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.
40 	struct nvs_region *region;  in acpi_nvs_register()  local
42 	region = kmalloc(sizeof(*region), GFP_KERNEL);  in acpi_nvs_register()
43 	if (!region)  in acpi_nvs_register()
44 		return -ENOMEM;  in acpi_nvs_register()
45 	region->phys_start = start;  in acpi_nvs_register()
46 	region->size = size;  in acpi_nvs_register()
47 	list_add_tail(&region->node, &nvs_region_list);  in acpi_nvs_register()
56 	struct nvs_region *region;  in acpi_nvs_for_each_region()  local
58 	list_for_each_entry(region, &nvs_region_list, node) {  in acpi_nvs_for_each_region()
59 		rc = func(region->phys_start, region->size, data);  in acpi_nvs_for_each_region()
70  * Platforms, like ACPI, may want us to save some memory used by them during
71  * suspend and to restore the contents of this memory during the subsequent
87  * suspend_nvs_register - register platform NVS memory region to save
88  * @start: Physical address of the region.
89  * @size: Size of the region.
91  * The NVS region need not be page-aligned (both ends) and we arrange
92  * things so that the data from page-aligned addresses in this region will
99 	pr_info("Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",  in suspend_nvs_register()
100 		start, start + size - 1, size);  in suspend_nvs_register()
109 		list_add_tail(&entry->node, &nvs_list);  in suspend_nvs_register()
110 		entry->phys_start = start;  in suspend_nvs_register()
111 		nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);  in suspend_nvs_register()
112 		entry->size = (size < nr_bytes) ? size : nr_bytes;  in suspend_nvs_register()
114 		start += entry->size;  in suspend_nvs_register()
115 		size -= entry->size;  in suspend_nvs_register()
121 		list_del(&entry->node);  in suspend_nvs_register()
124 	return -ENOMEM;  in suspend_nvs_register()
128  * suspend_nvs_free - free data pages allocated for saving NVS regions
135 		if (entry->data) {  in suspend_nvs_free()
136 			free_page((unsigned long)entry->data);  in suspend_nvs_free()
137 			entry->data = NULL;  in suspend_nvs_free()
138 			if (entry->kaddr) {  in suspend_nvs_free()
139 				if (entry->unmap) {  in suspend_nvs_free()
140 					iounmap(entry->kaddr);  in suspend_nvs_free()
141 					entry->unmap = false;  in suspend_nvs_free()
143 					acpi_os_unmap_iomem(entry->kaddr,  in suspend_nvs_free()
144 							    entry->size);  in suspend_nvs_free()
146 				entry->kaddr = NULL;  in suspend_nvs_free()
152  * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
159 		entry->data = (void *)__get_free_page(GFP_KERNEL);  in suspend_nvs_alloc()
160 		if (!entry->data) {  in suspend_nvs_alloc()
162 			return -ENOMEM;  in suspend_nvs_alloc()
169  * suspend_nvs_save - save NVS memory regions
175 	pr_info("Saving platform NVS memory\n");  in suspend_nvs_save()
178 		if (entry->data) {  in suspend_nvs_save()
179 			unsigned long phys = entry->phys_start;  in suspend_nvs_save()
180 			unsigned int size = entry->size;  in suspend_nvs_save()
182 			entry->kaddr = acpi_os_get_iomem(phys, size);  in suspend_nvs_save()
183 			if (!entry->kaddr) {  in suspend_nvs_save()
184 				entry->kaddr = acpi_os_ioremap(phys, size);  in suspend_nvs_save()
185 				entry->unmap = !!entry->kaddr;  in suspend_nvs_save()
187 			if (!entry->kaddr) {  in suspend_nvs_save()
189 				return -ENOMEM;  in suspend_nvs_save()
191 			memcpy(entry->data, entry->kaddr, entry->size);  in suspend_nvs_save()
198  * suspend_nvs_restore - restore NVS memory regions
201  * cannot iounmap the virtual addresses used to access the NVS region.
207 	pr_info("Restoring platform NVS memory\n");  in suspend_nvs_restore()
210 		if (entry->data)  in suspend_nvs_restore()
211 			memcpy(entry->kaddr, entry->data, entry->size);  in suspend_nvs_restore()