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
 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		check_other_bugs();
 40	}
 41
 42	return ret;
 43}
 44#else
 45int 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 */
 58void __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
 90extern struct sleep_save_sp sleep_save_sp;
 91
 92static 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}
105early_initcall(cpu_suspend_alloc_sp);