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// SPDX-License-Identifier: GPL-2.0
/*
* PARISC64 Huge TLB page support.
*
* This parisc implementation is heavily based on the SPARC and x86 code.
*
* Copyright (C) 2015 Helge Deller <deller@gmx.de>
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/sysctl.h>
#include <asm/mman.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
unsigned long
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
if (len & ~huge_page_mask(h))
return -EINVAL;
if (len > TASK_SIZE)
return -ENOMEM;
if (flags & MAP_FIXED)
if (prepare_hugepage_range(file, addr, len))
return -EINVAL;
if (addr)
addr = ALIGN(addr, huge_page_size(h));
/* we need to make sure the colouring is OK */
return arch_get_unmapped_area(file, addr, len, pgoff, flags);
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
p4d_t *p4d;
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);
p4d = p4d_offset(pgd, addr);
pud = pud_alloc(mm, p4d, addr);
if (pud) {
pmd = pmd_alloc(mm, pud, addr);
if (pmd)
pte = pte_alloc_map(mm, pmd, addr);
}
return pte;
}
pte_t *huge_pte_offset(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
addr &= HPAGE_MASK;
pgd = pgd_offset(mm, addr);
if (!pgd_none(*pgd)) {
p4d = p4d_offset(pgd, addr);
if (!p4d_none(*p4d)) {
pud = pud_offset(p4d, addr);
if (!pud_none(*pud)) {
pmd = pmd_offset(pud, addr);
if (!pmd_none(*pmd))
pte = pte_offset_map(pmd, addr);
}
}
}
return pte;
}
/* Purge data and instruction TLB entries. Must be called holding
* the pa_tlb_lock. The TLB purge instructions are slow on SMP
* machines since the purge must be broadcast to all CPUs.
*/
static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr)
{
int i;
/* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate
* Linux standard huge pages (e.g. 2 MB) */
BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT);
addr &= HPAGE_MASK;
addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT;
for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) {
purge_tlb_entries(mm, addr);
addr += (1UL << REAL_HPAGE_SHIFT);
}
}
/* __set_huge_pte_at() must be called holding the pa_tlb_lock. */
static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t entry)
{
unsigned long addr_start;
int i;
addr &= HPAGE_MASK;
addr_start = addr;
for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
set_pte(ptep, entry);
ptep++;
addr += PAGE_SIZE;
pte_val(entry) += PAGE_SIZE;
}
purge_tlb_entries_huge(mm, addr_start);
}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t entry)
{
unsigned long flags;
spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
__set_huge_pte_at(mm, addr, ptep, entry);
spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
unsigned long flags;
pte_t entry;
spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
entry = *ptep;
__set_huge_pte_at(mm, addr, ptep, __pte(0));
spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
return entry;
}
void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
unsigned long flags;
pte_t old_pte;
spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
old_pte = *ptep;
__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
}
int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t pte, int dirty)
{
unsigned long flags;
int changed;
struct mm_struct *mm = vma->vm_mm;
spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags);
changed = !pte_same(*ptep, pte);
if (changed) {
__set_huge_pte_at(mm, addr, ptep, pte);
}
spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags);
return changed;
}
int pmd_huge(pmd_t pmd)
{
return 0;
}
int pud_huge(pud_t pud)
{
return 0;
}
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