xref: /openbmc/linux/arch/sparc/prom/ranges.c (revision 842ed298)
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 
16 static struct linux_prom_ranges promlib_obio_ranges[PROMREG_MAX];
17 static int num_obio_ranges;
18 
19 /* Adjust register values based upon the ranges parameters. */
20 static 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 
37 static 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. */
58 void 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 }
63 EXPORT_SYMBOL(prom_apply_obio_ranges);
64 
65 void __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 
88 void 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