--- /dev/null
+/*
+ * nvs.c - Routines for saving and restoring ACPI NVS memory region
+ *
+ * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+
+#include "internal.h"
+
+/* ACPI NVS regions, APEI may use it */
+
+struct nvs_region {
+ __u64 phys_start;
+ __u64 size;
+ struct list_head node;
+};
+
+static LIST_HEAD(nvs_region_list);
+
+#ifdef CONFIG_ACPI_SLEEP
+static int suspend_nvs_register(unsigned long start, unsigned long size);
+#else
+static inline int suspend_nvs_register(unsigned long a, unsigned long b)
+{
+ return 0;
+}
+#endif
+
+int acpi_nvs_register(__u64 start, __u64 size)
+{
+ struct nvs_region *region;
+
+ region = kmalloc(sizeof(*region), GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+ region->phys_start = start;
+ region->size = size;
+ list_add_tail(®ion->node, &nvs_region_list);
+
+ return suspend_nvs_register(start, size);
+}
+
+int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data),
+ void *data)
+{
+ int rc;
+ struct nvs_region *region;
+
+ list_for_each_entry(region, &nvs_region_list, node) {
+ rc = func(region->phys_start, region->size, data);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+
+#ifdef CONFIG_ACPI_SLEEP
+/*
+ * Platforms, like ACPI, may want us to save some memory used by them during
+ * suspend and to restore the contents of this memory during the subsequent
+ * resume. The code below implements a mechanism allowing us to do that.
+ */
+
+struct nvs_page {
+ unsigned long phys_start;
+ unsigned int size;
+ void *kaddr;
+ void *data;
+ bool unmap;
+ struct list_head node;
+};
+
+static LIST_HEAD(nvs_list);
+
+/**
+ * suspend_nvs_register - register platform NVS memory region to save
+ * @start - physical address of the region
+ * @size - size of the region
+ *
+ * The NVS region need not be page-aligned (both ends) and we arrange
+ * things so that the data from page-aligned addresses in this region will
+ * be copied into separate RAM pages.
+ */
+static int suspend_nvs_register(unsigned long start, unsigned long size)
+{
+ struct nvs_page *entry, *next;
+
+ pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",
+ start, start + size - 1, size);
+
+ while (size > 0) {
+ unsigned int nr_bytes;
+
+ entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
+ if (!entry)
+ goto Error;
+
+ list_add_tail(&entry->node, &nvs_list);
+ entry->phys_start = start;
+ nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
+ entry->size = (size < nr_bytes) ? size : nr_bytes;
+
+ start += entry->size;
+ size -= entry->size;
+ }
+ return 0;
+
+ Error:
+ list_for_each_entry_safe(entry, next, &nvs_list, node) {
+ list_del(&entry->node);
+ kfree(entry);
+ }
+ return -ENOMEM;
+}
+
+/**
+ * suspend_nvs_free - free data pages allocated for saving NVS regions
+ */
+void suspend_nvs_free(void)
+{
+ struct nvs_page *entry;
+
+ list_for_each_entry(entry, &nvs_list, node)
+ if (entry->data) {
+ free_page((unsigned long)entry->data);
+ entry->data = NULL;
+ if (entry->kaddr) {
+ if (entry->unmap) {
+ iounmap(entry->kaddr);
+ entry->unmap = false;
+ } else {
+ acpi_os_unmap_iomem(entry->kaddr,
+ entry->size);
+ }
+ entry->kaddr = NULL;
+ }
+ }
+}
+
+/**
+ * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
+ */
+int suspend_nvs_alloc(void)
+{
+ struct nvs_page *entry;
+
+ list_for_each_entry(entry, &nvs_list, node) {
+ entry->data = (void *)__get_free_page(GFP_KERNEL);
+ if (!entry->data) {
+ suspend_nvs_free();
+ return -ENOMEM;
+ }
+ }
+ return 0;
+}
+
+/**
+ * suspend_nvs_save - save NVS memory regions
+ */
+int suspend_nvs_save(void)
+{
+ struct nvs_page *entry;
+
+ printk(KERN_INFO "PM: Saving platform NVS memory\n");
+
+ list_for_each_entry(entry, &nvs_list, node)
+ if (entry->data) {
+ unsigned long phys = entry->phys_start;
+ unsigned int size = entry->size;
+
+ entry->kaddr = acpi_os_get_iomem(phys, size);
+ if (!entry->kaddr) {
+ entry->kaddr = acpi_os_ioremap(phys, size);
+ entry->unmap = !!entry->kaddr;
+ }
+ if (!entry->kaddr) {
+ suspend_nvs_free();
+ return -ENOMEM;
+ }
+ memcpy(entry->data, entry->kaddr, entry->size);
+ }
+
+ return 0;
+}
+
+/**
+ * suspend_nvs_restore - restore NVS memory regions
+ *
+ * This function is going to be called with interrupts disabled, so it
+ * cannot iounmap the virtual addresses used to access the NVS region.
+ */
+void suspend_nvs_restore(void)
+{
+ struct nvs_page *entry;
+
+ printk(KERN_INFO "PM: Restoring platform NVS memory\n");
+
+ list_for_each_entry(entry, &nvs_list, node)
+ if (entry->data)
+ memcpy(entry->kaddr, entry->data, entry->size);
+}
+#endif
Code Review / kvmfornfv.git / blobdiff