/* SPDX-License-Identifier: GPL-2.0-only */
|
/*
|
* Page table support for the Hexagon architecture
|
*
|
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
|
*/
|
|
#ifndef _ASM_PGALLOC_H
|
#define _ASM_PGALLOC_H
|
|
#include <asm/mem-layout.h>
|
#include <asm/atomic.h>
|
|
#include <asm-generic/pgalloc.h>
|
|
extern unsigned long long kmap_generation;
|
|
/*
|
* Page table creation interface
|
*/
|
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
|
{
|
pgd_t *pgd;
|
|
pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
|
|
/*
|
* There may be better ways to do this, but to ensure
|
* that new address spaces always contain the kernel
|
* base mapping, and to ensure that the user area is
|
* initially marked invalid, initialize the new map
|
* map with a copy of the kernel's persistent map.
|
*/
|
|
memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t));
|
mm->context.generation = kmap_generation;
|
|
/* Physical version is what is passed to virtual machine on switch */
|
mm->context.ptbase = __pa(pgd);
|
|
return pgd;
|
}
|
|
static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
|
pgtable_t pte)
|
{
|
/*
|
* Conveniently, zero in 3 LSB means indirect 4K page table.
|
* Not so convenient when you're trying to vary the page size.
|
*/
|
set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |
|
HEXAGON_L1_PTE_SIZE));
|
}
|
|
/*
|
* Other architectures seem to have ways of making all processes
|
* share the same pmd's for their kernel mappings, but the v0.3
|
* Hexagon VM spec has a "monolithic" L1 table for user and kernel
|
* segments. We track "generations" of the kernel map to minimize
|
* overhead, and update the "slave" copies of the kernel mappings
|
* as part of switch_mm. However, we still need to update the
|
* kernel map of the active thread who's calling pmd_populate_kernel...
|
*/
|
static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
|
pte_t *pte)
|
{
|
extern spinlock_t kmap_gen_lock;
|
pmd_t *ppmd;
|
int pmdindex;
|
|
spin_lock(&kmap_gen_lock);
|
kmap_generation++;
|
mm->context.generation = kmap_generation;
|
current->active_mm->context.generation = kmap_generation;
|
spin_unlock(&kmap_gen_lock);
|
|
set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
|
|
/*
|
* Now the "slave" copy of the current thread.
|
* This is pointer arithmetic, not byte addresses!
|
*/
|
pmdindex = (pgd_t *)pmd - mm->pgd;
|
ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;
|
set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
|
if (pmdindex > max_kernel_seg)
|
max_kernel_seg = pmdindex;
|
}
|
|
#define __pte_free_tlb(tlb, pte, addr) \
|
do { \
|
pgtable_pte_page_dtor((pte)); \
|
tlb_remove_page((tlb), (pte)); \
|
} while (0)
|
|
#endif
|
