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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <as-layout.h>
#include <mem_user.h>
#include <os.h>
#include <skas.h>
#include <kern_util.h>
struct vm_ops {
struct mm_id *mm_idp;
int (*mmap)(struct mm_id *mm_idp,
unsigned long virt, unsigned long len, int prot,
int phys_fd, unsigned long long offset);
int (*unmap)(struct mm_id *mm_idp,
unsigned long virt, unsigned long len);
int (*mprotect)(struct mm_id *mm_idp,
unsigned long virt, unsigned long len,
unsigned int prot);
};
static int kern_map(struct mm_id *mm_idp,
unsigned long virt, unsigned long len, int prot,
int phys_fd, unsigned long long offset)
{
/* TODO: Why is executable needed to be always set in the kernel? */
return os_map_memory((void *)virt, phys_fd, offset, len,
prot & UM_PROT_READ, prot & UM_PROT_WRITE,
1);
}
static int kern_unmap(struct mm_id *mm_idp,
unsigned long virt, unsigned long len)
{
return os_unmap_memory((void *)virt, len);
}
static int kern_mprotect(struct mm_id *mm_idp,
unsigned long virt, unsigned long len,
unsigned int prot)
{
return os_protect_memory((void *)virt, len,
prot & UM_PROT_READ, prot & UM_PROT_WRITE,
1);
}
void report_enomem(void)
{
printk(KERN_ERR "UML ran out of memory on the host side! "
"This can happen due to a memory limitation or "
"vm.max_map_count has been reached.\n");
}
static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long end,
struct vm_ops *ops)
{
pte_t *pte;
int r, w, x, prot, ret = 0;
pte = pte_offset_kernel(pmd, addr);
do {
r = pte_read(*pte);
w = pte_write(*pte);
x = pte_exec(*pte);
if (!pte_young(*pte)) {
r = 0;
w = 0;
} else if (!pte_dirty(*pte))
w = 0;
prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
(x ? UM_PROT_EXEC : 0));
if (pte_newpage(*pte)) {
if (pte_present(*pte)) {
__u64 offset;
unsigned long phys = pte_val(*pte) & PAGE_MASK;
int fd = phys_mapping(phys, &offset);
ret = ops->mmap(ops->mm_idp, addr, PAGE_SIZE,
prot, fd, offset);
} else
ret = ops->unmap(ops->mm_idp, addr, PAGE_SIZE);
} else if (pte_newprot(*pte))
ret = ops->mprotect(ops->mm_idp, addr, PAGE_SIZE, prot);
*pte = pte_mkuptodate(*pte);
} while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
return ret;
}
static inline int update_pmd_range(pud_t *pud, unsigned long addr,
unsigned long end,
struct vm_ops *ops)
{
pmd_t *pmd;
unsigned long next;
int ret = 0;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (!pmd_present(*pmd)) {
if (pmd_newpage(*pmd)) {
ret = ops->unmap(ops->mm_idp, addr,
next - addr);
pmd_mkuptodate(*pmd);
}
}
else ret = update_pte_range(pmd, addr, next, ops);
} while (pmd++, addr = next, ((addr < end) && !ret));
return ret;
}
static inline int update_pud_range(p4d_t *p4d, unsigned long addr,
unsigned long end,
struct vm_ops *ops)
{
pud_t *pud;
unsigned long next;
int ret = 0;
pud = pud_offset(p4d, addr);
do {
next = pud_addr_end(addr, end);
if (!pud_present(*pud)) {
if (pud_newpage(*pud)) {
ret = ops->unmap(ops->mm_idp, addr,
next - addr);
pud_mkuptodate(*pud);
}
}
else ret = update_pmd_range(pud, addr, next, ops);
} while (pud++, addr = next, ((addr < end) && !ret));
return ret;
}
static inline int update_p4d_range(pgd_t *pgd, unsigned long addr,
unsigned long end,
struct vm_ops *ops)
{
p4d_t *p4d;
unsigned long next;
int ret = 0;
p4d = p4d_offset(pgd, addr);
do {
next = p4d_addr_end(addr, end);
if (!p4d_present(*p4d)) {
if (p4d_newpage(*p4d)) {
ret = ops->unmap(ops->mm_idp, addr,
next - addr);
p4d_mkuptodate(*p4d);
}
} else
ret = update_pud_range(p4d, addr, next, ops);
} while (p4d++, addr = next, ((addr < end) && !ret));
return ret;
}
int um_tlb_sync(struct mm_struct *mm)
{
pgd_t *pgd;
struct vm_ops ops;
unsigned long addr = mm->context.sync_tlb_range_from, next;
int ret = 0;
if (mm->context.sync_tlb_range_to == 0)
return 0;
ops.mm_idp = &mm->context.id;
if (mm == &init_mm) {
ops.mmap = kern_map;
ops.unmap = kern_unmap;
ops.mprotect = kern_mprotect;
} else {
ops.mmap = map;
ops.unmap = unmap;
ops.mprotect = protect;
}
pgd = pgd_offset(mm, addr);
do {
next = pgd_addr_end(addr, mm->context.sync_tlb_range_to);
if (!pgd_present(*pgd)) {
if (pgd_newpage(*pgd)) {
ret = ops.unmap(ops.mm_idp, addr,
next - addr);
pgd_mkuptodate(*pgd);
}
} else
ret = update_p4d_range(pgd, addr, next, &ops);
} while (pgd++, addr = next,
((addr < mm->context.sync_tlb_range_to) && !ret));
if (ret == -ENOMEM)
report_enomem();
mm->context.sync_tlb_range_from = 0;
mm->context.sync_tlb_range_to = 0;
return ret;
}
void flush_tlb_all(void)
{
/*
* Don't bother flushing if this address space is about to be
* destroyed.
*/
if (atomic_read(¤t->mm->mm_users) == 0)
return;
flush_tlb_mm(current->mm);
}
void flush_tlb_mm(struct mm_struct *mm)
{
struct vm_area_struct *vma;
VMA_ITERATOR(vmi, mm, 0);
for_each_vma(vmi, vma)
um_tlb_mark_sync(mm, vma->vm_start, vma->vm_end);
}
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