1 /**
2  * Functions for generating pseudo-random CXL protocol error sections.
3  *
4  * Author: Lawrence.Tang@arm.com
5  **/
6 
7 #include <stdlib.h>
8 #include "../../edk/BaseTypes.h"
9 #include "../gen-utils.h"
10 #include "gen-section.h"
11 
12 //Generates a single pseudo-random CXL protocol error section, saving the resulting address to the given
13 //location. Returns the size of the newly created section.
generate_section_cxl_protocol(void ** location)14 size_t generate_section_cxl_protocol(void **location)
15 {
16 	//Create a random length for the CXL DVSEC and CXL error log.
17 	//The logs attached here do not necessarily conform to the specification, and are simply random.
18 	int dvsec_len = rand() % 64;
19 	int error_log_len = rand() % 64;
20 
21 	//Create random bytes.
22 	int size = 116 + dvsec_len + error_log_len;
23 	UINT8 *bytes = generate_random_bytes(size);
24 
25 	//Set CXL agent type.
26 	int cxl_agent_type = rand() % 2;
27 	*(bytes + 8) = cxl_agent_type;
28 
29 	//Set reserved areas to zero.
30 	UINT64 *validation = (UINT64 *)bytes;
31 	*validation &= 0x3F;	      //Validation bits 6-63.
32 	for (int i = 0; i < 7; i++) {
33 		*(bytes + 9 + i) = 0; //Reserved bytes 9-15.
34 	}
35 
36 	//We only reserve bytes if it's a CXL 1.1 device, and not a host downstream port.
37 	if (cxl_agent_type == 0) {
38 		for (int i = 0; i < 3; i++) {
39 			*(bytes + 21 + i) = 0; //CXL agent address bytes 5-7.
40 		}
41 	}
42 
43 	*(bytes + 34) &= ~0x7; //Device ID byte 10 bits 0-2.
44 	UINT32 *reserved = (UINT32 *)(bytes + 36);
45 	*reserved = 0;	       //Device ID bytes 12-15.
46 	reserved = (UINT32 *)(bytes + 112);
47 	*reserved = 0;	       //Reserved bytes 112-115.
48 
49 	//If the device is a host downstream port, serial/capability structure is invalid.
50 	if (cxl_agent_type != 0) {
51 		for (int i = 0; i < 68; i++) {
52 			*(bytes + 40 + i) =
53 				0; //Device serial & capability structure.
54 		}
55 	}
56 
57 	//Set expected values.
58 	UINT16 *dvsec_length_field = (UINT16 *)(bytes + 108);
59 	UINT16 *error_log_len_field = (UINT16 *)(bytes + 110);
60 	*dvsec_length_field = dvsec_len;
61 	*error_log_len_field = error_log_len;
62 
63 	//Set return values, exit.
64 	*location = bytes;
65 	return size;
66 }
67