summaryrefslogtreecommitdiffstats
path: root/kernel/arch/mips/bcm47xx/prom.c
blob: ab698bad6d627a1c29856f7c0e30e1214e781f84 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
 *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
 *  Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
 *  Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/ssb/ssb_driver_chipcommon.h>
#include <linux/ssb/ssb_regs.h>
#include <linux/smp.h>
#include <asm/bootinfo.h>
#include <bcm47xx.h>
#include <bcm47xx_board.h>

static char bcm47xx_system_type[20] = "Broadcom BCM47XX";

const char *get_system_type(void)
{
	return bcm47xx_system_type;
}

__init void bcm47xx_set_system_type(u16 chip_id)
{
	snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type),
		 (chip_id > 0x9999) ? "Broadcom BCM%d" :
				      "Broadcom BCM%04X",
		 chip_id);
}

static unsigned long lowmem __initdata;

static __init void prom_init_mem(void)
{
	unsigned long mem;
	unsigned long max;
	unsigned long off;
	struct cpuinfo_mips *c = &current_cpu_data;

	/* Figure out memory size by finding aliases.
	 *
	 * We should theoretically use the mapping from CFE using cfe_enummem().
	 * However as the BCM47XX is mostly used on low-memory systems, we
	 * want to reuse the memory used by CFE (around 4MB). That means cfe_*
	 * functions stop to work at some point during the boot, we should only
	 * call them at the beginning of the boot.
	 *
	 * BCM47XX uses 128MB for addressing the ram, if the system contains
	 * less that that amount of ram it remaps the ram more often into the
	 * available space.
	 */

	/* Physical address, without mapping to any kernel segment */
	off = CPHYSADDR((unsigned long)prom_init);

	/* Accessing memory after 128 MiB will cause an exception */
	max = 128 << 20;

	for (mem = 1 << 20; mem < max; mem += 1 << 20) {
		/* Loop condition may be not enough, off may be over 1 MiB */
		if (off + mem >= max) {
			mem = max;
			pr_debug("Assume 128MB RAM\n");
			break;
		}
		if (!memcmp(prom_init, prom_init + mem, 32))
			break;
	}
	lowmem = mem;

	/* Ignoring the last page when ddr size is 128M. Cached
	 * accesses to last page is causing the processor to prefetch
	 * using address above 128M stepping out of the ddr address
	 * space.
	 */
	if (c->cputype == CPU_74K && (mem == (128  << 20)))
		mem -= 0x1000;
	add_memory_region(0, mem, BOOT_MEM_RAM);
}

/*
 * This is the first serial on the chip common core, it is at this position
 * for sb (ssb) and ai (bcma) bus.
 */
#define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)

void __init prom_init(void)
{
	prom_init_mem();
	setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
}

void __init prom_free_prom_memory(void)
{
}

#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)

#define EXTVBASE	0xc0000000
#define ENTRYLO(x)	((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)

#include <asm/tlbflush.h>

/* Stripped version of tlb_init, with the call to build_tlb_refill_handler
 * dropped. Calling it at this stage causes a hang.
 */
void __cpuinit early_tlb_init(void)
{
	write_c0_pagemask(PM_DEFAULT_MASK);
	write_c0_wired(0);
	temp_tlb_entry = current_cpu_data.tlbsize - 1;
	local_flush_tlb_all();
}

void __init bcm47xx_prom_highmem_init(void)
{
	unsigned long off = (unsigned long)prom_init;
	unsigned long extmem = 0;
	bool highmem_region = false;

	if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
		return;

	if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
		highmem_region = true;

	if (lowmem != 128 << 20 || !highmem_region)
		return;

	early_tlb_init();

	/* Add one temporary TLB entry to map SDRAM Region 2.
	 *      Physical        Virtual
	 *      0x80000000      0xc0000000      (1st: 256MB)
	 *      0x90000000      0xd0000000      (2nd: 256MB)
	 */
	add_temporary_entry(ENTRYLO(0x80000000),
			    ENTRYLO(0x80000000 + (256 << 20)),
			    EXTVBASE, PM_256M);

	off = EXTVBASE + __pa(off);
	for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
		if (!memcmp(prom_init, (void *)(off + extmem), 16))
			break;
	}
	extmem -= lowmem;

	early_tlb_init();

	if (!extmem)
		return;

	pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
		extmem >> 20);

	/* TODO: Register extra memory */
}

#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */