util/intelmetool/rcba.c

   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. */
  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  */
  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  */
  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 }