1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/*******************************************************************************
3 *
4 * Module Name: rslist - Linked list utilities
5 *
6 ******************************************************************************/
7
8#include <acpi/acpi.h>
9#include "accommon.h"
10#include "acresrc.h"
11
12#define _COMPONENT          ACPI_RESOURCES
13ACPI_MODULE_NAME("rslist")
14
15/*******************************************************************************
16 *
17 * FUNCTION:    acpi_rs_convert_aml_to_resources
18 *
19 * PARAMETERS:  acpi_walk_aml_callback
20 *              resource_ptr            - Pointer to the buffer that will
21 *                                        contain the output structures
22 *
23 * RETURN:      Status
24 *
25 * DESCRIPTION: Convert an AML resource to an internal representation of the
26 *              resource that is aligned and easier to access.
27 *
28 ******************************************************************************/
29acpi_status
30acpi_rs_convert_aml_to_resources(u8 * aml,
31				 u32 length,
32				 u32 offset, u8 resource_index, void **context)
33{
34	struct acpi_resource **resource_ptr =
35	    ACPI_CAST_INDIRECT_PTR(struct acpi_resource, context);
36	struct acpi_resource *resource;
37	union aml_resource *aml_resource;
38	struct acpi_rsconvert_info *conversion_table;
39	acpi_status status;
40
41	ACPI_FUNCTION_TRACE(rs_convert_aml_to_resources);
42
43	/*
44	 * Check that the input buffer and all subsequent pointers into it
45	 * are aligned on a native word boundary. Most important on IA64
46	 */
47	resource = *resource_ptr;
48	if (ACPI_IS_MISALIGNED(resource)) {
49		ACPI_WARNING((AE_INFO,
50			      "Misaligned resource pointer %p", resource));
51	}
52
53	/* Get the appropriate conversion info table */
54
55	aml_resource = ACPI_CAST_PTR(union aml_resource, aml);
56
57	if (acpi_ut_get_resource_type(aml) == ACPI_RESOURCE_NAME_SERIAL_BUS) {
58
59		/* Avoid undefined behavior: member access within misaligned address */
60
61		struct aml_resource_common_serialbus common_serial_bus;
62		memcpy(&common_serial_bus, aml_resource,
63		       sizeof(common_serial_bus));
64
65		if (common_serial_bus.type > AML_RESOURCE_MAX_SERIALBUSTYPE) {
66			conversion_table = NULL;
67		} else {
68			/* This is an I2C, SPI, UART, or CSI2 serial_bus descriptor */
69
70			conversion_table =
71			    acpi_gbl_convert_resource_serial_bus_dispatch
72			    [common_serial_bus.type];
73		}
74	} else {
75		conversion_table =
76		    acpi_gbl_get_resource_dispatch[resource_index];
77	}
78
79	if (!conversion_table) {
80		ACPI_ERROR((AE_INFO,
81			    "Invalid/unsupported resource descriptor: Type 0x%2.2X",
82			    resource_index));
83		return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
84	}
85
86	/* Convert the AML byte stream resource to a local resource struct */
87
88	status =
89	    acpi_rs_convert_aml_to_resource(resource, aml_resource,
90					    conversion_table);
91	if (ACPI_FAILURE(status)) {
92		ACPI_EXCEPTION((AE_INFO, status,
93				"Could not convert AML resource (Type 0x%X)",
94				*aml));
95		return_ACPI_STATUS(status);
96	}
97
98	if (!resource->length) {
99		ACPI_EXCEPTION((AE_INFO, status,
100				"Zero-length resource returned from RsConvertAmlToResource"));
101	}
102
103	ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES,
104			  "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
105			  acpi_ut_get_resource_type(aml), length,
106			  resource->length));
107
108	/* Point to the next structure in the output buffer */
109
110	*resource_ptr = ACPI_NEXT_RESOURCE(resource);
111	return_ACPI_STATUS(AE_OK);
112}
113
114/*******************************************************************************
115 *
116 * FUNCTION:    acpi_rs_convert_resources_to_aml
117 *
118 * PARAMETERS:  resource            - Pointer to the resource linked list
119 *              aml_size_needed     - Calculated size of the byte stream
120 *                                    needed from calling acpi_rs_get_aml_length()
121 *                                    The size of the output_buffer is
122 *                                    guaranteed to be >= aml_size_needed
123 *              output_buffer       - Pointer to the buffer that will
124 *                                    contain the byte stream
125 *
126 * RETURN:      Status
127 *
128 * DESCRIPTION: Takes the resource linked list and parses it, creating a
129 *              byte stream of resources in the caller's output buffer
130 *
131 ******************************************************************************/
132
133acpi_status
134acpi_rs_convert_resources_to_aml(struct acpi_resource *resource,
135				 acpi_size aml_size_needed, u8 * output_buffer)
136{
137	u8 *aml = output_buffer;
138	u8 *end_aml = output_buffer + aml_size_needed;
139	struct acpi_rsconvert_info *conversion_table;
140	acpi_status status;
141
142	ACPI_FUNCTION_TRACE(rs_convert_resources_to_aml);
143
144	/* Walk the resource descriptor list, convert each descriptor */
145
146	while (aml < end_aml) {
147
148		/* Validate the (internal) Resource Type */
149
150		if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
151			ACPI_ERROR((AE_INFO,
152				    "Invalid descriptor type (0x%X) in resource list",
153				    resource->type));
154			return_ACPI_STATUS(AE_BAD_DATA);
155		}
156
157		/* Sanity check the length. It must not be zero, or we loop forever */
158
159		if (!resource->length) {
160			ACPI_ERROR((AE_INFO,
161				    "Invalid zero length descriptor in resource list\n"));
162			return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
163		}
164
165		/* Perform the conversion */
166
167		if (resource->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
168			if (resource->data.common_serial_bus.type >
169			    AML_RESOURCE_MAX_SERIALBUSTYPE) {
170				conversion_table = NULL;
171			} else {
172				/* This is an I2C, SPI, UART or CSI2 serial_bus descriptor */
173
174				conversion_table =
175				    acpi_gbl_convert_resource_serial_bus_dispatch
176				    [resource->data.common_serial_bus.type];
177			}
178		} else {
179			conversion_table =
180			    acpi_gbl_set_resource_dispatch[resource->type];
181		}
182
183		if (!conversion_table) {
184			ACPI_ERROR((AE_INFO,
185				    "Invalid/unsupported resource descriptor: Type 0x%2.2X",
186				    resource->type));
187			return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
188		}
189
190		status = acpi_rs_convert_resource_to_aml(resource,
191						         ACPI_CAST_PTR(union
192								       aml_resource,
193								       aml),
194							 conversion_table);
195		if (ACPI_FAILURE(status)) {
196			ACPI_EXCEPTION((AE_INFO, status,
197					"Could not convert resource (type 0x%X) to AML",
198					resource->type));
199			return_ACPI_STATUS(status);
200		}
201
202		/* Perform final sanity check on the new AML resource descriptor */
203
204		status =
205		    acpi_ut_validate_resource(NULL,
206					      ACPI_CAST_PTR(union aml_resource,
207							    aml), NULL);
208		if (ACPI_FAILURE(status)) {
209			return_ACPI_STATUS(status);
210		}
211
212		/* Check for end-of-list, normal exit */
213
214		if (resource->type == ACPI_RESOURCE_TYPE_END_TAG) {
215
216			/* An End Tag indicates the end of the input Resource Template */
217
218			return_ACPI_STATUS(AE_OK);
219		}
220
221		/*
222		 * Extract the total length of the new descriptor and set the
223		 * Aml to point to the next (output) resource descriptor
224		 */
225		aml += acpi_ut_get_descriptor_length(aml);
226
227		/* Point to the next input resource descriptor */
228
229		resource = ACPI_NEXT_RESOURCE(resource);
230	}
231
232	/* Completed buffer, but did not find an end_tag resource descriptor */
233
234	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
235}
236