xref: /openbmc/u-boot/arch/x86/cpu/ivybridge/sdram.c (revision 63e22517)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2011 The Chromium OS Authors.
4  * (C) Copyright 2010,2011
5  * Graeme Russ, <graeme.russ@gmail.com>
6  *
7  * Portions from Coreboot mainboard/google/link/romstage.c
8  * Copyright (C) 2007-2010 coresystems GmbH
9  * Copyright (C) 2011 Google Inc.
10  */
11 
12 #include <common.h>
13 #include <errno.h>
14 #include <fdtdec.h>
15 #include <malloc.h>
16 #include <net.h>
17 #include <rtc.h>
18 #include <spi.h>
19 #include <spi_flash.h>
20 #include <syscon.h>
21 #include <asm/cpu.h>
22 #include <asm/processor.h>
23 #include <asm/gpio.h>
24 #include <asm/global_data.h>
25 #include <asm/intel_regs.h>
26 #include <asm/mrccache.h>
27 #include <asm/mrc_common.h>
28 #include <asm/mtrr.h>
29 #include <asm/pci.h>
30 #include <asm/report_platform.h>
31 #include <asm/arch/me.h>
32 #include <asm/arch/pei_data.h>
33 #include <asm/arch/pch.h>
34 #include <asm/post.h>
35 #include <asm/arch/sandybridge.h>
36 
37 DECLARE_GLOBAL_DATA_PTR;
38 
39 #define CMOS_OFFSET_MRC_SEED		152
40 #define CMOS_OFFSET_MRC_SEED_S3		156
41 #define CMOS_OFFSET_MRC_SEED_CHK	160
42 
43 ulong board_get_usable_ram_top(ulong total_size)
44 {
45 	return mrc_common_board_get_usable_ram_top(total_size);
46 }
47 
48 int dram_init_banksize(void)
49 {
50 	mrc_common_dram_init_banksize();
51 
52 	return 0;
53 }
54 
55 static int read_seed_from_cmos(struct pei_data *pei_data)
56 {
57 	u16 c1, c2, checksum, seed_checksum;
58 	struct udevice *dev;
59 	int ret = 0;
60 
61 	ret = uclass_get_device(UCLASS_RTC, 0, &dev);
62 	if (ret) {
63 		debug("Cannot find RTC: err=%d\n", ret);
64 		return -ENODEV;
65 	}
66 
67 	/*
68 	 * Read scrambler seeds from CMOS RAM. We don't want to store them in
69 	 * SPI flash since they change on every boot and that would wear down
70 	 * the flash too much. So we store these in CMOS and the large MRC
71 	 * data in SPI flash.
72 	 */
73 	ret = rtc_read32(dev, CMOS_OFFSET_MRC_SEED, &pei_data->scrambler_seed);
74 	if (!ret) {
75 		ret = rtc_read32(dev, CMOS_OFFSET_MRC_SEED_S3,
76 				 &pei_data->scrambler_seed_s3);
77 	}
78 	if (ret) {
79 		debug("Failed to read from RTC %s\n", dev->name);
80 		return ret;
81 	}
82 
83 	debug("Read scrambler seed    0x%08x from CMOS 0x%02x\n",
84 	      pei_data->scrambler_seed, CMOS_OFFSET_MRC_SEED);
85 	debug("Read S3 scrambler seed 0x%08x from CMOS 0x%02x\n",
86 	      pei_data->scrambler_seed_s3, CMOS_OFFSET_MRC_SEED_S3);
87 
88 	/* Compute seed checksum and compare */
89 	c1 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed,
90 				 sizeof(u32));
91 	c2 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed_s3,
92 				 sizeof(u32));
93 	checksum = add_ip_checksums(sizeof(u32), c1, c2);
94 
95 	seed_checksum = rtc_read8(dev, CMOS_OFFSET_MRC_SEED_CHK);
96 	seed_checksum |= rtc_read8(dev, CMOS_OFFSET_MRC_SEED_CHK + 1) << 8;
97 
98 	if (checksum != seed_checksum) {
99 		debug("%s: invalid seed checksum\n", __func__);
100 		pei_data->scrambler_seed = 0;
101 		pei_data->scrambler_seed_s3 = 0;
102 		return -EINVAL;
103 	}
104 
105 	return 0;
106 }
107 
108 static int prepare_mrc_cache(struct pei_data *pei_data)
109 {
110 	struct mrc_data_container *mrc_cache;
111 	struct mrc_region entry;
112 	int ret;
113 
114 	ret = read_seed_from_cmos(pei_data);
115 	if (ret)
116 		return ret;
117 	ret = mrccache_get_region(NULL, &entry);
118 	if (ret)
119 		return ret;
120 	mrc_cache = mrccache_find_current(&entry);
121 	if (!mrc_cache)
122 		return -ENOENT;
123 
124 	pei_data->mrc_input = mrc_cache->data;
125 	pei_data->mrc_input_len = mrc_cache->data_size;
126 	debug("%s: at %p, size %x checksum %04x\n", __func__,
127 	      pei_data->mrc_input, pei_data->mrc_input_len,
128 	      mrc_cache->checksum);
129 
130 	return 0;
131 }
132 
133 static int write_seeds_to_cmos(struct pei_data *pei_data)
134 {
135 	u16 c1, c2, checksum;
136 	struct udevice *dev;
137 	int ret = 0;
138 
139 	ret = uclass_get_device(UCLASS_RTC, 0, &dev);
140 	if (ret) {
141 		debug("Cannot find RTC: err=%d\n", ret);
142 		return -ENODEV;
143 	}
144 
145 	/* Save the MRC seed values to CMOS */
146 	rtc_write32(dev, CMOS_OFFSET_MRC_SEED, pei_data->scrambler_seed);
147 	debug("Save scrambler seed    0x%08x to CMOS 0x%02x\n",
148 	      pei_data->scrambler_seed, CMOS_OFFSET_MRC_SEED);
149 
150 	rtc_write32(dev, CMOS_OFFSET_MRC_SEED_S3, pei_data->scrambler_seed_s3);
151 	debug("Save s3 scrambler seed 0x%08x to CMOS 0x%02x\n",
152 	      pei_data->scrambler_seed_s3, CMOS_OFFSET_MRC_SEED_S3);
153 
154 	/* Save a simple checksum of the seed values */
155 	c1 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed,
156 				 sizeof(u32));
157 	c2 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed_s3,
158 				 sizeof(u32));
159 	checksum = add_ip_checksums(sizeof(u32), c1, c2);
160 
161 	rtc_write8(dev, CMOS_OFFSET_MRC_SEED_CHK, checksum & 0xff);
162 	rtc_write8(dev, CMOS_OFFSET_MRC_SEED_CHK + 1, (checksum >> 8) & 0xff);
163 
164 	return 0;
165 }
166 
167 /* Use this hook to save our SDRAM parameters */
168 int misc_init_r(void)
169 {
170 	int ret;
171 
172 	ret = mrccache_save();
173 	if (ret)
174 		printf("Unable to save MRC data: %d\n", ret);
175 
176 	return 0;
177 }
178 
179 static void post_system_agent_init(struct udevice *dev, struct udevice *me_dev,
180 				   struct pei_data *pei_data)
181 {
182 	uint16_t done;
183 
184 	/*
185 	 * Send ME init done for SandyBridge here.  This is done inside the
186 	 * SystemAgent binary on IvyBridge
187 	 */
188 	dm_pci_read_config16(dev, PCI_DEVICE_ID, &done);
189 	done &= BASE_REV_MASK;
190 	if (BASE_REV_SNB == done)
191 		intel_early_me_init_done(dev, me_dev, ME_INIT_STATUS_SUCCESS);
192 	else
193 		intel_me_status(me_dev);
194 
195 	/* If PCIe init is skipped, set the PEG clock gating */
196 	if (!pei_data->pcie_init)
197 		setbits_le32(MCHBAR_REG(0x7010), 1);
198 }
199 
200 static int recovery_mode_enabled(void)
201 {
202 	return false;
203 }
204 
205 static int copy_spd(struct udevice *dev, struct pei_data *peid)
206 {
207 	const void *data;
208 	int ret;
209 
210 	ret = mrc_locate_spd(dev, sizeof(peid->spd_data[0]), &data);
211 	if (ret) {
212 		debug("%s: Could not locate SPD (ret=%d)\n", __func__, ret);
213 		return ret;
214 	}
215 
216 	memcpy(peid->spd_data[0], data, sizeof(peid->spd_data[0]));
217 
218 	return 0;
219 }
220 
221 /**
222  * sdram_find() - Find available memory
223  *
224  * This is a bit complicated since on x86 there are system memory holes all
225  * over the place. We create a list of available memory blocks
226  *
227  * @dev:	Northbridge device
228  */
229 static int sdram_find(struct udevice *dev)
230 {
231 	struct memory_info *info = &gd->arch.meminfo;
232 	uint32_t tseg_base, uma_size, tolud;
233 	uint64_t tom, me_base, touud;
234 	uint64_t uma_memory_base = 0;
235 	unsigned long long tomk;
236 	uint16_t ggc;
237 	u32 val;
238 
239 	/* Total Memory 2GB example:
240 	 *
241 	 *  00000000  0000MB-1992MB  1992MB  RAM     (writeback)
242 	 *  7c800000  1992MB-2000MB     8MB  TSEG    (SMRR)
243 	 *  7d000000  2000MB-2002MB     2MB  GFX GTT (uncached)
244 	 *  7d200000  2002MB-2034MB    32MB  GFX UMA (uncached)
245 	 *  7f200000   2034MB TOLUD
246 	 *  7f800000   2040MB MEBASE
247 	 *  7f800000  2040MB-2048MB     8MB  ME UMA  (uncached)
248 	 *  80000000   2048MB TOM
249 	 * 100000000  4096MB-4102MB     6MB  RAM     (writeback)
250 	 *
251 	 * Total Memory 4GB example:
252 	 *
253 	 *  00000000  0000MB-2768MB  2768MB  RAM     (writeback)
254 	 *  ad000000  2768MB-2776MB     8MB  TSEG    (SMRR)
255 	 *  ad800000  2776MB-2778MB     2MB  GFX GTT (uncached)
256 	 *  ada00000  2778MB-2810MB    32MB  GFX UMA (uncached)
257 	 *  afa00000   2810MB TOLUD
258 	 *  ff800000   4088MB MEBASE
259 	 *  ff800000  4088MB-4096MB     8MB  ME UMA  (uncached)
260 	 * 100000000   4096MB TOM
261 	 * 100000000  4096MB-5374MB  1278MB  RAM     (writeback)
262 	 * 14fe00000   5368MB TOUUD
263 	 */
264 
265 	/* Top of Upper Usable DRAM, including remap */
266 	dm_pci_read_config32(dev, TOUUD + 4, &val);
267 	touud = (uint64_t)val << 32;
268 	dm_pci_read_config32(dev, TOUUD, &val);
269 	touud |= val;
270 
271 	/* Top of Lower Usable DRAM */
272 	dm_pci_read_config32(dev, TOLUD, &tolud);
273 
274 	/* Top of Memory - does not account for any UMA */
275 	dm_pci_read_config32(dev, 0xa4, &val);
276 	tom = (uint64_t)val << 32;
277 	dm_pci_read_config32(dev, 0xa0, &val);
278 	tom |= val;
279 
280 	debug("TOUUD %llx TOLUD %08x TOM %llx\n", touud, tolud, tom);
281 
282 	/* ME UMA needs excluding if total memory <4GB */
283 	dm_pci_read_config32(dev, 0x74, &val);
284 	me_base = (uint64_t)val << 32;
285 	dm_pci_read_config32(dev, 0x70, &val);
286 	me_base |= val;
287 
288 	debug("MEBASE %llx\n", me_base);
289 
290 	/* TODO: Get rid of all this shifting by 10 bits */
291 	tomk = tolud >> 10;
292 	if (me_base == tolud) {
293 		/* ME is from MEBASE-TOM */
294 		uma_size = (tom - me_base) >> 10;
295 		/* Increment TOLUD to account for ME as RAM */
296 		tolud += uma_size << 10;
297 		/* UMA starts at old TOLUD */
298 		uma_memory_base = tomk * 1024ULL;
299 		debug("ME UMA base %llx size %uM\n", me_base, uma_size >> 10);
300 	}
301 
302 	/* Graphics memory comes next */
303 	dm_pci_read_config16(dev, GGC, &ggc);
304 	if (!(ggc & 2)) {
305 		debug("IGD decoded, subtracting ");
306 
307 		/* Graphics memory */
308 		uma_size = ((ggc >> 3) & 0x1f) * 32 * 1024ULL;
309 		debug("%uM UMA", uma_size >> 10);
310 		tomk -= uma_size;
311 		uma_memory_base = tomk * 1024ULL;
312 
313 		/* GTT Graphics Stolen Memory Size (GGMS) */
314 		uma_size = ((ggc >> 8) & 0x3) * 1024ULL;
315 		tomk -= uma_size;
316 		uma_memory_base = tomk * 1024ULL;
317 		debug(" and %uM GTT\n", uma_size >> 10);
318 	}
319 
320 	/* Calculate TSEG size from its base which must be below GTT */
321 	dm_pci_read_config32(dev, 0xb8, &tseg_base);
322 	uma_size = (uma_memory_base - tseg_base) >> 10;
323 	tomk -= uma_size;
324 	uma_memory_base = tomk * 1024ULL;
325 	debug("TSEG base 0x%08x size %uM\n", tseg_base, uma_size >> 10);
326 
327 	debug("Available memory below 4GB: %lluM\n", tomk >> 10);
328 
329 	/* Report the memory regions */
330 	mrc_add_memory_area(info, 1 << 20, 2 << 28);
331 	mrc_add_memory_area(info, (2 << 28) + (2 << 20), 4 << 28);
332 	mrc_add_memory_area(info, (4 << 28) + (2 << 20), tseg_base);
333 	mrc_add_memory_area(info, 1ULL << 32, touud);
334 
335 	/* Add MTRRs for memory */
336 	mtrr_add_request(MTRR_TYPE_WRBACK, 0, 2ULL << 30);
337 	mtrr_add_request(MTRR_TYPE_WRBACK, 2ULL << 30, 512 << 20);
338 	mtrr_add_request(MTRR_TYPE_WRBACK, 0xaULL << 28, 256 << 20);
339 	mtrr_add_request(MTRR_TYPE_UNCACHEABLE, tseg_base, 16 << 20);
340 	mtrr_add_request(MTRR_TYPE_UNCACHEABLE, tseg_base + (16 << 20),
341 			 32 << 20);
342 
343 	/*
344 	 * If >= 4GB installed then memory from TOLUD to 4GB
345 	 * is remapped above TOM, TOUUD will account for both
346 	 */
347 	if (touud > (1ULL << 32ULL)) {
348 		debug("Available memory above 4GB: %lluM\n",
349 		      (touud >> 20) - 4096);
350 	}
351 
352 	return 0;
353 }
354 
355 static void rcba_config(void)
356 {
357 	/*
358 	 *             GFX    INTA -> PIRQA (MSI)
359 	 * D28IP_P3IP  WLAN   INTA -> PIRQB
360 	 * D29IP_E1P   EHCI1  INTA -> PIRQD
361 	 * D26IP_E2P   EHCI2  INTA -> PIRQF
362 	 * D31IP_SIP   SATA   INTA -> PIRQF (MSI)
363 	 * D31IP_SMIP  SMBUS  INTB -> PIRQH
364 	 * D31IP_TTIP  THRT   INTC -> PIRQA
365 	 * D27IP_ZIP   HDA    INTA -> PIRQA (MSI)
366 	 *
367 	 * TRACKPAD                -> PIRQE (Edge Triggered)
368 	 * TOUCHSCREEN             -> PIRQG (Edge Triggered)
369 	 */
370 
371 	/* Device interrupt pin register (board specific) */
372 	writel((INTC << D31IP_TTIP) | (NOINT << D31IP_SIP2) |
373 	       (INTB << D31IP_SMIP) | (INTA << D31IP_SIP), RCB_REG(D31IP));
374 	writel(NOINT << D30IP_PIP, RCB_REG(D30IP));
375 	writel(INTA << D29IP_E1P, RCB_REG(D29IP));
376 	writel(INTA << D28IP_P3IP, RCB_REG(D28IP));
377 	writel(INTA << D27IP_ZIP, RCB_REG(D27IP));
378 	writel(INTA << D26IP_E2P, RCB_REG(D26IP));
379 	writel(NOINT << D25IP_LIP, RCB_REG(D25IP));
380 	writel(NOINT << D22IP_MEI1IP, RCB_REG(D22IP));
381 
382 	/* Device interrupt route registers */
383 	writel(DIR_ROUTE(PIRQB, PIRQH, PIRQA, PIRQC), RCB_REG(D31IR));
384 	writel(DIR_ROUTE(PIRQD, PIRQE, PIRQF, PIRQG), RCB_REG(D29IR));
385 	writel(DIR_ROUTE(PIRQB, PIRQC, PIRQD, PIRQE), RCB_REG(D28IR));
386 	writel(DIR_ROUTE(PIRQA, PIRQH, PIRQA, PIRQB), RCB_REG(D27IR));
387 	writel(DIR_ROUTE(PIRQF, PIRQE, PIRQG, PIRQH), RCB_REG(D26IR));
388 	writel(DIR_ROUTE(PIRQA, PIRQB, PIRQC, PIRQD), RCB_REG(D25IR));
389 	writel(DIR_ROUTE(PIRQA, PIRQB, PIRQC, PIRQD), RCB_REG(D22IR));
390 
391 	/* Enable IOAPIC (generic) */
392 	writew(0x0100, RCB_REG(OIC));
393 	/* PCH BWG says to read back the IOAPIC enable register */
394 	(void)readw(RCB_REG(OIC));
395 
396 	/* Disable unused devices (board specific) */
397 	setbits_le32(RCB_REG(FD), PCH_DISABLE_ALWAYS);
398 }
399 
400 int dram_init(void)
401 {
402 	struct pei_data _pei_data __aligned(8) = {
403 		.pei_version = PEI_VERSION,
404 		.mchbar = MCH_BASE_ADDRESS,
405 		.dmibar = DEFAULT_DMIBAR,
406 		.epbar = DEFAULT_EPBAR,
407 		.pciexbar = CONFIG_PCIE_ECAM_BASE,
408 		.smbusbar = SMBUS_IO_BASE,
409 		.wdbbar = 0x4000000,
410 		.wdbsize = 0x1000,
411 		.hpet_address = CONFIG_HPET_ADDRESS,
412 		.rcba = DEFAULT_RCBABASE,
413 		.pmbase = DEFAULT_PMBASE,
414 		.gpiobase = DEFAULT_GPIOBASE,
415 		.thermalbase = 0xfed08000,
416 		.system_type = 0, /* 0 Mobile, 1 Desktop/Server */
417 		.tseg_size = CONFIG_SMM_TSEG_SIZE,
418 		.ts_addresses = { 0x00, 0x00, 0x00, 0x00 },
419 		.ec_present = 1,
420 		.ddr3lv_support = 1,
421 		/*
422 		 * 0 = leave channel enabled
423 		 * 1 = disable dimm 0 on channel
424 		 * 2 = disable dimm 1 on channel
425 		 * 3 = disable dimm 0+1 on channel
426 		 */
427 		.dimm_channel0_disabled = 2,
428 		.dimm_channel1_disabled = 2,
429 		.max_ddr3_freq = 1600,
430 		.usb_port_config = {
431 			/*
432 			 * Empty and onboard Ports 0-7, set to un-used pin
433 			 * OC3
434 			 */
435 			{ 0, 3, 0x0000 }, /* P0= Empty */
436 			{ 1, 0, 0x0040 }, /* P1= Left USB 1  (OC0) */
437 			{ 1, 1, 0x0040 }, /* P2= Left USB 2  (OC1) */
438 			{ 1, 3, 0x0040 }, /* P3= SDCARD      (no OC) */
439 			{ 0, 3, 0x0000 }, /* P4= Empty */
440 			{ 1, 3, 0x0040 }, /* P5= WWAN        (no OC) */
441 			{ 0, 3, 0x0000 }, /* P6= Empty */
442 			{ 0, 3, 0x0000 }, /* P7= Empty */
443 			/*
444 			 * Empty and onboard Ports 8-13, set to un-used pin
445 			 * OC4
446 			 */
447 			{ 1, 4, 0x0040 }, /* P8= Camera      (no OC) */
448 			{ 1, 4, 0x0040 }, /* P9= Bluetooth   (no OC) */
449 			{ 0, 4, 0x0000 }, /* P10= Empty */
450 			{ 0, 4, 0x0000 }, /* P11= Empty */
451 			{ 0, 4, 0x0000 }, /* P12= Empty */
452 			{ 0, 4, 0x0000 }, /* P13= Empty */
453 		},
454 	};
455 	struct pei_data *pei_data = &_pei_data;
456 	struct udevice *dev, *me_dev;
457 	int ret;
458 
459 	/* We need the pinctrl set up early */
460 	ret = syscon_get_by_driver_data(X86_SYSCON_PINCONF, &dev);
461 	if (ret) {
462 		debug("%s: Could not get pinconf (ret=%d)\n", __func__, ret);
463 		return ret;
464 	}
465 
466 	ret = uclass_first_device_err(UCLASS_NORTHBRIDGE, &dev);
467 	if (ret) {
468 		debug("%s: Could not get northbridge (ret=%d)\n", __func__,
469 		      ret);
470 		return ret;
471 	}
472 	ret = syscon_get_by_driver_data(X86_SYSCON_ME, &me_dev);
473 	if (ret) {
474 		debug("%s: Could not get ME (ret=%d)\n", __func__, ret);
475 		return ret;
476 	}
477 	ret = copy_spd(dev, pei_data);
478 	if (ret) {
479 		debug("%s: Could not get SPD (ret=%d)\n", __func__, ret);
480 		return ret;
481 	}
482 	pei_data->boot_mode = gd->arch.pei_boot_mode;
483 	debug("Boot mode %d\n", gd->arch.pei_boot_mode);
484 	debug("mrc_input %p\n", pei_data->mrc_input);
485 
486 	/*
487 	 * Do not pass MRC data in for recovery mode boot,
488 	 * Always pass it in for S3 resume.
489 	 */
490 	if (!recovery_mode_enabled() ||
491 	    pei_data->boot_mode == PEI_BOOT_RESUME) {
492 		ret = prepare_mrc_cache(pei_data);
493 		if (ret)
494 			debug("prepare_mrc_cache failed: %d\n", ret);
495 	}
496 
497 	/* If MRC data is not found we cannot continue S3 resume. */
498 	if (pei_data->boot_mode == PEI_BOOT_RESUME && !pei_data->mrc_input) {
499 		debug("Giving up in sdram_initialize: No MRC data\n");
500 		reset_cpu(0);
501 	}
502 
503 	/* Pass console handler in pei_data */
504 	pei_data->tx_byte = sdram_console_tx_byte;
505 
506 	/* Wait for ME to be ready */
507 	ret = intel_early_me_init(me_dev);
508 	if (ret) {
509 		debug("%s: Could not init ME (ret=%d)\n", __func__, ret);
510 		return ret;
511 	}
512 	ret = intel_early_me_uma_size(me_dev);
513 	if (ret < 0) {
514 		debug("%s: Could not get UMA size (ret=%d)\n", __func__, ret);
515 		return ret;
516 	}
517 
518 	ret = mrc_common_init(dev, pei_data, false);
519 	if (ret) {
520 		debug("%s: mrc_common_init() failed (ret=%d)\n", __func__, ret);
521 		return ret;
522 	}
523 
524 	ret = sdram_find(dev);
525 	if (ret) {
526 		debug("%s: sdram_find() failed (ret=%d)\n", __func__, ret);
527 		return ret;
528 	}
529 	gd->ram_size = gd->arch.meminfo.total_32bit_memory;
530 
531 	debug("MRC output data length %#x at %p\n", pei_data->mrc_output_len,
532 	      pei_data->mrc_output);
533 
534 	post_system_agent_init(dev, me_dev, pei_data);
535 	report_memory_config();
536 
537 	/* S3 resume: don't save scrambler seed or MRC data */
538 	if (pei_data->boot_mode != PEI_BOOT_RESUME) {
539 		/*
540 		 * This will be copied to SDRAM in reserve_arch(), then written
541 		 * to SPI flash in mrccache_save()
542 		 */
543 		gd->arch.mrc_output = (char *)pei_data->mrc_output;
544 		gd->arch.mrc_output_len = pei_data->mrc_output_len;
545 		ret = write_seeds_to_cmos(pei_data);
546 		if (ret)
547 			debug("Failed to write seeds to CMOS: %d\n", ret);
548 	}
549 
550 	writew(0xCAFE, MCHBAR_REG(SSKPD));
551 	if (ret)
552 		return ret;
553 
554 	rcba_config();
555 
556 	return 0;
557 }
558