1 #include <linux/init.h> 2 3 #include <asm/idmap.h> 4 #include <asm/pgalloc.h> 5 #include <asm/pgtable.h> 6 #include <asm/memory.h> 7 #include <asm/suspend.h> 8 #include <asm/tlbflush.h> 9 10 extern int __cpu_suspend(unsigned long, int (*)(unsigned long)); 11 extern void cpu_resume_mmu(void); 12 13 /* 14 * This is called by __cpu_suspend() to save the state, and do whatever 15 * flushing is required to ensure that when the CPU goes to sleep we have 16 * the necessary data available when the caches are not searched. 17 */ 18 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) 19 { 20 u32 *ctx = ptr; 21 22 *save_ptr = virt_to_phys(ptr); 23 24 /* This must correspond to the LDM in cpu_resume() assembly */ 25 *ptr++ = virt_to_phys(idmap_pgd); 26 *ptr++ = sp; 27 *ptr++ = virt_to_phys(cpu_do_resume); 28 29 cpu_do_suspend(ptr); 30 31 flush_cache_louis(); 32 33 /* 34 * flush_cache_louis does not guarantee that 35 * save_ptr and ptr are cleaned to main memory, 36 * just up to the Level of Unification Inner Shareable. 37 * Since the context pointer and context itself 38 * are to be retrieved with the MMU off that 39 * data must be cleaned from all cache levels 40 * to main memory using "area" cache primitives. 41 */ 42 __cpuc_flush_dcache_area(ctx, ptrsz); 43 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); 44 45 outer_clean_range(*save_ptr, *save_ptr + ptrsz); 46 outer_clean_range(virt_to_phys(save_ptr), 47 virt_to_phys(save_ptr) + sizeof(*save_ptr)); 48 } 49 50 /* 51 * Hide the first two arguments to __cpu_suspend - these are an implementation 52 * detail which platform code shouldn't have to know about. 53 */ 54 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 55 { 56 struct mm_struct *mm = current->active_mm; 57 int ret; 58 59 if (!idmap_pgd) 60 return -EINVAL; 61 62 /* 63 * Provide a temporary page table with an identity mapping for 64 * the MMU-enable code, required for resuming. On successful 65 * resume (indicated by a zero return code), we need to switch 66 * back to the correct page tables. 67 */ 68 ret = __cpu_suspend(arg, fn); 69 if (ret == 0) { 70 cpu_switch_mm(mm->pgd, mm); 71 local_flush_tlb_all(); 72 } 73 74 return ret; 75 } 76