1 files changed, 72 insertions, 80 deletions

diff --git a/drivers/acpi/parser/psargs.c b/drivers/acpi/parser/psargs.c
index 562d0f822ab1..6eae35febccd 100644
--- a/drivers/acpi/parser/psargs.c
+++ b/drivers/acpi/parser/psargs.c
@@ -62,61 +62,51 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
  *
  * PARAMETERS:  parser_state        - Current parser state object
  *
- * RETURN:      Decoded package length.  On completion, the AML pointer points
+ * RETURN:      Decoded package length. On completion, the AML pointer points
  *              past the length byte or bytes.
  *
- * DESCRIPTION: Decode and return a package length field
+ * DESCRIPTION: Decode and return a package length field.
+ *              Note: Largest package length is 28 bits, from ACPI specification
  *
  ******************************************************************************/
 
 static u32
 acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
 {
-        u32 encoded_length;
-        u32 length = 0;
+        u8 *aml = parser_state->aml;
+        u32 package_length = 0;
+        acpi_native_uint byte_count;
+        u8 byte_zero_mask = 0x3F;       /* Default [0:5] */
 
         ACPI_FUNCTION_TRACE("ps_get_next_package_length");
 
-        encoded_length = (u32) ACPI_GET8(parser_state->aml);
-        parser_state->aml++;
-
-        switch (encoded_length >> 6) {  /* bits 6-7 contain encoding scheme */
-        case 0:         /* 1-byte encoding (bits 0-5) */
-
-                length = (encoded_length & 0x3F);
-                break;
-
-        case 1:         /* 2-byte encoding (next byte + bits 0-3) */
-
-                length = ((ACPI_GET8(parser_state->aml) << 04) |
-                          (encoded_length & 0x0F));
-                parser_state->aml++;
-                break;
-
-        case 2:         /* 3-byte encoding (next 2 bytes + bits 0-3) */
-
-                length = ((ACPI_GET8(parser_state->aml + 1) << 12) |
-                          (ACPI_GET8(parser_state->aml) << 04) |
-                          (encoded_length & 0x0F));
-                parser_state->aml += 2;
-                break;
-
-        case 3:         /* 4-byte encoding (next 3 bytes + bits 0-3) */
+        /*
+         * Byte 0 bits [6:7] contain the number of additional bytes
+         * used to encode the package length, either 0,1,2, or 3
+         */
+        byte_count = (aml[0] >> 6);
+        parser_state->aml += (byte_count + 1);
 
-                length = ((ACPI_GET8(parser_state->aml + 2) << 20) |
-                          (ACPI_GET8(parser_state->aml + 1) << 12) |
-                          (ACPI_GET8(parser_state->aml) << 04) |
-                          (encoded_length & 0x0F));
-                parser_state->aml += 3;
-                break;
+        /* Get bytes 3, 2, 1 as needed */
 
-        default:
+        while (byte_count) {
+                /*
+                 * Final bit positions for the package length bytes:
+                 *      Byte3->[20:27]
+                 *      Byte2->[12:19]
+                 *      Byte1->[04:11]
+                 *      Byte0->[00:03]
+                 */
+                package_length |= (aml[byte_count] << ((byte_count << 3) - 4));
 
-                /* Can't get here, only 2 bits / 4 cases */
-                break;
+                byte_zero_mask = 0x0F;  /* Use bits [0:3] of byte 0 */
+                byte_count--;
         }
 
-        return_UINT32(length);
+        /* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
+
+        package_length |= (aml[0] & byte_zero_mask);
+        return_UINT32(package_length);
 }
 
 /*******************************************************************************
@@ -135,16 +125,15 @@ acpi_ps_get_next_package_length(struct acpi_parse_state *parser_state)
 u8 *acpi_ps_get_next_package_end(struct acpi_parse_state *parser_state)
 {
         u8 *start = parser_state->aml;
-        acpi_native_uint length;
+        u32 package_length;
 
         ACPI_FUNCTION_TRACE("ps_get_next_package_end");
 
-        /* Function below changes parser_state->Aml */
+        /* Function below updates parser_state->Aml */
 
-        length =
-            (acpi_native_uint) acpi_ps_get_next_package_length(parser_state);
+        package_length = acpi_ps_get_next_package_length(parser_state);
 
-        return_PTR(start + length);     /* end of package */
+        return_PTR(start + package_length);     /* end of package */
 }
 
 /*******************************************************************************
@@ -169,17 +158,15 @@ char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
 
         ACPI_FUNCTION_TRACE("ps_get_next_namestring");
 
-        /* Handle multiple prefix characters */
-
-        while (acpi_ps_is_prefix_char(ACPI_GET8(end))) {
-                /* Include prefix '\\' or '^' */
+        /* Point past any namestring prefix characters (backslash or carat) */
 
+        while (acpi_ps_is_prefix_char(*end)) {
                 end++;
         }
 
-        /* Decode the path */
+        /* Decode the path prefix character */
 
-        switch (ACPI_GET8(end)) {
+        switch (*end) {
         case 0:
 
                 /* null_name */
@@ -199,9 +186,9 @@ char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
 
         case AML_MULTI_NAME_PREFIX_OP:
 
-                /* Multiple name segments, 4 chars each */
+                /* Multiple name segments, 4 chars each, count in next byte */
 
-                end += 2 + ((acpi_size) ACPI_GET8(end + 1) * ACPI_NAME_SIZE);
+                end += 2 + (*(end + 1) * ACPI_NAME_SIZE);
                 break;
 
         default:
@@ -212,7 +199,7 @@ char *acpi_ps_get_next_namestring(struct acpi_parse_state *parser_state)
                 break;
         }
 
-        parser_state->aml = (u8 *) end;
+        parser_state->aml = end;
         return_PTR((char *)start);
 }
 
@@ -342,7 +329,6 @@ acpi_ps_get_next_namepath(struct acpi_walk_state *walk_state,
                                     ("search_node %p start_node %p return_node %p\n",
                                      scope_info.scope.node,
                                      parser_state->start_node, node);
-
                         } else {
                                 /*
                                  * We got a NOT_FOUND during table load or we encountered
@@ -382,59 +368,63 @@ void
 acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
                             u32 arg_type, union acpi_parse_object *arg)
 {
+        u32 length;
+        u16 opcode;
+        u8 *aml = parser_state->aml;
 
         ACPI_FUNCTION_TRACE_U32("ps_get_next_simple_arg", arg_type);
 
         switch (arg_type) {
         case ARGP_BYTEDATA:
 
-                acpi_ps_init_op(arg, AML_BYTE_OP);
-                arg->common.value.integer = (u32) ACPI_GET8(parser_state->aml);
-                parser_state->aml++;
+                /* Get 1 byte from the AML stream */
+
+                opcode = AML_BYTE_OP;
+                arg->common.value.integer = (acpi_integer) * aml;
+                length = 1;
                 break;
 
         case ARGP_WORDDATA:
 
-                acpi_ps_init_op(arg, AML_WORD_OP);
-
                 /* Get 2 bytes from the AML stream */
 
-                ACPI_MOVE_16_TO_32(&arg->common.value.integer,
-                                   parser_state->aml);
-                parser_state->aml += 2;
+                opcode = AML_WORD_OP;
+                ACPI_MOVE_16_TO_64(&arg->common.value.integer, aml);
+                length = 2;
                 break;
 
         case ARGP_DWORDDATA:
 
-                acpi_ps_init_op(arg, AML_DWORD_OP);
-
                 /* Get 4 bytes from the AML stream */
 
-                ACPI_MOVE_32_TO_32(&arg->common.value.integer,
-                                   parser_state->aml);
-                parser_state->aml += 4;
+                opcode = AML_DWORD_OP;
+                ACPI_MOVE_32_TO_64(&arg->common.value.integer, aml);
+                length = 4;
                 break;
 
         case ARGP_QWORDDATA:
 
-                acpi_ps_init_op(arg, AML_QWORD_OP);
-
                 /* Get 8 bytes from the AML stream */
 
-                ACPI_MOVE_64_TO_64(&arg->common.value.integer,
-                                   parser_state->aml);
-                parser_state->aml += 8;
+                opcode = AML_QWORD_OP;
+                ACPI_MOVE_64_TO_64(&arg->common.value.integer, aml);
+                length = 8;
                 break;
 
         case ARGP_CHARLIST:
 
-                acpi_ps_init_op(arg, AML_STRING_OP);
-                arg->common.value.string = (char *)parser_state->aml;
+                /* Get a pointer to the string, point past the string */
+
+                opcode = AML_STRING_OP;
+                arg->common.value.string = ACPI_CAST_PTR(char, aml);
 
-                while (ACPI_GET8(parser_state->aml) != '\0') {
-                        parser_state->aml++;
+                /* Find the null terminator */
+
+                length = 0;
+                while (aml[length]) {
+                        length++;
                 }
-                parser_state->aml++;
+                length++;
                 break;
 
         case ARGP_NAME:
@@ -443,14 +433,16 @@ acpi_ps_get_next_simple_arg(struct acpi_parse_state *parser_state,
                 acpi_ps_init_op(arg, AML_INT_NAMEPATH_OP);
                 arg->common.value.name =
                     acpi_ps_get_next_namestring(parser_state);
-                break;
+                return_VOID;
 
         default:
 
                 ACPI_REPORT_ERROR(("Invalid arg_type %X\n", arg_type));
-                break;
+                return_VOID;
         }
 
+        acpi_ps_init_op(arg, opcode);
+        parser_state->aml += length;
         return_VOID;
 }
 
@@ -540,7 +532,7 @@ static union acpi_parse_object *acpi_ps_get_next_field(struct acpi_parse_state
                  * access_type is first operand, access_attribute is second
                  */
                 field->common.value.integer =
-                    (ACPI_GET8(parser_state->aml) << 8);
+                    (((u32) ACPI_GET8(parser_state->aml) << 8));
                 parser_state->aml++;
                 field->common.value.integer |= ACPI_GET8(parser_state->aml);
                 parser_state->aml++;