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