xref: /openbmc/u-boot/arch/powerpc/cpu/mpc83xx/law.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2011 Freescale Semiconductor, Inc.
4  */
5 
6 #include <common.h>
7 #include <asm/fsl_law.h>
8 #include <asm/mmu.h>
9 #include <linux/log2.h>
10 
11 int set_ddr_laws(u64 start, u64 sz, enum law_trgt_if id)
12 {
13 	immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
14 	law83xx_t *ecm = &immap->sysconf.ddrlaw[0];
15 	u64 start_align, law_sz;
16 	int law_sz_enc;
17 
18 	if (start == 0)
19 		start_align = 1ull << (LAW_SIZE_2G + 1);
20 	else
21 		start_align = 1ull << (__ffs64(start));
22 	law_sz = min(start_align, sz);
23 	law_sz_enc = __ilog2_u64(law_sz) - 1;
24 
25 	/*
26 	 * Set up LAWBAR for all of DDR.
27 	 */
28 	ecm->bar = start & 0xfffff000;
29 	ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
30 	debug("DDR:bar=0x%08x\n", ecm->bar);
31 	debug("DDR:ar=0x%08x\n", ecm->ar);
32 
33 	/* recalculate size based on what was actually covered by the law */
34 	law_sz = 1ull << __ilog2_u64(law_sz);
35 
36 	/* do we still have anything to map */
37 	sz = sz - law_sz;
38 	if (sz) {
39 		start += law_sz;
40 
41 		start_align = 1ull << (__ffs64(start));
42 		law_sz = min(start_align, sz);
43 		law_sz_enc = __ilog2_u64(law_sz) - 1;
44 		ecm = &immap->sysconf.ddrlaw[1];
45 		ecm->bar = start & 0xfffff000;
46 		ecm->ar  = (LAWAR_EN | (id << 20) | (LAWAR_SIZE & law_sz_enc));
47 		debug("DDR:bar=0x%08x\n", ecm->bar);
48 		debug("DDR:ar=0x%08x\n", ecm->ar);
49 	} else {
50 		return 0;
51 	}
52 
53 	/* do we still have anything to map */
54 	sz = sz - law_sz;
55 	if (sz)
56 		return 1;
57 
58 	return 0;
59 }
60