1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ranges.c: Handle ranges in newer proms for obio/sbus.
4 *
5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7 */
8
9#include <linux/init.h>
10#include <linux/module.h>
11
12#include <asm/openprom.h>
13#include <asm/oplib.h>
14#include <asm/types.h>
15
16static struct linux_prom_ranges promlib_obio_ranges[PROMREG_MAX];
17static int num_obio_ranges;
18
19/* Adjust register values based upon the ranges parameters. */
20static void prom_adjust_regs(struct linux_prom_registers *regp, int nregs,
21			     struct linux_prom_ranges *rangep, int nranges)
22{
23	int regc, rngc;
24
25	for (regc = 0; regc < nregs; regc++) {
26		for (rngc = 0; rngc < nranges; rngc++)
27			if (regp[regc].which_io == rangep[rngc].ot_child_space)
28				break; /* Fount it */
29		if (rngc == nranges) /* oops */
30			prom_printf("adjust_regs: Could not find range with matching bus type...\n");
31		regp[regc].which_io = rangep[rngc].ot_parent_space;
32		regp[regc].phys_addr -= rangep[rngc].ot_child_base;
33		regp[regc].phys_addr += rangep[rngc].ot_parent_base;
34	}
35}
36
37static void prom_adjust_ranges(struct linux_prom_ranges *ranges1, int nranges1,
38			       struct linux_prom_ranges *ranges2, int nranges2)
39{
40	int rng1c, rng2c;
41
42	for (rng1c = 0; rng1c < nranges1; rng1c++) {
43		for (rng2c = 0; rng2c < nranges2; rng2c++)
44			if (ranges1[rng1c].ot_parent_space == ranges2[rng2c].ot_child_space &&
45			   ranges1[rng1c].ot_parent_base >= ranges2[rng2c].ot_child_base &&
46			   ranges2[rng2c].ot_child_base + ranges2[rng2c].or_size - ranges1[rng1c].ot_parent_base > 0U)
47			break;
48		if (rng2c == nranges2) /* oops */
49			prom_printf("adjust_ranges: Could not find matching bus type...\n");
50		else if (ranges1[rng1c].ot_parent_base + ranges1[rng1c].or_size > ranges2[rng2c].ot_child_base + ranges2[rng2c].or_size)
51			ranges1[rng1c].or_size = ranges2[rng2c].ot_child_base + ranges2[rng2c].or_size - ranges1[rng1c].ot_parent_base;
52		ranges1[rng1c].ot_parent_space = ranges2[rng2c].ot_parent_space;
53		ranges1[rng1c].ot_parent_base += ranges2[rng2c].ot_parent_base;
54	}
55}
56
57/* Apply probed obio ranges to registers passed, if no ranges return. */
58void prom_apply_obio_ranges(struct linux_prom_registers *regs, int nregs)
59{
60	if (num_obio_ranges)
61		prom_adjust_regs(regs, nregs, promlib_obio_ranges, num_obio_ranges);
62}
63EXPORT_SYMBOL(prom_apply_obio_ranges);
64
65void __init prom_ranges_init(void)
66{
67	phandle node, obio_node;
68	int success;
69
70	num_obio_ranges = 0;
71
72	/* Check for obio and sbus ranges. */
73	node = prom_getchild(prom_root_node);
74	obio_node = prom_searchsiblings(node, "obio");
75
76	if (obio_node) {
77		success = prom_getproperty(obio_node, "ranges",
78					   (char *) promlib_obio_ranges,
79					   sizeof(promlib_obio_ranges));
80		if (success != -1)
81			num_obio_ranges = (success / sizeof(struct linux_prom_ranges));
82	}
83
84	if (num_obio_ranges)
85		prom_printf("PROMLIB: obio_ranges %d\n", num_obio_ranges);
86}
87
88void prom_apply_generic_ranges(phandle node, phandle parent,
89			       struct linux_prom_registers *regs, int nregs)
90{
91	int success;
92	int num_ranges;
93	struct linux_prom_ranges ranges[PROMREG_MAX];
94
95	success = prom_getproperty(node, "ranges",
96				   (char *) ranges,
97				   sizeof(ranges));
98	if (success != -1) {
99		num_ranges = (success / sizeof(struct linux_prom_ranges));
100		if (parent) {
101			struct linux_prom_ranges parent_ranges[PROMREG_MAX];
102			int num_parent_ranges;
103
104			success = prom_getproperty(parent, "ranges",
105						   (char *) parent_ranges,
106						   sizeof(parent_ranges));
107			if (success != -1) {
108				num_parent_ranges = (success / sizeof(struct linux_prom_ranges));
109				prom_adjust_ranges(ranges, num_ranges, parent_ranges, num_parent_ranges);
110			}
111		}
112		prom_adjust_regs(regs, nregs, ranges, num_ranges);
113	}
114}
115