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213 lines
4.6 KiB
213 lines
4.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* nvs.c - Routines for saving and restoring ACPI NVS memory region |
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* |
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* Copyright (C) 2008-2011 Rafael J. Wysocki <[email protected]>, Novell Inc. |
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*/ |
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#define pr_fmt(fmt) "ACPI: PM: " fmt |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/list.h> |
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#include <linux/mm.h> |
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#include <linux/slab.h> |
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#include <linux/acpi.h> |
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#include "internal.h" |
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/* ACPI NVS regions, APEI may use it */ |
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struct nvs_region { |
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__u64 phys_start; |
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__u64 size; |
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struct list_head node; |
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}; |
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static LIST_HEAD(nvs_region_list); |
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#ifdef CONFIG_ACPI_SLEEP |
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static int suspend_nvs_register(unsigned long start, unsigned long size); |
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#else |
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static inline int suspend_nvs_register(unsigned long a, unsigned long b) |
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{ |
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return 0; |
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} |
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#endif |
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int acpi_nvs_register(__u64 start, __u64 size) |
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{ |
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struct nvs_region *region; |
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region = kmalloc(sizeof(*region), GFP_KERNEL); |
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if (!region) |
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return -ENOMEM; |
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region->phys_start = start; |
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region->size = size; |
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list_add_tail(®ion->node, &nvs_region_list); |
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return suspend_nvs_register(start, size); |
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} |
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int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data), |
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void *data) |
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{ |
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int rc; |
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struct nvs_region *region; |
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list_for_each_entry(region, &nvs_region_list, node) { |
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rc = func(region->phys_start, region->size, data); |
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if (rc) |
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return rc; |
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} |
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return 0; |
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} |
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#ifdef CONFIG_ACPI_SLEEP |
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/* |
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* Platforms, like ACPI, may want us to save some memory used by them during |
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* suspend and to restore the contents of this memory during the subsequent |
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* resume. The code below implements a mechanism allowing us to do that. |
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*/ |
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struct nvs_page { |
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unsigned long phys_start; |
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unsigned int size; |
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void *kaddr; |
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void *data; |
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bool unmap; |
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struct list_head node; |
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}; |
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static LIST_HEAD(nvs_list); |
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/** |
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* suspend_nvs_register - register platform NVS memory region to save |
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* @start: Physical address of the region. |
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* @size: Size of the region. |
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* |
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* The NVS region need not be page-aligned (both ends) and we arrange |
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* things so that the data from page-aligned addresses in this region will |
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* be copied into separate RAM pages. |
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*/ |
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static int suspend_nvs_register(unsigned long start, unsigned long size) |
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{ |
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struct nvs_page *entry, *next; |
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pr_info("Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n", |
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start, start + size - 1, size); |
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while (size > 0) { |
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unsigned int nr_bytes; |
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entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL); |
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if (!entry) |
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goto Error; |
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list_add_tail(&entry->node, &nvs_list); |
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entry->phys_start = start; |
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nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK); |
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entry->size = (size < nr_bytes) ? size : nr_bytes; |
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start += entry->size; |
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size -= entry->size; |
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} |
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return 0; |
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Error: |
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list_for_each_entry_safe(entry, next, &nvs_list, node) { |
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list_del(&entry->node); |
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kfree(entry); |
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} |
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return -ENOMEM; |
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} |
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/** |
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* suspend_nvs_free - free data pages allocated for saving NVS regions |
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*/ |
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void suspend_nvs_free(void) |
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{ |
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struct nvs_page *entry; |
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list_for_each_entry(entry, &nvs_list, node) |
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if (entry->data) { |
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free_page((unsigned long)entry->data); |
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entry->data = NULL; |
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if (entry->kaddr) { |
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if (entry->unmap) { |
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iounmap(entry->kaddr); |
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entry->unmap = false; |
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} else { |
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acpi_os_unmap_iomem(entry->kaddr, |
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entry->size); |
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} |
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entry->kaddr = NULL; |
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} |
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} |
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} |
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/** |
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* suspend_nvs_alloc - allocate memory necessary for saving NVS regions |
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*/ |
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int suspend_nvs_alloc(void) |
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{ |
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struct nvs_page *entry; |
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list_for_each_entry(entry, &nvs_list, node) { |
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entry->data = (void *)__get_free_page(GFP_KERNEL); |
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if (!entry->data) { |
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suspend_nvs_free(); |
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return -ENOMEM; |
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} |
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} |
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return 0; |
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} |
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/** |
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* suspend_nvs_save - save NVS memory regions |
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*/ |
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int suspend_nvs_save(void) |
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{ |
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struct nvs_page *entry; |
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pr_info("Saving platform NVS memory\n"); |
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list_for_each_entry(entry, &nvs_list, node) |
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if (entry->data) { |
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unsigned long phys = entry->phys_start; |
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unsigned int size = entry->size; |
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entry->kaddr = acpi_os_get_iomem(phys, size); |
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if (!entry->kaddr) { |
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entry->kaddr = acpi_os_ioremap(phys, size); |
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entry->unmap = !!entry->kaddr; |
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} |
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if (!entry->kaddr) { |
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suspend_nvs_free(); |
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return -ENOMEM; |
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} |
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memcpy(entry->data, entry->kaddr, entry->size); |
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} |
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return 0; |
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} |
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/** |
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* suspend_nvs_restore - restore NVS memory regions |
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* |
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* This function is going to be called with interrupts disabled, so it |
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* cannot iounmap the virtual addresses used to access the NVS region. |
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*/ |
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void suspend_nvs_restore(void) |
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{ |
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struct nvs_page *entry; |
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pr_info("Restoring platform NVS memory\n"); |
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list_for_each_entry(entry, &nvs_list, node) |
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if (entry->data) |
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memcpy(entry->kaddr, entry->data, entry->size); |
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} |
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#endif
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