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