xref: /openbmc/u-boot/arch/x86/cpu/ivybridge/sdram.c (revision dd1033e4)
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 <sysreset.h>
22 #include <asm/cpu.h>
23 #include <asm/processor.h>
24 #include <asm/gpio.h>
25 #include <asm/global_data.h>
26 #include <asm/intel_regs.h>
27 #include <asm/mrccache.h>
28 #include <asm/mrc_common.h>
29 #include <asm/mtrr.h>
30 #include <asm/pci.h>
31 #include <asm/report_platform.h>
32 #include <asm/arch/me.h>
33 #include <asm/arch/pei_data.h>
34 #include <asm/arch/pch.h>
35 #include <asm/post.h>
36 #include <asm/arch/sandybridge.h>
37 
38 DECLARE_GLOBAL_DATA_PTR;
39 
40 #define CMOS_OFFSET_MRC_SEED		152
41 #define CMOS_OFFSET_MRC_SEED_S3		156
42 #define CMOS_OFFSET_MRC_SEED_CHK	160
43 
44 ulong board_get_usable_ram_top(ulong total_size)
45 {
46 	return mrc_common_board_get_usable_ram_top(total_size);
47 }
48 
49 int dram_init_banksize(void)
50 {
51 	mrc_common_dram_init_banksize();
52 
53 	return 0;
54 }
55 
56 static int read_seed_from_cmos(struct pei_data *pei_data)
57 {
58 	u16 c1, c2, checksum, seed_checksum;
59 	struct udevice *dev;
60 	int ret = 0;
61 
62 	ret = uclass_get_device(UCLASS_RTC, 0, &dev);
63 	if (ret) {
64 		debug("Cannot find RTC: err=%d\n", ret);
65 		return -ENODEV;
66 	}
67 
68 	/*
69 	 * Read scrambler seeds from CMOS RAM. We don't want to store them in
70 	 * SPI flash since they change on every boot and that would wear down
71 	 * the flash too much. So we store these in CMOS and the large MRC
72 	 * data in SPI flash.
73 	 */
74 	ret = rtc_read32(dev, CMOS_OFFSET_MRC_SEED, &pei_data->scrambler_seed);
75 	if (!ret) {
76 		ret = rtc_read32(dev, CMOS_OFFSET_MRC_SEED_S3,
77 				 &pei_data->scrambler_seed_s3);
78 	}
79 	if (ret) {
80 		debug("Failed to read from RTC %s\n", dev->name);
81 		return ret;
82 	}
83 
84 	debug("Read scrambler seed    0x%08x from CMOS 0x%02x\n",
85 	      pei_data->scrambler_seed, CMOS_OFFSET_MRC_SEED);
86 	debug("Read S3 scrambler seed 0x%08x from CMOS 0x%02x\n",
87 	      pei_data->scrambler_seed_s3, CMOS_OFFSET_MRC_SEED_S3);
88 
89 	/* Compute seed checksum and compare */
90 	c1 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed,
91 				 sizeof(u32));
92 	c2 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed_s3,
93 				 sizeof(u32));
94 	checksum = add_ip_checksums(sizeof(u32), c1, c2);
95 
96 	seed_checksum = rtc_read8(dev, CMOS_OFFSET_MRC_SEED_CHK);
97 	seed_checksum |= rtc_read8(dev, CMOS_OFFSET_MRC_SEED_CHK + 1) << 8;
98 
99 	if (checksum != seed_checksum) {
100 		debug("%s: invalid seed checksum\n", __func__);
101 		pei_data->scrambler_seed = 0;
102 		pei_data->scrambler_seed_s3 = 0;
103 		return -EINVAL;
104 	}
105 
106 	return 0;
107 }
108 
109 static int prepare_mrc_cache(struct pei_data *pei_data)
110 {
111 	struct mrc_data_container *mrc_cache;
112 	struct mrc_region entry;
113 	int ret;
114 
115 	ret = read_seed_from_cmos(pei_data);
116 	if (ret)
117 		return ret;
118 	ret = mrccache_get_region(NULL, &entry);
119 	if (ret)
120 		return ret;
121 	mrc_cache = mrccache_find_current(&entry);
122 	if (!mrc_cache)
123 		return -ENOENT;
124 
125 	pei_data->mrc_input = mrc_cache->data;
126 	pei_data->mrc_input_len = mrc_cache->data_size;
127 	debug("%s: at %p, size %x checksum %04x\n", __func__,
128 	      pei_data->mrc_input, pei_data->mrc_input_len,
129 	      mrc_cache->checksum);
130 
131 	return 0;
132 }
133 
134 static int write_seeds_to_cmos(struct pei_data *pei_data)
135 {
136 	u16 c1, c2, checksum;
137 	struct udevice *dev;
138 	int ret = 0;
139 
140 	ret = uclass_get_device(UCLASS_RTC, 0, &dev);
141 	if (ret) {
142 		debug("Cannot find RTC: err=%d\n", ret);
143 		return -ENODEV;
144 	}
145 
146 	/* Save the MRC seed values to CMOS */
147 	rtc_write32(dev, CMOS_OFFSET_MRC_SEED, pei_data->scrambler_seed);
148 	debug("Save scrambler seed    0x%08x to CMOS 0x%02x\n",
149 	      pei_data->scrambler_seed, CMOS_OFFSET_MRC_SEED);
150 
151 	rtc_write32(dev, CMOS_OFFSET_MRC_SEED_S3, pei_data->scrambler_seed_s3);
152 	debug("Save s3 scrambler seed 0x%08x to CMOS 0x%02x\n",
153 	      pei_data->scrambler_seed_s3, CMOS_OFFSET_MRC_SEED_S3);
154 
155 	/* Save a simple checksum of the seed values */
156 	c1 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed,
157 				 sizeof(u32));
158 	c2 = compute_ip_checksum((u8 *)&pei_data->scrambler_seed_s3,
159 				 sizeof(u32));
160 	checksum = add_ip_checksums(sizeof(u32), c1, c2);
161 
162 	rtc_write8(dev, CMOS_OFFSET_MRC_SEED_CHK, checksum & 0xff);
163 	rtc_write8(dev, CMOS_OFFSET_MRC_SEED_CHK + 1, (checksum >> 8) & 0xff);
164 
165 	return 0;
166 }
167 
168 /* Use this hook to save our SDRAM parameters */
169 int misc_init_r(void)
170 {
171 	int ret;
172 
173 	ret = mrccache_save();
174 	if (ret)
175 		printf("Unable to save MRC data: %d\n", ret);
176 
177 	return 0;
178 }
179 
180 static void post_system_agent_init(struct udevice *dev, struct udevice *me_dev,
181 				   struct pei_data *pei_data)
182 {
183 	uint16_t done;
184 
185 	/*
186 	 * Send ME init done for SandyBridge here.  This is done inside the
187 	 * SystemAgent binary on IvyBridge
188 	 */
189 	dm_pci_read_config16(dev, PCI_DEVICE_ID, &done);
190 	done &= BASE_REV_MASK;
191 	if (BASE_REV_SNB == done)
192 		intel_early_me_init_done(dev, me_dev, ME_INIT_STATUS_SUCCESS);
193 	else
194 		intel_me_status(me_dev);
195 
196 	/* If PCIe init is skipped, set the PEG clock gating */
197 	if (!pei_data->pcie_init)
198 		setbits_le32(MCHBAR_REG(0x7010), 1);
199 }
200 
201 static int recovery_mode_enabled(void)
202 {
203 	return false;
204 }
205 
206 static int copy_spd(struct udevice *dev, struct pei_data *peid)
207 {
208 	const void *data;
209 	int ret;
210 
211 	ret = mrc_locate_spd(dev, sizeof(peid->spd_data[0]), &data);
212 	if (ret) {
213 		debug("%s: Could not locate SPD (ret=%d)\n", __func__, ret);
214 		return ret;
215 	}
216 
217 	memcpy(peid->spd_data[0], data, sizeof(peid->spd_data[0]));
218 
219 	return 0;
220 }
221 
222 /**
223  * sdram_find() - Find available memory
224  *
225  * This is a bit complicated since on x86 there are system memory holes all
226  * over the place. We create a list of available memory blocks
227  *
228  * @dev:	Northbridge device
229  */
230 static int sdram_find(struct udevice *dev)
231 {
232 	struct memory_info *info = &gd->arch.meminfo;
233 	uint32_t tseg_base, uma_size, tolud;
234 	uint64_t tom, me_base, touud;
235 	uint64_t uma_memory_base = 0;
236 	unsigned long long tomk;
237 	uint16_t ggc;
238 	u32 val;
239 
240 	/* Total Memory 2GB example:
241 	 *
242 	 *  00000000  0000MB-1992MB  1992MB  RAM     (writeback)
243 	 *  7c800000  1992MB-2000MB     8MB  TSEG    (SMRR)
244 	 *  7d000000  2000MB-2002MB     2MB  GFX GTT (uncached)
245 	 *  7d200000  2002MB-2034MB    32MB  GFX UMA (uncached)
246 	 *  7f200000   2034MB TOLUD
247 	 *  7f800000   2040MB MEBASE
248 	 *  7f800000  2040MB-2048MB     8MB  ME UMA  (uncached)
249 	 *  80000000   2048MB TOM
250 	 * 100000000  4096MB-4102MB     6MB  RAM     (writeback)
251 	 *
252 	 * Total Memory 4GB example:
253 	 *
254 	 *  00000000  0000MB-2768MB  2768MB  RAM     (writeback)
255 	 *  ad000000  2768MB-2776MB     8MB  TSEG    (SMRR)
256 	 *  ad800000  2776MB-2778MB     2MB  GFX GTT (uncached)
257 	 *  ada00000  2778MB-2810MB    32MB  GFX UMA (uncached)
258 	 *  afa00000   2810MB TOLUD
259 	 *  ff800000   4088MB MEBASE
260 	 *  ff800000  4088MB-4096MB     8MB  ME UMA  (uncached)
261 	 * 100000000   4096MB TOM
262 	 * 100000000  4096MB-5374MB  1278MB  RAM     (writeback)
263 	 * 14fe00000   5368MB TOUUD
264 	 */
265 
266 	/* Top of Upper Usable DRAM, including remap */
267 	dm_pci_read_config32(dev, TOUUD + 4, &val);
268 	touud = (uint64_t)val << 32;
269 	dm_pci_read_config32(dev, TOUUD, &val);
270 	touud |= val;
271 
272 	/* Top of Lower Usable DRAM */
273 	dm_pci_read_config32(dev, TOLUD, &tolud);
274 
275 	/* Top of Memory - does not account for any UMA */
276 	dm_pci_read_config32(dev, 0xa4, &val);
277 	tom = (uint64_t)val << 32;
278 	dm_pci_read_config32(dev, 0xa0, &val);
279 	tom |= val;
280 
281 	debug("TOUUD %llx TOLUD %08x TOM %llx\n", touud, tolud, tom);
282 
283 	/* ME UMA needs excluding if total memory <4GB */
284 	dm_pci_read_config32(dev, 0x74, &val);
285 	me_base = (uint64_t)val << 32;
286 	dm_pci_read_config32(dev, 0x70, &val);
287 	me_base |= val;
288 
289 	debug("MEBASE %llx\n", me_base);
290 
291 	/* TODO: Get rid of all this shifting by 10 bits */
292 	tomk = tolud >> 10;
293 	if (me_base == tolud) {
294 		/* ME is from MEBASE-TOM */
295 		uma_size = (tom - me_base) >> 10;
296 		/* Increment TOLUD to account for ME as RAM */
297 		tolud += uma_size << 10;
298 		/* UMA starts at old TOLUD */
299 		uma_memory_base = tomk * 1024ULL;
300 		debug("ME UMA base %llx size %uM\n", me_base, uma_size >> 10);
301 	}
302 
303 	/* Graphics memory comes next */
304 	dm_pci_read_config16(dev, GGC, &ggc);
305 	if (!(ggc & 2)) {
306 		debug("IGD decoded, subtracting ");
307 
308 		/* Graphics memory */
309 		uma_size = ((ggc >> 3) & 0x1f) * 32 * 1024ULL;
310 		debug("%uM UMA", uma_size >> 10);
311 		tomk -= uma_size;
312 		uma_memory_base = tomk * 1024ULL;
313 
314 		/* GTT Graphics Stolen Memory Size (GGMS) */
315 		uma_size = ((ggc >> 8) & 0x3) * 1024ULL;
316 		tomk -= uma_size;
317 		uma_memory_base = tomk * 1024ULL;
318 		debug(" and %uM GTT\n", uma_size >> 10);
319 	}
320 
321 	/* Calculate TSEG size from its base which must be below GTT */
322 	dm_pci_read_config32(dev, 0xb8, &tseg_base);
323 	uma_size = (uma_memory_base - tseg_base) >> 10;
324 	tomk -= uma_size;
325 	uma_memory_base = tomk * 1024ULL;
326 	debug("TSEG base 0x%08x size %uM\n", tseg_base, uma_size >> 10);
327 
328 	debug("Available memory below 4GB: %lluM\n", tomk >> 10);
329 
330 	/* Report the memory regions */
331 	mrc_add_memory_area(info, 1 << 20, 2 << 28);
332 	mrc_add_memory_area(info, (2 << 28) + (2 << 20), 4 << 28);
333 	mrc_add_memory_area(info, (4 << 28) + (2 << 20), tseg_base);
334 	mrc_add_memory_area(info, 1ULL << 32, touud);
335 
336 	/* Add MTRRs for memory */
337 	mtrr_add_request(MTRR_TYPE_WRBACK, 0, 2ULL << 30);
338 	mtrr_add_request(MTRR_TYPE_WRBACK, 2ULL << 30, 512 << 20);
339 	mtrr_add_request(MTRR_TYPE_WRBACK, 0xaULL << 28, 256 << 20);
340 	mtrr_add_request(MTRR_TYPE_UNCACHEABLE, tseg_base, 16 << 20);
341 	mtrr_add_request(MTRR_TYPE_UNCACHEABLE, tseg_base + (16 << 20),
342 			 32 << 20);
343 
344 	/*
345 	 * If >= 4GB installed then memory from TOLUD to 4GB
346 	 * is remapped above TOM, TOUUD will account for both
347 	 */
348 	if (touud > (1ULL << 32ULL)) {
349 		debug("Available memory above 4GB: %lluM\n",
350 		      (touud >> 20) - 4096);
351 	}
352 
353 	return 0;
354 }
355 
356 static void rcba_config(void)
357 {
358 	/*
359 	 *             GFX    INTA -> PIRQA (MSI)
360 	 * D28IP_P3IP  WLAN   INTA -> PIRQB
361 	 * D29IP_E1P   EHCI1  INTA -> PIRQD
362 	 * D26IP_E2P   EHCI2  INTA -> PIRQF
363 	 * D31IP_SIP   SATA   INTA -> PIRQF (MSI)
364 	 * D31IP_SMIP  SMBUS  INTB -> PIRQH
365 	 * D31IP_TTIP  THRT   INTC -> PIRQA
366 	 * D27IP_ZIP   HDA    INTA -> PIRQA (MSI)
367 	 *
368 	 * TRACKPAD                -> PIRQE (Edge Triggered)
369 	 * TOUCHSCREEN             -> PIRQG (Edge Triggered)
370 	 */
371 
372 	/* Device interrupt pin register (board specific) */
373 	writel((INTC << D31IP_TTIP) | (NOINT << D31IP_SIP2) |
374 	       (INTB << D31IP_SMIP) | (INTA << D31IP_SIP), RCB_REG(D31IP));
375 	writel(NOINT << D30IP_PIP, RCB_REG(D30IP));
376 	writel(INTA << D29IP_E1P, RCB_REG(D29IP));
377 	writel(INTA << D28IP_P3IP, RCB_REG(D28IP));
378 	writel(INTA << D27IP_ZIP, RCB_REG(D27IP));
379 	writel(INTA << D26IP_E2P, RCB_REG(D26IP));
380 	writel(NOINT << D25IP_LIP, RCB_REG(D25IP));
381 	writel(NOINT << D22IP_MEI1IP, RCB_REG(D22IP));
382 
383 	/* Device interrupt route registers */
384 	writel(DIR_ROUTE(PIRQB, PIRQH, PIRQA, PIRQC), RCB_REG(D31IR));
385 	writel(DIR_ROUTE(PIRQD, PIRQE, PIRQF, PIRQG), RCB_REG(D29IR));
386 	writel(DIR_ROUTE(PIRQB, PIRQC, PIRQD, PIRQE), RCB_REG(D28IR));
387 	writel(DIR_ROUTE(PIRQA, PIRQH, PIRQA, PIRQB), RCB_REG(D27IR));
388 	writel(DIR_ROUTE(PIRQF, PIRQE, PIRQG, PIRQH), RCB_REG(D26IR));
389 	writel(DIR_ROUTE(PIRQA, PIRQB, PIRQC, PIRQD), RCB_REG(D25IR));
390 	writel(DIR_ROUTE(PIRQA, PIRQB, PIRQC, PIRQD), RCB_REG(D22IR));
391 
392 	/* Enable IOAPIC (generic) */
393 	writew(0x0100, RCB_REG(OIC));
394 	/* PCH BWG says to read back the IOAPIC enable register */
395 	(void)readw(RCB_REG(OIC));
396 
397 	/* Disable unused devices (board specific) */
398 	setbits_le32(RCB_REG(FD), PCH_DISABLE_ALWAYS);
399 }
400 
401 int dram_init(void)
402 {
403 	struct pei_data _pei_data __aligned(8) = {
404 		.pei_version = PEI_VERSION,
405 		.mchbar = MCH_BASE_ADDRESS,
406 		.dmibar = DEFAULT_DMIBAR,
407 		.epbar = DEFAULT_EPBAR,
408 		.pciexbar = CONFIG_PCIE_ECAM_BASE,
409 		.smbusbar = SMBUS_IO_BASE,
410 		.wdbbar = 0x4000000,
411 		.wdbsize = 0x1000,
412 		.hpet_address = CONFIG_HPET_ADDRESS,
413 		.rcba = DEFAULT_RCBABASE,
414 		.pmbase = DEFAULT_PMBASE,
415 		.gpiobase = DEFAULT_GPIOBASE,
416 		.thermalbase = 0xfed08000,
417 		.system_type = 0, /* 0 Mobile, 1 Desktop/Server */
418 		.tseg_size = CONFIG_SMM_TSEG_SIZE,
419 		.ts_addresses = { 0x00, 0x00, 0x00, 0x00 },
420 		.ec_present = 1,
421 		.ddr3lv_support = 1,
422 		/*
423 		 * 0 = leave channel enabled
424 		 * 1 = disable dimm 0 on channel
425 		 * 2 = disable dimm 1 on channel
426 		 * 3 = disable dimm 0+1 on channel
427 		 */
428 		.dimm_channel0_disabled = 2,
429 		.dimm_channel1_disabled = 2,
430 		.max_ddr3_freq = 1600,
431 		.usb_port_config = {
432 			/*
433 			 * Empty and onboard Ports 0-7, set to un-used pin
434 			 * OC3
435 			 */
436 			{ 0, 3, 0x0000 }, /* P0= Empty */
437 			{ 1, 0, 0x0040 }, /* P1= Left USB 1  (OC0) */
438 			{ 1, 1, 0x0040 }, /* P2= Left USB 2  (OC1) */
439 			{ 1, 3, 0x0040 }, /* P3= SDCARD      (no OC) */
440 			{ 0, 3, 0x0000 }, /* P4= Empty */
441 			{ 1, 3, 0x0040 }, /* P5= WWAN        (no OC) */
442 			{ 0, 3, 0x0000 }, /* P6= Empty */
443 			{ 0, 3, 0x0000 }, /* P7= Empty */
444 			/*
445 			 * Empty and onboard Ports 8-13, set to un-used pin
446 			 * OC4
447 			 */
448 			{ 1, 4, 0x0040 }, /* P8= Camera      (no OC) */
449 			{ 1, 4, 0x0040 }, /* P9= Bluetooth   (no OC) */
450 			{ 0, 4, 0x0000 }, /* P10= Empty */
451 			{ 0, 4, 0x0000 }, /* P11= Empty */
452 			{ 0, 4, 0x0000 }, /* P12= Empty */
453 			{ 0, 4, 0x0000 }, /* P13= Empty */
454 		},
455 	};
456 	struct pei_data *pei_data = &_pei_data;
457 	struct udevice *dev, *me_dev;
458 	int ret;
459 
460 	/* We need the pinctrl set up early */
461 	ret = syscon_get_by_driver_data(X86_SYSCON_PINCONF, &dev);
462 	if (ret) {
463 		debug("%s: Could not get pinconf (ret=%d)\n", __func__, ret);
464 		return ret;
465 	}
466 
467 	ret = uclass_first_device_err(UCLASS_NORTHBRIDGE, &dev);
468 	if (ret) {
469 		debug("%s: Could not get northbridge (ret=%d)\n", __func__,
470 		      ret);
471 		return ret;
472 	}
473 	ret = syscon_get_by_driver_data(X86_SYSCON_ME, &me_dev);
474 	if (ret) {
475 		debug("%s: Could not get ME (ret=%d)\n", __func__, ret);
476 		return ret;
477 	}
478 	ret = copy_spd(dev, pei_data);
479 	if (ret) {
480 		debug("%s: Could not get SPD (ret=%d)\n", __func__, ret);
481 		return ret;
482 	}
483 	pei_data->boot_mode = gd->arch.pei_boot_mode;
484 	debug("Boot mode %d\n", gd->arch.pei_boot_mode);
485 	debug("mrc_input %p\n", pei_data->mrc_input);
486 
487 	/*
488 	 * Do not pass MRC data in for recovery mode boot,
489 	 * Always pass it in for S3 resume.
490 	 */
491 	if (!recovery_mode_enabled() ||
492 	    pei_data->boot_mode == PEI_BOOT_RESUME) {
493 		ret = prepare_mrc_cache(pei_data);
494 		if (ret)
495 			debug("prepare_mrc_cache failed: %d\n", ret);
496 	}
497 
498 	/* If MRC data is not found we cannot continue S3 resume. */
499 	if (pei_data->boot_mode == PEI_BOOT_RESUME && !pei_data->mrc_input) {
500 		debug("Giving up in sdram_initialize: No MRC data\n");
501 		sysreset_walk_halt(SYSRESET_COLD);
502 	}
503 
504 	/* Pass console handler in pei_data */
505 	pei_data->tx_byte = sdram_console_tx_byte;
506 
507 	/* Wait for ME to be ready */
508 	ret = intel_early_me_init(me_dev);
509 	if (ret) {
510 		debug("%s: Could not init ME (ret=%d)\n", __func__, ret);
511 		return ret;
512 	}
513 	ret = intel_early_me_uma_size(me_dev);
514 	if (ret < 0) {
515 		debug("%s: Could not get UMA size (ret=%d)\n", __func__, ret);
516 		return ret;
517 	}
518 
519 	ret = mrc_common_init(dev, pei_data, false);
520 	if (ret) {
521 		debug("%s: mrc_common_init() failed (ret=%d)\n", __func__, ret);
522 		return ret;
523 	}
524 
525 	ret = sdram_find(dev);
526 	if (ret) {
527 		debug("%s: sdram_find() failed (ret=%d)\n", __func__, ret);
528 		return ret;
529 	}
530 	gd->ram_size = gd->arch.meminfo.total_32bit_memory;
531 
532 	debug("MRC output data length %#x at %p\n", pei_data->mrc_output_len,
533 	      pei_data->mrc_output);
534 
535 	post_system_agent_init(dev, me_dev, pei_data);
536 	report_memory_config();
537 
538 	/* S3 resume: don't save scrambler seed or MRC data */
539 	if (pei_data->boot_mode != PEI_BOOT_RESUME) {
540 		/*
541 		 * This will be copied to SDRAM in reserve_arch(), then written
542 		 * to SPI flash in mrccache_save()
543 		 */
544 		gd->arch.mrc_output = (char *)pei_data->mrc_output;
545 		gd->arch.mrc_output_len = pei_data->mrc_output_len;
546 		ret = write_seeds_to_cmos(pei_data);
547 		if (ret)
548 			debug("Failed to write seeds to CMOS: %d\n", ret);
549 	}
550 
551 	writew(0xCAFE, MCHBAR_REG(SSKPD));
552 	if (ret)
553 		return ret;
554 
555 	rcba_config();
556 
557 	return 0;
558 }
559