Commit ba528f28 authored by Jan Beulich's avatar Jan Beulich Committed by Linus Torvalds
Browse files

[PATCH] fix x86 microcode driver handling of multiple matching revisions 



When multiple updates matching a given CPU are found in the update file, the
action taken by the microcode update driver was inappropriate:

- when lower revision microcode was found before matching or higher revision
  one, the driver would needlessly complain that it would not downgrade the
  CPU
- when microcode matching the currently installed revision was found before
  newer revision code, no update would actually take place

To change this behavior, the driver now concludes about possibly updates and
issues messages only when the entire input was parsed.

Additionally, this adds back (in different places, and conditionalized upon
a new module option) some messages removed by a previous patch.

Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Tigran Aivazian <tigran_aivazian@symantec.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 27b07da7

arch/i386/kernel/microcode.c

+49 −24
Original line number Diff line number Diff line
@@ -91,7 +91,10 @@ MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver"); 
MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");

MODULE_LICENSE("GPL");



#define MICROCODE_VERSION 	"1.14"

static int verbose;

module_param(verbose, int, 0644);



#define MICROCODE_VERSION 	"1.14a"



#define DEFAULT_UCODE_DATASIZE 	(2000) 	  /* 2000 bytes */

#define MC_HEADER_SIZE		(sizeof (microcode_header_t))  	  /* 48 bytes */
@@ -122,14 +125,15 @@ static unsigned int user_buffer_size; /* it's size */ 


typedef enum mc_error_code {

	MC_SUCCESS 	= 0,

	MC_NOTFOUND 	= 1,

	MC_MARKED 	= 2,

	MC_ALLOCATED 	= 3,

	MC_IGNORED 	= 1,

	MC_NOTFOUND 	= 2,

	MC_MARKED 	= 3,

	MC_ALLOCATED 	= 4,

} mc_error_code_t;



static struct ucode_cpu_info {

	unsigned int sig;

	unsigned int pf;

	unsigned int pf, orig_pf;

	unsigned int rev;

	unsigned int cksum;

	mc_error_code_t err;
@@ -164,6 +168,7 @@ static void collect_cpu_info (void *unused) 
			rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);

			uci->pf = 1 << ((val[1] >> 18) & 7);

		}

		uci->orig_pf = uci->pf;

	}



	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
@@ -197,21 +202,34 @@ static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_he 
	pr_debug("   Checksum 0x%x\n", cksum);



	if (mc_header->rev < uci->rev) {

		printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"

		       " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);

		goto out;

		if (uci->err == MC_NOTFOUND) {

			uci->err = MC_IGNORED;

			uci->cksum = mc_header->rev;

		} else if (uci->err == MC_IGNORED && uci->cksum < mc_header->rev)

			uci->cksum = mc_header->rev;

	} else if (mc_header->rev == uci->rev) {

		if (uci->err < MC_MARKED) {

			/* notify the caller of success on this cpu */

			uci->err = MC_SUCCESS;

		goto out;

		}



	} else if (uci->err != MC_ALLOCATED || mc_header->rev > uci->mc->hdr.rev) {

		pr_debug("microcode: CPU%d found a matching microcode update with "

			" revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);

		uci->cksum = cksum;

		uci->pf = pf; /* keep the original mc pf for cksum calculation */

		uci->err = MC_MARKED; /* found the match */

out:

		for_each_online_cpu(cpu_num) {

			if (ucode_cpu_info + cpu_num != uci

			    && ucode_cpu_info[cpu_num].mc == uci->mc) {

				uci->mc = NULL;

				break;

			}

		}

		if (uci->mc != NULL) {

			vfree(uci->mc);

			uci->mc = NULL;

		}

	}

	return;

}
@@ -253,10 +271,8 @@ static int find_matching_ucodes (void) 


		for_each_online_cpu(cpu_num) {

			struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

			if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/

				continue;



			if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))

			if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->orig_pf))

				mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);

		}
@@ -295,9 +311,8 @@ static int find_matching_ucodes (void) 
				}

				for_each_online_cpu(cpu_num) {

					struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

					if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/

						continue;

					if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {



					if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->orig_pf)) {

						mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);

					}

				}
@@ -368,6 +383,13 @@ static void do_update_one (void * unused) 
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;



	if (uci->mc == NULL) {

		if (verbose) {

			if (uci->err == MC_SUCCESS)

				printk(KERN_INFO "microcode: CPU%d already at revision 0x%x\n",

					cpu_num, uci->rev);

			else

				printk(KERN_INFO "microcode: No new microcode data for CPU%d\n", cpu_num);

		}

		return;

	}
@@ -426,6 +448,9 @@ out_free: 
					ucode_cpu_info[j].mc = NULL;

			}

		}

		if (ucode_cpu_info[i].err == MC_IGNORED && verbose)

			printk(KERN_WARNING "microcode: CPU%d not 'upgrading' to earlier revision"

			       " 0x%x (current=0x%x)\n", i, ucode_cpu_info[i].cksum, ucode_cpu_info[i].rev);

	}

out:

	return error;

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