xref: /openbmc/linux/arch/mips/bcm47xx/prom.c (revision f7777dcc)
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/spinlock.h>
31 #include <linux/smp.h>
32 #include <asm/bootinfo.h>
33 #include <asm/fw/cfe/cfe_api.h>
34 #include <asm/fw/cfe/cfe_error.h>
35 #include <bcm47xx.h>
36 #include <bcm47xx_board.h>
37 
38 static int cfe_cons_handle;
39 
40 static u16 get_chip_id(void)
41 {
42 	switch (bcm47xx_bus_type) {
43 #ifdef CONFIG_BCM47XX_SSB
44 	case BCM47XX_BUS_TYPE_SSB:
45 		return bcm47xx_bus.ssb.chip_id;
46 #endif
47 #ifdef CONFIG_BCM47XX_BCMA
48 	case BCM47XX_BUS_TYPE_BCMA:
49 		return bcm47xx_bus.bcma.bus.chipinfo.id;
50 #endif
51 	}
52 	return 0;
53 }
54 
55 const char *get_system_type(void)
56 {
57 	static char buf[50];
58 	u16 chip_id = get_chip_id();
59 
60 	snprintf(buf, sizeof(buf),
61 		 (chip_id > 0x9999) ? "Broadcom BCM%d (%s)" :
62 				      "Broadcom BCM%04X (%s)",
63 		 chip_id, bcm47xx_board_get_name());
64 
65 	return buf;
66 }
67 
68 void prom_putchar(char c)
69 {
70 	while (cfe_write(cfe_cons_handle, &c, 1) == 0)
71 		;
72 }
73 
74 static __init void prom_init_cfe(void)
75 {
76 	uint32_t cfe_ept;
77 	uint32_t cfe_handle;
78 	uint32_t cfe_eptseal;
79 	int argc = fw_arg0;
80 	char **envp = (char **) fw_arg2;
81 	int *prom_vec = (int *) fw_arg3;
82 
83 	/*
84 	 * Check if a loader was used; if NOT, the 4 arguments are
85 	 * what CFE gives us (handle, 0, EPT and EPTSEAL)
86 	 */
87 	if (argc < 0) {
88 		cfe_handle = (uint32_t)argc;
89 		cfe_ept = (uint32_t)envp;
90 		cfe_eptseal = (uint32_t)prom_vec;
91 	} else {
92 		if ((int)prom_vec < 0) {
93 			/*
94 			 * Old loader; all it gives us is the handle,
95 			 * so use the "known" entrypoint and assume
96 			 * the seal.
97 			 */
98 			cfe_handle = (uint32_t)prom_vec;
99 			cfe_ept = 0xBFC00500;
100 			cfe_eptseal = CFE_EPTSEAL;
101 		} else {
102 			/*
103 			 * Newer loaders bundle the handle/ept/eptseal
104 			 * Note: prom_vec is in the loader's useg
105 			 * which is still alive in the TLB.
106 			 */
107 			cfe_handle = prom_vec[0];
108 			cfe_ept = prom_vec[2];
109 			cfe_eptseal = prom_vec[3];
110 		}
111 	}
112 
113 	if (cfe_eptseal != CFE_EPTSEAL) {
114 		/* too early for panic to do any good */
115 		printk(KERN_ERR "CFE's entrypoint seal doesn't match.");
116 		while (1) ;
117 	}
118 
119 	cfe_init(cfe_handle, cfe_ept);
120 }
121 
122 static __init void prom_init_console(void)
123 {
124 	/* Initialize CFE console */
125 	cfe_cons_handle = cfe_getstdhandle(CFE_STDHANDLE_CONSOLE);
126 }
127 
128 static __init void prom_init_cmdline(void)
129 {
130 	static char buf[COMMAND_LINE_SIZE] __initdata;
131 
132 	/* Get the kernel command line from CFE */
133 	if (cfe_getenv("LINUX_CMDLINE", buf, COMMAND_LINE_SIZE) >= 0) {
134 		buf[COMMAND_LINE_SIZE - 1] = 0;
135 		strcpy(arcs_cmdline, buf);
136 	}
137 
138 	/* Force a console handover by adding a console= argument if needed,
139 	 * as CFE is not available anymore later in the boot process. */
140 	if ((strstr(arcs_cmdline, "console=")) == NULL) {
141 		/* Try to read the default serial port used by CFE */
142 		if ((cfe_getenv("BOOT_CONSOLE", buf, COMMAND_LINE_SIZE) < 0)
143 		    || (strncmp("uart", buf, 4)))
144 			/* Default to uart0 */
145 			strcpy(buf, "uart0");
146 
147 		/* Compute the new command line */
148 		snprintf(arcs_cmdline, COMMAND_LINE_SIZE, "%s console=ttyS%c,115200",
149 			 arcs_cmdline, buf[4]);
150 	}
151 }
152 
153 static __init void prom_init_mem(void)
154 {
155 	unsigned long mem;
156 	unsigned long max;
157 	unsigned long off;
158 	struct cpuinfo_mips *c = &current_cpu_data;
159 
160 	/* Figure out memory size by finding aliases.
161 	 *
162 	 * We should theoretically use the mapping from CFE using cfe_enummem().
163 	 * However as the BCM47XX is mostly used on low-memory systems, we
164 	 * want to reuse the memory used by CFE (around 4MB). That means cfe_*
165 	 * functions stop to work at some point during the boot, we should only
166 	 * call them at the beginning of the boot.
167 	 *
168 	 * BCM47XX uses 128MB for addressing the ram, if the system contains
169 	 * less that that amount of ram it remaps the ram more often into the
170 	 * available space.
171 	 * Accessing memory after 128MB will cause an exception.
172 	 * max contains the biggest possible address supported by the platform.
173 	 * If the method wants to try something above we assume 128MB ram.
174 	 */
175 	off = (unsigned long)prom_init;
176 	max = off | ((128 << 20) - 1);
177 	for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
178 		if ((off + mem) > max) {
179 			mem = (128 << 20);
180 			printk(KERN_DEBUG "assume 128MB RAM\n");
181 			break;
182 		}
183 		if (!memcmp(prom_init, prom_init + mem, 32))
184 			break;
185 	}
186 
187 	/* Ignoring the last page when ddr size is 128M. Cached
188 	 * accesses to last page is causing the processor to prefetch
189 	 * using address above 128M stepping out of the ddr address
190 	 * space.
191 	 */
192 	if (c->cputype == CPU_74K && (mem == (128  << 20)))
193 		mem -= 0x1000;
194 
195 	add_memory_region(0, mem, BOOT_MEM_RAM);
196 }
197 
198 void __init prom_init(void)
199 {
200 	prom_init_cfe();
201 	prom_init_console();
202 	prom_init_cmdline();
203 	prom_init_mem();
204 }
205 
206 void __init prom_free_prom_memory(void)
207 {
208 }
209