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Diffstat (limited to '')
| -rw-r--r-- | drivers/acpi/acpica/exstorob.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/exstorob.c b/drivers/acpi/acpica/exstorob.c new file mode 100644 index 000000000..45c757bbf --- /dev/null +++ b/drivers/acpi/acpica/exstorob.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 +/****************************************************************************** + * + * Module Name: exstorob - AML object store support, store to object + * + * Copyright (C) 2000 - 2022, Intel Corp. + * + *****************************************************************************/ + +#include <acpi/acpi.h> +#include "accommon.h" +#include "acinterp.h" + +#define _COMPONENT ACPI_EXECUTER +ACPI_MODULE_NAME("exstorob") + +/******************************************************************************* + * + * FUNCTION: acpi_ex_store_buffer_to_buffer + * + * PARAMETERS: source_desc - Source object to copy + * target_desc - Destination object of the copy + * + * RETURN: Status + * + * DESCRIPTION: Copy a buffer object to another buffer object. + * + ******************************************************************************/ +acpi_status +acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc, + union acpi_operand_object *target_desc) +{ + u32 length; + u8 *buffer; + + ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc); + + /* If Source and Target are the same, just return */ + + if (source_desc == target_desc) { + return_ACPI_STATUS(AE_OK); + } + + /* We know that source_desc is a buffer by now */ + + buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer); + length = source_desc->buffer.length; + + /* + * If target is a buffer of length zero or is a static buffer, + * allocate a new buffer of the proper length + */ + if ((target_desc->buffer.length == 0) || + (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) { + target_desc->buffer.pointer = ACPI_ALLOCATE(length); + if (!target_desc->buffer.pointer) { + return_ACPI_STATUS(AE_NO_MEMORY); + } + + target_desc->buffer.length = length; + } + + /* Copy source buffer to target buffer */ + + if (length <= target_desc->buffer.length) { + + /* Clear existing buffer and copy in the new one */ + + memset(target_desc->buffer.pointer, 0, + target_desc->buffer.length); + memcpy(target_desc->buffer.pointer, buffer, length); + +#ifdef ACPI_OBSOLETE_BEHAVIOR + /* + * NOTE: ACPI versions up to 3.0 specified that the buffer must be + * truncated if the string is smaller than the buffer. However, "other" + * implementations of ACPI never did this and thus became the defacto + * standard. ACPI 3.0A changes this behavior such that the buffer + * is no longer truncated. + */ + + /* + * OBSOLETE BEHAVIOR: + * If the original source was a string, we must truncate the buffer, + * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer + * copy must not truncate the original buffer. + */ + if (original_src_type == ACPI_TYPE_STRING) { + + /* Set the new length of the target */ + + target_desc->buffer.length = length; + } +#endif + } else { + /* Truncate the source, copy only what will fit */ + + memcpy(target_desc->buffer.pointer, buffer, + target_desc->buffer.length); + + ACPI_DEBUG_PRINT((ACPI_DB_INFO, + "Truncating source buffer from %X to %X\n", + length, target_desc->buffer.length)); + } + + /* Copy flags */ + + target_desc->buffer.flags = source_desc->buffer.flags; + target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER; + return_ACPI_STATUS(AE_OK); +} + +/******************************************************************************* + * + * FUNCTION: acpi_ex_store_string_to_string + * + * PARAMETERS: source_desc - Source object to copy + * target_desc - Destination object of the copy + * + * RETURN: Status + * + * DESCRIPTION: Copy a String object to another String object + * + ******************************************************************************/ + +acpi_status +acpi_ex_store_string_to_string(union acpi_operand_object *source_desc, + union acpi_operand_object *target_desc) +{ + u32 length; + u8 *buffer; + + ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc); + + /* If Source and Target are the same, just return */ + + if (source_desc == target_desc) { + return_ACPI_STATUS(AE_OK); + } + + /* We know that source_desc is a string by now */ + + buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer); + length = source_desc->string.length; + + /* + * Replace existing string value if it will fit and the string + * pointer is not a static pointer (part of an ACPI table) + */ + if ((length < target_desc->string.length) && + (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) { + /* + * String will fit in existing non-static buffer. + * Clear old string and copy in the new one + */ + memset(target_desc->string.pointer, 0, + (acpi_size)target_desc->string.length + 1); + memcpy(target_desc->string.pointer, buffer, length); + } else { + /* + * Free the current buffer, then allocate a new buffer + * large enough to hold the value + */ + if (target_desc->string.pointer && + (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) { + + /* Only free if not a pointer into the DSDT */ + + ACPI_FREE(target_desc->string.pointer); + } + + target_desc->string.pointer = + ACPI_ALLOCATE_ZEROED((acpi_size)length + 1); + + if (!target_desc->string.pointer) { + return_ACPI_STATUS(AE_NO_MEMORY); + } + + target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER; + memcpy(target_desc->string.pointer, buffer, length); + } + + /* Set the new target length */ + + target_desc->string.length = length; + return_ACPI_STATUS(AE_OK); +} |