1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/init.h> 3 #include <linux/slab.h> 4 #include <linux/mm_types.h> 5 6 #include <asm/bugs.h> 7 #include <asm/cacheflush.h> 8 #include <asm/idmap.h> 9 #include <asm/pgalloc.h> 10 #include <asm/pgtable.h> 11 #include <asm/memory.h> 12 #include <asm/smp_plat.h> 13 #include <asm/suspend.h> 14 #include <asm/tlbflush.h> 15 16 extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid); 17 extern void cpu_resume_mmu(void); 18 19 #ifdef CONFIG_MMU 20 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 21 { 22 struct mm_struct *mm = current->active_mm; 23 u32 __mpidr = cpu_logical_map(smp_processor_id()); 24 int ret; 25 26 if (!idmap_pgd) 27 return -EINVAL; 28 29 /* 30 * Provide a temporary page table with an identity mapping for 31 * the MMU-enable code, required for resuming. On successful 32 * resume (indicated by a zero return code), we need to switch 33 * back to the correct page tables. 34 */ 35 ret = __cpu_suspend(arg, fn, __mpidr); 36 if (ret == 0) { 37 cpu_switch_mm(mm->pgd, mm); 38 local_flush_bp_all(); 39 local_flush_tlb_all(); 40 check_other_bugs(); 41 } 42 43 return ret; 44 } 45 #else 46 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 47 { 48 u32 __mpidr = cpu_logical_map(smp_processor_id()); 49 return __cpu_suspend(arg, fn, __mpidr); 50 } 51 #define idmap_pgd NULL 52 #endif 53 54 /* 55 * This is called by __cpu_suspend() to save the state, and do whatever 56 * flushing is required to ensure that when the CPU goes to sleep we have 57 * the necessary data available when the caches are not searched. 58 */ 59 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) 60 { 61 u32 *ctx = ptr; 62 63 *save_ptr = virt_to_phys(ptr); 64 65 /* This must correspond to the LDM in cpu_resume() assembly */ 66 *ptr++ = virt_to_phys(idmap_pgd); 67 *ptr++ = sp; 68 *ptr++ = virt_to_phys(cpu_do_resume); 69 70 cpu_do_suspend(ptr); 71 72 flush_cache_louis(); 73 74 /* 75 * flush_cache_louis does not guarantee that 76 * save_ptr and ptr are cleaned to main memory, 77 * just up to the Level of Unification Inner Shareable. 78 * Since the context pointer and context itself 79 * are to be retrieved with the MMU off that 80 * data must be cleaned from all cache levels 81 * to main memory using "area" cache primitives. 82 */ 83 __cpuc_flush_dcache_area(ctx, ptrsz); 84 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); 85 86 outer_clean_range(*save_ptr, *save_ptr + ptrsz); 87 outer_clean_range(virt_to_phys(save_ptr), 88 virt_to_phys(save_ptr) + sizeof(*save_ptr)); 89 } 90 91 extern struct sleep_save_sp sleep_save_sp; 92 93 static int cpu_suspend_alloc_sp(void) 94 { 95 void *ctx_ptr; 96 /* ctx_ptr is an array of physical addresses */ 97 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL); 98 99 if (WARN_ON(!ctx_ptr)) 100 return -ENOMEM; 101 sleep_save_sp.save_ptr_stash = ctx_ptr; 102 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); 103 sync_cache_w(&sleep_save_sp); 104 return 0; 105 } 106 early_initcall(cpu_suspend_alloc_sp); 107