xref: /openbmc/linux/arch/x86/kernel/cpu/microcode/intel.c (revision 206204a1)
1 /*
2  *	Intel CPU Microcode Update Driver for Linux
3  *
4  *	Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5  *		      2006	Shaohua Li <shaohua.li@intel.com>
6  *
7  *	This driver allows to upgrade microcode on Intel processors
8  *	belonging to IA-32 family - PentiumPro, Pentium II,
9  *	Pentium III, Xeon, Pentium 4, etc.
10  *
11  *	Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
12  *	Software Developer's Manual
13  *	Order Number 253668 or free download from:
14  *
15  *	http://developer.intel.com/Assets/PDF/manual/253668.pdf
16  *
17  *	For more information, go to http://www.urbanmyth.org/microcode
18  *
19  *	This program is free software; you can redistribute it and/or
20  *	modify it under the terms of the GNU General Public License
21  *	as published by the Free Software Foundation; either version
22  *	2 of the License, or (at your option) any later version.
23  *
24  *	1.0	16 Feb 2000, Tigran Aivazian <tigran@sco.com>
25  *		Initial release.
26  *	1.01	18 Feb 2000, Tigran Aivazian <tigran@sco.com>
27  *		Added read() support + cleanups.
28  *	1.02	21 Feb 2000, Tigran Aivazian <tigran@sco.com>
29  *		Added 'device trimming' support. open(O_WRONLY) zeroes
30  *		and frees the saved copy of applied microcode.
31  *	1.03	29 Feb 2000, Tigran Aivazian <tigran@sco.com>
32  *		Made to use devfs (/dev/cpu/microcode) + cleanups.
33  *	1.04	06 Jun 2000, Simon Trimmer <simon@veritas.com>
34  *		Added misc device support (now uses both devfs and misc).
35  *		Added MICROCODE_IOCFREE ioctl to clear memory.
36  *	1.05	09 Jun 2000, Simon Trimmer <simon@veritas.com>
37  *		Messages for error cases (non Intel & no suitable microcode).
38  *	1.06	03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
39  *		Removed ->release(). Removed exclusive open and status bitmap.
40  *		Added microcode_rwsem to serialize read()/write()/ioctl().
41  *		Removed global kernel lock usage.
42  *	1.07	07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
43  *		Write 0 to 0x8B msr and then cpuid before reading revision,
44  *		so that it works even if there were no update done by the
45  *		BIOS. Otherwise, reading from 0x8B gives junk (which happened
46  *		to be 0 on my machine which is why it worked even when I
47  *		disabled update by the BIOS)
48  *		Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
49  *	1.08	11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
50  *			     Tigran Aivazian <tigran@veritas.com>
51  *		Intel Pentium 4 processor support and bugfixes.
52  *	1.09	30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
53  *		Bugfix for HT (Hyper-Threading) enabled processors
54  *		whereby processor resources are shared by all logical processors
55  *		in a single CPU package.
56  *	1.10	28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
57  *		Tigran Aivazian <tigran@veritas.com>,
58  *		Serialize updates as required on HT processors due to
59  *		speculative nature of implementation.
60  *	1.11	22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
61  *		Fix the panic when writing zero-length microcode chunk.
62  *	1.12	29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
63  *		Jun Nakajima <jun.nakajima@intel.com>
64  *		Support for the microcode updates in the new format.
65  *	1.13	10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
66  *		Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
67  *		because we no longer hold a copy of applied microcode
68  *		in kernel memory.
69  *	1.14	25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
70  *		Fix sigmatch() macro to handle old CPUs with pf == 0.
71  *		Thanks to Stuart Swales for pointing out this bug.
72  */
73 
74 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
75 
76 #include <linux/firmware.h>
77 #include <linux/uaccess.h>
78 #include <linux/kernel.h>
79 #include <linux/module.h>
80 #include <linux/vmalloc.h>
81 
82 #include <asm/microcode_intel.h>
83 #include <asm/processor.h>
84 #include <asm/msr.h>
85 
86 MODULE_DESCRIPTION("Microcode Update Driver");
87 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
88 MODULE_LICENSE("GPL");
89 
90 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
91 {
92 	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
93 	unsigned int val[2];
94 
95 	memset(csig, 0, sizeof(*csig));
96 
97 	csig->sig = cpuid_eax(0x00000001);
98 
99 	if ((c->x86_model >= 5) || (c->x86 > 6)) {
100 		/* get processor flags from MSR 0x17 */
101 		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
102 		csig->pf = 1 << ((val[1] >> 18) & 7);
103 	}
104 
105 	csig->rev = c->microcode;
106 	pr_info("CPU%d sig=0x%x, pf=0x%x, revision=0x%x\n",
107 		cpu_num, csig->sig, csig->pf, csig->rev);
108 
109 	return 0;
110 }
111 
112 /*
113  * return 0 - no update found
114  * return 1 - found update
115  */
116 static int get_matching_mc(struct microcode_intel *mc_intel, int cpu)
117 {
118 	struct cpu_signature cpu_sig;
119 	unsigned int csig, cpf, crev;
120 
121 	collect_cpu_info(cpu, &cpu_sig);
122 
123 	csig = cpu_sig.sig;
124 	cpf = cpu_sig.pf;
125 	crev = cpu_sig.rev;
126 
127 	return get_matching_microcode(csig, cpf, mc_intel, crev);
128 }
129 
130 int apply_microcode(int cpu)
131 {
132 	struct microcode_intel *mc_intel;
133 	struct ucode_cpu_info *uci;
134 	unsigned int val[2];
135 	int cpu_num = raw_smp_processor_id();
136 	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
137 
138 	uci = ucode_cpu_info + cpu;
139 	mc_intel = uci->mc;
140 
141 	/* We should bind the task to the CPU */
142 	BUG_ON(cpu_num != cpu);
143 
144 	if (mc_intel == NULL)
145 		return 0;
146 
147 	/*
148 	 * Microcode on this CPU could be updated earlier. Only apply the
149 	 * microcode patch in mc_intel when it is newer than the one on this
150 	 * CPU.
151 	 */
152 	if (get_matching_mc(mc_intel, cpu) == 0)
153 		return 0;
154 
155 	/* write microcode via MSR 0x79 */
156 	wrmsr(MSR_IA32_UCODE_WRITE,
157 	      (unsigned long) mc_intel->bits,
158 	      (unsigned long) mc_intel->bits >> 16 >> 16);
159 	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
160 
161 	/* As documented in the SDM: Do a CPUID 1 here */
162 	sync_core();
163 
164 	/* get the current revision from MSR 0x8B */
165 	rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
166 
167 	if (val[1] != mc_intel->hdr.rev) {
168 		pr_err("CPU%d update to revision 0x%x failed\n",
169 		       cpu_num, mc_intel->hdr.rev);
170 		return -1;
171 	}
172 	pr_info("CPU%d updated to revision 0x%x, date = %04x-%02x-%02x\n",
173 		cpu_num, val[1],
174 		mc_intel->hdr.date & 0xffff,
175 		mc_intel->hdr.date >> 24,
176 		(mc_intel->hdr.date >> 16) & 0xff);
177 
178 	uci->cpu_sig.rev = val[1];
179 	c->microcode = val[1];
180 
181 	return 0;
182 }
183 
184 static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
185 				int (*get_ucode_data)(void *, const void *, size_t))
186 {
187 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
188 	u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
189 	int new_rev = uci->cpu_sig.rev;
190 	unsigned int leftover = size;
191 	enum ucode_state state = UCODE_OK;
192 	unsigned int curr_mc_size = 0;
193 	unsigned int csig, cpf;
194 
195 	while (leftover) {
196 		struct microcode_header_intel mc_header;
197 		unsigned int mc_size;
198 
199 		if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header)))
200 			break;
201 
202 		mc_size = get_totalsize(&mc_header);
203 		if (!mc_size || mc_size > leftover) {
204 			pr_err("error! Bad data in microcode data file\n");
205 			break;
206 		}
207 
208 		/* For performance reasons, reuse mc area when possible */
209 		if (!mc || mc_size > curr_mc_size) {
210 			vfree(mc);
211 			mc = vmalloc(mc_size);
212 			if (!mc)
213 				break;
214 			curr_mc_size = mc_size;
215 		}
216 
217 		if (get_ucode_data(mc, ucode_ptr, mc_size) ||
218 		    microcode_sanity_check(mc, 1) < 0) {
219 			break;
220 		}
221 
222 		csig = uci->cpu_sig.sig;
223 		cpf = uci->cpu_sig.pf;
224 		if (get_matching_microcode(csig, cpf, mc, new_rev)) {
225 			vfree(new_mc);
226 			new_rev = mc_header.rev;
227 			new_mc  = mc;
228 			mc = NULL;	/* trigger new vmalloc */
229 		}
230 
231 		ucode_ptr += mc_size;
232 		leftover  -= mc_size;
233 	}
234 
235 	vfree(mc);
236 
237 	if (leftover) {
238 		vfree(new_mc);
239 		state = UCODE_ERROR;
240 		goto out;
241 	}
242 
243 	if (!new_mc) {
244 		state = UCODE_NFOUND;
245 		goto out;
246 	}
247 
248 	vfree(uci->mc);
249 	uci->mc = (struct microcode_intel *)new_mc;
250 
251 	/*
252 	 * If early loading microcode is supported, save this mc into
253 	 * permanent memory. So it will be loaded early when a CPU is hot added
254 	 * or resumes.
255 	 */
256 	save_mc_for_early(new_mc);
257 
258 	pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
259 		 cpu, new_rev, uci->cpu_sig.rev);
260 out:
261 	return state;
262 }
263 
264 static int get_ucode_fw(void *to, const void *from, size_t n)
265 {
266 	memcpy(to, from, n);
267 	return 0;
268 }
269 
270 static enum ucode_state request_microcode_fw(int cpu, struct device *device,
271 					     bool refresh_fw)
272 {
273 	char name[30];
274 	struct cpuinfo_x86 *c = &cpu_data(cpu);
275 	const struct firmware *firmware;
276 	enum ucode_state ret;
277 
278 	sprintf(name, "intel-ucode/%02x-%02x-%02x",
279 		c->x86, c->x86_model, c->x86_mask);
280 
281 	if (request_firmware_direct(&firmware, name, device)) {
282 		pr_debug("data file %s load failed\n", name);
283 		return UCODE_NFOUND;
284 	}
285 
286 	ret = generic_load_microcode(cpu, (void *)firmware->data,
287 				     firmware->size, &get_ucode_fw);
288 
289 	release_firmware(firmware);
290 
291 	return ret;
292 }
293 
294 static int get_ucode_user(void *to, const void *from, size_t n)
295 {
296 	return copy_from_user(to, from, n);
297 }
298 
299 static enum ucode_state
300 request_microcode_user(int cpu, const void __user *buf, size_t size)
301 {
302 	return generic_load_microcode(cpu, (void *)buf, size, &get_ucode_user);
303 }
304 
305 static void microcode_fini_cpu(int cpu)
306 {
307 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
308 
309 	vfree(uci->mc);
310 	uci->mc = NULL;
311 }
312 
313 static struct microcode_ops microcode_intel_ops = {
314 	.request_microcode_user		  = request_microcode_user,
315 	.request_microcode_fw             = request_microcode_fw,
316 	.collect_cpu_info                 = collect_cpu_info,
317 	.apply_microcode                  = apply_microcode,
318 	.microcode_fini_cpu               = microcode_fini_cpu,
319 };
320 
321 struct microcode_ops * __init init_intel_microcode(void)
322 {
323 	struct cpuinfo_x86 *c = &cpu_data(0);
324 
325 	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
326 	    cpu_has(c, X86_FEATURE_IA64)) {
327 		pr_err("Intel CPU family 0x%x not supported\n", c->x86);
328 		return NULL;
329 	}
330 
331 	return &microcode_intel_ops;
332 }
333 
334