182 lines
4.6 KiB
C
182 lines
4.6 KiB
C
/*
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* File: include/asm-blackfin/mmu_context.h
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* Based on:
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* Author:
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*
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* Created:
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* Description:
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef __BLACKFIN_MMU_CONTEXT_H__
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#define __BLACKFIN_MMU_CONTEXT_H__
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#include <linux/gfp.h>
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#include <linux/sched.h>
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#include <asm/setup.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include <asm/cplbinit.h>
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extern void *current_l1_stack_save;
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extern int nr_l1stack_tasks;
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extern void *l1_stack_base;
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extern unsigned long l1_stack_len;
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extern int l1sram_free(const void*);
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extern void *l1sram_alloc_max(void*);
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static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
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{
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}
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/* Called when creating a new context during fork() or execve(). */
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static inline int
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init_new_context(struct task_struct *tsk, struct mm_struct *mm)
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{
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#ifdef CONFIG_MPU
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unsigned long p = __get_free_pages(GFP_KERNEL, page_mask_order);
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mm->context.page_rwx_mask = (unsigned long *)p;
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memset(mm->context.page_rwx_mask, 0,
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page_mask_nelts * 3 * sizeof(long));
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#endif
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return 0;
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}
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static inline void free_l1stack(void)
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{
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nr_l1stack_tasks--;
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if (nr_l1stack_tasks == 0)
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l1sram_free(l1_stack_base);
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}
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static inline void destroy_context(struct mm_struct *mm)
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{
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struct sram_list_struct *tmp;
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if (current_l1_stack_save == mm->context.l1_stack_save)
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current_l1_stack_save = NULL;
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if (mm->context.l1_stack_save)
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free_l1stack();
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while ((tmp = mm->context.sram_list)) {
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mm->context.sram_list = tmp->next;
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sram_free(tmp->addr);
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kfree(tmp);
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}
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#ifdef CONFIG_MPU
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if (current_rwx_mask == mm->context.page_rwx_mask)
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current_rwx_mask = NULL;
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free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order);
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#endif
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}
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static inline unsigned long
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alloc_l1stack(unsigned long length, unsigned long *stack_base)
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{
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if (nr_l1stack_tasks == 0) {
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l1_stack_base = l1sram_alloc_max(&l1_stack_len);
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if (!l1_stack_base)
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return 0;
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}
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if (l1_stack_len < length) {
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if (nr_l1stack_tasks == 0)
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l1sram_free(l1_stack_base);
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return 0;
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}
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*stack_base = (unsigned long)l1_stack_base;
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nr_l1stack_tasks++;
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return l1_stack_len;
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}
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static inline int
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activate_l1stack(struct mm_struct *mm, unsigned long sp_base)
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{
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if (current_l1_stack_save)
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memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
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mm->context.l1_stack_save = current_l1_stack_save = (void*)sp_base;
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memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
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return 1;
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}
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#define deactivate_mm(tsk,mm) do { } while (0)
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#define activate_mm(prev, next) switch_mm(prev, next, NULL)
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static inline void switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
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struct task_struct *tsk)
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{
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if (prev_mm == next_mm)
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return;
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#ifdef CONFIG_MPU
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if (prev_mm->context.page_rwx_mask == current_rwx_mask) {
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flush_switched_cplbs();
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set_mask_dcplbs(next_mm->context.page_rwx_mask);
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}
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#endif
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/* L1 stack switching. */
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if (!next_mm->context.l1_stack_save)
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return;
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if (next_mm->context.l1_stack_save == current_l1_stack_save)
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return;
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if (current_l1_stack_save) {
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memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
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}
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current_l1_stack_save = next_mm->context.l1_stack_save;
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memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
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}
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#ifdef CONFIG_MPU
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static inline void protect_page(struct mm_struct *mm, unsigned long addr,
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unsigned long flags)
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{
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unsigned long *mask = mm->context.page_rwx_mask;
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unsigned long page = addr >> 12;
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unsigned long idx = page >> 5;
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unsigned long bit = 1 << (page & 31);
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if (flags & VM_MAYREAD)
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mask[idx] |= bit;
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else
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mask[idx] &= ~bit;
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mask += page_mask_nelts;
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if (flags & VM_MAYWRITE)
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mask[idx] |= bit;
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else
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mask[idx] &= ~bit;
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mask += page_mask_nelts;
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if (flags & VM_MAYEXEC)
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mask[idx] |= bit;
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else
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mask[idx] &= ~bit;
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}
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static inline void update_protections(struct mm_struct *mm)
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{
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flush_switched_cplbs();
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set_mask_dcplbs(mm->context.page_rwx_mask);
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}
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#endif
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#endif
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