// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mm/init.c
*
* Copyright (C) 1995-2005 Russell King
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/mman.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/export.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <linux/of_fdt.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/dma-map-ops.h>
#include <linux/sizes.h>
#include <linux/stop_machine.h>
#include <linux/swiotlb.h>
#include <linux/execmem.h>
#include <asm/cp15.h>
#include <asm/mach-types.h>
#include <asm/memblock.h>
#include <asm/page.h>
#include <asm/prom.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/set_memory.h>
#include <asm/system_info.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>
#include <asm/ptdump.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include "mm.h"
#ifdef CONFIG_CPU_CP15_MMU
unsigned long __init __clear_cr(unsigned long mask)
{
cr_alignment = cr_alignment & ~mask;
return cr_alignment;
}
#endif
#ifdef CONFIG_BLK_DEV_INITRD
static int __init parse_tag_initrd(const struct tag *tag)
{
pr_warn("ATAG_INITRD is deprecated; "
"please update your bootloader.\n");
phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
phys_initrd_size = tag->u.initrd.size;
return 0;
}
__tagtable(ATAG_INITRD, parse_tag_initrd);
static int __init parse_tag_initrd2(const struct tag *tag)
{
phys_initrd_start = tag->u.initrd.start;
phys_initrd_size = tag->u.initrd.size;
return 0;
}
__tagtable(ATAG_INITRD2, parse_tag_initrd2);
#endif
static void __init find_limits(unsigned long *min, unsigned long *max_low,
unsigned long *max_high)
{
*max_low = PFN_DOWN(memblock_get_current_limit());
*min = PFN_UP(memblock_start_of_DRAM());
*max_high = PFN_DOWN(memblock_end_of_DRAM());
}
#ifdef CONFIG_ZONE_DMA
phys_addr_t arm_dma_zone_size __read_mostly;
EXPORT_SYMBOL(arm_dma_zone_size);
/*
* The DMA mask corresponding to the maximum bus address allocatable
* using GFP_DMA. The default here places no restriction on DMA
* allocations. This must be the smallest DMA mask in the system,
* so a successful GFP_DMA allocation will always satisfy this.
*/
phys_addr_t arm_dma_limit;
unsigned long arm_dma_pfn_limit;
#endif
void __init setup_dma_zone(const struct machine_desc *mdesc)
{
#ifdef CONFIG_ZONE_DMA
if (mdesc->dma_zone_size) {
arm_dma_zone_size = mdesc->dma_zone_size;
arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
} else
arm_dma_limit = 0xffffffff;
arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
#endif
}
static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
unsigned long max_high)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
#ifdef CONFIG_ZONE_DMA
max_zone_pfn[ZONE_DMA] = min(arm_dma_pfn_limit, max_low);
#endif
max_zone_pfn[ZONE_NORMAL] = max_low;
#ifdef CONFIG_HIGHMEM
max_zone_pfn[ZONE_HIGHMEM] = max_high;
#endif
free_area_init(max_zone_pfn);
}
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
int pfn_valid(unsigned long pfn)
{
phys_addr_t addr = __pfn_to_phys(pfn);
unsigned long pageblock_size = PAGE_SIZE * pageblock_nr_pages;
if (__phys_to_pfn(addr) != pfn)
return 0;
/*
* If address less than pageblock_size bytes away from a present
* memory chunk there still will be a memory map entry for it
* because we round freed memory map to the pageblock boundaries.
*/
if (memblock_overlaps_region(&memblock.memory,
ALIGN_DOWN(addr, pageblock_size),
pageblock_size))
return 1;
return 0;
}
EXPORT_SYMBOL(pfn_valid);
#endif
static bool arm_memblock_steal_permitted = true;
phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
{
phys_addr_t phys;
BUG_ON(!arm_memblock_steal_permitted);
phys = memblock_phys_alloc(size, align);
if (!phys)
panic("Failed to steal %pa bytes at %pS\n",
&size, (void *)_RET_IP_);
memblock_phys_free(phys, size);
memblock_remove(phys, size);
return phys;
}
#ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
void check_cpu_icache_size(int cpuid)
{
u32 size, ctr;
asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
size = 1 << ((ctr & 0xf) + 2);
if (cpuid != 0 && icache_size != size)
pr_info("CPU%u: detected I-Cache line size mismatch, workaround enabled\n",
cpuid);
if (icache_size > size)
icache_size = size;
}
#endif
void __init arm_memblock_init(const struct machine_desc *mdesc)
{
/* Register the kernel text, kernel data and initrd with memblock. */
memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
reserve_initrd_mem();
arm_mm_memblock_reserve();
/* reserve any platform specific memblock areas */
if (mdesc->reserve)
mdesc->reserve();
early_init_fdt_scan_reserved_mem();
/* reserve memory for DMA contiguous allocations */
dma_contiguous_reserve(arm_dma_limit);
arm_memblock_steal_permitted = false;
memblock_dump_all();
}
void __init bootmem_init(void)
{
memblock_allow_resize();
find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
(phys_addr_t)max_low_pfn << PAGE_SHIFT);
/*
* sparse_init() tries to allocate memory from memblock, so must be
* done after the fixed reservations
*/
sparse_init();
/*
* Now free the memory - free_area_init needs
* the sparse mem_map arrays initialized by sparse_init()
* for memmap_init_zone(), otherwise all PFNs are invalid.
*/
zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn);
}
/*
* Poison init memory with an undefined instruction (ARM) or a branch to an
* undefined instruction (Thumb).
*/
static inline void poison_init_mem(void *s, size_t count)
{
u32 *p = (u32 *)s;
for (; count != 0; count -= 4)
*p++ = 0xe7fddef0;
}
static void __init free_highpages(void)
{
#ifdef CONFIG_HIGHMEM
unsigned long max_low = max_low_pfn;
phys_addr_t range_start, range_end;
u64 i;
/* set highmem page free */
for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
&range_start, &range_end, NULL) {
unsigned long start = PFN_UP(range_start);
unsigned long end = PFN_DOWN(range_end);
/* Ignore complete lowmem entries */
if (end <= max_low)
continue;
/* Truncate partial highmem entries */
if (start < max_low)
start = max_low;
for (; start < end; start++)
free_highmem_page(pfn_to_page(start));
}
#endif
}
/*
* mem_init() marks the free areas in the mem_map and tells us how much
* memory is free. This is done after various parts of the system have
* claimed their memory after the kernel image.
*/
void __init mem_init(void)
{
#ifdef CONFIG_ARM_LPAE
swiotlb_init(max_pfn > arm_dma_pfn_limit, SWIOTLB_VERBOSE);
#endif
set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
/* this will put all unused low memory onto the freelists */
memblock_free_all();
#ifdef CONFIG_SA1111
/* now that our DMA memory is actually so designated, we can free it */
free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
#endif
free_highpages();
/*
* Check boundaries twice: Some fundamental inconsistencies can
* be detected at build time already.
*/
#ifdef CONFIG_MMU
BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
BUG_ON(TASK_SIZE > MODULES_VADDR);
#endif
#ifdef CONFIG_HIGHMEM
BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
#endif
}
#ifdef CONFIG_STRICT_KERNEL_RWX
struct section_perm {
const char *name;
unsigned long start;
unsigned long end;
pmdval_t mask;
pmdval_t prot;
pmdval_t clear;
};
/* First section-aligned location at or after __start_rodata. */
extern char __start_rodata_section_aligned[];
static struct section_perm nx_perms[] = {
/* Make pages tables, etc before _stext RW (set NX). */
{
.name = "pre-text NX",
.start = PAGE_OFFSET,
.end = (unsigned long)_stext,
.mask = ~PMD_SECT_XN,
.prot = PMD_SECT_XN,
},
/* Make init RW (set NX). */
{
.name = "init NX",
.start = (unsigned long)__init_begin,
.end = (unsigned long)_sdata,
.mask = ~PMD_SECT_XN,
.prot = PMD_SECT_XN,
},
/* Make rodata NX (set RO in ro_perms below). */
{
.name = "rodata NX",
.start = (unsigned long)__start_rodata_section_aligned,
.end = (unsigned long)__init_begin,
.mask = ~PMD_SECT_XN,
.prot = PMD_SECT_XN,
},
};
static struct section_perm ro_perms[] = {
/* Make kernel code and rodata RX (set RO). */
{
.name = "text/rodata RO",
.start = (unsigned long)_stext,
.end = (unsigned long)__init_begin,
#ifdef CONFIG_ARM_LPAE
.mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
.prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
#else
.mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
.prot = PMD_SECT_APX | PMD_SECT_AP_WRITE,
.clear = PMD_SECT_AP_WRITE,
#endif
},
};
/*
* Updates section permissions only for the current mm (sections are
* copied into each mm). During startup, this is the init_mm. Is only
* safe to be called with preemption disabled, as under stop_machine().
*/
static inline void section_update(unsigned long addr, pmdval_t mask,
pmdval_t prot, struct mm_struct *mm)
{
pmd_t *pmd;
pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, addr), addr), addr), addr);
#ifdef CONFIG_ARM_LPAE
pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
#else
if (addr & SECTION_SIZE)
pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
else
pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
#endif
flush_pmd_entry(pmd);
local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
}
/* Make sure extended page tables are in use. */
static inline bool arch_has_strict_perms(void)
{
if (cpu_architecture() < CPU_ARCH_ARMv6)
return false;
return !!(get_cr() & CR_XP);
}
static void set_section_perms(struct section_perm *perms, int n, bool set,
struct mm_struct *mm)
{
size_t i;
unsigned long addr;
if (!arch_has_strict_perms())
return;
for (i = 0; i < n; i++) {
if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
!IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
perms[i].name, perms[i].start, perms[i].end,
SECTION_SIZE);
continue;
}
for (addr = perms[i].start;
addr < perms[i].end;
addr += SECTION_SIZE)
section_update(addr, perms[i].mask,
set ? perms[i].prot : perms[i].clear, mm);
}
}
/*
* update_sections_early intended to be called only through stop_machine
* framework and executed by only one CPU while all other CPUs will spin and
* wait, so no locking is required in this function.
*/
static void update_sections_early(struct section_perm perms[], int n)
{
struct task_struct *t, *s;
for_each_process(t) {
if (t->flags & PF_KTHREAD)
continue;
for_each_thread(t, s)
if (s->mm)
set_section_perms(perms, n, true, s->mm);
}
set_section_perms(perms, n, true, current->active_mm);
set_section_perms(perms, n, true, &init_mm);
}
static int __fix_kernmem_perms(void *unused)
{
update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
return 0;
}
static void fix_kernmem_perms(void)
{
stop_machine(__fix_kernmem_perms, NULL, NULL);
}
static int __mark_rodata_ro(void *unused)
{
update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
return 0;
}
void mark_rodata_ro(void)
{
stop_machine(__mark_rodata_ro, NULL, NULL);
arm_debug_checkwx();
}
#else
static inline void fix_kernmem_perms(void) { }
#endif /* CONFIG_STRICT_KERNEL_RWX */
void free_initmem(void)
{
fix_kernmem_perms();
poison_init_mem(__init_begin, __init_end - __init_begin);
if (!machine_is_integrator() && !machine_is_cintegrator())
free_initmem_default(-1);
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (start == initrd_start)
start = round_down(start, PAGE_SIZE);
if (end == initrd_end)
end = round_up(end, PAGE_SIZE);
poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
free_reserved_area((void *)start, (void *)end, -1, "initrd");
}
#endif
#ifdef CONFIG_EXECMEM
#ifdef CONFIG_XIP_KERNEL
/*
* The XIP kernel text is mapped in the module area for modules and
* some other stuff to work without any indirect relocations.
* MODULES_VADDR is redefined here and not in asm/memory.h to avoid
* recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
*/
#undef MODULES_VADDR
#define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
#endif
#ifdef CONFIG_MMU
static struct execmem_info execmem_info __ro_after_init;
struct execmem_info __init *execmem_arch_setup(void)
{
unsigned long fallback_start = 0, fallback_end = 0;
if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS)) {
fallback_start = VMALLOC_START;
fallback_end = VMALLOC_END;
}
execmem_info = (struct execmem_info){
.ranges = {
[EXECMEM_DEFAULT] = {
.start = MODULES_VADDR,
.end = MODULES_END,
.pgprot = PAGE_KERNEL_EXEC,
.alignment = 1,
.fallback_start = fallback_start,
.fallback_end = fallback_end,
},
},
};
return &execmem_info;
}
#endif /* CONFIG_MMU */
#endif /* CONFIG_EXECMEM */
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