgd_next_mapping(nextp, va, pa, sz, prot);
}
static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
{
uintptr_t map_size = PAGE_SIZE;
/* Upgrade to PMD/PGDIR mappings whenever possible */
if (!(base & (PTE_PARENT_SIZE - 1)) &&
!(size & (PTE_PARENT_SIZE - 1)))
map_size = PTE_PARENT_SIZE;
return map_size;
}
/*
* 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(uintptr_t dtb_pa)
{
uintptr_t va, end_va;
uintptr_t load_pa = (uintptr_t)(&_start);
uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
va_pa_offset = PAGE_OFFSET - load_pa;
pfn_base = PFN_DOWN(load_pa);
/*
* Enforce boot alignment requirements of RV32 and
* RV64 by only allowing PMD or PGD mappings.
*/
BUG_ON(map_size == PAGE_SIZE);
/* Sanity check alignment and size */
BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
BUG_ON((load_pa % map_size) != 0);
BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
/* Setup early PGD for fixmap */
create_pgd_mapping(early_pg_dir, FIXADDR_START,
(uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
#ifndef __PAGETABLE_PMD_FOLDED
/* Setup fixmap PMD */
create_pmd_mapping(fixmap_pmd, FIXADDR_START,
(uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
/* Setup trampoline PGD and PMD */
create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
(uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
#else
/* Setup trampoline PGD */
create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
#endif
/*
* Setup early PGD covering entire kernel which will allows
* us to reach paging_init(). We map all memory banks later
* in setup_vm_final() below.
*/
end_va = PAGE_OFFSET + load_sz;
for (va = PAGE_OFFSET; va < end_va; va += map_size)
create_pgd_mapping(early_pg_dir, va,
load_pa + (va - PAGE_OFFSET),
map_size, PAGE_KERNEL_EXEC);
/* Create fixed mapping for early FDT parsing */
end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
create_pte_mapping(fixmap_pte, va,
dtb_pa + (va - __fix_to_virt(FIX_FDT)),
PAGE_SIZE, PAGE_KERNEL);
/* Save pointer to DTB for early FDT parsing */
dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
/* Save physical address for memblock reservation */
dtb_early_pa = dtb_pa;
}
static void __init setup_vm_final(void)
{
uintptr_t va, map_size;
phys_addr_t pa, start, end;
struct memblock_region *reg;
/* Set mmu_enabled flag */
mmu_enabled = true;
/* Setup swapper PGD for fixmap */
create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
__pa(fixmap_pgd_next),
PGDIR_SIZE, PAGE_TABLE);
/* Map all memory banks */
for_each_memblock(memory, reg) {
start = reg->base;
end = start + reg->size;
if (start >= end)
break;
if (memblock_is_nomap(reg))
continue;
if (start <= __pa(PAGE_OFFSET) &&
__pa(PAGE_OFFSET) < end)
start = __pa(PAGE_OFFSET);
map_size = best_map_size(start, end - start);
for (pa = start; pa < end; pa += map_size) {
va = (uintptr_t)__va(pa);
create_pgd_mapping(swapper_pg_dir, va, pa,
map_size, PAGE_KERNEL_EXEC);
}
}
/* Clear fixmap PTE and PMD mappings */
clear_fixmap(FIX_PTE);
clear_fixmap(FIX_PMD);
/* Move to swapper page table */
csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
local_flush_tlb_all();
}
void __init paging_init(void)
{
setup_vm_final();
memblocks_present();
sparse_init();
setup_zero_page();
zone_sizes_init();
}
#ifdef CONFIG_SPARSEMEM_VMEMMAP
int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
struct vmem_altmap *altmap)
{
return vmemmap_populate_basepages(start, end, node);
}
#endif