/****************************************************************************** * * Module Name: amfield - ACPI AML (p-code) execution - field manipulation * $Revision: 1.1 $ * *****************************************************************************/ /* * Copyright (C) 2000, 2001 R. Byron Moore * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #define _COMPONENT ACPI_EXECUTER MODULE_NAME ("amfield") /******************************************************************************* * * FUNCTION: Acpi_aml_setup_field * * PARAMETERS: *Obj_desc - Field to be read or written * *Rgn_desc - Region containing field * Field_bit_width - Field Width in bits (8, 16, or 32) * * RETURN: Status * * DESCRIPTION: Common processing for Acpi_aml_read_field and Acpi_aml_write_field * * ACPI SPECIFICATION REFERENCES: * Each of the Type1_opcodes is defined as specified in in-line * comments below. For each one, use the following definitions. * * Def_bit_field := Bit_field_op Src_buf Bit_idx Destination * Def_byte_field := Byte_field_op Src_buf Byte_idx Destination * Def_create_field := Create_field_op Src_buf Bit_idx Num_bits Name_string * Def_dWord_field := DWord_field_op Src_buf Byte_idx Destination * Def_word_field := Word_field_op Src_buf Byte_idx Destination * Bit_index := Term_arg=>Integer * Byte_index := Term_arg=>Integer * Destination := Name_string * Num_bits := Term_arg=>Integer * Source_buf := Term_arg=>Buffer * ******************************************************************************/ ACPI_STATUS acpi_aml_setup_field ( ACPI_OPERAND_OBJECT *obj_desc, ACPI_OPERAND_OBJECT *rgn_desc, u32 field_bit_width) { ACPI_STATUS status = AE_OK; u32 field_byte_width; /* Parameter validation */ if (!obj_desc || !rgn_desc) { return (AE_AML_NO_OPERAND); } if (ACPI_TYPE_REGION != rgn_desc->common.type) { return (AE_AML_OPERAND_TYPE); } /* * TBD: [Future] Acpi 2.0 supports Qword fields * * Init and validate Field width * Possible values are 1, 2, 4 */ field_byte_width = DIV_8 (field_bit_width); if ((field_bit_width != 8) && (field_bit_width != 16) && (field_bit_width != 32)) { return (AE_AML_OPERAND_VALUE); } /* * If the Region Address and Length have not been previously evaluated, * evaluate them and save the results. */ if (!(rgn_desc->region.flags & AOPOBJ_DATA_VALID)) { status = acpi_ds_get_region_arguments (rgn_desc); if (ACPI_FAILURE (status)) { return (status); } } if ((obj_desc->common.type == ACPI_TYPE_FIELD_UNIT) && (!(obj_desc->common.flags & AOPOBJ_DATA_VALID))) { /* * Field Buffer and Index have not been previously evaluated, */ return (AE_AML_INTERNAL); } if (rgn_desc->region.length < (obj_desc->field.offset & ~((u32) field_byte_width - 1)) + field_byte_width) { /* * Offset rounded up to next multiple of field width * exceeds region length, indicate an error */ return (AE_AML_REGION_LIMIT); } return (AE_OK); } /******************************************************************************* * * FUNCTION: Acpi_aml_access_named_field * * PARAMETERS: Mode - ACPI_READ or ACPI_WRITE * Named_field - Handle for field to be accessed * *Buffer - Value(s) to be read or written * Buffer_length - Number of bytes to transfer * * RETURN: Status * * DESCRIPTION: Read or write a named field * ******************************************************************************/ ACPI_STATUS acpi_aml_access_named_field ( u32 mode, ACPI_HANDLE named_field, void *buffer, u32 buffer_length) { ACPI_OPERAND_OBJECT *obj_desc = NULL; ACPI_STATUS status = AE_OK; u8 locked = FALSE; u32 bit_granularity = 0; u32 byte_granularity; u32 datum_length; u32 actual_byte_length; u32 byte_field_length; /* Parameter validation */ if ((!named_field) || (ACPI_READ == mode && !buffer)) { return (AE_AML_INTERNAL); } /* Get the attached field object */ obj_desc = acpi_ns_get_attached_object (named_field); if (!obj_desc) { return (AE_AML_INTERNAL); } /* Check the type */ if (INTERNAL_TYPE_DEF_FIELD != acpi_ns_get_type (named_field)) { return (AE_AML_OPERAND_TYPE); } /* Obj_desc valid and Named_field is a defined field */ /* Double-check that the attached object is also a field */ if (INTERNAL_TYPE_DEF_FIELD != obj_desc->common.type) { return (AE_AML_OPERAND_TYPE); } /* * Granularity was decoded from the field access type * (Any_acc will be the same as Byte_acc) */ bit_granularity = obj_desc->field_unit.granularity; byte_granularity = DIV_8 (bit_granularity); /* * Check if request is too large for the field, and silently truncate * if necessary */ /* TBD: [Errors] should an error be returned in this case? */ byte_field_length = (u32) DIV_8 (obj_desc->field_unit.length + 7); actual_byte_length = buffer_length; if (buffer_length > byte_field_length) { actual_byte_length = byte_field_length; } /* TBD: should these round down to a power of 2? */ if (DIV_8 (bit_granularity) > byte_field_length) { bit_granularity = MUL_8(byte_field_length); } if (byte_granularity > byte_field_length) { byte_granularity = byte_field_length; } /* Convert byte count to datum count, round up if necessary */ datum_length = (actual_byte_length + (byte_granularity-1)) / byte_granularity; /* Get the global lock if needed */ locked = acpi_aml_acquire_global_lock (obj_desc->field_unit.lock_rule); /* Perform the actual read or write of the buffer */ switch (mode) { case ACPI_READ: status = acpi_aml_read_field (obj_desc, buffer, buffer_length, actual_byte_length, datum_length, bit_granularity, byte_granularity); break; case ACPI_WRITE: status = acpi_aml_write_field (obj_desc, buffer, buffer_length, actual_byte_length, datum_length, bit_granularity, byte_granularity); break; default: status = AE_BAD_PARAMETER; break; } /* Release global lock if we acquired it earlier */ acpi_aml_release_global_lock (locked); return (status); }