/* * File: include/asm-blackfin/mmu_context.h * Based on: * Author: * * Created: * Description: * * Modified: * Copyright 2004-2006 Analog Devices Inc. * * Bugs: Enter bugs at http://blackfin.uclinux.org/ * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see the file COPYING, or write * to the Free Software Foundation, Inc., * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef __BLACKFIN_MMU_CONTEXT_H__ #define __BLACKFIN_MMU_CONTEXT_H__ #include <linux/gfp.h> #include <linux/sched.h> #include <asm/setup.h> #include <asm/page.h> #include <asm/pgalloc.h> #include <asm/cplbinit.h> extern void *current_l1_stack_save; extern int nr_l1stack_tasks; extern void *l1_stack_base; extern unsigned long l1_stack_len; extern int l1sram_free(const void*); extern void *l1sram_alloc_max(void*); static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) { } /* Called when creating a new context during fork() or execve(). */ static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { #ifdef CONFIG_MPU unsigned long p = __get_free_pages(GFP_KERNEL, page_mask_order); mm->context.page_rwx_mask = (unsigned long *)p; memset(mm->context.page_rwx_mask, 0, page_mask_nelts * 3 * sizeof(long)); #endif return 0; } static inline void free_l1stack(void) { nr_l1stack_tasks--; if (nr_l1stack_tasks == 0) l1sram_free(l1_stack_base); } static inline void destroy_context(struct mm_struct *mm) { struct sram_list_struct *tmp; if (current_l1_stack_save == mm->context.l1_stack_save) current_l1_stack_save = 0; if (mm->context.l1_stack_save) free_l1stack(); while ((tmp = mm->context.sram_list)) { mm->context.sram_list = tmp->next; sram_free(tmp->addr); kfree(tmp); } #ifdef CONFIG_MPU if (current_rwx_mask == mm->context.page_rwx_mask) current_rwx_mask = NULL; free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order); #endif } static inline unsigned long alloc_l1stack(unsigned long length, unsigned long *stack_base) { if (nr_l1stack_tasks == 0) { l1_stack_base = l1sram_alloc_max(&l1_stack_len); if (!l1_stack_base) return 0; } if (l1_stack_len < length) { if (nr_l1stack_tasks == 0) l1sram_free(l1_stack_base); return 0; } *stack_base = (unsigned long)l1_stack_base; nr_l1stack_tasks++; return l1_stack_len; } static inline int activate_l1stack(struct mm_struct *mm, unsigned long sp_base) { if (current_l1_stack_save) memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len); mm->context.l1_stack_save = current_l1_stack_save = (void*)sp_base; memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len); return 1; } #define deactivate_mm(tsk,mm) do { } while (0) #define activate_mm(prev, next) switch_mm(prev, next, NULL) static inline void switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm, struct task_struct *tsk) { if (prev_mm == next_mm) return; #ifdef CONFIG_MPU if (prev_mm->context.page_rwx_mask == current_rwx_mask) { flush_switched_cplbs(); set_mask_dcplbs(next_mm->context.page_rwx_mask); } #endif /* L1 stack switching. */ if (!next_mm->context.l1_stack_save) return; if (next_mm->context.l1_stack_save == current_l1_stack_save) return; if (current_l1_stack_save) { memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len); } current_l1_stack_save = next_mm->context.l1_stack_save; memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len); } #ifdef CONFIG_MPU static inline void protect_page(struct mm_struct *mm, unsigned long addr, unsigned long flags) { unsigned long *mask = mm->context.page_rwx_mask; unsigned long page = addr >> 12; unsigned long idx = page >> 5; unsigned long bit = 1 << (page & 31); if (flags & VM_MAYREAD) mask[idx] |= bit; else mask[idx] &= ~bit; mask += page_mask_nelts; if (flags & VM_MAYWRITE) mask[idx] |= bit; else mask[idx] &= ~bit; mask += page_mask_nelts; if (flags & VM_MAYEXEC) mask[idx] |= bit; else mask[idx] &= ~bit; } static inline void update_protections(struct mm_struct *mm) { flush_switched_cplbs(); set_mask_dcplbs(mm->context.page_rwx_mask); } #endif #endif