107 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			107 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| #include <linux/init.h>
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| #include <linux/slab.h>
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| #include <linux/mm_types.h>
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| 
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| #include <asm/bugs.h>
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| #include <asm/cacheflush.h>
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| #include <asm/idmap.h>
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| #include <asm/pgalloc.h>
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| #include <asm/pgtable.h>
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| #include <asm/memory.h>
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| #include <asm/smp_plat.h>
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| #include <asm/suspend.h>
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| #include <asm/tlbflush.h>
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| 
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| extern int __cpu_suspend(unsigned long, int (*)(unsigned long), u32 cpuid);
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| extern void cpu_resume_mmu(void);
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| 
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| #ifdef CONFIG_MMU
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| int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
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| {
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| 	struct mm_struct *mm = current->active_mm;
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| 	u32 __mpidr = cpu_logical_map(smp_processor_id());
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| 	int ret;
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| 
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| 	if (!idmap_pgd)
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| 		return -EINVAL;
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| 
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| 	/*
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| 	 * Provide a temporary page table with an identity mapping for
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| 	 * the MMU-enable code, required for resuming.  On successful
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| 	 * resume (indicated by a zero return code), we need to switch
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| 	 * back to the correct page tables.
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| 	 */
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| 	ret = __cpu_suspend(arg, fn, __mpidr);
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| 	if (ret == 0) {
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| 		cpu_switch_mm(mm->pgd, mm);
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| 		local_flush_bp_all();
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| 		local_flush_tlb_all();
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| 		check_other_bugs();
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| 	}
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| 
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| 	return ret;
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| }
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| #else
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| int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
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| {
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| 	u32 __mpidr = cpu_logical_map(smp_processor_id());
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| 	return __cpu_suspend(arg, fn, __mpidr);
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| }
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| #define	idmap_pgd	NULL
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| #endif
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| 
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| /*
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|  * This is called by __cpu_suspend() to save the state, and do whatever
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|  * flushing is required to ensure that when the CPU goes to sleep we have
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|  * the necessary data available when the caches are not searched.
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|  */
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| void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr)
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| {
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| 	u32 *ctx = ptr;
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| 
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| 	*save_ptr = virt_to_phys(ptr);
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| 
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| 	/* This must correspond to the LDM in cpu_resume() assembly */
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| 	*ptr++ = virt_to_phys(idmap_pgd);
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| 	*ptr++ = sp;
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| 	*ptr++ = virt_to_phys(cpu_do_resume);
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| 
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| 	cpu_do_suspend(ptr);
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| 
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| 	flush_cache_louis();
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| 
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| 	/*
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| 	 * flush_cache_louis does not guarantee that
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| 	 * save_ptr and ptr are cleaned to main memory,
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| 	 * just up to the Level of Unification Inner Shareable.
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| 	 * Since the context pointer and context itself
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| 	 * are to be retrieved with the MMU off that
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| 	 * data must be cleaned from all cache levels
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| 	 * to main memory using "area" cache primitives.
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| 	*/
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| 	__cpuc_flush_dcache_area(ctx, ptrsz);
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| 	__cpuc_flush_dcache_area(save_ptr, sizeof(*save_ptr));
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| 
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| 	outer_clean_range(*save_ptr, *save_ptr + ptrsz);
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| 	outer_clean_range(virt_to_phys(save_ptr),
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| 			  virt_to_phys(save_ptr) + sizeof(*save_ptr));
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| }
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| 
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| extern struct sleep_save_sp sleep_save_sp;
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| 
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| static int cpu_suspend_alloc_sp(void)
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| {
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| 	void *ctx_ptr;
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| 	/* ctx_ptr is an array of physical addresses */
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| 	ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL);
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| 
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| 	if (WARN_ON(!ctx_ptr))
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| 		return -ENOMEM;
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| 	sleep_save_sp.save_ptr_stash = ctx_ptr;
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| 	sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
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| 	sync_cache_w(&sleep_save_sp);
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| 	return 0;
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| }
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| early_initcall(cpu_suspend_alloc_sp);
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