1 // SPDX-License-Identifier: GPL-2.0-only
3  * nvs.c - Routines for saving and restoring ACPI NVS memory region
5  * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
38 	struct nvs_region *region;  in acpi_nvs_register()  local
40 	region = kmalloc(sizeof(*region), GFP_KERNEL);  in acpi_nvs_register()
41 	if (!region)  in acpi_nvs_register()
42 		return -ENOMEM;  in acpi_nvs_register()
43 	region->phys_start = start;  in acpi_nvs_register()
44 	region->size = size;  in acpi_nvs_register()
45 	list_add_tail(&region->node, &nvs_region_list);  in acpi_nvs_register()
54 	struct nvs_region *region;  in acpi_nvs_for_each_region()  local
56 	list_for_each_entry(region, &nvs_region_list, node) {  in acpi_nvs_for_each_region()
57 		rc = func(region->phys_start, region->size, data);  in acpi_nvs_for_each_region()
68  * Platforms, like ACPI, may want us to save some memory used by them during
69  * suspend and to restore the contents of this memory during the subsequent
85  *	suspend_nvs_register - register platform NVS memory region to save
86  *	@start - physical address of the region
87  *	@size - size of the region
89  *	The NVS region need not be page-aligned (both ends) and we arrange
90  *	things so that the data from page-aligned addresses in this region will
97 	pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",  in suspend_nvs_register()
98 		start, start + size - 1, size);  in suspend_nvs_register()
107 		list_add_tail(&entry->node, &nvs_list);  in suspend_nvs_register()
108 		entry->phys_start = start;  in suspend_nvs_register()
109 		nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);  in suspend_nvs_register()
110 		entry->size = (size < nr_bytes) ? size : nr_bytes;  in suspend_nvs_register()
112 		start += entry->size;  in suspend_nvs_register()
113 		size -= entry->size;  in suspend_nvs_register()
119 		list_del(&entry->node);  in suspend_nvs_register()
122 	return -ENOMEM;  in suspend_nvs_register()
126  *	suspend_nvs_free - free data pages allocated for saving NVS regions
133 		if (entry->data) {  in suspend_nvs_free()
134 			free_page((unsigned long)entry->data);  in suspend_nvs_free()
135 			entry->data = NULL;  in suspend_nvs_free()
136 			if (entry->kaddr) {  in suspend_nvs_free()
137 				if (entry->unmap) {  in suspend_nvs_free()
138 					iounmap(entry->kaddr);  in suspend_nvs_free()
139 					entry->unmap = false;  in suspend_nvs_free()
141 					acpi_os_unmap_iomem(entry->kaddr,  in suspend_nvs_free()
142 							    entry->size);  in suspend_nvs_free()
144 				entry->kaddr = NULL;  in suspend_nvs_free()
150  *	suspend_nvs_alloc - allocate memory necessary for saving NVS regions
157 		entry->data = (void *)__get_free_page(GFP_KERNEL);  in suspend_nvs_alloc()
158 		if (!entry->data) {  in suspend_nvs_alloc()
160 			return -ENOMEM;  in suspend_nvs_alloc()
167  *	suspend_nvs_save - save NVS memory regions
173 	printk(KERN_INFO "PM: Saving platform NVS memory\n");  in suspend_nvs_save()
176 		if (entry->data) {  in suspend_nvs_save()
177 			unsigned long phys = entry->phys_start;  in suspend_nvs_save()
178 			unsigned int size = entry->size;  in suspend_nvs_save()
180 			entry->kaddr = acpi_os_get_iomem(phys, size);  in suspend_nvs_save()
181 			if (!entry->kaddr) {  in suspend_nvs_save()
182 				entry->kaddr = acpi_os_ioremap(phys, size);  in suspend_nvs_save()
183 				entry->unmap = !!entry->kaddr;  in suspend_nvs_save()
185 			if (!entry->kaddr) {  in suspend_nvs_save()
187 				return -ENOMEM;  in suspend_nvs_save()
189 			memcpy(entry->data, entry->kaddr, entry->size);  in suspend_nvs_save()
196  *	suspend_nvs_restore - restore NVS memory regions
199  *	cannot iounmap the virtual addresses used to access the NVS region.
205 	printk(KERN_INFO "PM: Restoring platform NVS memory\n");  in suspend_nvs_restore()
208 		if (entry->data)  in suspend_nvs_restore()
209 			memcpy(entry->kaddr, entry->data, entry->size);  in suspend_nvs_restore()