alistair23-linux/arch/powerpc/mm/pgtable-book3e.c
Aneesh Kumar K.V dd1842a2a4 powerpc/mm: Make page table size a variable
Radix and hash MMU models support different page table sizes. Make
the #defines a variable so that existing code can work with variable
sizes.

Slice related code is only used by hash, so use hash constants there. We
will replicate some of the boundary conditions with resepct to TASK_SIZE
using radix values too. Right now we do boundary condition check using
hash constants.

Swapper pgdir size is initialized in asm code. We select the max pgd
size to keep it simple. For now we select hash pgdir. When adding radix
we will switch that to radix pgdir which is 64K.

BUILD_BUG_ON check which is removed is already done in hugepage_init()
using MAYBE_BUILD_BUG_ON().

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-05-01 18:32:48 +10:00

123 lines
3.2 KiB
C

/*
* Copyright 2005, Paul Mackerras, IBM Corporation.
* Copyright 2009, Benjamin Herrenschmidt, IBM Corporation.
* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <linux/memblock.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/dma.h>
#include "mmu_decl.h"
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
* On Book3E CPUs, the vmemmap is currently mapped in the top half of
* the vmalloc space using normal page tables, though the size of
* pages encoded in the PTEs can be different
*/
int __meminit vmemmap_create_mapping(unsigned long start,
unsigned long page_size,
unsigned long phys)
{
/* Create a PTE encoding without page size */
unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
_PAGE_KERNEL_RW;
/* PTEs only contain page size encodings up to 32M */
BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
/* Encode the size in the PTE */
flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
/* For each PTE for that area, map things. Note that we don't
* increment phys because all PTEs are of the large size and
* thus must have the low bits clear
*/
for (i = 0; i < page_size; i += PAGE_SIZE)
BUG_ON(map_kernel_page(start + i, phys, flags));
return 0;
}
#ifdef CONFIG_MEMORY_HOTPLUG
void vmemmap_remove_mapping(unsigned long start,
unsigned long page_size)
{
}
#endif
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
static __ref void *early_alloc_pgtable(unsigned long size)
{
void *pt;
pt = __va(memblock_alloc_base(size, size, __pa(MAX_DMA_ADDRESS)));
memset(pt, 0, size);
return pt;
}
/*
* map_kernel_page currently only called by __ioremap
* map_kernel_page adds an entry to the ioremap page table
* and adds an entry to the HPT, possibly bolting it
*/
int map_kernel_page(unsigned long ea, unsigned long pa, unsigned long flags)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
if (slab_is_available()) {
pgdp = pgd_offset_k(ea);
pudp = pud_alloc(&init_mm, pgdp, ea);
if (!pudp)
return -ENOMEM;
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
} else {
pgdp = pgd_offset_k(ea);
#ifndef __PAGETABLE_PUD_FOLDED
if (pgd_none(*pgdp)) {
pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
BUG_ON(pudp == NULL);
pgd_populate(&init_mm, pgdp, pudp);
}
#endif /* !__PAGETABLE_PUD_FOLDED */
pudp = pud_offset(pgdp, ea);
if (pud_none(*pudp)) {
pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
BUG_ON(pmdp == NULL);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (!pmd_present(*pmdp)) {
ptep = early_alloc_pgtable(PAGE_SIZE);
BUG_ON(ptep == NULL);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
}
smp_wmb();
return 0;
}