DMI: Parse memory device (type 17) in SMBIOS

This patch adds a new interface to decode memory device (type 17)
to help error reporting on DIMMs.

Original-author: Tony Luck <tony.luck@intel.com>
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

4 files changed, 67 insertions, 0 deletions

diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 4fc2e9569bb2..d86669bcdfb2 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -1063,6 +1063,7 @@ check_bugs (void)
 static int __init run_dmi_scan(void)
 {
         dmi_scan_machine();
+        dmi_memdev_walk();
         dmi_set_dump_stack_arch_desc();
         return 0;
 }
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f0de6294b955..918d489fa53d 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -993,6 +993,7 @@ void __init setup_arch(char **cmdline_p)
                 efi_init();
 
         dmi_scan_machine();
+        dmi_memdev_walk();
         dmi_set_dump_stack_arch_desc();
 
         /*
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index fa0affb699b4..59579a744d58 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -25,6 +25,13 @@ static int dmi_initialized;
 /* DMI system identification string used during boot */
 static char dmi_ids_string[128] __initdata;
 
+static struct dmi_memdev_info {
+        const char *device;
+        const char *bank;
+        u16 handle;
+} *dmi_memdev;
+static int dmi_memdev_nr;
+
 static const char * __init dmi_string_nosave(const struct dmi_header *dm, u8 s)
 {
         const u8 *bp = ((u8 *) dm) + dm->length;
@@ -322,6 +329,42 @@ static void __init dmi_save_extended_devices(const struct dmi_header *dm)
         dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
 }
 
+static void __init count_mem_devices(const struct dmi_header *dm, void *v)
+{
+        if (dm->type != DMI_ENTRY_MEM_DEVICE)
+                return;
+        dmi_memdev_nr++;
+}
+
+static void __init save_mem_devices(const struct dmi_header *dm, void *v)
+{
+        const char *d = (const char *)dm;
+        static int nr;
+
+        if (dm->type != DMI_ENTRY_MEM_DEVICE)
+                return;
+        if (nr >= dmi_memdev_nr) {
+                pr_warn(FW_BUG "Too many DIMM entries in SMBIOS table\n");
+                return;
+        }
+        dmi_memdev[nr].handle = dm->handle;
+        dmi_memdev[nr].device = dmi_string(dm, d[0x10]);
+        dmi_memdev[nr].bank = dmi_string(dm, d[0x11]);
+        nr++;
+}
+
+void __init dmi_memdev_walk(void)
+{
+        if (!dmi_available)
+                return;
+
+        if (dmi_walk_early(count_mem_devices) == 0 && dmi_memdev_nr) {
+                dmi_memdev = dmi_alloc(sizeof(*dmi_memdev) * dmi_memdev_nr);
+                if (dmi_memdev)
+                        dmi_walk_early(save_mem_devices);
+        }
+}
+
 /*
  *      Process a DMI table entry. Right now all we care about are the BIOS
  *      and machine entries. For 2.5 we should pull the smbus controller info
@@ -815,3 +858,20 @@ bool dmi_match(enum dmi_field f, const char *str)
         return !strcmp(info, str);
 }
 EXPORT_SYMBOL_GPL(dmi_match);
+
+void dmi_memdev_name(u16 handle, const char **bank, const char **device)
+{
+        int n;
+
+        if (dmi_memdev == NULL)
+                return;
+
+        for (n = 0; n < dmi_memdev_nr; n++) {
+                if (handle == dmi_memdev[n].handle) {
+                        *bank = dmi_memdev[n].bank;
+                        *device = dmi_memdev[n].device;
+                        break;
+                }
+        }
+}
+EXPORT_SYMBOL_GPL(dmi_memdev_name);
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index b6eb7a05d58e..f820f0a336c9 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -99,6 +99,7 @@ extern const char * dmi_get_system_info(int field);
 extern const struct dmi_device * dmi_find_device(int type, const char *name,
         const struct dmi_device *from);
 extern void dmi_scan_machine(void);
+extern void dmi_memdev_walk(void);
 extern void dmi_set_dump_stack_arch_desc(void);
 extern bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp);
 extern int dmi_name_in_vendors(const char *str);
@@ -107,6 +108,7 @@ extern int dmi_available;
 extern int dmi_walk(void (*decode)(const struct dmi_header *, void *),
         void *private_data);
 extern bool dmi_match(enum dmi_field f, const char *str);
+extern void dmi_memdev_name(u16 handle, const char **bank, const char **device);
 
 #else
 
@@ -115,6 +117,7 @@ static inline const char * dmi_get_system_info(int field) { return NULL; }
 static inline const struct dmi_device * dmi_find_device(int type, const char *name,
         const struct dmi_device *from) { return NULL; }
 static inline void dmi_scan_machine(void) { return; }
+static inline void dmi_memdev_walk(void) { }
 static inline void dmi_set_dump_stack_arch_desc(void) { }
 static inline bool dmi_get_date(int field, int *yearp, int *monthp, int *dayp)
 {
@@ -133,6 +136,8 @@ static inline int dmi_walk(void (*decode)(const struct dmi_header *, void *),
         void *private_data) { return -1; }
 static inline bool dmi_match(enum dmi_field f, const char *str)
         { return false; }
+static inline void dmi_memdev_name(u16 handle, const char **bank,
+                const char **device) { }
 static inline const struct dmi_system_id *
         dmi_first_match(const struct dmi_system_id *list) { return NULL; }