linux/arch/parisc/mm/hugetlbpage.c

162 lines
3.4 KiB
C

/*
* 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/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/sysctl.h>
#include <asm/mman.h>
#include <asm/pgalloc.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;
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, NULL, pmd, addr);
}
return pte;
}
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;
addr &= HPAGE_MASK;
pgd = pgd_offset(mm, addr);
if (!pgd_none(*pgd)) {
pud = pud_offset(pgd, 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++) {
mtsp(mm->context, 1);
pdtlb(addr);
if (unlikely(split_tlb))
pitlb(addr);
addr += (1UL << REAL_HPAGE_SHIFT);
}
}
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++) {
/* Directly write pte entry. We could call set_pte_at(mm, addr, ptep, entry)
* instead, but then we get double locking on pa_tlb_lock. */
*ptep = entry;
ptep++;
/* Drop the PAGE_SIZE/non-huge tlb entry */
purge_tlb_entries(mm, addr);
addr += PAGE_SIZE;
pte_val(entry) += PAGE_SIZE;
}
purge_tlb_entries_huge(mm, addr_start);
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
pte_t entry;
entry = *ptep;
set_huge_pte_at(mm, addr, ptep, __pte(0));
return entry;
}
int pmd_huge(pmd_t pmd)
{
return 0;
}
int pud_huge(pud_t pud)
{
return 0;
}