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>
9 #include <asm/cacheflush.h>
10 #include <asm/idmap.h>
11 #include <asm/memory.h>
12 #include <asm/smp_plat.h>
13 #include <asm/suspend.h>
14 #include <asm/tlbflush.h>
16 extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
17 extern void cpu_resume_mmu(void);
20 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
22 struct mm_struct *mm = current->active_mm;
23 u32 __mpidr = cpu_logical_map(smp_processor_id());
30 * Function graph tracer state gets incosistent when the kernel
31 * calls functions that never return (aka suspend finishers) hence
32 * disable graph tracing during their execution.
34 pause_graph_tracing();
37 * Provide a temporary page table with an identity mapping for
38 * the MMU-enable code, required for resuming. On successful
39 * resume (indicated by a zero return code), we need to switch
40 * back to the correct page tables.
42 ret = __cpu_suspend(arg, fn, __mpidr);
44 unpause_graph_tracing();
47 cpu_switch_mm(mm->pgd, mm);
49 local_flush_tlb_all();
56 int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
58 u32 __mpidr = cpu_logical_map(smp_processor_id());
61 pause_graph_tracing();
62 ret = __cpu_suspend(arg, fn, __mpidr);
63 unpause_graph_tracing();
67 #define idmap_pgd NULL
71 * This is called by __cpu_suspend() to save the state, and do whatever
72 * flushing is required to ensure that when the CPU goes to sleep we have
73 * the necessary data available when the caches are not searched.
75 void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
79 *save_ptr = virt_to_phys(ptr);
81 /* This must correspond to the LDM in cpu_resume() assembly */
82 *ptr++ = virt_to_phys(idmap_pgd);
84 *ptr++ = virt_to_phys(cpu_do_resume);
91 * flush_cache_louis does not guarantee that
92 * save_ptr and ptr are cleaned to main memory,
93 * just up to the Level of Unification Inner Shareable.
94 * Since the context pointer and context itself
95 * are to be retrieved with the MMU off that
96 * data must be cleaned from all cache levels
97 * to main memory using "area" cache primitives.
99 __cpuc_flush_dcache_area(ctx, ptrsz);
100 __cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
102 outer_clean_range(*save_ptr, *save_ptr + ptrsz);
103 outer_clean_range(virt_to_phys(save_ptr),
104 virt_to_phys(save_ptr) + sizeof(*save_ptr));
107 extern struct sleep_save_sp sleep_save_sp;
109 static int cpu_suspend_alloc_sp(void)
112 /* ctx_ptr is an array of physical addresses */
113 ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
115 if (WARN_ON(!ctx_ptr))
117 sleep_save_sp.save_ptr_stash = ctx_ptr;
118 sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
119 sync_cache_w(&sleep_save_sp);
122 early_initcall(cpu_suspend_alloc_sp);