ACPI, Record ACPI NVS regions

Some firmware will access memory in ACPI NVS region via APEI.  That
is, instructions in APEI ERST/EINJ table will read/write ACPI NVS
region.  The original resource conflict checking in APEI code will
check memory/ioport accessed by APEI via general resource management
mechanism.  But ACPI NVS region is marked as busy already, so that the
false resource conflict will prevent APEI ERST/EINJ to work.

To fix this, this patch record ACPI NVS regions, so that we can avoid
request resources for memory region inside it.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

4 files changed, 70 insertions, 10 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 303a0e48f076..51c3b186e5b9 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -714,7 +714,7 @@ void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 }
 #endif
 
-#ifdef CONFIG_HIBERNATION
+#ifdef CONFIG_ACPI
 /**
  * Mark ACPI NVS memory region, so that we can save/restore it during
  * hibernation and the subsequent resume.
@@ -727,7 +727,7 @@ static int __init e820_mark_nvs_memory(void)
                 struct e820entry *ei = &e820.map[i];
 
                 if (ei->type == E820_NVS)
-                        suspend_nvs_register(ei->addr, ei->size);
+                        acpi_nvs_register(ei->addr, ei->size);
         }
 
         return 0;
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index ecb26b4f29a0..c07f44f05f9d 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -20,11 +20,12 @@ obj-y				+= acpi.o \
 # All the builtin files are in the "acpi." module_param namespace.
 acpi-y                          += osl.o utils.o reboot.o
 acpi-y                          += atomicio.o
+acpi-y                          += nvs.o
 
 # sleep related files
 acpi-y                          += wakeup.o
 acpi-y                          += sleep.o
-acpi-$(CONFIG_ACPI_SLEEP)       += proc.o nvs.o
+acpi-$(CONFIG_ACPI_SLEEP)       += proc.o
 
 
 #
diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c
index 096787b43c96..7a2035fa8c71 100644
--- a/drivers/acpi/nvs.c
+++ b/drivers/acpi/nvs.c
@@ -15,6 +15,56 @@
 #include <linux/acpi_io.h>
 #include <acpi/acpiosxf.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(&region->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
@@ -41,7 +91,7 @@ static LIST_HEAD(nvs_list);
  *      things so that the data from page-aligned addresses in this region will
  *      be copied into separate RAM pages.
  */
-int suspend_nvs_register(unsigned long start, unsigned long size)
+static int suspend_nvs_register(unsigned long start, unsigned long size)
 {
         struct nvs_page *entry, *next;
 
@@ -159,3 +209,4 @@ void suspend_nvs_restore(void)
                 if (entry->data)
                         memcpy(entry->kaddr, entry->data, entry->size);
 }
+#endif
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 6001b4da39dd..26b75442ff7a 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -306,6 +306,11 @@ extern acpi_status acpi_pci_osc_control_set(acpi_handle handle,
                                              u32 *mask, u32 req);
 extern void acpi_early_init(void);
 
+extern int acpi_nvs_register(__u64 start, __u64 size);
+
+extern int acpi_nvs_for_each_region(int (*func)(__u64, __u64, void *),
+                                    void *data);
+
 #else   /* !CONFIG_ACPI */
 
 #define acpi_disabled 1
@@ -348,15 +353,18 @@ static inline int acpi_table_parse(char *id,
 {
         return -1;
 }
-#endif  /* !CONFIG_ACPI */
 
-#ifdef CONFIG_ACPI_SLEEP
-int suspend_nvs_register(unsigned long start, unsigned long size);
-#else
-static inline int suspend_nvs_register(unsigned long a, unsigned long b)
+static inline int acpi_nvs_register(__u64 start, __u64 size)
 {
         return 0;
 }
-#endif
+
+static inline int acpi_nvs_for_each_region(int (*func)(__u64, __u64, void *),
+                                           void *data)
+{
+        return 0;
+}
+
+#endif  /* !CONFIG_ACPI */
 
 #endif  /*_LINUX_ACPI_H*/