149 lines
4.1 KiB
C
Executable file
149 lines
4.1 KiB
C
Executable file
/*
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* Page table support for the Hexagon architecture
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*
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* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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#ifndef _ASM_PGALLOC_H
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#define _ASM_PGALLOC_H
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#include <asm/mem-layout.h>
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#include <asm/atomic.h>
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#define check_pgt_cache() do {} while (0)
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extern unsigned long long kmap_generation;
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/*
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* Page table creation interface
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*/
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *pgd;
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pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
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/*
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* There may be better ways to do this, but to ensure
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* that new address spaces always contain the kernel
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* base mapping, and to ensure that the user area is
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* initially marked invalid, initialize the new map
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* map with a copy of the kernel's persistent map.
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*/
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memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t));
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mm->context.generation = kmap_generation;
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/* Physical version is what is passed to virtual machine on switch */
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mm->context.ptbase = __pa(pgd);
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return pgd;
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}
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static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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free_page((unsigned long) pgd);
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}
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static inline struct page *pte_alloc_one(struct mm_struct *mm,
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unsigned long address)
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{
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struct page *pte;
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pte = alloc_page(GFP_KERNEL | __GFP_ZERO);
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if (!pte)
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return NULL;
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if (!pgtable_page_ctor(pte)) {
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__free_page(pte);
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return NULL;
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}
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return pte;
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}
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/* _kernel variant gets to use a different allocator */
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static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
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unsigned long address)
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{
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gfp_t flags = GFP_KERNEL | __GFP_ZERO;
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return (pte_t *) __get_free_page(flags);
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}
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static inline void pte_free(struct mm_struct *mm, struct page *pte)
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{
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pgtable_page_dtor(pte);
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__free_page(pte);
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}
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static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
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{
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free_page((unsigned long)pte);
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}
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static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
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pgtable_t pte)
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{
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/*
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* Conveniently, zero in 3 LSB means indirect 4K page table.
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* Not so convenient when you're trying to vary the page size.
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*/
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set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |
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HEXAGON_L1_PTE_SIZE));
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}
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/*
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* Other architectures seem to have ways of making all processes
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* share the same pmd's for their kernel mappings, but the v0.3
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* Hexagon VM spec has a "monolithic" L1 table for user and kernel
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* segments. We track "generations" of the kernel map to minimize
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* overhead, and update the "slave" copies of the kernel mappings
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* as part of switch_mm. However, we still need to update the
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* kernel map of the active thread who's calling pmd_populate_kernel...
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*/
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static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
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pte_t *pte)
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{
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extern spinlock_t kmap_gen_lock;
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pmd_t *ppmd;
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int pmdindex;
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spin_lock(&kmap_gen_lock);
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kmap_generation++;
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mm->context.generation = kmap_generation;
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current->active_mm->context.generation = kmap_generation;
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spin_unlock(&kmap_gen_lock);
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set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
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/*
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* Now the "slave" copy of the current thread.
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* This is pointer arithmetic, not byte addresses!
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*/
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pmdindex = (pgd_t *)pmd - mm->pgd;
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ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;
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set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
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if (pmdindex > max_kernel_seg)
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max_kernel_seg = pmdindex;
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}
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#define __pte_free_tlb(tlb, pte, addr) \
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do { \
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pgtable_page_dtor((pte)); \
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tlb_remove_page((tlb), (pte)); \
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} while (0)
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#endif
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