/*
* Map the 32bit vsyscall page on demand.
*
* RED-PEN: This knows too much about high level VM.
*
* Alternative would be to generate a vma with appropriate backing options
* and let it be handled by generic VM.
*/
int __map_syscall32(struct mm_struct *mm, unsigned long address)
{
pgd_t *pgd;
pud_t *pud;
pte_t *pte;
pmd_t *pmd;
int err = -ENOMEM;
spin_lock(&mm->page_table_lock);
pgd = pgd_offset(mm, address);
pud = pud_alloc(mm, pgd, address);
if (pud) {
pmd = pmd_alloc(mm, pud, address);
if (pmd && (pte = pte_alloc_map(mm, pmd, address)) != NULL) {
if (pte_none(*pte)) {
set_pte(pte,
mk_pte(virt_to_page(syscall32_page),
PAGE_KERNEL_VSYSCALL32));
}
/* Flush only the local CPU. Other CPUs taking a fault
will just end up here again
This probably not needed and just paranoia. */
__flush_tlb_one(address);
err = 0;
}
}
spin_unlock(&mm->page_table_lock);
return err;
}
static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
unsigned long kernel)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(mm, proc);
pud = pud_alloc(mm, pgd, proc);
if (!pud)
goto out;
pmd = pmd_alloc(mm, pud, proc);
if (!pmd)
goto out_pmd;
pte = pte_alloc_map(mm, NULL, pmd, proc);
if (!pte)
goto out_pte;
*pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
*pte = pte_mkread(*pte);
return 0;
out_pte:
pmd_free(mm, pmd);
out_pmd:
pud_free(mm, pud);
out:
return -ENOMEM;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
pud_t *pud;
addr &= -sz; /* Mask off any low bits in the address. */
pgd = pgd_offset(mm, addr);
pud = pud_alloc(mm, pgd, addr);
#ifdef CONFIG_HUGETLB_SUPER_PAGES
if (sz >= PGDIR_SIZE) {
BUG_ON(sz != PGDIR_SIZE &&
sz != PGDIR_SIZE << huge_shift[HUGE_SHIFT_PGDIR]);
return (pte_t *)pud;
} else {
pmd_t *pmd = pmd_alloc(mm, pud, addr);
if (sz >= PMD_SIZE) {
BUG_ON(sz != PMD_SIZE &&
sz != (PMD_SIZE << huge_shift[HUGE_SHIFT_PMD]));
return (pte_t *)pmd;
}
else {
if (sz != PAGE_SIZE << huge_shift[HUGE_SHIFT_PAGE])
panic("Unexpected page size %#lx\n", sz);
return pte_alloc_map(mm, NULL, pmd, addr);
}
}
#else
BUG_ON(sz != PMD_SIZE);
return (pte_t *) pmd_alloc(mm, pud, addr);
#endif
}
/*
* need to get a 16k page for level 1
*/
pgd_t *get_pgd_slow(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
unsigned long flags;
new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
/*
* Copy over the kernel and IO PGD entries
*/
init_pgd = pgd_offset_k(0);
pgd_list_lock(flags);
memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
(PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
pgd_list_add(new_pgd);
pgd_list_unlock(flags);
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
if (!vectors_high()) {
#ifdef CONFIG_ARM_FCSE
/* FCSE does not work without high vectors. */
BUG();
#endif /* CONFIG_ARM_FCSE */
/*
* On ARM, first page must always be allocated since it
* contains the machine vectors.
*/
new_pmd = pmd_alloc(mm, new_pgd, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pmd = pmd_offset(init_pgd, 0);
init_pte = pte_offset_map_nested(init_pmd, 0);
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap_nested(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
free_pages((unsigned long)new_pgd, 2);
no_pgd:
return NULL;
}
/*
* need to get a 16k page for level 1
*/
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pud_t *new_pud, *init_pud;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
/*
* Copy over the kernel and IO PGD entries
*/
init_pgd = pgd_offset_k(0);
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
if (!vectors_high()) {
/*
* On ARM, first page must always be allocated since it
* contains the machine vectors.
*/
new_pud = pud_alloc(mm, new_pgd, 0);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pud = pud_offset(init_pgd, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
pud_free(mm, new_pud);
no_pud:
free_pages((unsigned long)new_pgd, 2);
no_pgd:
return NULL;
}
static inline pte_t *alloc_one_pte_map(struct mm_struct *mm, unsigned long addr)
{
pmd_t * pmd;
pte_t * pte = NULL;
pmd = pmd_alloc(mm, pgd_offset(mm, addr), addr);
if (pmd)
pte = pte_alloc_map(mm, pmd, addr);
return pte;
}
/*
* get_pgd_slow:申请一个pgd项
* notice:一个pgd占用4个页框,每一个pgt项大小为8字节
*/
pgd_t *get_pgd_slow(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
/*pgd占用四个页框*/
new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
/*
* 复制内核与I/O PGD entries
*/
init_pgd = pgd_offset_k(0);
memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
(PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
if (!vectors_high()) {
/*
* On ARM, first page must always be allocated since it
* contains the machine vectors.
*/
new_pmd = pmd_alloc(mm, new_pgd, 0);
if (!new_pmd)
goto no_pmd;
/*返回pmd的第0项页表项,因为第0项用于映射中断向量*/
new_pte = pte_alloc_map(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
/*返回中断向量的页表项,中断向量位于低地址空间时(0地址开始处)*/
init_pmd = pmd_offset(init_pgd, 0);
init_pte = pte_offset_map_nested(init_pmd, 0);
/*给新的页表项映射中断向量的页表项*/
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap_nested(init_pte);
/*取消new_pte的高端内存的页表映射*/
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
free_pages((unsigned long)new_pgd, 2);
no_pgd:
return NULL;
}
static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
unsigned long kernel)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(mm, proc);
pud = pud_alloc(mm, pgd, proc);
if (!pud)
goto out;
pmd = pmd_alloc(mm, pud, proc);
if (!pmd)
goto out_pmd;
pte = pte_alloc_map(mm, pmd, proc);
if (!pte)
goto out_pte;
/* There's an interaction between the skas0 stub pages, stack
* randomization, and the BUG at the end of exit_mmap. exit_mmap
* checks that the number of page tables freed is the same as had
* been allocated. If the stack is on the last page table page,
* then the stack pte page will be freed, and if not, it won't. To
* avoid having to know where the stack is, or if the process mapped
* something at the top of its address space for some other reason,
* we set TASK_SIZE to end at the start of the last page table.
* This keeps exit_mmap off the last page, but introduces a leak
* of that page. So, we hang onto it here and free it in
* destroy_context_skas.
*/
mm->context.skas.last_page_table = pmd_page_kernel(*pmd);
#ifdef CONFIG_3_LEVEL_PGTABLES
mm->context.skas.last_pmd = (unsigned long) __va(pud_val(*pud));
#endif
*pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
*pte = pte_mkexec(*pte);
*pte = pte_wrprotect(*pte);
return(0);
out_pmd:
pud_free(pud);
out_pte:
pmd_free(pmd);
out:
return(-ENOMEM);
}
pgd_t *get_pgd_slow(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = alloc_pgd_table();
if (!new_pgd)
goto no_pgd;
/*
* On ARM, first page must always be allocated since it contains
* the machine vectors.
*/
new_pmd = pmd_alloc(mm, new_pgd, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pgd = pgd_offset(&init_mm, 0);
init_pmd = pmd_offset(init_pgd, 0);
init_pte = pte_offset(init_pmd, 0);
set_pte(new_pte, *init_pte);
pte_unmap(new_pte);
/*
* the page table entries are zeroed
* when the table is created. (see the cache_ctor functions below)
* Now we need to plonk the kernel (vmalloc) area at the end of
* the address space. We copy this from the init thread, just like
* the init_pte we copied above...
*/
memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
(PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
/* update MEMC tables */
cpu_memc_update_all(new_pgd);
return new_pgd;
no_pte:
pmd_free(new_pmd);
no_pmd:
free_pgd_slow(new_pgd);
no_pgd:
return NULL;
}
pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, addr);
if (pgd) {
pmd = pmd_alloc(mm, pgd, addr);
if (pmd)
pte = pte_alloc_map(mm, pmd, addr);
}
return pte;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(mm, addr);
pud = pud_offset(pgd, addr);
pmd = pmd_offset(pud, addr);
pte = pte_alloc_map(mm, pmd, addr);
pgd->pgd &= ~_PAGE_SZ_MASK;
pgd->pgd |= _PAGE_SZHUGE;
return pte;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
pud_t *pud;
pte_t *pte = NULL;
pr_debug("%s: addr:0x%lx sz:0x%lx\n", __func__, addr, sz);
pgd = pgd_offset(mm, addr);
pud = pud_alloc(mm, pgd, addr);
if (!pud)
return NULL;
if (sz == PUD_SIZE) {
pte = (pte_t *)pud;
} else if (sz == (PAGE_SIZE * CONT_PTES)) {
pmd_t *pmd = pmd_alloc(mm, pud, addr);
WARN_ON(addr & (sz - 1));
/*
* Note that if this code were ever ported to the
* 32-bit arm platform then it will cause trouble in
* the case where CONFIG_HIGHPTE is set, since there
* will be no pte_unmap() to correspond with this
* pte_alloc_map().
*/
pte = pte_alloc_map(mm, pmd, addr);
} else if (sz == PMD_SIZE) {
if (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) &&
pud_none(*pud))
pte = huge_pmd_share(mm, addr, pud);
else
pte = (pte_t *)pmd_alloc(mm, pud, addr);
} else if (sz == (PMD_SIZE * CONT_PMDS)) {
pmd_t *pmd;
pmd = pmd_alloc(mm, pud, addr);
WARN_ON(addr & (sz - 1));
return (pte_t *)pmd;
}
pr_debug("%s: addr:0x%lx sz:0x%lx ret pte=%p/0x%llx\n", __func__, addr,
sz, pte, pte_val(*pte));
return pte;
}
pte_t *
huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, taddr);
pud = pud_alloc(mm, pgd, taddr);
if (pud) {
pmd = pmd_alloc(mm, pud, taddr);
if (pmd)
pte = pte_alloc_map(mm, pmd, taddr);
}
return pte;
}
static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
unsigned long offset, pgprot_t prot, int space)
{
unsigned long end;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
offset -= address;
do {
pte_t * pte = pte_alloc_map(mm, pmd, address);
if (!pte)
return -ENOMEM;
io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
} while (address < end);
return 0;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep = NULL;
pgdp = pgd_offset(mm, addr);
pudp = pud_alloc(mm, pgdp, addr);
if (!pudp)
return NULL;
if (sz == PUD_SIZE) {
ptep = (pte_t *)pudp;
} else if (sz == (PAGE_SIZE * CONT_PTES)) {
pmdp = pmd_alloc(mm, pudp, addr);
WARN_ON(addr & (sz - 1));
/*
* Note that if this code were ever ported to the
* 32-bit arm platform then it will cause trouble in
* the case where CONFIG_HIGHPTE is set, since there
* will be no pte_unmap() to correspond with this
* pte_alloc_map().
*/
ptep = pte_alloc_map(mm, pmdp, addr);
} else if (sz == PMD_SIZE) {
if (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) &&
pud_none(READ_ONCE(*pudp)))
ptep = huge_pmd_share(mm, addr, pudp);
else
ptep = (pte_t *)pmd_alloc(mm, pudp, addr);
} else if (sz == (PMD_SIZE * CONT_PMDS)) {
pmdp = pmd_alloc(mm, pudp, addr);
WARN_ON(addr & (sz - 1));
return (pte_t *)pmdp;
}
return ptep;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz,
bool *shared)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, addr);
if (pgd) {
pud = pud_alloc(mm, pgd, addr);
if (pud) {
pmd = pmd_alloc(mm, pud, addr);
if (pmd)
pte = pte_alloc_map(mm, pmd, addr);
}
}
return pte;
}
static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
pgprot_t prot)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = pgd_offset(&tboot_mm, vaddr);
pud = pud_alloc(&tboot_mm, pgd, vaddr);
if (!pud)
return -1;
pmd = pmd_alloc(&tboot_mm, pud, vaddr);
if (!pmd)
return -1;
pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
if (!pte)
return -1;
set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
pte_unmap(pte);
return 0;
}
/*
* Map the 32bit vsyscall page on demand.
*
* RED-PEN: This knows too much about high level VM.
*
* Alternative would be to generate a vma with appropriate backing options
* and let it be handled by generic VM.
*/
int __map_syscall32(struct mm_struct *mm, unsigned long address)
{
pte_t *pte;
pmd_t *pmd;
int err = 0;
spin_lock(&mm->page_table_lock);
pmd = pmd_alloc(mm, pgd_offset(mm, address), address);
if (pmd && (pte = pte_alloc_map(mm, pmd, address)) != NULL) {
if (pte_none(*pte)) {
set_pte(pte,
mk_pte(virt_to_page(syscall32_page),
PAGE_KERNEL_VSYSCALL));
}
/* Flush only the local CPU. Other CPUs taking a fault
will just end up here again */
__flush_tlb_one(address);
} else
err = -ENOMEM;
spin_unlock(&mm->page_table_lock);
return err;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
pgd = pgd_offset(mm, addr);
pud = pud_alloc(mm, pgd, addr);
if (pud) {
pmd = pmd_alloc(mm, pud, addr);
if (!pmd)
return NULL;
if (sz >= PMD_SIZE)
pte = (pte_t *)pmd;
else
pte = pte_alloc_map(mm, pmd, addr);
}
return pte;
}
pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
/* We must align the address, because our caller will run
* set_huge_pte_at() on whatever we return, which writes out
* all of the sub-ptes for the hugepage range. So we have
* to give it the first such sub-pte.
*/
addr &= HPAGE_MASK;
pgd = pgd_offset(mm, addr);
pud = pud_alloc(mm, pgd, addr);
if (pud) {
pmd = pmd_alloc(mm, pud, addr);
if (pmd)
pte = pte_alloc_map(mm, pmd, addr);
}
return pte;
}
/*
* need to get a 16k page for level 1
*/
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pud_t *new_pud, *init_pud;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = __pgd_alloc();
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
/*
* Copy over the kernel and IO PGD entries
*/
init_pgd = pgd_offset_k(0);
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
#ifdef CONFIG_ARM_LPAE
/*
* Allocate PMD table for modules and pkmap mappings.
*/
new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
MODULES_VADDR);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
#endif
if (!vectors_high()) {
/*
* On ARM, first page must always be allocated since it
* contains the machine vectors. The vectors are always high
* with LPAE.
*/
new_pud = pud_alloc(mm, new_pgd, 0);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
#ifndef CONFIG_ARM_LPAE
/*
* Modify the PTE pointer to have the correct domain. This
* needs to be the vectors domain to avoid the low vectors
* being unmapped.
*/
pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;
pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
#endif
init_pud = pud_offset(init_pgd, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);
set_pte_ext(new_pte + 0, init_pte[0], 0);
set_pte_ext(new_pte + 1, init_pte[1], 0);
pte_unmap(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
mm_dec_nr_pmds(mm);
no_pmd:
pud_free(mm, new_pud);
no_pud:
__pgd_free(new_pgd);
no_pgd:
return NULL;
}
/*
* need to get a 16k page for level 1
*/
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pud_t *new_pud, *init_pud;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
#if defined(CONFIG_SYNO_ARMADA_ARCH)
new_pgd = __pgd_alloc();
#elif defined(CONFIG_SYNO_COMCERTO)
new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, get_order(16384));
#else
new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
#endif
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
/*
* Copy over the kernel and IO PGD entries
*/
init_pgd = pgd_offset_k(0);
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
#if defined(CONFIG_SYNO_ARMADA_ARCH) && defined(CONFIG_ARM_LPAE)
/*
* Allocate PMD table for modules and pkmap mappings.
*/
new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
MODULES_VADDR);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
#endif
if (!vectors_high()) {
/*
* On ARM, first page must always be allocated since it
#if defined(CONFIG_SYNO_ARMADA_ARCH)
* contains the machine vectors. The vectors are always high
* with LPAE.
#else
* contains the machine vectors.
#endif
*/
new_pud = pud_alloc(mm, new_pgd, 0);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pud = pud_offset(init_pgd, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
pud_free(mm, new_pud);
no_pud:
#if defined(CONFIG_SYNO_ARMADA_ARCH)
__pgd_free(new_pgd);
#elif defined(CONFIG_SYNO_COMCERTO)
free_pages((unsigned long)new_pgd, get_order(16384));
#else
free_pages((unsigned long)new_pgd, 2);
#endif
no_pgd:
return NULL;
}
/*
* need to get a 16k page for level 1
*/
pgd_t *get_pgd_slow(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, 2);
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, FIRST_KERNEL_PGD_NR * sizeof(pgd_t));
/*
* Copy over the kernel and IO PGD entries
*/
//#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
//其实就是要拷贝内核空间的页表项...
init_pgd = pgd_offset_k(0);
//拷贝内核空间的pgd表项到新创建的pgd表项
memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR,
(PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t));
//把Dcache行的数据写回到主存，并清除cache行的脏标记.
//参数:主存的物理地址,(确定cache行) 需要写回的长度...
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
//异常向量表是在高端地址或是在低端地址...
if (!vectors_high()) {
//如果是在低端地址.那么异常向量表在第一页..
/*
* On ARM, first page must always be allocated since it
* contains the machine vectors.
*/
//该函数是在new_pgd指定的PGD页表上找到地址0对应的表项，然后分配一个页.
//接着填充PGD的页表项(PMD).
//哦，好像略过了PUD了、对于ARM来说PMD也是直接返回pgd.
new_pmd = pmd_alloc(mm, new_pgd, 0);
if (!new_pmd)
goto no_pmd;
//如果为空则分配一个页面，然后设置PGD的页表项.
new_pte = pte_alloc_map(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
//init_pgd就是init进程的页表,这里得到地址0的PGD页表的表项(PMD)
init_pmd = pmd_offset(init_pgd, 0);
//根据init_pmd，得到了PMD页表，然后根据0地址得到了PMD的表项(PTE)
init_pte = pte_offset_map_nested(init_pmd, 0);
//new_pte指定了要存放PTE的地址，init_pte就是PTE的值。
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap_nested(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
free_pages((unsigned long)new_pgd, 2);
no_pgd:
return NULL;
}
/*
* need to get a 16k page for level 1
*/
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pud_t *new_pud, *init_pud;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = __pgd_alloc();
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
/*
* Copy over the kernel and IO PGD entries
*/
init_pgd = pgd_offset_k(0);
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
#ifdef CONFIG_ARM_LPAE
/*
* Allocate PMD table for modules and pkmap mappings.
*/
new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
MODULES_VADDR);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
#endif
if (!vectors_high()) {
/*
* On ARM, first page must always be allocated since it
* contains the machine vectors. The vectors are always high
* with LPAE.
*/
new_pud = pud_alloc(mm, new_pgd, 0);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pud = pud_offset(init_pgd, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
pud_free(mm, new_pud);
no_pud:
__pgd_free(new_pgd);
no_pgd:
return NULL;
}
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
pud_t *new_pud, *init_pud;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
new_pgd = __pgd_alloc();
if (!new_pgd)
goto no_pgd;
memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
init_pgd = pgd_offset_k(0);
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
#ifdef CONFIG_ARM_LPAE
new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
MODULES_VADDR);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
#endif
if (!vectors_high()) {
new_pud = pud_alloc(mm, new_pgd, 0);
if (!new_pud)
goto no_pud;
new_pmd = pmd_alloc(mm, new_pud, 0);
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
if (!new_pte)
goto no_pte;
init_pud = pud_offset(init_pgd, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);
set_pte_ext(new_pte, *init_pte, 0);
pte_unmap(init_pte);
pte_unmap(new_pte);
}
return new_pgd;
no_pte:
pmd_free(mm, new_pmd);
no_pmd:
pud_free(mm, new_pud);
no_pud:
__pgd_free(new_pgd);
no_pgd:
return NULL;
}
