1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/init.h> 3 #include <linux/slab.h> 4 #include <linux/mm_types.h> 5 #include <linux/pgtable.h> 6 7 #include <asm/bugs.h> 8 #include <asm/cacheflush.h> 9 #include <asm/idmap.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 check_other_bugs(); 40 } 41 42 return ret; 43 } 44 #else 45 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) 46 { 47 u32 __mpidr = cpu_logical_map(smp_processor_id()); 48 return __cpu_suspend(arg, fn, __mpidr); 49 } 50 #define idmap_pgd NULL 51 #endif 52 53 /* 54 * This is called by __cpu_suspend() to save the state, and do whatever 55 * flushing is required to ensure that when the CPU goes to sleep we have 56 * the necessary data available when the caches are not searched. 57 */ 58 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) 59 { 60 u32 *ctx = ptr; 61 62 *save_ptr = virt_to_phys(ptr); 63 64 /* This must correspond to the LDM in cpu_resume() assembly */ 65 *ptr++ = virt_to_phys(idmap_pgd); 66 *ptr++ = sp; 67 *ptr++ = virt_to_phys(cpu_do_resume); 68 69 cpu_do_suspend(ptr); 70 71 flush_cache_louis(); 72 73 /* 74 * flush_cache_louis does not guarantee that 75 * save_ptr and ptr are cleaned to main memory, 76 * just up to the Level of Unification Inner Shareable. 77 * Since the context pointer and context itself 78 * are to be retrieved with the MMU off that 79 * data must be cleaned from all cache levels 80 * to main memory using "area" cache primitives. 81 */ 82 __cpuc_flush_dcache_area(ctx, ptrsz); 83 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr)); 84 85 outer_clean_range(*save_ptr, *save_ptr + ptrsz); 86 outer_clean_range(virt_to_phys(save_ptr), 87 virt_to_phys(save_ptr) + sizeof(*save_ptr)); 88 } 89 90 extern struct sleep_save_sp sleep_save_sp; 91 92 static int cpu_suspend_alloc_sp(void) 93 { 94 void *ctx_ptr; 95 /* ctx_ptr is an array of physical addresses */ 96 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL); 97 98 if (WARN_ON(!ctx_ptr)) 99 return -ENOMEM; 100 sleep_save_sp.save_ptr_stash = ctx_ptr; 101 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); 102 sync_cache_w(&sleep_save_sp); 103 return 0; 104 } 105 early_initcall(cpu_suspend_alloc_sp); 106