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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/ftrace.h>
3#include <linux/init.h>
4#include <linux/slab.h>
5#include <linux/mm_types.h>
6#include <linux/pgtable.h>
7
8#include <asm/bugs.h>
9#include <asm/cacheflush.h>
10#include <asm/idmap.h>
11#include <asm/page.h>
12#include <asm/smp_plat.h>
13#include <asm/suspend.h>
14#include <asm/tlbflush.h>
15#include <asm/uaccess.h>
16
17extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
18extern void cpu_resume_mmu(void);
19
20#ifdef CONFIG_MMU
21int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
22{
23 struct mm_struct *mm = current->active_mm;
24 u32 __mpidr = cpu_logical_map(smp_processor_id());
25 int ret;
26
27 if (!idmap_pgd)
28 return -EINVAL;
29
30 /*
31 * Needed for the MMU disabling/enabing code to be able to run from
32 * TTBR0 addresses.
33 */
34 if (IS_ENABLED(CONFIG_CPU_TTBR0_PAN))
35 uaccess_save_and_enable();
36
37 /*
38 * Function graph tracer state gets incosistent when the kernel
39 * calls functions that never return (aka suspend finishers) hence
40 * disable graph tracing during their execution.
41 */
42 pause_graph_tracing();
43
44 /*
45 * Provide a temporary page table with an identity mapping for
46 * the MMU-enable code, required for resuming. On successful
47 * resume (indicated by a zero return code), we need to switch
48 * back to the correct page tables.
49 */
50 ret = __cpu_suspend(arg, fn, __mpidr);
51
52 unpause_graph_tracing();
53
54 if (ret == 0) {
55 cpu_switch_mm(mm->pgd, mm);
56 local_flush_bp_all();
57 local_flush_tlb_all();
58 check_other_bugs();
59 }
60
61 return ret;
62}
63#else
64int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
65{
66 u32 __mpidr = cpu_logical_map(smp_processor_id());
67 int ret;
68
69 pause_graph_tracing();
70 ret = __cpu_suspend(arg, fn, __mpidr);
71 unpause_graph_tracing();
72
73 return ret;
74}
75#define idmap_pgd NULL
76#endif
77
78/*
79 * This is called by __cpu_suspend() to save the state, and do whatever
80 * flushing is required to ensure that when the CPU goes to sleep we have
81 * the necessary data available when the caches are not searched.
82 */
83void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
84{
85 u32 *ctx = ptr;
86
87 *save_ptr = virt_to_phys(ptr);
88
89 /* This must correspond to the LDM in cpu_resume() assembly */
90 *ptr++ = virt_to_phys(idmap_pgd);
91 *ptr++ = sp;
92 *ptr++ = virt_to_phys(cpu_do_resume);
93
94 cpu_do_suspend(ptr);
95
96 flush_cache_louis();
97
98 /*
99 * flush_cache_louis does not guarantee that
100 * save_ptr and ptr are cleaned to main memory,
101 * just up to the Level of Unification Inner Shareable.
102 * Since the context pointer and context itself
103 * are to be retrieved with the MMU off that
104 * data must be cleaned from all cache levels
105 * to main memory using "area" cache primitives.
106 */
107 __cpuc_flush_dcache_area(ctx, ptrsz);
108 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
109
110 outer_clean_range(*save_ptr, *save_ptr + ptrsz);
111 outer_clean_range(virt_to_phys(save_ptr),
112 virt_to_phys(save_ptr) + sizeof(*save_ptr));
113}
114
115extern struct sleep_save_sp sleep_save_sp;
116
117static int cpu_suspend_alloc_sp(void)
118{
119 void *ctx_ptr;
120 /* ctx_ptr is an array of physical addresses */
121 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
122
123 if (WARN_ON(!ctx_ptr))
124 return -ENOMEM;
125 sleep_save_sp.save_ptr_stash = ctx_ptr;
126 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
127 sync_cache_w(&sleep_save_sp);
128 return 0;
129}
130early_initcall(cpu_suspend_alloc_sp);
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
15extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
16extern void cpu_resume_mmu(void);
17
18#ifdef CONFIG_MMU
19int 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
44int 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 */
57void __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
89extern struct sleep_save_sp sleep_save_sp;
90
91static 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}
104early_initcall(cpu_suspend_alloc_sp);