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a238317ce8
ACPICA doesn't include protections around address space checking, Linux build tests always complain increased sparse warnings around ACPICA internal acpi_os_map/unmap_memory() invocations. This patch tries to fix this issue permanently. There are 2 choices left for us to solve this issue: 1. Add __iomem address space awareness into ACPICA. 2. Remove sparse checker of __iomem from ACPICA source code. This patch chooses solution 2, because: 1. Most of the acpi_os_map/unmap_memory() invocations are used for ACPICA. table mappings, which in fact are not IO addresses. 2. The only IO addresses usage is for "system memory space" mapping code in: drivers/acpi/acpica/exregion.c drivers/acpi/acpica/evrgnini.c drivers/acpi/acpica/exregion.c The mapped address is accessed in the handler of "system memory space" - acpi_ex_system_memory_space_handler(). This function in fact can be changed to invoke acpi_os_read/write_memory() so that __iomem can always be type-casted in the OSL layer. According to the above investigation, we drew the following conclusion: It is not a good idea to introduce __iomem address space awareness into ACPICA mostly in order to protect non-IO addresses. We can simply remove __iomem for acpi_os_map/unmap_memory() to remove __iomem checker for ACPICA code. Then we need to enforce external usages to invoke other APIs that are aware of __iomem address space. The external usages are: drivers/acpi/apei/einj.c drivers/acpi/acpi_extlog.c drivers/char/tpm/tpm_acpi.c drivers/acpi/nvs.c This patch thus performs cleanups in this way: 1. Add acpi_os_map/unmap_iomem() to be invoked by non-ACPICA code. 2. Remove __iomem from acpi_os_map/unmap_memory(). Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
213 lines
4.6 KiB
C
213 lines
4.6 KiB
C
/*
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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 <rjw@sisk.pl>, Novell Inc.
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*
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* This file is released under the GPLv2.
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*/
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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("PM: 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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printk(KERN_INFO "PM: 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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printk(KERN_INFO "PM: 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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