diff options
Diffstat (limited to 'kernel/arch/blackfin/include/asm/mmu_context.h')
| -rw-r--r-- | kernel/arch/blackfin/include/asm/mmu_context.h | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/kernel/arch/blackfin/include/asm/mmu_context.h b/kernel/arch/blackfin/include/asm/mmu_context.h new file mode 100644 index 000000000..15b16d3e8 --- /dev/null +++ b/kernel/arch/blackfin/include/asm/mmu_context.h @@ -0,0 +1,216 @@ +/* + * Copyright 2004-2009 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#ifndef __BLACKFIN_MMU_CONTEXT_H__ +#define __BLACKFIN_MMU_CONTEXT_H__ + +#include <linux/slab.h> +#include <linux/sched.h> +#include <asm/setup.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/cplbinit.h> +#include <asm/sections.h> + +/* Note: L1 stacks are CPU-private things, so we bluntly disable this + feature in SMP mode, and use the per-CPU scratch SRAM bank only to + store the PDA instead. */ + +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 free_l1stack(void) +{ + nr_l1stack_tasks--; + if (nr_l1stack_tasks == 0) { + l1sram_free(l1_stack_base); + l1_stack_base = NULL; + l1_stack_len = 0; + } +} + +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) +{ +#ifdef CONFIG_MPU + unsigned int cpu = smp_processor_id(); +#endif + if (prev_mm == next_mm) + return; +#ifdef CONFIG_MPU + if (prev_mm->context.page_rwx_mask == current_rwx_mask[cpu]) { + flush_switched_cplbs(cpu); + set_mask_dcplbs(next_mm->context.page_rwx_mask, cpu); + } +#endif + +#ifdef CONFIG_APP_STACK_L1 + /* 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); +#endif +} + +#ifdef CONFIG_IPIPE +#define lock_mm_switch(flags) flags = hard_local_irq_save_cond() +#define unlock_mm_switch(flags) hard_local_irq_restore_cond(flags) +#else +#define lock_mm_switch(flags) do { (void)(flags); } while (0) +#define unlock_mm_switch(flags) do { (void)(flags); } while (0) +#endif /* CONFIG_IPIPE */ + +#ifdef CONFIG_MPU +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + unsigned long flags; + lock_mm_switch(flags); + __switch_mm(prev, next, tsk); + unlock_mm_switch(flags); +} + +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; + unsigned long idx; + unsigned long bit; + + if (unlikely(addr >= ASYNC_BANK0_BASE && addr < ASYNC_BANK3_BASE + ASYNC_BANK3_SIZE)) + page = (addr - (ASYNC_BANK0_BASE - _ramend)) >> 12; + else + page = addr >> 12; + idx = page >> 5; + bit = 1 << (page & 31); + + if (flags & VM_READ) + mask[idx] |= bit; + else + mask[idx] &= ~bit; + mask += page_mask_nelts; + if (flags & VM_WRITE) + mask[idx] |= bit; + else + mask[idx] &= ~bit; + mask += page_mask_nelts; + if (flags & VM_EXEC) + mask[idx] |= bit; + else + mask[idx] &= ~bit; +} + +static inline void update_protections(struct mm_struct *mm) +{ + unsigned int cpu = smp_processor_id(); + if (mm->context.page_rwx_mask == current_rwx_mask[cpu]) { + flush_switched_cplbs(cpu); + set_mask_dcplbs(mm->context.page_rwx_mask, cpu); + } +} +#else /* !CONFIG_MPU */ +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + __switch_mm(prev, next, tsk); +} +#endif + +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 destroy_context(struct mm_struct *mm) +{ + struct sram_list_struct *tmp; +#ifdef CONFIG_MPU + unsigned int cpu = smp_processor_id(); +#endif + +#ifdef CONFIG_APP_STACK_L1 + if (current_l1_stack_save == mm->context.l1_stack_save) + current_l1_stack_save = 0; + if (mm->context.l1_stack_save) + free_l1stack(); +#endif + + 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[cpu] == mm->context.page_rwx_mask) + current_rwx_mask[cpu] = NULL; + free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order); +#endif +} + +#define ipipe_mm_switch_protect(flags) \ + flags = hard_local_irq_save_cond() + +#define ipipe_mm_switch_unprotect(flags) \ + hard_local_irq_restore_cond(flags) + +#endif |