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