Commit 94605eff authored by Siddha, Suresh B's avatar Siddha, Suresh B Committed by Linus Torvalds
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[PATCH] x86-64/i386: Intel HT, Multi core detection fixes 

Fields obtained through cpuid vector 0x1(ebx[16:23]) and
vector 0x4(eax[14:25], eax[26:31]) indicate the maximum values and might not
always be the same as what is available and what OS sees.  So make sure
"siblings" and "cpu cores" values in /proc/cpuinfo reflect the values as seen
by OS instead of what cpuid instruction says. This will also fix the buggy BIOS
cases (for example where cpuid on a single core cpu says there are "2" siblings,
even when HT is disabled in the BIOS.
http://bugzilla.kernel.org/show_bug.cgi?id=4359

)

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e90f22ed

arch/i386/kernel/cpu/amd.c

+6 −6
Original line number Diff line number Diff line
@@ -206,9 +206,9 @@ static void __init init_amd(struct cpuinfo_x86 *c) 
	display_cacheinfo(c);



	if (cpuid_eax(0x80000000) >= 0x80000008) {

		c->x86_num_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;

		if (c->x86_num_cores & (c->x86_num_cores - 1))

			c->x86_num_cores = 1;

		c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;

		if (c->x86_max_cores & (c->x86_max_cores - 1))

			c->x86_max_cores = 1;

	}



#ifdef CONFIG_X86_HT
@@ -217,15 +217,15 @@ static void __init init_amd(struct cpuinfo_x86 *c) 
	 * distingush the cores.  Assumes number of cores is a power

	 * of two.

	 */

	if (c->x86_num_cores > 1) {

	if (c->x86_max_cores > 1) {

		int cpu = smp_processor_id();

		unsigned bits = 0;

		while ((1 << bits) < c->x86_num_cores)

		while ((1 << bits) < c->x86_max_cores)

			bits++;

		cpu_core_id[cpu] = phys_proc_id[cpu] & ((1<<bits)-1);

		phys_proc_id[cpu] >>= bits;

		printk(KERN_INFO "CPU %d(%d) -> Core %d\n",

		       cpu, c->x86_num_cores, cpu_core_id[cpu]);

		       cpu, c->x86_max_cores, cpu_core_id[cpu]);

	}

#endif

}

arch/i386/kernel/cpu/common.c

+14 −22
Original line number Diff line number Diff line
@@ -335,7 +335,7 @@ void __devinit identify_cpu(struct cpuinfo_x86 *c) 
	c->x86_model = c->x86_mask = 0;	/* So far unknown... */

	c->x86_vendor_id[0] = '\0'; /* Unset */

	c->x86_model_id[0] = '\0';  /* Unset */

	c->x86_num_cores = 1;

	c->x86_max_cores = 1;

	memset(&c->x86_capability, 0, sizeof c->x86_capability);



	if (!have_cpuid_p()) {
@@ -446,52 +446,44 @@ void __devinit identify_cpu(struct cpuinfo_x86 *c) 
void __devinit detect_ht(struct cpuinfo_x86 *c)

{

	u32 	eax, ebx, ecx, edx;

	int 	index_msb, tmp;

	int 	index_msb, core_bits;

	int 	cpu = smp_processor_id();



	cpuid(1, &eax, &ebx, &ecx, &edx);



	c->apicid = phys_pkg_id((ebx >> 24) & 0xFF, 0);



	if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY))

		return;



	cpuid(1, &eax, &ebx, &ecx, &edx);

	smp_num_siblings = (ebx & 0xff0000) >> 16;



	if (smp_num_siblings == 1) {

		printk(KERN_INFO  "CPU: Hyper-Threading is disabled\n");

	} else if (smp_num_siblings > 1 ) {

		index_msb = 31;



		if (smp_num_siblings > NR_CPUS) {

			printk(KERN_WARNING "CPU: Unsupported number of the siblings %d", smp_num_siblings);

			smp_num_siblings = 1;

			return;

		}

		tmp = smp_num_siblings;

		while ((tmp & 0x80000000 ) == 0) {

			tmp <<=1 ;

			index_msb--;

		}

		if (smp_num_siblings & (smp_num_siblings - 1))

			index_msb++;



		index_msb = get_count_order(smp_num_siblings);

		phys_proc_id[cpu] = phys_pkg_id((ebx >> 24) & 0xFF, index_msb);



		printk(KERN_INFO  "CPU: Physical Processor ID: %d\n",

		       phys_proc_id[cpu]);



		smp_num_siblings = smp_num_siblings / c->x86_num_cores;

		smp_num_siblings = smp_num_siblings / c->x86_max_cores;



		tmp = smp_num_siblings;

		index_msb = 31;

		while ((tmp & 0x80000000) == 0) {

			tmp <<=1 ;

			index_msb--;

		}

		index_msb = get_count_order(smp_num_siblings) ;



		if (smp_num_siblings & (smp_num_siblings - 1))

			index_msb++;

		core_bits = get_count_order(c->x86_max_cores);



		cpu_core_id[cpu] = phys_pkg_id((ebx >> 24) & 0xFF, index_msb);

		cpu_core_id[cpu] = phys_pkg_id((ebx >> 24) & 0xFF, index_msb) &

					       ((1 << core_bits) - 1);



		if (c->x86_num_cores > 1)

		if (c->x86_max_cores > 1)

			printk(KERN_INFO  "CPU: Processor Core ID: %d\n",

			       cpu_core_id[cpu]);

	}

arch/i386/kernel/cpu/intel.c

+1 −1
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ static void __devinit init_intel(struct cpuinfo_x86 *c) 
	if ( p )

		strcpy(c->x86_model_id, p);

	

	c->x86_num_cores = num_cpu_cores(c);

	c->x86_max_cores = num_cpu_cores(c);



	detect_ht(c);

arch/i386/kernel/cpu/intel_cacheinfo.c

+1 −1
Original line number Diff line number Diff line
@@ -307,7 +307,7 @@ static void __cpuinit cache_shared_cpu_map_setup(unsigned int cpu, int index) 
#ifdef CONFIG_X86_HT

	else if (num_threads_sharing == smp_num_siblings)

		this_leaf->shared_cpu_map = cpu_sibling_map[cpu];

	else if (num_threads_sharing == (c->x86_num_cores * smp_num_siblings))

	else if (num_threads_sharing == (c->x86_max_cores * smp_num_siblings))

		this_leaf->shared_cpu_map = cpu_core_map[cpu];

	else

		printk(KERN_DEBUG "Number of CPUs sharing cache didn't match "

arch/i386/kernel/cpu/proc.c

+3 −4
Original line number Diff line number Diff line
@@ -94,12 +94,11 @@ static int show_cpuinfo(struct seq_file *m, void *v) 
	if (c->x86_cache_size >= 0)

		seq_printf(m, "cache size\t: %d KB\n", c->x86_cache_size);

#ifdef CONFIG_X86_HT

	if (c->x86_num_cores * smp_num_siblings > 1) {

	if (c->x86_max_cores * smp_num_siblings > 1) {

		seq_printf(m, "physical id\t: %d\n", phys_proc_id[n]);

		seq_printf(m, "siblings\t: %d\n",

				c->x86_num_cores * smp_num_siblings);

		seq_printf(m, "siblings\t: %d\n", cpus_weight(cpu_core_map[n]));

		seq_printf(m, "core id\t\t: %d\n", cpu_core_id[n]);

		seq_printf(m, "cpu cores\t: %d\n", c->x86_num_cores);

		seq_printf(m, "cpu cores\t: %d\n", c->booted_cores);

	}

#endif

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