1/*
2 * Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
3 * Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
4 * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
12 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
14 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
15 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
16 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
17 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
18 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
19 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
20 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
21 *
22 * You should have received a copy of the GNU General Public License along
23 * with this program; if not, write to the Free Software Foundation, Inc.,
24 * 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27#include <linux/init.h>
28#include <linux/types.h>
29#include <linux/kernel.h>
30#include <linux/memblock.h>
31#include <linux/spinlock.h>
32#include <linux/ssb/ssb_driver_chipcommon.h>
33#include <linux/ssb/ssb_regs.h>
34#include <linux/smp.h>
35#include <asm/bootinfo.h>
36#include <bcm47xx.h>
37#include <bcm47xx_board.h>
38
39static char bcm47xx_system_type[20] = "Broadcom BCM47XX";
40
41const char *get_system_type(void)
42{
43 return bcm47xx_system_type;
44}
45
46__init void bcm47xx_set_system_type(u16 chip_id)
47{
48 snprintf(buf: bcm47xx_system_type, size: sizeof(bcm47xx_system_type),
49 fmt: (chip_id > 0x9999) ? "Broadcom BCM%d" :
50 "Broadcom BCM%04X",
51 chip_id);
52}
53
54static unsigned long lowmem __initdata;
55
56static __init void prom_init_mem(void)
57{
58 unsigned long mem;
59 unsigned long max;
60 unsigned long off;
61 struct cpuinfo_mips *c = &current_cpu_data;
62
63 /* Figure out memory size by finding aliases.
64 *
65 * We should theoretically use the mapping from CFE using cfe_enummem().
66 * However as the BCM47XX is mostly used on low-memory systems, we
67 * want to reuse the memory used by CFE (around 4MB). That means cfe_*
68 * functions stop to work at some point during the boot, we should only
69 * call them at the beginning of the boot.
70 *
71 * BCM47XX uses 128MB for addressing the ram, if the system contains
72 * less than that amount of ram it remaps the ram more often into the
73 * available space.
74 */
75
76 /* Physical address, without mapping to any kernel segment */
77 off = CPHYSADDR((unsigned long)prom_init);
78
79 /* Accessing memory after 128 MiB will cause an exception */
80 max = 128 << 20;
81
82 for (mem = 1 << 20; mem < max; mem += 1 << 20) {
83 /* Loop condition may be not enough, off may be over 1 MiB */
84 if (off + mem >= max) {
85 mem = max;
86 pr_debug("Assume 128MB RAM\n");
87 break;
88 }
89 if (!memcmp((void *)prom_init, (void *)prom_init + mem, 32))
90 break;
91 }
92 lowmem = mem;
93
94 /* Ignoring the last page when ddr size is 128M. Cached
95 * accesses to last page is causing the processor to prefetch
96 * using address above 128M stepping out of the ddr address
97 * space.
98 */
99 if (c->cputype == CPU_74K && (mem == (128 << 20)))
100 mem -= 0x1000;
101 memblock_add(base: 0, size: mem);
102}
103
104/*
105 * This is the first serial on the chip common core, it is at this position
106 * for sb (ssb) and ai (bcma) bus.
107 */
108#define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)
109
110void __init prom_init(void)
111{
112 prom_init_mem();
113 setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
114}
115
116#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)
117
118#define EXTVBASE 0xc0000000
119#define ENTRYLO(x) ((pte_val(pfn_pte((x) >> PFN_PTE_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)
120
121#include <asm/tlbflush.h>
122
123/* Stripped version of tlb_init, with the call to build_tlb_refill_handler
124 * dropped. Calling it at this stage causes a hang.
125 */
126void early_tlb_init(void)
127{
128 write_c0_pagemask(PM_DEFAULT_MASK);
129 write_c0_wired(0);
130 temp_tlb_entry = current_cpu_data.tlbsize - 1;
131 local_flush_tlb_all();
132}
133
134void __init bcm47xx_prom_highmem_init(void)
135{
136 unsigned long off = (unsigned long)prom_init;
137 unsigned long extmem = 0;
138 bool highmem_region = false;
139
140 if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
141 return;
142
143 if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
144 highmem_region = true;
145
146 if (lowmem != 128 << 20 || !highmem_region)
147 return;
148
149 early_tlb_init();
150
151 /* Add one temporary TLB entry to map SDRAM Region 2.
152 * Physical Virtual
153 * 0x80000000 0xc0000000 (1st: 256MB)
154 * 0x90000000 0xd0000000 (2nd: 256MB)
155 */
156 add_temporary_entry(ENTRYLO(0x80000000),
157 ENTRYLO(0x80000000 + (256 << 20)),
158 EXTVBASE, PM_256M);
159
160 off = EXTVBASE + __pa(off);
161 for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
162 if (!memcmp((void *)prom_init, (void *)(off + extmem), 16))
163 break;
164 }
165 extmem -= lowmem;
166
167 early_tlb_init();
168
169 if (!extmem)
170 return;
171
172 pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
173 extmem >> 20);
174
175 /* TODO: Register extra memory */
176}
177
178#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */
179

source code of linux/arch/mips/bcm47xx/prom.c