diff options
Diffstat (limited to 'arch/blackfin/include/asm/mmu_context.h')
| -rw-r--r-- | arch/blackfin/include/asm/mmu_context.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/mmu_context.h b/arch/blackfin/include/asm/mmu_context.h new file mode 100644 index 000000000000..8529552a981f --- /dev/null +++ b/arch/blackfin/include/asm/mmu_context.h @@ -0,0 +1,183 @@ +/* + * 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 = NULL; + 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) +{ + if (mm->context.page_rwx_mask == current_rwx_mask) { + flush_switched_cplbs(); + set_mask_dcplbs(mm->context.page_rwx_mask); + } +} +#endif + +#endif |