1#include <linux/init.h>
2#include <linux/slab.h>
3
4#include <asm/cacheflush.h>
5#include <asm/idmap.h>
6#include <asm/pgalloc.h>
7#include <asm/pgtable.h>
8#include <asm/memory.h>
9#include <asm/smp_plat.h>
10#include <asm/suspend.h>
11#include <asm/tlbflush.h>
12
13extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
14extern void cpu_resume_mmu(void);
15
16#ifdef CONFIG_MMU
17int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
18{
19	struct mm_struct *mm = current->active_mm;
20	u32 __mpidr = cpu_logical_map(smp_processor_id());
21	int ret;
22
23	if (!idmap_pgd)
24		return -EINVAL;
25
26	/*
27	 * Provide a temporary page table with an identity mapping for
28	 * the MMU-enable code, required for resuming.  On successful
29	 * resume (indicated by a zero return code), we need to switch
30	 * back to the correct page tables.
31	 */
32	ret = __cpu_suspend(arg, fn, __mpidr);
33	if (ret == 0) {
34		cpu_switch_mm(mm->pgd, mm);
35		local_flush_bp_all();
36		local_flush_tlb_all();
37	}
38
39	return ret;
40}
41#else
42int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
43{
44	u32 __mpidr = cpu_logical_map(smp_processor_id());
45	return __cpu_suspend(arg, fn, __mpidr);
46}
47#define	idmap_pgd	NULL
48#endif
49
50/*
51 * This is called by __cpu_suspend() to save the state, and do whatever
52 * flushing is required to ensure that when the CPU goes to sleep we have
53 * the necessary data available when the caches are not searched.
54 */
55void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
56{
57	u32 *ctx = ptr;
58
59	*save_ptr = virt_to_phys(ptr);
60
61	/* This must correspond to the LDM in cpu_resume() assembly */
62	*ptr++ = virt_to_phys(idmap_pgd);
63	*ptr++ = sp;
64	*ptr++ = virt_to_phys(cpu_do_resume);
65
66	cpu_do_suspend(ptr);
67
68	flush_cache_louis();
69
70	/*
71	 * flush_cache_louis does not guarantee that
72	 * save_ptr and ptr are cleaned to main memory,
73	 * just up to the Level of Unification Inner Shareable.
74	 * Since the context pointer and context itself
75	 * are to be retrieved with the MMU off that
76	 * data must be cleaned from all cache levels
77	 * to main memory using "area" cache primitives.
78	*/
79	__cpuc_flush_dcache_area(ctx, ptrsz);
80	__cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
81
82	outer_clean_range(*save_ptr, *save_ptr + ptrsz);
83	outer_clean_range(virt_to_phys(save_ptr),
84			  virt_to_phys(save_ptr) + sizeof(*save_ptr));
85}
86
87extern struct sleep_save_sp sleep_save_sp;
88
89static int cpu_suspend_alloc_sp(void)
90{
91	void *ctx_ptr;
92	/* ctx_ptr is an array of physical addresses */
93	ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
94
95	if (WARN_ON(!ctx_ptr))
96		return -ENOMEM;
97	sleep_save_sp.save_ptr_stash = ctx_ptr;
98	sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
99	sync_cache_w(&sleep_save_sp);
100	return 0;
101}
102early_initcall(cpu_suspend_alloc_sp);
103