The current implementation of acpi_parse_entries_array() assumes that each
subtable has a standard ACPI subtable entry of type struct
acpi_subtable_header.  This standard subtable header has a one byte length
followed by a one byte type.

The HMAT subtables have to allow for a longer length so they have subtable
headers of type struct acpi_hmat_structure which has a 2 byte type and a 4
byte length.

Enhance the subtable parsing in acpi_parse_entries_array() so that it can
handle these new HMAT subtables.

Signed-off-by: Ross Zwisler <ross.zwis...@linux.intel.com>
---
 drivers/acpi/tables.c | 52 ++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 41 insertions(+), 11 deletions(-)

diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 80ce2a7d224b..f777b94c234a 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -218,6 +218,33 @@ void acpi_table_print_madt_entry(struct 
acpi_subtable_header *header)
        }
 }
 
+static unsigned long __init
+acpi_get_entry_type(char *id, void *entry)
+{
+       if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
+               return ((struct acpi_hmat_structure *)entry)->type;
+       else
+               return ((struct acpi_subtable_header *)entry)->type;
+}
+
+static unsigned long __init
+acpi_get_entry_length(char *id, void *entry)
+{
+       if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
+               return ((struct acpi_hmat_structure *)entry)->length;
+       else
+               return ((struct acpi_subtable_header *)entry)->length;
+}
+
+static unsigned long __init
+acpi_get_subtable_header_length(char *id)
+{
+       if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
+               return sizeof(struct acpi_hmat_structure);
+       else
+               return sizeof(struct acpi_subtable_header);
+}
+
 /**
  * acpi_parse_entries_array - for each proc_num find a suitable subtable
  *
@@ -242,10 +269,10 @@ acpi_parse_entries_array(char *id, unsigned long 
table_size,
                struct acpi_subtable_proc *proc, int proc_num,
                unsigned int max_entries)
 {
-       struct acpi_subtable_header *entry;
-       unsigned long table_end;
+       unsigned long table_end, subtable_header_length;
        int count = 0;
        int errs = 0;
+       void *entry;
        int i;
 
        if (acpi_disabled)
@@ -263,19 +290,23 @@ acpi_parse_entries_array(char *id, unsigned long 
table_size,
        }
 
        table_end = (unsigned long)table_header + table_header->length;
+       subtable_header_length = acpi_get_subtable_header_length(id);
 
        /* Parse all entries looking for a match. */
 
-       entry = (struct acpi_subtable_header *)
-           ((unsigned long)table_header + table_size);
+       entry = (void *)table_header + table_size;
+
+       while (((unsigned long)entry) + subtable_header_length  < table_end) {
+               unsigned long entry_type, entry_length;
 
-       while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
-              table_end) {
                if (max_entries && count >= max_entries)
                        break;
 
+               entry_type = acpi_get_entry_type(id, entry);
+               entry_length = acpi_get_entry_length(id, entry);
+
                for (i = 0; i < proc_num; i++) {
-                       if (entry->type != proc[i].id)
+                       if (entry_type != proc[i].id)
                                continue;
                        if (!proc[i].handler ||
                             (!errs && proc[i].handler(entry, table_end))) {
@@ -290,16 +321,15 @@ acpi_parse_entries_array(char *id, unsigned long 
table_size,
                        count++;
 
                /*
-                * If entry->length is 0, break from this loop to avoid
+                * If entry_length is 0, break from this loop to avoid
                 * infinite loop.
                 */
-               if (entry->length == 0) {
+               if (entry_length == 0) {
                        pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, 
proc->id);
                        return -EINVAL;
                }
 
-               entry = (struct acpi_subtable_header *)
-                   ((unsigned long)entry + entry->length);
+               entry += entry_length;
        }
 
        if (max_entries && count > max_entries) {
-- 
2.14.3

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