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Commit 3c763fd7 authored by Andreas Herrmann's avatar Andreas Herrmann Committed by Ingo Molnar
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x86: microcode_amd: fix wrong handling of equivalent CPU id 



Impact: fix bug resulting in non-loaded AMD microcode

mc_header->processor_rev_id is a 2 byte value. Similar is true for
equiv_cpu in an equiv_cpu_entry -- only 2 bytes are of interest.

Signed-off-by: default avatarAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 5279585f

arch/x86/kernel/microcode_amd.c

+6 −17
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ struct microcode_header_amd { 
	unsigned int  mc_patch_data_checksum;

	unsigned int  nb_dev_id;

	unsigned int  sb_dev_id;

	unsigned char processor_rev_id[2];

	u16 processor_rev_id;

	unsigned char nb_rev_id;

	unsigned char sb_rev_id;

	unsigned char bios_api_rev;
@@ -125,7 +125,7 @@ static int get_matching_microcode(int cpu, void *mc, int rev) 


	while (equiv_cpu_table[i].installed_cpu != 0) {

		if (current_cpu_id == equiv_cpu_table[i].installed_cpu) {

			equiv_cpu_id = equiv_cpu_table[i].equiv_cpu;

			equiv_cpu_id = equiv_cpu_table[i].equiv_cpu & 0xffff;

			break;

		}

		i++;
@@ -137,21 +137,10 @@ static int get_matching_microcode(int cpu, void *mc, int rev) 
		return 0;

	}



	if ((mc_header->processor_rev_id[0]) != (equiv_cpu_id & 0xff)) {

		printk(KERN_ERR

			"microcode: CPU%d patch does not match "

			"(patch is %x, cpu extended is %x) \n",

			cpu, mc_header->processor_rev_id[0],

			(equiv_cpu_id & 0xff));

		return 0;

	}



	if ((mc_header->processor_rev_id[1]) != ((equiv_cpu_id >> 16) & 0xff)) {

	if (mc_header->processor_rev_id != equiv_cpu_id) {

		printk(KERN_ERR	"microcode: CPU%d patch does not match "

			"(patch is %x, cpu base id is %x) \n",

			cpu, mc_header->processor_rev_id[1],

			((equiv_cpu_id >> 16) & 0xff));



		       "(processor_rev_id: %x, eqiv_cpu_id: %x)\n",

		       cpu, mc_header->processor_rev_id, equiv_cpu_id);

		return 0;

	}