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
 16extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
 17extern void cpu_resume_mmu(void);
 18
 19#ifdef CONFIG_MMU
 20int 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
 46int 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 */
 59void __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
 91extern struct sleep_save_sp sleep_save_sp;
 92
 93static 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}
106early_initcall(cpu_suspend_alloc_sp);