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
acpi_rs_convert_aml_to_resources(u8 * aml,u32 length,u32 offset,u8 resource_index,void ** context)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  
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  
133  acpi_status
acpi_rs_convert_resources_to_aml(struct acpi_resource * resource,acpi_size aml_size_needed,u8 * output_buffer)134  acpi_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