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 struct pt_regs die_regs;
68 static bool have_die_regs;
70 static void register_panic_notifier(void);
71 static int panic_handler(struct notifier_block *notifier_block,
72 unsigned long event, void *cause_string);
74 const char *get_system_type(void)
79 void __init plat_mem_setup(void)
82 register_panic_notifier();
91 * Install a panic notifier for platform-specific diagnostics
93 static void register_panic_notifier()
95 static struct notifier_block panic_notifier = {
96 .notifier_call = panic_handler,
100 atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
103 static int panic_handler(struct notifier_block *notifier_block,
104 unsigned long event, void *cause_string)
106 struct pt_regs my_regs;
108 /* Save all of the registers */
110 unsigned long at, v0, v1; /* Must be on the stack */
112 /* Start by saving $at and v0 on the stack. We use $at
113 * ourselves, but it looks like the compiler may use v0 or v1
114 * to load the address of the pt_regs structure. We'll come
115 * back later to store the registers in the pt_regs
117 __asm__ __volatile__ (
119 LONG_S "$at, %[at]\n"
130 __asm__ __volatile__ (
132 "move $at, %[pt_regs]\n"
134 /* Argument registers */
135 LONG_S "$4, " VAL(PT_R4) "($at)\n"
136 LONG_S "$5, " VAL(PT_R5) "($at)\n"
137 LONG_S "$6, " VAL(PT_R6) "($at)\n"
138 LONG_S "$7, " VAL(PT_R7) "($at)\n"
141 LONG_S "$8, " VAL(PT_R8) "($at)\n"
142 LONG_S "$9, " VAL(PT_R9) "($at)\n"
143 LONG_S "$10, " VAL(PT_R10) "($at)\n"
144 LONG_S "$11, " VAL(PT_R11) "($at)\n"
145 LONG_S "$12, " VAL(PT_R12) "($at)\n"
146 LONG_S "$13, " VAL(PT_R13) "($at)\n"
147 LONG_S "$14, " VAL(PT_R14) "($at)\n"
148 LONG_S "$15, " VAL(PT_R15) "($at)\n"
150 /* "Saved" registers */
151 LONG_S "$16, " VAL(PT_R16) "($at)\n"
152 LONG_S "$17, " VAL(PT_R17) "($at)\n"
153 LONG_S "$18, " VAL(PT_R18) "($at)\n"
154 LONG_S "$19, " VAL(PT_R19) "($at)\n"
155 LONG_S "$20, " VAL(PT_R20) "($at)\n"
156 LONG_S "$21, " VAL(PT_R21) "($at)\n"
157 LONG_S "$22, " VAL(PT_R22) "($at)\n"
158 LONG_S "$23, " VAL(PT_R23) "($at)\n"
160 /* Add'l temp regs */
161 LONG_S "$24, " VAL(PT_R24) "($at)\n"
162 LONG_S "$25, " VAL(PT_R25) "($at)\n"
164 /* Kernel temp regs */
165 LONG_S "$26, " VAL(PT_R26) "($at)\n"
166 LONG_S "$27, " VAL(PT_R27) "($at)\n"
168 /* Global pointer, stack pointer, frame pointer and
170 LONG_S "$gp, " VAL(PT_R28) "($at)\n"
171 LONG_S "$sp, " VAL(PT_R29) "($at)\n"
172 LONG_S "$fp, " VAL(PT_R30) "($at)\n"
173 LONG_S "$ra, " VAL(PT_R31) "($at)\n"
175 /* Now we can get the $at and v0 registers back and
178 LONG_S "$8, " VAL(PT_R1) "($at)\n"
180 LONG_S "$8, " VAL(PT_R2) "($at)\n"
182 LONG_S "$8, " VAL(PT_R3) "($at)\n"
188 [pt_regs] "r" (&my_regs)
192 /* Set the current EPC value to be the current location in this
194 __asm__ __volatile__ (
198 LONG_S "$at, %[cp0_epc]\n"
200 [cp0_epc] "=m" (my_regs.cp0_epc)
205 my_regs.cp0_cause = read_c0_cause();
206 my_regs.cp0_status = read_c0_status();
209 #ifdef CONFIG_DIAGNOSTICS
210 failure_report((char *) cause_string,
211 have_die_regs ? &die_regs : &my_regs);
212 have_die_regs = false;
214 pr_crit("I'm feeling a bit sleepy. hmmmmm... perhaps a nap would... "
222 * Platform-specific handling of oops
223 * @str: Pointer to the oops string
224 * @regs: Pointer to the oops registers
225 * All we do here is to save the registers for subsequent printing through
226 * the panic notifier.
228 void platform_die(const char *str, const struct pt_regs *regs)
230 /* If we already have saved registers, don't overwrite them as they
231 * they apply to the initial fault */
233 if (!have_die_regs) {
234 have_die_regs = true;
239 /* Information about the RF MAC address, if one was supplied on the
241 static bool have_rfmac;
242 static u8 rfmac[ETH_ALEN];
244 static int rfmac_param(char *p)
250 /* Skip a leading "0x", if present */
251 if (*p == '0' && *(p+1) == 'x')
255 is_high_nibble = true;
257 for (c = (unsigned char) *p++;
258 isxdigit(c) && q - rfmac < ETH_ALEN;
259 c = (unsigned char) *p++) {
262 nibble = (isdigit(c) ? (c - '0') :
263 (isupper(c) ? c - 'A' + 10 : c - 'a' + 10));
270 is_high_nibble = !is_high_nibble;
273 /* If we parsed all the way to the end of the parameter value and
274 * parsed all ETH_ALEN bytes, we have a usable RF MAC address */
275 have_rfmac = (c == '\0' && q - rfmac == ETH_ALEN);
280 early_param("rfmac", rfmac_param);
283 * Generate an Ethernet MAC address that has a good chance of being unique.
284 * @addr: Pointer to six-byte array containing the Ethernet address
285 * Generates an Ethernet MAC address that is highly likely to be unique for
286 * this particular system on a network with other systems of the same type.
288 * The problem we are solving is that, when random_ether_addr() is used to
289 * generate MAC addresses at startup, there isn't much entropy for the random
290 * number generator to use and the addresses it produces are fairly likely to
291 * be the same as those of other identical systems on the same local network.
292 * This is true even for relatively small numbers of systems (for the reason
293 * why, see the Wikipedia entry for "Birthday problem" at:
294 * http://en.wikipedia.org/wiki/Birthday_problem
296 * The good news is that we already have a MAC address known to be unique, the
297 * RF MAC address. The bad news is that this address is already in use on the
298 * RF interface. Worse, the obvious trick, taking the RF MAC address and
299 * turning on the locally managed bit, has already been used for other devices.
300 * Still, this does give us something to work with.
302 * The approach we take is:
303 * 1. If we can't get the RF MAC Address, just call random_ether_addr.
304 * 2. Use the 24-bit NIC-specific bits of the RF MAC address as the last 24
305 * bits of the new address. This is very likely to be unique, except for
307 * 3. To avoid using addresses already on the current box, we set the top
308 * six bits of the address with a value different from any currently
309 * registered Scientific Atlanta organizationally unique identifyer
310 * (OUI). This avoids duplication with any addresses on the system that
311 * were generated from valid Scientific Atlanta-registered address by
312 * simply flipping the locally managed bit.
313 * 4. We aren't generating a multicast address, so we leave the multicast
314 * bit off. Since we aren't using a registered address, we have to set
315 * the locally managed bit.
316 * 5. We then randomly generate the remaining 16-bits. This does two
318 * a. It allows us to call this function for more than one device
320 * b. It ensures that things will probably still work even if
321 * some device on the device network has a locally managed
322 * address that matches the top six bits from step 2.
324 void platform_random_ether_addr(u8 addr[ETH_ALEN])
326 const int num_random_bytes = 2;
327 const unsigned char non_sciatl_oui_bits = 0xc0u;
328 const unsigned char mac_addr_locally_managed = (1 << 1);
331 pr_warning("rfmac not available on command line; "
332 "generating random MAC address\n");
333 random_ether_addr(addr);
339 /* Set the first byte to something that won't match a Scientific
340 * Atlanta OUI, is locally managed, and isn't a multicast
342 addr[0] = non_sciatl_oui_bits | mac_addr_locally_managed;
344 /* Get some bytes of random address information */
345 get_random_bytes(&addr[1], num_random_bytes);
347 /* Copy over the NIC-specific bits of the RF MAC address */
348 for (i = 1 + num_random_bytes; i < ETH_ALEN; i++)