2 * Carsten Langgaard, carstenl@mips.com
3 * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
4 * Portions copyright (C) 2009 Cisco Systems, Inc.
6 * This program is free software; you can distribute it and/or modify it
7 * under the terms of the GNU General Public License (Version 2) as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
19 #include <linux/init.h>
20 #include <linux/sched.h>
21 #include <linux/ioport.h>
22 #include <linux/pci.h>
23 #include <linux/screen_info.h>
24 #include <linux/notifier.h>
25 #include <linux/etherdevice.h>
26 #include <linux/if_ether.h>
27 #include <linux/ctype.h>
29 #include <linux/cpu.h>
30 #include <asm/bootinfo.h>
32 #include <asm/mips-boards/generic.h>
33 #include <asm/mips-boards/prom.h>
35 #include <linux/time.h>
36 #include <asm/traps.h>
37 #include <asm/asm-offsets.h>
43 * Macros for loading addresses and storing registers:
44 * PTR_LA Load the address into a register
45 * LONG_S Store the full width of the given register.
46 * LONG_L Load the full width of the given register
47 * PTR_ADDIU Add a constant value to a register used as a pointer
48 * REG_SIZE Number of 8-bit bytes in a full width register
51 #warning TODO: 64-bit code needs to be verified
55 #define PTR_ADDIU "daddiu "
56 #define REG_SIZE "8" /* In bytes */
63 #define PTR_ADDIU "addiu "
64 #define REG_SIZE "4" /* In bytes */
67 static void register_panic_notifier(void);
68 static int panic_handler(struct notifier_block
*notifier_block
,
69 unsigned long event
, void *cause_string
);
71 const char *get_system_type(void)
76 void __init
plat_mem_setup(void)
79 register_panic_notifier();
88 * Install a panic notifier for platform-specific diagnostics
90 static void register_panic_notifier()
92 static struct notifier_block panic_notifier
= {
93 .notifier_call
= panic_handler
,
97 atomic_notifier_chain_register(&panic_notifier_list
, &panic_notifier
);
100 static int panic_handler(struct notifier_block
*notifier_block
,
101 unsigned long event
, void *cause_string
)
103 struct pt_regs my_regs
;
105 /* Save all of the registers */
107 unsigned long at
, v0
, v1
; /* Must be on the stack */
109 /* Start by saving $at and v0 on the stack. We use $at
110 * ourselves, but it looks like the compiler may use v0 or v1
111 * to load the address of the pt_regs structure. We'll come
112 * back later to store the registers in the pt_regs
114 __asm__
__volatile__ (
116 LONG_S
"$at, %[at]\n"
127 __asm__
__volatile__ (
129 "move $at, %[pt_regs]\n"
131 /* Argument registers */
132 LONG_S
"$4, " VAL(PT_R4
) "($at)\n"
133 LONG_S
"$5, " VAL(PT_R5
) "($at)\n"
134 LONG_S
"$6, " VAL(PT_R6
) "($at)\n"
135 LONG_S
"$7, " VAL(PT_R7
) "($at)\n"
138 LONG_S
"$8, " VAL(PT_R8
) "($at)\n"
139 LONG_S
"$9, " VAL(PT_R9
) "($at)\n"
140 LONG_S
"$10, " VAL(PT_R10
) "($at)\n"
141 LONG_S
"$11, " VAL(PT_R11
) "($at)\n"
142 LONG_S
"$12, " VAL(PT_R12
) "($at)\n"
143 LONG_S
"$13, " VAL(PT_R13
) "($at)\n"
144 LONG_S
"$14, " VAL(PT_R14
) "($at)\n"
145 LONG_S
"$15, " VAL(PT_R15
) "($at)\n"
147 /* "Saved" registers */
148 LONG_S
"$16, " VAL(PT_R16
) "($at)\n"
149 LONG_S
"$17, " VAL(PT_R17
) "($at)\n"
150 LONG_S
"$18, " VAL(PT_R18
) "($at)\n"
151 LONG_S
"$19, " VAL(PT_R19
) "($at)\n"
152 LONG_S
"$20, " VAL(PT_R20
) "($at)\n"
153 LONG_S
"$21, " VAL(PT_R21
) "($at)\n"
154 LONG_S
"$22, " VAL(PT_R22
) "($at)\n"
155 LONG_S
"$23, " VAL(PT_R23
) "($at)\n"
157 /* Add'l temp regs */
158 LONG_S
"$24, " VAL(PT_R24
) "($at)\n"
159 LONG_S
"$25, " VAL(PT_R25
) "($at)\n"
161 /* Kernel temp regs */
162 LONG_S
"$26, " VAL(PT_R26
) "($at)\n"
163 LONG_S
"$27, " VAL(PT_R27
) "($at)\n"
165 /* Global pointer, stack pointer, frame pointer and
167 LONG_S
"$gp, " VAL(PT_R28
) "($at)\n"
168 LONG_S
"$sp, " VAL(PT_R29
) "($at)\n"
169 LONG_S
"$fp, " VAL(PT_R30
) "($at)\n"
170 LONG_S
"$ra, " VAL(PT_R31
) "($at)\n"
172 /* Now we can get the $at and v0 registers back and
175 LONG_S
"$8, " VAL(PT_R1
) "($at)\n"
177 LONG_S
"$8, " VAL(PT_R2
) "($at)\n"
179 LONG_S
"$8, " VAL(PT_R3
) "($at)\n"
185 [pt_regs
] "r" (&my_regs
)
189 /* Set the current EPC value to be the current location in this
191 __asm__
__volatile__ (
195 LONG_S
"$at, %[cp0_epc]\n"
197 [cp0_epc
] "=m" (my_regs
.cp0_epc
)
202 my_regs
.cp0_cause
= read_c0_cause();
203 my_regs
.cp0_status
= read_c0_status();
206 #ifdef CONFIG_DIAGNOSTICS
207 failure_report((char *) cause_string
,
208 have_die_regs
? &die_regs
: &my_regs
);
209 have_die_regs
= false;
211 pr_crit("I'm feeling a bit sleepy. hmmmmm... perhaps a nap would... "
218 /* Information about the RF MAC address, if one was supplied on the
220 static bool have_rfmac
;
221 static u8 rfmac
[ETH_ALEN
];
223 static int rfmac_param(char *p
)
229 /* Skip a leading "0x", if present */
230 if (*p
== '0' && *(p
+1) == 'x')
234 is_high_nibble
= true;
236 for (c
= (unsigned char) *p
++;
237 isxdigit(c
) && q
- rfmac
< ETH_ALEN
;
238 c
= (unsigned char) *p
++) {
241 nibble
= (isdigit(c
) ? (c
- '0') :
242 (isupper(c
) ? c
- 'A' + 10 : c
- 'a' + 10));
249 is_high_nibble
= !is_high_nibble
;
252 /* If we parsed all the way to the end of the parameter value and
253 * parsed all ETH_ALEN bytes, we have a usable RF MAC address */
254 have_rfmac
= (c
== '\0' && q
- rfmac
== ETH_ALEN
);
259 early_param("rfmac", rfmac_param
);
262 * Generate an Ethernet MAC address that has a good chance of being unique.
263 * @addr: Pointer to six-byte array containing the Ethernet address
264 * Generates an Ethernet MAC address that is highly likely to be unique for
265 * this particular system on a network with other systems of the same type.
267 * The problem we are solving is that, when random_ether_addr() is used to
268 * generate MAC addresses at startup, there isn't much entropy for the random
269 * number generator to use and the addresses it produces are fairly likely to
270 * be the same as those of other identical systems on the same local network.
271 * This is true even for relatively small numbers of systems (for the reason
272 * why, see the Wikipedia entry for "Birthday problem" at:
273 * http://en.wikipedia.org/wiki/Birthday_problem
275 * The good news is that we already have a MAC address known to be unique, the
276 * RF MAC address. The bad news is that this address is already in use on the
277 * RF interface. Worse, the obvious trick, taking the RF MAC address and
278 * turning on the locally managed bit, has already been used for other devices.
279 * Still, this does give us something to work with.
281 * The approach we take is:
282 * 1. If we can't get the RF MAC Address, just call random_ether_addr.
283 * 2. Use the 24-bit NIC-specific bits of the RF MAC address as the last 24
284 * bits of the new address. This is very likely to be unique, except for
286 * 3. To avoid using addresses already on the current box, we set the top
287 * six bits of the address with a value different from any currently
288 * registered Scientific Atlanta organizationally unique identifyer
289 * (OUI). This avoids duplication with any addresses on the system that
290 * were generated from valid Scientific Atlanta-registered address by
291 * simply flipping the locally managed bit.
292 * 4. We aren't generating a multicast address, so we leave the multicast
293 * bit off. Since we aren't using a registered address, we have to set
294 * the locally managed bit.
295 * 5. We then randomly generate the remaining 16-bits. This does two
297 * a. It allows us to call this function for more than one device
299 * b. It ensures that things will probably still work even if
300 * some device on the device network has a locally managed
301 * address that matches the top six bits from step 2.
303 void platform_random_ether_addr(u8 addr
[ETH_ALEN
])
305 const int num_random_bytes
= 2;
306 const unsigned char non_sciatl_oui_bits
= 0xc0u
;
307 const unsigned char mac_addr_locally_managed
= (1 << 1);
310 pr_warning("rfmac not available on command line; "
311 "generating random MAC address\n");
312 random_ether_addr(addr
);
318 /* Set the first byte to something that won't match a Scientific
319 * Atlanta OUI, is locally managed, and isn't a multicast
321 addr
[0] = non_sciatl_oui_bits
| mac_addr_locally_managed
;
323 /* Get some bytes of random address information */
324 get_random_bytes(&addr
[1], num_random_bytes
);
326 /* Copy over the NIC-specific bits of the RF MAC address */
327 for (i
= 1 + num_random_bytes
; i
< ETH_ALEN
; i
++)