xref: /linux/drivers/acpi/acpica/rslist.c (revision 96ac6d435100450f0565708d9b885ea2a7400e0a)
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
13 ACPI_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  ******************************************************************************/
29 acpi_status
30 acpi_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 		if (aml_resource->common_serial_bus.type >
59 		    AML_RESOURCE_MAX_SERIALBUSTYPE) {
60 			conversion_table = NULL;
61 		} else {
62 			/* This is an I2C, SPI, or UART serial_bus descriptor */
63 
64 			conversion_table =
65 			    acpi_gbl_convert_resource_serial_bus_dispatch
66 			    [aml_resource->common_serial_bus.type];
67 		}
68 	} else {
69 		conversion_table =
70 		    acpi_gbl_get_resource_dispatch[resource_index];
71 	}
72 
73 	if (!conversion_table) {
74 		ACPI_ERROR((AE_INFO,
75 			    "Invalid/unsupported resource descriptor: Type 0x%2.2X",
76 			    resource_index));
77 		return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
78 	}
79 
80 	/* Convert the AML byte stream resource to a local resource struct */
81 
82 	status =
83 	    acpi_rs_convert_aml_to_resource(resource, aml_resource,
84 					    conversion_table);
85 	if (ACPI_FAILURE(status)) {
86 		ACPI_EXCEPTION((AE_INFO, status,
87 				"Could not convert AML resource (Type 0x%X)",
88 				*aml));
89 		return_ACPI_STATUS(status);
90 	}
91 
92 	ACPI_DEBUG_PRINT((ACPI_DB_RESOURCES,
93 			  "Type %.2X, AmlLength %.2X InternalLength %.2X\n",
94 			  acpi_ut_get_resource_type(aml), length,
95 			  resource->length));
96 
97 	/* Point to the next structure in the output buffer */
98 
99 	*resource_ptr = ACPI_NEXT_RESOURCE(resource);
100 	return_ACPI_STATUS(AE_OK);
101 }
102 
103 /*******************************************************************************
104  *
105  * FUNCTION:    acpi_rs_convert_resources_to_aml
106  *
107  * PARAMETERS:  resource            - Pointer to the resource linked list
108  *              aml_size_needed     - Calculated size of the byte stream
109  *                                    needed from calling acpi_rs_get_aml_length()
110  *                                    The size of the output_buffer is
111  *                                    guaranteed to be >= aml_size_needed
112  *              output_buffer       - Pointer to the buffer that will
113  *                                    contain the byte stream
114  *
115  * RETURN:      Status
116  *
117  * DESCRIPTION: Takes the resource linked list and parses it, creating a
118  *              byte stream of resources in the caller's output buffer
119  *
120  ******************************************************************************/
121 
122 acpi_status
123 acpi_rs_convert_resources_to_aml(struct acpi_resource *resource,
124 				 acpi_size aml_size_needed, u8 * output_buffer)
125 {
126 	u8 *aml = output_buffer;
127 	u8 *end_aml = output_buffer + aml_size_needed;
128 	struct acpi_rsconvert_info *conversion_table;
129 	acpi_status status;
130 
131 	ACPI_FUNCTION_TRACE(rs_convert_resources_to_aml);
132 
133 	/* Walk the resource descriptor list, convert each descriptor */
134 
135 	while (aml < end_aml) {
136 
137 		/* Validate the (internal) Resource Type */
138 
139 		if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
140 			ACPI_ERROR((AE_INFO,
141 				    "Invalid descriptor type (0x%X) in resource list",
142 				    resource->type));
143 			return_ACPI_STATUS(AE_BAD_DATA);
144 		}
145 
146 		/* Sanity check the length. It must not be zero, or we loop forever */
147 
148 		if (!resource->length) {
149 			ACPI_ERROR((AE_INFO,
150 				    "Invalid zero length descriptor in resource list\n"));
151 			return_ACPI_STATUS(AE_AML_BAD_RESOURCE_LENGTH);
152 		}
153 
154 		/* Perform the conversion */
155 
156 		if (resource->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
157 			if (resource->data.common_serial_bus.type >
158 			    AML_RESOURCE_MAX_SERIALBUSTYPE) {
159 				conversion_table = NULL;
160 			} else {
161 				/* This is an I2C, SPI, or UART serial_bus descriptor */
162 
163 				conversion_table =
164 				    acpi_gbl_convert_resource_serial_bus_dispatch
165 				    [resource->data.common_serial_bus.type];
166 			}
167 		} else {
168 			conversion_table =
169 			    acpi_gbl_set_resource_dispatch[resource->type];
170 		}
171 
172 		if (!conversion_table) {
173 			ACPI_ERROR((AE_INFO,
174 				    "Invalid/unsupported resource descriptor: Type 0x%2.2X",
175 				    resource->type));
176 			return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
177 		}
178 
179 		status = acpi_rs_convert_resource_to_aml(resource,
180 						         ACPI_CAST_PTR(union
181 								       aml_resource,
182 								       aml),
183 							 conversion_table);
184 		if (ACPI_FAILURE(status)) {
185 			ACPI_EXCEPTION((AE_INFO, status,
186 					"Could not convert resource (type 0x%X) to AML",
187 					resource->type));
188 			return_ACPI_STATUS(status);
189 		}
190 
191 		/* Perform final sanity check on the new AML resource descriptor */
192 
193 		status =
194 		    acpi_ut_validate_resource(NULL,
195 					      ACPI_CAST_PTR(union aml_resource,
196 							    aml), NULL);
197 		if (ACPI_FAILURE(status)) {
198 			return_ACPI_STATUS(status);
199 		}
200 
201 		/* Check for end-of-list, normal exit */
202 
203 		if (resource->type == ACPI_RESOURCE_TYPE_END_TAG) {
204 
205 			/* An End Tag indicates the end of the input Resource Template */
206 
207 			return_ACPI_STATUS(AE_OK);
208 		}
209 
210 		/*
211 		 * Extract the total length of the new descriptor and set the
212 		 * Aml to point to the next (output) resource descriptor
213 		 */
214 		aml += acpi_ut_get_descriptor_length(aml);
215 
216 		/* Point to the next input resource descriptor */
217 
218 		resource = ACPI_NEXT_RESOURCE(resource);
219 	}
220 
221 	/* Completed buffer, but did not find an end_tag resource descriptor */
222 
223 	return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
224 }
225