1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2
3 #include <stdio.h>
4 #include <inttypes.h>
5
6 #include "intelmetool.h"
7 #include "mmap.h"
8 #include "rcba.h"
9
10 static const int size = 0x4000;
11
12 /* Returns the physical RCBA base address or zero on error. */
get_rcba_phys(void)13 u32 get_rcba_phys(void)
14 {
15 struct pci_access *pacc;
16 struct pci_dev *sb;
17 uint32_t rcba_phys;
18
19 pacc = pci_alloc();
20 pacc->method = PCI_ACCESS_I386_TYPE1;
21
22 pci_init(pacc);
23 pci_scan_bus(pacc);
24
25 sb = pci_get_dev(pacc, 0, 0, 0x1f, 0);
26 if (!sb) {
27 printf("Uh oh, southbridge not on BDF(0:31:0), please report "
28 "this error, exiting.\n");
29 pci_cleanup(pacc);
30 return 0;
31 }
32 pci_fill_info(sb, PCI_FILL_IDENT | PCI_FILL_BASES | PCI_FILL_SIZES |
33 PCI_FILL_CLASS);
34
35 rcba_phys = pci_read_long(sb, 0xf0) & 0xfffffffe;
36
37 pci_free_dev(sb);
38 pci_cleanup(pacc);
39
40 return rcba_phys;
41 }
42
43 /*
44 * Writes 'val' to RCBA register at address 'addr'.
45 * Returns 1 on error and 0 on success.
46 */
write_rcba32(uint32_t addr,uint32_t val)47 int write_rcba32(uint32_t addr, uint32_t val)
48 {
49 volatile uint8_t *rcba;
50 const uint32_t rcba_phys = get_rcba_phys();
51
52 if (!rcba_phys) {
53 printf("Could not get RCBA address\n");
54 return 1;
55 }
56
57 rcba = map_physical((off_t)rcba_phys, size);
58 if (rcba == NULL) {
59 printf("Could not map RCBA\n"
60 "Do you have kernel cmdline argument 'iomem=relaxed' set ?\n");
61 return 1;
62 }
63 *(uint32_t *)(rcba + addr) = val;
64
65 munmap((void *)rcba, size);
66 return 0;
67 }
68
69 /*
70 * Reads RCBA register at address 'addr' and stores it in 'val'.
71 * Returns 1 on error and 0 on success.
72 */
read_rcba32(uint32_t addr,uint32_t * val)73 int read_rcba32(uint32_t addr, uint32_t *val)
74 {
75 volatile uint8_t *rcba;
76 const uint32_t rcba_phys = get_rcba_phys();
77
78 if (!rcba_phys) {
79 printf("Could not get RCBA address\n");
80 return 1;
81 }
82
83 rcba = map_physical((off_t)rcba_phys, size);
84 if (rcba == NULL) {
85 printf("Could not map RCBA\n"
86 "Do you have kernel cmdline argument 'iomem=relaxed' set ?\n");
87 return 1;
88 }
89
90 *val = *(uint32_t *)(rcba + addr);
91
92 munmap((void *)rcba, size);
93 return 0;
94 }
95