1 #include <linux/init.h> 2 #include <linux/slab.h> 3 #include <linux/mm_types.h> 4 5 #include <asm/cacheflush.h> 6 #include <asm/idmap.h> 7 #include <asm/pgalloc.h> 8 #include <asm/pgtable.h> 9 #include <asm/memory.h> 10 #include <asm/smp_plat.h> 11 #include <asm/suspend.h> 12 #include <asm/tlbflush.h> 13 14 extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid); 15 extern void cpu_resume_mmu(void); 16 17 #ifdef CONFIG_MMU 18 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 19 { 20 struct mm_struct *mm = current->active_mm; 21 u32 __mpidr = cpu_logical_map(smp_processor_id()); 22 int ret; 23 24 if (!idmap_pgd) 25 return -EINVAL; 26 27 /* 28 * Provide a temporary page table with an identity mapping for 29 * the MMU-enable code, required for resuming. On successful 30 * resume (indicated by a zero return code), we need to switch 31 * back to the correct page tables. 32 */ 33 ret = __cpu_suspend(arg, fn, __mpidr); 34 if (ret == 0) { 35 cpu_switch_mm(mm->pgd, mm); 36 local_flush_bp_all(); 37 local_flush_tlb_all(); 38 } 39 40 return ret; 41 } 42 #else 43 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 44 { 45 u32 __mpidr = cpu_logical_map(smp_processor_id()); 46 return __cpu_suspend(arg, fn, __mpidr); 47 } 48 #define idmap_pgd NULL 49 #endif 50 51 /* 52 * This is called by __cpu_suspend() to save the state, and do whatever 53 * flushing is required to ensure that when the CPU goes to sleep we have 54 * the necessary data available when the caches are not searched. 55 */ 56 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) 57 { 58 u32 *ctx = ptr; 59 60 *save_ptr = virt_to_phys(ptr); 61 62 /* This must correspond to the LDM in cpu_resume() assembly */ 63 *ptr++ = virt_to_phys(idmap_pgd); 64 *ptr++ = sp; 65 *ptr++ = virt_to_phys(cpu_do_resume); 66 67 cpu_do_suspend(ptr); 68 69 flush_cache_louis(); 70 71 /* 72 * flush_cache_louis does not guarantee that 73 * save_ptr and ptr are cleaned to main memory, 74 * just up to the Level of Unification Inner Shareable. 75 * Since the context pointer and context itself 76 * are to be retrieved with the MMU off that 77 * data must be cleaned from all cache levels 78 * to main memory using "area" cache primitives. 79 */ 80 __cpuc_flush_dcache_area(ctx, ptrsz); 81 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); 82 83 outer_clean_range(*save_ptr, *save_ptr + ptrsz); 84 outer_clean_range(virt_to_phys(save_ptr), 85 virt_to_phys(save_ptr) + sizeof(*save_ptr)); 86 } 87 88 extern struct sleep_save_sp sleep_save_sp; 89 90 static int cpu_suspend_alloc_sp(void) 91 { 92 void *ctx_ptr; 93 /* ctx_ptr is an array of physical addresses */ 94 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL); 95 96 if (WARN_ON(!ctx_ptr)) 97 return -ENOMEM; 98 sleep_save_sp.save_ptr_stash = ctx_ptr; 99 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); 100 sync_cache_w(&sleep_save_sp); 101 return 0; 102 } 103 early_initcall(cpu_suspend_alloc_sp); 104