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(bcm47xx_system_type, sizeof(bcm47xx_system_type),
49		 (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(0, 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