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Diffstat (limited to 'drivers/acpi/acpica/dscontrol.c')
| -rw-r--r-- | drivers/acpi/acpica/dscontrol.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/dscontrol.c b/drivers/acpi/acpica/dscontrol.c new file mode 100644 index 00000000000..26c49fff58d --- /dev/null +++ b/drivers/acpi/acpica/dscontrol.c @@ -0,0 +1,410 @@ +/****************************************************************************** + * + * Module Name: dscontrol - Support for execution control opcodes - + * if/else/while/return + * + *****************************************************************************/ + +/* + * Copyright (C) 2000 - 2011, Intel Corp. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce at minimum a disclaimer + * substantially similar to the "NO WARRANTY" disclaimer below + * ("Disclaimer") and any redistribution must be conditioned upon + * including a substantially similar Disclaimer requirement for further + * binary redistribution. + * 3. Neither the names of the above-listed copyright holders nor the names + * of any contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * NO WARRANTY + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGES. + */ + +#include <acpi/acpi.h> +#include "accommon.h" +#include "amlcode.h" +#include "acdispat.h" +#include "acinterp.h" + +#define _COMPONENT ACPI_DISPATCHER +ACPI_MODULE_NAME("dscontrol") + +/******************************************************************************* + * + * FUNCTION: acpi_ds_exec_begin_control_op + * + * PARAMETERS: walk_list - The list that owns the walk stack + * Op - The control Op + * + * RETURN: Status + * + * DESCRIPTION: Handles all control ops encountered during control method + * execution. + * + ******************************************************************************/ +acpi_status +acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state, + union acpi_parse_object *op) +{ + acpi_status status = AE_OK; + union acpi_generic_state *control_state; + + ACPI_FUNCTION_NAME(ds_exec_begin_control_op); + + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", + op, op->common.aml_opcode, walk_state)); + + switch (op->common.aml_opcode) { + case AML_WHILE_OP: + + /* + * If this is an additional iteration of a while loop, continue. + * There is no need to allocate a new control state. + */ + if (walk_state->control_state) { + if (walk_state->control_state->control. + aml_predicate_start == + (walk_state->parser_state.aml - 1)) { + + /* Reset the state to start-of-loop */ + + walk_state->control_state->common.state = + ACPI_CONTROL_CONDITIONAL_EXECUTING; + break; + } + } + + /*lint -fallthrough */ + + case AML_IF_OP: + + /* + * IF/WHILE: Create a new control state to manage these + * constructs. We need to manage these as a stack, in order + * to handle nesting. + */ + control_state = acpi_ut_create_control_state(); + if (!control_state) { + status = AE_NO_MEMORY; + break; + } + /* + * Save a pointer to the predicate for multiple executions + * of a loop + */ + control_state->control.aml_predicate_start = + walk_state->parser_state.aml - 1; + control_state->control.package_end = + walk_state->parser_state.pkg_end; + control_state->control.opcode = op->common.aml_opcode; + + /* Push the control state on this walk's control stack */ + + acpi_ut_push_generic_state(&walk_state->control_state, + control_state); + break; + + case AML_ELSE_OP: + + /* Predicate is in the state object */ + /* If predicate is true, the IF was executed, ignore ELSE part */ + + if (walk_state->last_predicate) { + status = AE_CTRL_TRUE; + } + + break; + + case AML_RETURN_OP: + + break; + + default: + break; + } + + return (status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ds_exec_end_control_op + * + * PARAMETERS: walk_list - The list that owns the walk stack + * Op - The control Op + * + * RETURN: Status + * + * DESCRIPTION: Handles all control ops encountered during control method + * execution. + * + ******************************************************************************/ + +acpi_status +acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state, + union acpi_parse_object * op) +{ + acpi_status status = AE_OK; + union acpi_generic_state *control_state; + + ACPI_FUNCTION_NAME(ds_exec_end_control_op); + + switch (op->common.aml_opcode) { + case AML_IF_OP: + + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", op)); + + /* + * Save the result of the predicate in case there is an + * ELSE to come + */ + walk_state->last_predicate = + (u8)walk_state->control_state->common.value; + + /* + * Pop the control state that was created at the start + * of the IF and free it + */ + control_state = + acpi_ut_pop_generic_state(&walk_state->control_state); + acpi_ut_delete_generic_state(control_state); + break; + + case AML_ELSE_OP: + + break; + + case AML_WHILE_OP: + + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op)); + + control_state = walk_state->control_state; + if (control_state->common.value) { + + /* Predicate was true, the body of the loop was just executed */ + + /* + * This loop counter mechanism allows the interpreter to escape + * possibly infinite loops. This can occur in poorly written AML + * when the hardware does not respond within a while loop and the + * loop does not implement a timeout. + */ + control_state->control.loop_count++; + if (control_state->control.loop_count > + ACPI_MAX_LOOP_ITERATIONS) { + status = AE_AML_INFINITE_LOOP; + break; + } + + /* + * Go back and evaluate the predicate and maybe execute the loop + * another time + */ + status = AE_CTRL_PENDING; + walk_state->aml_last_while = + control_state->control.aml_predicate_start; + break; + } + + /* Predicate was false, terminate this while loop */ + + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, + "[WHILE_OP] termination! Op=%p\n", op)); + + /* Pop this control state and free it */ + + control_state = + acpi_ut_pop_generic_state(&walk_state->control_state); + acpi_ut_delete_generic_state(control_state); + break; + + case AML_RETURN_OP: + + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, + "[RETURN_OP] Op=%p Arg=%p\n", op, + op->common.value.arg)); + + /* + * One optional operand -- the return value + * It can be either an immediate operand or a result that + * has been bubbled up the tree + */ + if (op->common.value.arg) { + + /* Since we have a real Return(), delete any implicit return */ + + acpi_ds_clear_implicit_return(walk_state); + + /* Return statement has an immediate operand */ + + status = + acpi_ds_create_operands(walk_state, + op->common.value.arg); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* + * If value being returned is a Reference (such as + * an arg or local), resolve it now because it may + * cease to exist at the end of the method. + */ + status = + acpi_ex_resolve_to_value(&walk_state->operands[0], + walk_state); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* + * Get the return value and save as the last result + * value. This is the only place where walk_state->return_desc + * is set to anything other than zero! + */ + walk_state->return_desc = walk_state->operands[0]; + } else if (walk_state->result_count) { + + /* Since we have a real Return(), delete any implicit return */ + + acpi_ds_clear_implicit_return(walk_state); + + /* + * The return value has come from a previous calculation. + * + * If value being returned is a Reference (such as + * an arg or local), resolve it now because it may + * cease to exist at the end of the method. + * + * Allow references created by the Index operator to return + * unchanged. + */ + if ((ACPI_GET_DESCRIPTOR_TYPE + (walk_state->results->results.obj_desc[0]) == + ACPI_DESC_TYPE_OPERAND) + && ((walk_state->results->results.obj_desc[0])-> + common.type == ACPI_TYPE_LOCAL_REFERENCE) + && ((walk_state->results->results.obj_desc[0])-> + reference.class != ACPI_REFCLASS_INDEX)) { + status = + acpi_ex_resolve_to_value(&walk_state-> + results->results. + obj_desc[0], + walk_state); + if (ACPI_FAILURE(status)) { + return (status); + } + } + + walk_state->return_desc = + walk_state->results->results.obj_desc[0]; + } else { + /* No return operand */ + + if (walk_state->num_operands) { + acpi_ut_remove_reference(walk_state-> + operands[0]); + } + + walk_state->operands[0] = NULL; + walk_state->num_operands = 0; + walk_state->return_desc = NULL; + } + + ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, + "Completed RETURN_OP State=%p, RetVal=%p\n", + walk_state, walk_state->return_desc)); + + /* End the control method execution right now */ + + status = AE_CTRL_TERMINATE; + break; + + case AML_NOOP_OP: + + /* Just do nothing! */ + break; + + case AML_BREAK_POINT_OP: + + /* + * Set the single-step flag. This will cause the debugger (if present) + * to break to the console within the AML debugger at the start of the + * next AML instruction. + */ + ACPI_DEBUGGER_EXEC(acpi_gbl_cm_single_step = TRUE); + ACPI_DEBUGGER_EXEC(acpi_os_printf + ("**break** Executed AML BreakPoint opcode\n")); + + /* Call to the OSL in case OS wants a piece of the action */ + + status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT, + "Executed AML Breakpoint opcode"); + break; + + case AML_BREAK_OP: + case AML_CONTINUE_OP: /* ACPI 2.0 */ + + /* Pop and delete control states until we find a while */ + + while (walk_state->control_state && + (walk_state->control_state->control.opcode != + AML_WHILE_OP)) { + control_state = + acpi_ut_pop_generic_state(&walk_state-> + control_state); + acpi_ut_delete_generic_state(control_state); + } + + /* No while found? */ + + if (!walk_state->control_state) { + return (AE_AML_NO_WHILE); + } + + /* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */ + + walk_state->aml_last_while = + walk_state->control_state->control.package_end; + + /* Return status depending on opcode */ + + if (op->common.aml_opcode == AML_BREAK_OP) { + status = AE_CTRL_BREAK; + } else { + status = AE_CTRL_CONTINUE; + } + break; + + default: + + ACPI_ERROR((AE_INFO, "Unknown control opcode=0x%X Op=%p", + op->common.aml_opcode, op)); + + status = AE_AML_BAD_OPCODE; + break; + } + + return (status); +} |