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
cpu_suspend(unsigned long arg,int (* fn)(unsigned long))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
cpu_suspend(unsigned long arg,int (* fn)(unsigned long))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 */
__cpu_suspend_save(u32 * ptr,u32 ptrsz,u32 sp,u32 * save_ptr)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
cpu_suspend_alloc_sp(void)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
