xref: /linux/arch/x86/kernel/cpu/microcode/intel.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Intel CPU Microcode Update Driver for Linux
4  *
5  * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
6  *		 2006 Shaohua Li <shaohua.li@intel.com>
7  *
8  * Intel CPU microcode early update for Linux
9  *
10  * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
11  *		      H Peter Anvin" <hpa@zytor.com>
12  */
13 #define pr_fmt(fmt) "microcode: " fmt
14 #include <linux/earlycpio.h>
15 #include <linux/firmware.h>
16 #include <linux/pci_ids.h>
17 #include <linux/uaccess.h>
18 #include <linux/initrd.h>
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
22 #include <linux/cpu.h>
23 #include <linux/uio.h>
24 #include <linux/io.h>
25 #include <linux/mm.h>
26 
27 #include <asm/cpu_device_id.h>
28 #include <asm/processor.h>
29 #include <asm/tlbflush.h>
30 #include <asm/setup.h>
31 #include <asm/msr.h>
32 
33 #include "internal.h"
34 
35 static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
36 
37 #define UCODE_BSP_LOADED	((struct microcode_intel *)0x1UL)
38 
39 /* Defines for the microcode staging mailbox interface */
40 #define MBOX_REG_NUM		4
41 #define MBOX_REG_SIZE		sizeof(u32)
42 
43 #define MBOX_CONTROL_OFFSET	0x0
44 #define MBOX_STATUS_OFFSET	0x4
45 #define MBOX_WRDATA_OFFSET	0x8
46 #define MBOX_RDDATA_OFFSET	0xc
47 
48 #define MASK_MBOX_CTRL_ABORT	BIT(0)
49 #define MASK_MBOX_CTRL_GO	BIT(31)
50 
51 #define MASK_MBOX_STATUS_ERROR	BIT(2)
52 #define MASK_MBOX_STATUS_READY	BIT(31)
53 
54 #define MASK_MBOX_RESP_SUCCESS	BIT(0)
55 #define MASK_MBOX_RESP_PROGRESS	BIT(1)
56 #define MASK_MBOX_RESP_ERROR	BIT(2)
57 
58 #define MBOX_CMD_LOAD		0x3
59 #define MBOX_OBJ_STAGING	0xb
60 #define MBOX_HEADER(size)	((PCI_VENDOR_ID_INTEL)    | \
61 				 (MBOX_OBJ_STAGING << 16) | \
62 				 ((u64)((size) / sizeof(u32)) << 32))
63 
64 /* The size of each mailbox header */
65 #define MBOX_HEADER_SIZE	sizeof(u64)
66 /* The size of staging hardware response */
67 #define MBOX_RESPONSE_SIZE	sizeof(u64)
68 
69 #define MBOX_XACTION_TIMEOUT_MS	(10 * MSEC_PER_SEC)
70 
71 /* Current microcode patch used in early patching on the APs. */
72 static struct microcode_intel *ucode_patch_va __read_mostly;
73 static struct microcode_intel *ucode_patch_late __read_mostly;
74 
75 /* last level cache size per core */
76 static unsigned int llc_size_per_core __ro_after_init;
77 
78 /* microcode format is extended from prescott processors */
79 struct extended_signature {
80 	unsigned int	sig;
81 	unsigned int	pf;
82 	unsigned int	cksum;
83 };
84 
85 struct extended_sigtable {
86 	unsigned int			count;
87 	unsigned int			cksum;
88 	unsigned int			reserved[3];
89 	struct extended_signature	sigs[];
90 };
91 
92 /**
93  * struct staging_state - Track the current staging process state
94  *
95  * @mmio_base:		MMIO base address for staging
96  * @ucode_len:		Total size of the microcode image
97  * @chunk_size:		Size of each data piece
98  * @bytes_sent:		Total bytes transmitted so far
99  * @offset:		Current offset in the microcode image
100  */
101 struct staging_state {
102 	void __iomem		*mmio_base;
103 	unsigned int		ucode_len;
104 	unsigned int		chunk_size;
105 	unsigned int		bytes_sent;
106 	unsigned int		offset;
107 };
108 
109 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE)
110 #define EXT_HEADER_SIZE		(sizeof(struct extended_sigtable))
111 #define EXT_SIGNATURE_SIZE	(sizeof(struct extended_signature))
112 
113 static inline unsigned int get_totalsize(struct microcode_header_intel *hdr)
114 {
115 	return hdr->datasize ? hdr->totalsize : DEFAULT_UCODE_TOTALSIZE;
116 }
117 
118 static inline unsigned int exttable_size(struct extended_sigtable *et)
119 {
120 	return et->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE;
121 }
122 
123 void intel_collect_cpu_info(struct cpu_signature *sig)
124 {
125 	sig->sig = cpuid_eax(1);
126 	sig->pf = 0;
127 	sig->rev = intel_get_microcode_revision();
128 
129 	if (IFM(x86_family(sig->sig), x86_model(sig->sig)) >= INTEL_PENTIUM_III_DESCHUTES) {
130 		unsigned int val[2];
131 
132 		/* get processor flags from MSR 0x17 */
133 		native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
134 		sig->pf = 1 << ((val[1] >> 18) & 7);
135 	}
136 }
137 EXPORT_SYMBOL_GPL(intel_collect_cpu_info);
138 
139 static inline bool cpu_signatures_match(struct cpu_signature *s1, unsigned int sig2,
140 					unsigned int pf2)
141 {
142 	if (s1->sig != sig2)
143 		return false;
144 
145 	/* Processor flags are either both 0 or they intersect. */
146 	return ((!s1->pf && !pf2) || (s1->pf & pf2));
147 }
148 
149 bool intel_find_matching_signature(void *mc, struct cpu_signature *sig)
150 {
151 	struct microcode_header_intel *mc_hdr = mc;
152 	struct extended_signature *ext_sig;
153 	struct extended_sigtable *ext_hdr;
154 	int i;
155 
156 	if (cpu_signatures_match(sig, mc_hdr->sig, mc_hdr->pf))
157 		return true;
158 
159 	/* Look for ext. headers: */
160 	if (get_totalsize(mc_hdr) <= intel_microcode_get_datasize(mc_hdr) + MC_HEADER_SIZE)
161 		return false;
162 
163 	ext_hdr = mc + intel_microcode_get_datasize(mc_hdr) + MC_HEADER_SIZE;
164 	ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
165 
166 	for (i = 0; i < ext_hdr->count; i++) {
167 		if (cpu_signatures_match(sig, ext_sig->sig, ext_sig->pf))
168 			return true;
169 		ext_sig++;
170 	}
171 	return 0;
172 }
173 EXPORT_SYMBOL_GPL(intel_find_matching_signature);
174 
175 /**
176  * intel_microcode_sanity_check() - Sanity check microcode file.
177  * @mc: Pointer to the microcode file contents.
178  * @print_err: Display failure reason if true, silent if false.
179  * @hdr_type: Type of file, i.e. normal microcode file or In Field Scan file.
180  *            Validate if the microcode header type matches with the type
181  *            specified here.
182  *
183  * Validate certain header fields and verify if computed checksum matches
184  * with the one specified in the header.
185  *
186  * Return: 0 if the file passes all the checks, -EINVAL if any of the checks
187  * fail.
188  */
189 int intel_microcode_sanity_check(void *mc, bool print_err, int hdr_type)
190 {
191 	unsigned long total_size, data_size, ext_table_size;
192 	struct microcode_header_intel *mc_header = mc;
193 	struct extended_sigtable *ext_header = NULL;
194 	u32 sum, orig_sum, ext_sigcount = 0, i;
195 	struct extended_signature *ext_sig;
196 
197 	total_size = get_totalsize(mc_header);
198 	data_size = intel_microcode_get_datasize(mc_header);
199 
200 	if (data_size + MC_HEADER_SIZE > total_size) {
201 		if (print_err)
202 			pr_err("Error: bad microcode data file size.\n");
203 		return -EINVAL;
204 	}
205 
206 	if (mc_header->ldrver != 1 || mc_header->hdrver != hdr_type) {
207 		if (print_err)
208 			pr_err("Error: invalid/unknown microcode update format. Header type %d\n",
209 			       mc_header->hdrver);
210 		return -EINVAL;
211 	}
212 
213 	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
214 	if (ext_table_size) {
215 		u32 ext_table_sum = 0;
216 		u32 *ext_tablep;
217 
218 		if (ext_table_size < EXT_HEADER_SIZE ||
219 		    ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
220 			if (print_err)
221 				pr_err("Error: truncated extended signature table.\n");
222 			return -EINVAL;
223 		}
224 
225 		ext_header = mc + MC_HEADER_SIZE + data_size;
226 		if (ext_table_size != exttable_size(ext_header)) {
227 			if (print_err)
228 				pr_err("Error: extended signature table size mismatch.\n");
229 			return -EFAULT;
230 		}
231 
232 		ext_sigcount = ext_header->count;
233 
234 		/*
235 		 * Check extended table checksum: the sum of all dwords that
236 		 * comprise a valid table must be 0.
237 		 */
238 		ext_tablep = (u32 *)ext_header;
239 
240 		i = ext_table_size / sizeof(u32);
241 		while (i--)
242 			ext_table_sum += ext_tablep[i];
243 
244 		if (ext_table_sum) {
245 			if (print_err)
246 				pr_warn("Bad extended signature table checksum, aborting.\n");
247 			return -EINVAL;
248 		}
249 	}
250 
251 	/*
252 	 * Calculate the checksum of update data and header. The checksum of
253 	 * valid update data and header including the extended signature table
254 	 * must be 0.
255 	 */
256 	orig_sum = 0;
257 	i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
258 	while (i--)
259 		orig_sum += ((u32 *)mc)[i];
260 
261 	if (orig_sum) {
262 		if (print_err)
263 			pr_err("Bad microcode data checksum, aborting.\n");
264 		return -EINVAL;
265 	}
266 
267 	if (!ext_table_size)
268 		return 0;
269 
270 	/*
271 	 * Check extended signature checksum: 0 => valid.
272 	 */
273 	for (i = 0; i < ext_sigcount; i++) {
274 		ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
275 			  EXT_SIGNATURE_SIZE * i;
276 
277 		sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
278 		      (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
279 		if (sum) {
280 			if (print_err)
281 				pr_err("Bad extended signature checksum, aborting.\n");
282 			return -EINVAL;
283 		}
284 	}
285 	return 0;
286 }
287 EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);
288 
289 static void update_ucode_pointer(struct microcode_intel *mc)
290 {
291 	kvfree(ucode_patch_va);
292 
293 	/*
294 	 * Save the virtual address for early loading and for eventual free
295 	 * on late loading.
296 	 */
297 	ucode_patch_va = mc;
298 }
299 
300 static void save_microcode_patch(struct microcode_intel *patch)
301 {
302 	unsigned int size = get_totalsize(&patch->hdr);
303 	struct microcode_intel *mc;
304 
305 	mc = kvmemdup(patch, size, GFP_KERNEL);
306 	if (mc)
307 		update_ucode_pointer(mc);
308 	else
309 		pr_err("Unable to allocate microcode memory size: %u\n", size);
310 }
311 
312 /* Scan blob for microcode matching the boot CPUs family, model, stepping */
313 static __init struct microcode_intel *scan_microcode(void *data, size_t size,
314 						     struct ucode_cpu_info *uci,
315 						     bool save)
316 {
317 	struct microcode_header_intel *mc_header;
318 	struct microcode_intel *patch = NULL;
319 	u32 cur_rev = uci->cpu_sig.rev;
320 	unsigned int mc_size;
321 
322 	for (; size >= sizeof(struct microcode_header_intel); size -= mc_size, data += mc_size) {
323 		mc_header = (struct microcode_header_intel *)data;
324 
325 		mc_size = get_totalsize(mc_header);
326 		if (!mc_size || mc_size > size ||
327 		    intel_microcode_sanity_check(data, false, MC_HEADER_TYPE_MICROCODE) < 0)
328 			break;
329 
330 		if (!intel_find_matching_signature(data, &uci->cpu_sig))
331 			continue;
332 
333 		/*
334 		 * For saving the early microcode, find the matching revision which
335 		 * was loaded on the BSP.
336 		 *
337 		 * On the BSP during early boot, find a newer revision than
338 		 * actually loaded in the CPU.
339 		 */
340 		if (save) {
341 			if (cur_rev != mc_header->rev)
342 				continue;
343 		} else if (cur_rev >= mc_header->rev) {
344 			continue;
345 		}
346 
347 		patch = data;
348 		cur_rev = mc_header->rev;
349 	}
350 
351 	return size ? NULL : patch;
352 }
353 
354 static inline u32 read_mbox_dword(void __iomem *mmio_base)
355 {
356 	u32 dword = readl(mmio_base + MBOX_RDDATA_OFFSET);
357 
358 	/* Acknowledge read completion to the staging hardware */
359 	writel(0, mmio_base + MBOX_RDDATA_OFFSET);
360 	return dword;
361 }
362 
363 static inline void write_mbox_dword(void __iomem *mmio_base, u32 dword)
364 {
365 	writel(dword, mmio_base + MBOX_WRDATA_OFFSET);
366 }
367 
368 static inline u64 read_mbox_header(void __iomem *mmio_base)
369 {
370 	u32 high, low;
371 
372 	low  = read_mbox_dword(mmio_base);
373 	high = read_mbox_dword(mmio_base);
374 
375 	return ((u64)high << 32) | low;
376 }
377 
378 static inline void write_mbox_header(void __iomem *mmio_base, u64 value)
379 {
380 	write_mbox_dword(mmio_base, value);
381 	write_mbox_dword(mmio_base, value >> 32);
382 }
383 
384 static void write_mbox_data(void __iomem *mmio_base, u32 *chunk, unsigned int chunk_bytes)
385 {
386 	int i;
387 
388 	/*
389 	 * The MMIO space is mapped as Uncached (UC). Each write arrives
390 	 * at the device as an individual transaction in program order.
391 	 * The device can then reassemble the sequence accordingly.
392 	 */
393 	for (i = 0; i < chunk_bytes / sizeof(u32); i++)
394 		write_mbox_dword(mmio_base, chunk[i]);
395 }
396 
397 /*
398  * Prepare for a new microcode transfer: reset hardware and record the
399  * image size.
400  */
401 static void init_stage(struct staging_state *ss)
402 {
403 	ss->ucode_len = get_totalsize(&ucode_patch_late->hdr);
404 
405 	/*
406 	 * Abort any ongoing process, effectively resetting the device.
407 	 * Unlike regular mailbox data processing requests, this
408 	 * operation does not require a status check.
409 	 */
410 	writel(MASK_MBOX_CTRL_ABORT, ss->mmio_base + MBOX_CONTROL_OFFSET);
411 }
412 
413 /*
414  * Update the chunk size and decide whether another chunk can be sent.
415  * This accounts for remaining data and retry limits.
416  */
417 static bool can_send_next_chunk(struct staging_state *ss, int *err)
418 {
419 	/* A page size or remaining bytes if this is the final chunk */
420 	ss->chunk_size = min(PAGE_SIZE, ss->ucode_len - ss->offset);
421 
422 	/*
423 	 * Each microcode image is divided into chunks, each at most
424 	 * one page size. A 10-chunk image would typically require 10
425 	 * transactions.
426 	 *
427 	 * However, the hardware managing the mailbox has limited
428 	 * resources and may not cache the entire image, potentially
429 	 * requesting the same chunk multiple times.
430 	 *
431 	 * To tolerate this behavior, allow up to twice the expected
432 	 * number of transactions (i.e., a 10-chunk image can take up to
433 	 * 20 attempts).
434 	 *
435 	 * If the number of attempts exceeds this limit, treat it as
436 	 * exceeding the maximum allowed transfer size.
437 	 */
438 	if (ss->bytes_sent + ss->chunk_size > ss->ucode_len * 2) {
439 		*err = -EMSGSIZE;
440 		return false;
441 	}
442 
443 	*err = 0;
444 	return true;
445 }
446 
447 /*
448  * The hardware indicates completion by returning a sentinel end offset.
449  */
450 static inline bool is_end_offset(u32 offset)
451 {
452 	return offset == UINT_MAX;
453 }
454 
455 /*
456  * Determine whether staging is complete: either the hardware signaled
457  * the end offset, or no more transactions are permitted (retry limit
458  * reached).
459  */
460 static inline bool staging_is_complete(struct staging_state *ss, int *err)
461 {
462 	return is_end_offset(ss->offset) || !can_send_next_chunk(ss, err);
463 }
464 
465 /*
466  * Wait for the hardware to complete a transaction.
467  * Return 0 on success, or an error code on failure.
468  */
469 static int wait_for_transaction(struct staging_state *ss)
470 {
471 	u32 timeout, status;
472 
473 	/* Allow time for hardware to complete the operation: */
474 	for (timeout = 0; timeout < MBOX_XACTION_TIMEOUT_MS; timeout++) {
475 		msleep(1);
476 
477 		status = readl(ss->mmio_base + MBOX_STATUS_OFFSET);
478 		/* Break out early if the hardware is ready: */
479 		if (status & MASK_MBOX_STATUS_READY)
480 			break;
481 	}
482 
483 	/* Check for explicit error response */
484 	if (status & MASK_MBOX_STATUS_ERROR)
485 		return -EIO;
486 
487 	/*
488 	 * Hardware has neither responded to the action nor signaled any
489 	 * error. Treat this as a timeout.
490 	 */
491 	if (!(status & MASK_MBOX_STATUS_READY))
492 		return -ETIMEDOUT;
493 
494 	return 0;
495 }
496 
497 /*
498  * Transmit a chunk of the microcode image to the hardware.
499  * Return 0 on success, or an error code on failure.
500  */
501 static int send_data_chunk(struct staging_state *ss, void *ucode_ptr)
502 {
503 	u32 *src_chunk = ucode_ptr + ss->offset;
504 	u16 mbox_size;
505 
506 	/*
507 	 * Write a 'request' mailbox object in this order:
508 	 *  1. Mailbox header includes total size
509 	 *  2. Command header specifies the load operation
510 	 *  3. Data section contains a microcode chunk
511 	 *
512 	 * Thus, the mailbox size is two headers plus the chunk size.
513 	 */
514 	mbox_size = MBOX_HEADER_SIZE * 2 + ss->chunk_size;
515 	write_mbox_header(ss->mmio_base, MBOX_HEADER(mbox_size));
516 	write_mbox_header(ss->mmio_base, MBOX_CMD_LOAD);
517 	write_mbox_data(ss->mmio_base, src_chunk, ss->chunk_size);
518 	ss->bytes_sent += ss->chunk_size;
519 
520 	/* Notify the hardware that the mailbox is ready for processing. */
521 	writel(MASK_MBOX_CTRL_GO, ss->mmio_base + MBOX_CONTROL_OFFSET);
522 
523 	return wait_for_transaction(ss);
524 }
525 
526 /*
527  * Retrieve the next offset from the hardware response.
528  * Return 0 on success, or an error code on failure.
529  */
530 static int fetch_next_offset(struct staging_state *ss)
531 {
532 	const u64 expected_header = MBOX_HEADER(MBOX_HEADER_SIZE + MBOX_RESPONSE_SIZE);
533 	u32 offset, status;
534 	u64 header;
535 
536 	/*
537 	 * The 'response' mailbox returns three fields, in order:
538 	 *  1. Header
539 	 *  2. Next offset in the microcode image
540 	 *  3. Status flags
541 	 */
542 	header = read_mbox_header(ss->mmio_base);
543 	offset = read_mbox_dword(ss->mmio_base);
544 	status = read_mbox_dword(ss->mmio_base);
545 
546 	/* All valid responses must start with the expected header. */
547 	if (header != expected_header) {
548 		pr_err_once("staging: invalid response header (0x%llx)\n", header);
549 		return -EBADR;
550 	}
551 
552 	/*
553 	 * Verify the offset: If not at the end marker, it must not
554 	 * exceed the microcode image length.
555 	 */
556 	if (!is_end_offset(offset) && offset > ss->ucode_len) {
557 		pr_err_once("staging: invalid offset (%u) past the image end (%u)\n",
558 			    offset, ss->ucode_len);
559 		return -EINVAL;
560 	}
561 
562 	/* Hardware may report errors explicitly in the status field */
563 	if (status & MASK_MBOX_RESP_ERROR)
564 		return -EPROTO;
565 
566 	ss->offset = offset;
567 	return 0;
568 }
569 
570 /*
571  * Handle the staging process using the mailbox MMIO interface. The
572  * microcode image is transferred in chunks until completion.
573  * Return 0 on success or an error code on failure.
574  */
575 static int do_stage(u64 mmio_pa)
576 {
577 	struct staging_state ss = {};
578 	int err;
579 
580 	ss.mmio_base = ioremap(mmio_pa, MBOX_REG_NUM * MBOX_REG_SIZE);
581 	if (WARN_ON_ONCE(!ss.mmio_base))
582 		return -EADDRNOTAVAIL;
583 
584 	init_stage(&ss);
585 
586 	/* Perform the staging process while within the retry limit */
587 	while (!staging_is_complete(&ss, &err)) {
588 		/* Send a chunk of microcode each time: */
589 		err = send_data_chunk(&ss, ucode_patch_late);
590 		if (err)
591 			break;
592 		/*
593 		 * Then, ask the hardware which piece of the image it
594 		 * needs next. The same piece may be sent more than once.
595 		 */
596 		err = fetch_next_offset(&ss);
597 		if (err)
598 			break;
599 	}
600 
601 	iounmap(ss.mmio_base);
602 
603 	return err;
604 }
605 
606 static void stage_microcode(void)
607 {
608 	unsigned int pkg_id = UINT_MAX;
609 	int cpu, err;
610 	u64 mmio_pa;
611 
612 	if (!IS_ALIGNED(get_totalsize(&ucode_patch_late->hdr), sizeof(u32))) {
613 		pr_err("Microcode image 32-bit misaligned (0x%x), staging failed.\n",
614 			get_totalsize(&ucode_patch_late->hdr));
615 		return;
616 	}
617 
618 	lockdep_assert_cpus_held();
619 
620 	/*
621 	 * The MMIO address is unique per package, and all the SMT
622 	 * primary threads are online here. Find each MMIO space by
623 	 * their package IDs to avoid duplicate staging.
624 	 */
625 	for_each_cpu(cpu, cpu_primary_thread_mask) {
626 		if (topology_logical_package_id(cpu) == pkg_id)
627 			continue;
628 
629 		pkg_id = topology_logical_package_id(cpu);
630 
631 		err = rdmsrq_on_cpu(cpu, MSR_IA32_MCU_STAGING_MBOX_ADDR, &mmio_pa);
632 		if (WARN_ON_ONCE(err))
633 			return;
634 
635 		err = do_stage(mmio_pa);
636 		if (err) {
637 			pr_err("Error: staging failed (%d) for CPU%d at package %u.\n",
638 			       err, cpu, pkg_id);
639 			return;
640 		}
641 	}
642 
643 	pr_info("Staging of patch revision 0x%x succeeded.\n", ucode_patch_late->hdr.rev);
644 }
645 
646 static enum ucode_state __apply_microcode(struct ucode_cpu_info *uci,
647 					  struct microcode_intel *mc,
648 					  u32 *cur_rev)
649 {
650 	u32 rev;
651 
652 	if (!mc)
653 		return UCODE_NFOUND;
654 
655 	/*
656 	 * Save us the MSR write below - which is a particular expensive
657 	 * operation - when the other hyperthread has updated the microcode
658 	 * already.
659 	 */
660 	*cur_rev = intel_get_microcode_revision();
661 	if (*cur_rev >= mc->hdr.rev) {
662 		uci->cpu_sig.rev = *cur_rev;
663 		return UCODE_OK;
664 	}
665 
666 	/* write microcode via MSR 0x79 */
667 	native_wrmsrq(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
668 
669 	rev = intel_get_microcode_revision();
670 	if (rev != mc->hdr.rev)
671 		return UCODE_ERROR;
672 
673 	uci->cpu_sig.rev = rev;
674 	return UCODE_UPDATED;
675 }
676 
677 static enum ucode_state apply_microcode_early(struct ucode_cpu_info *uci)
678 {
679 	struct microcode_intel *mc = uci->mc;
680 	u32 cur_rev;
681 
682 	return __apply_microcode(uci, mc, &cur_rev);
683 }
684 
685 static __init bool load_builtin_intel_microcode(struct cpio_data *cp)
686 {
687 	unsigned int eax = 1, ebx, ecx = 0, edx;
688 	struct firmware fw;
689 	char name[30];
690 
691 	if (IS_ENABLED(CONFIG_X86_32))
692 		return false;
693 
694 	native_cpuid(&eax, &ebx, &ecx, &edx);
695 
696 	sprintf(name, "intel-ucode/%02x-%02x-%02x",
697 		x86_family(eax), x86_model(eax), x86_stepping(eax));
698 
699 	if (firmware_request_builtin(&fw, name)) {
700 		cp->size = fw.size;
701 		cp->data = (void *)fw.data;
702 		return true;
703 	}
704 	return false;
705 }
706 
707 static __init struct microcode_intel *get_microcode_blob(struct ucode_cpu_info *uci, bool save)
708 {
709 	struct cpio_data cp;
710 
711 	intel_collect_cpu_info(&uci->cpu_sig);
712 
713 	if (!load_builtin_intel_microcode(&cp))
714 		cp = find_microcode_in_initrd(ucode_path);
715 
716 	if (!(cp.data && cp.size))
717 		return NULL;
718 
719 	return scan_microcode(cp.data, cp.size, uci, save);
720 }
721 
722 /*
723  * Invoked from an early init call to save the microcode blob which was
724  * selected during early boot when mm was not usable. The microcode must be
725  * saved because initrd is going away. It's an early init call so the APs
726  * just can use the pointer and do not have to scan initrd/builtin firmware
727  * again.
728  */
729 static int __init save_builtin_microcode(void)
730 {
731 	struct ucode_cpu_info uci;
732 
733 	if (xchg(&ucode_patch_va, NULL) != UCODE_BSP_LOADED)
734 		return 0;
735 
736 	if (microcode_loader_disabled() || boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
737 		return 0;
738 
739 	uci.mc = get_microcode_blob(&uci, true);
740 	if (uci.mc)
741 		save_microcode_patch(uci.mc);
742 	return 0;
743 }
744 early_initcall(save_builtin_microcode);
745 
746 /* Load microcode on BSP from initrd or builtin blobs */
747 void __init load_ucode_intel_bsp(struct early_load_data *ed)
748 {
749 	struct ucode_cpu_info uci;
750 
751 	uci.mc = get_microcode_blob(&uci, false);
752 	ed->old_rev = uci.cpu_sig.rev;
753 
754 	if (uci.mc && apply_microcode_early(&uci) == UCODE_UPDATED) {
755 		ucode_patch_va = UCODE_BSP_LOADED;
756 		ed->new_rev = uci.cpu_sig.rev;
757 	}
758 }
759 
760 void load_ucode_intel_ap(void)
761 {
762 	struct ucode_cpu_info uci;
763 
764 	uci.mc = ucode_patch_va;
765 	if (uci.mc)
766 		apply_microcode_early(&uci);
767 }
768 
769 /* Reload microcode on resume */
770 void reload_ucode_intel(void)
771 {
772 	struct ucode_cpu_info uci = { .mc = ucode_patch_va, };
773 
774 	if (uci.mc)
775 		apply_microcode_early(&uci);
776 }
777 
778 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
779 {
780 	intel_collect_cpu_info(csig);
781 	return 0;
782 }
783 
784 static enum ucode_state apply_microcode_late(int cpu)
785 {
786 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
787 	struct microcode_intel *mc = ucode_patch_late;
788 	enum ucode_state ret;
789 	u32 cur_rev;
790 
791 	if (WARN_ON_ONCE(smp_processor_id() != cpu))
792 		return UCODE_ERROR;
793 
794 	ret = __apply_microcode(uci, mc, &cur_rev);
795 	if (ret != UCODE_UPDATED && ret != UCODE_OK)
796 		return ret;
797 
798 	cpu_data(cpu).microcode	 = uci->cpu_sig.rev;
799 	if (!cpu)
800 		boot_cpu_data.microcode = uci->cpu_sig.rev;
801 
802 	return ret;
803 }
804 
805 static bool ucode_validate_minrev(struct microcode_header_intel *mc_header)
806 {
807 	int cur_rev = boot_cpu_data.microcode;
808 
809 	/*
810 	 * When late-loading, ensure the header declares a minimum revision
811 	 * required to perform a late-load. The previously reserved field
812 	 * is 0 in older microcode blobs.
813 	 */
814 	if (!mc_header->min_req_ver) {
815 		pr_info("Unsafe microcode update: Microcode header does not specify a required min version\n");
816 		return false;
817 	}
818 
819 	/*
820 	 * Check whether the current revision is either greater or equal to
821 	 * to the minimum revision specified in the header.
822 	 */
823 	if (cur_rev < mc_header->min_req_ver) {
824 		pr_info("Unsafe microcode update: Current revision 0x%x too old\n", cur_rev);
825 		pr_info("Current should be at 0x%x or higher. Use early loading instead\n", mc_header->min_req_ver);
826 		return false;
827 	}
828 	return true;
829 }
830 
831 static enum ucode_state parse_microcode_blobs(int cpu, struct iov_iter *iter)
832 {
833 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
834 	bool is_safe, new_is_safe = false;
835 	int cur_rev = uci->cpu_sig.rev;
836 	unsigned int curr_mc_size = 0;
837 	u8 *new_mc = NULL, *mc = NULL;
838 
839 	while (iov_iter_count(iter)) {
840 		struct microcode_header_intel mc_header;
841 		unsigned int mc_size, data_size;
842 		u8 *data;
843 
844 		if (!copy_from_iter_full(&mc_header, sizeof(mc_header), iter)) {
845 			pr_err("error! Truncated or inaccessible header in microcode data file\n");
846 			goto fail;
847 		}
848 
849 		mc_size = get_totalsize(&mc_header);
850 		if (mc_size < sizeof(mc_header)) {
851 			pr_err("error! Bad data in microcode data file (totalsize too small)\n");
852 			goto fail;
853 		}
854 		data_size = mc_size - sizeof(mc_header);
855 		if (data_size > iov_iter_count(iter)) {
856 			pr_err("error! Bad data in microcode data file (truncated file?)\n");
857 			goto fail;
858 		}
859 
860 		/* For performance reasons, reuse mc area when possible */
861 		if (!mc || mc_size > curr_mc_size) {
862 			kvfree(mc);
863 			mc = kvmalloc(mc_size, GFP_KERNEL);
864 			if (!mc)
865 				goto fail;
866 			curr_mc_size = mc_size;
867 		}
868 
869 		memcpy(mc, &mc_header, sizeof(mc_header));
870 		data = mc + sizeof(mc_header);
871 		if (!copy_from_iter_full(data, data_size, iter) ||
872 		    intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0)
873 			goto fail;
874 
875 		if (cur_rev >= mc_header.rev)
876 			continue;
877 
878 		if (!intel_find_matching_signature(mc, &uci->cpu_sig))
879 			continue;
880 
881 		is_safe = ucode_validate_minrev(&mc_header);
882 		if (force_minrev && !is_safe)
883 			continue;
884 
885 		kvfree(new_mc);
886 		cur_rev = mc_header.rev;
887 		new_mc  = mc;
888 		new_is_safe = is_safe;
889 		mc = NULL;
890 	}
891 
892 	if (iov_iter_count(iter))
893 		goto fail;
894 
895 	kvfree(mc);
896 	if (!new_mc)
897 		return UCODE_NFOUND;
898 
899 	ucode_patch_late = (struct microcode_intel *)new_mc;
900 	return new_is_safe ? UCODE_NEW_SAFE : UCODE_NEW;
901 
902 fail:
903 	kvfree(mc);
904 	kvfree(new_mc);
905 	return UCODE_ERROR;
906 }
907 
908 static bool is_blacklisted(unsigned int cpu)
909 {
910 	struct cpuinfo_x86 *c = &cpu_data(cpu);
911 
912 	/*
913 	 * Late loading on model 79 with microcode revision less than 0x0b000021
914 	 * and LLC size per core bigger than 2.5MB may result in a system hang.
915 	 * This behavior is documented in item BDX90, #334165 (Intel Xeon
916 	 * Processor E7-8800/4800 v4 Product Family).
917 	 */
918 	if (c->x86_vfm == INTEL_BROADWELL_X &&
919 	    c->x86_stepping == 0x01 &&
920 	    llc_size_per_core > 2621440 &&
921 	    c->microcode < 0x0b000021) {
922 		pr_err_once("Erratum BDX90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode);
923 		pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
924 		return true;
925 	}
926 
927 	return false;
928 }
929 
930 static enum ucode_state request_microcode_fw(int cpu, struct device *device)
931 {
932 	struct cpuinfo_x86 *c = &cpu_data(cpu);
933 	const struct firmware *firmware;
934 	struct iov_iter iter;
935 	enum ucode_state ret;
936 	struct kvec kvec;
937 	char name[30];
938 
939 	if (is_blacklisted(cpu))
940 		return UCODE_NFOUND;
941 
942 	sprintf(name, "intel-ucode/%02x-%02x-%02x",
943 		c->x86, c->x86_model, c->x86_stepping);
944 
945 	if (request_firmware_direct(&firmware, name, device)) {
946 		pr_debug("data file %s load failed\n", name);
947 		return UCODE_NFOUND;
948 	}
949 
950 	kvec.iov_base = (void *)firmware->data;
951 	kvec.iov_len = firmware->size;
952 	iov_iter_kvec(&iter, ITER_SOURCE, &kvec, 1, firmware->size);
953 	ret = parse_microcode_blobs(cpu, &iter);
954 
955 	release_firmware(firmware);
956 
957 	return ret;
958 }
959 
960 static void finalize_late_load(int result)
961 {
962 	if (!result)
963 		update_ucode_pointer(ucode_patch_late);
964 	else
965 		kvfree(ucode_patch_late);
966 	ucode_patch_late = NULL;
967 }
968 
969 static struct microcode_ops microcode_intel_ops = {
970 	.request_microcode_fw	= request_microcode_fw,
971 	.collect_cpu_info	= collect_cpu_info,
972 	.apply_microcode	= apply_microcode_late,
973 	.finalize_late_load	= finalize_late_load,
974 	.stage_microcode	= stage_microcode,
975 	.use_nmi		= IS_ENABLED(CONFIG_X86_64),
976 };
977 
978 static __init void calc_llc_size_per_core(struct cpuinfo_x86 *c)
979 {
980 	u64 llc_size = c->x86_cache_size * 1024ULL;
981 
982 	do_div(llc_size, topology_num_cores_per_package());
983 	llc_size_per_core = (unsigned int)llc_size;
984 }
985 
986 static __init bool staging_available(void)
987 {
988 	u64 val;
989 
990 	val = x86_read_arch_cap_msr();
991 	if (!(val & ARCH_CAP_MCU_ENUM))
992 		return false;
993 
994 	rdmsrq(MSR_IA32_MCU_ENUMERATION, val);
995 	return !!(val & MCU_STAGING);
996 }
997 
998 struct microcode_ops * __init init_intel_microcode(void)
999 {
1000 	struct cpuinfo_x86 *c = &boot_cpu_data;
1001 
1002 	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
1003 	    cpu_has(c, X86_FEATURE_IA64)) {
1004 		pr_err("Intel CPU family 0x%x not supported\n", c->x86);
1005 		return NULL;
1006 	}
1007 
1008 	if (staging_available()) {
1009 		microcode_intel_ops.use_staging = true;
1010 		pr_info("Enabled staging feature.\n");
1011 	}
1012 
1013 	calc_llc_size_per_core(c);
1014 
1015 	return &microcode_intel_ops;
1016 }
1017