Commit 13390861 authored by Babu Moger's avatar Babu Moger Committed by Borislav Petkov (AMD)
Browse files

x86,fs/resctrl: Detect Assignable Bandwidth Monitoring feature details 



ABMC feature details are reported via CPUID Fn8000_0020_EBX_x5.
Bits Description
15:0 MAX_ABMC Maximum Supported Assignable Bandwidth
     Monitoring Counter ID + 1

The ABMC feature details are documented in APM [1] available from [2].

  [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming
  Publication # 24593 Revision 3.41 section 19.3.3.3 Assignable Bandwidth
  Monitoring (ABMC).

Detect the feature and number of assignable counters supported. For backward
compatibility, upon detecting the assignable counter feature, enable the
mbm_total_bytes and mbm_local_bytes events that users are familiar with as
part of original L3 MBM support.

Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 # [2]
parent 5ad68c8f

arch/x86/kernel/cpu/resctrl/core.c

+5 −2
Original line number Diff line number Diff line
@@ -883,6 +883,8 @@ static __init bool get_rdt_mon_resources(void) 
		resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID);

		ret = true;

	}

	if (rdt_cpu_has(X86_FEATURE_ABMC))

		ret = true;



	if (!ret)

		return false;
@@ -978,7 +980,7 @@ static enum cpuhp_state rdt_online; 
/* Runs once on the BSP during boot. */

void resctrl_cpu_detect(struct cpuinfo_x86 *c)

{

	if (!cpu_has(c, X86_FEATURE_CQM_LLC)) {

	if (!cpu_has(c, X86_FEATURE_CQM_LLC) && !cpu_has(c, X86_FEATURE_ABMC)) {

		c->x86_cache_max_rmid  = -1;

		c->x86_cache_occ_scale = -1;

		c->x86_cache_mbm_width_offset = -1;
@@ -990,7 +992,8 @@ void resctrl_cpu_detect(struct cpuinfo_x86 *c) 


	if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC) ||

	    cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL) ||

	    cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)) {

	    cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL) ||

	    cpu_has(c, X86_FEATURE_ABMC)) {

		u32 eax, ebx, ecx, edx;



		/* QoS sub-leaf, EAX=0Fh, ECX=1 */

arch/x86/kernel/cpu/resctrl/monitor.c

+8 −3
Original line number Diff line number Diff line
@@ -339,6 +339,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) 
	unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;

	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);

	unsigned int threshold;

	u32 eax, ebx, ecx, edx;



	snc_nodes_per_l3_cache = snc_get_config();
@@ -368,14 +369,18 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) 
	 */

	resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(threshold);



	if (rdt_cpu_has(X86_FEATURE_BMEC)) {

		u32 eax, ebx, ecx, edx;



	if (rdt_cpu_has(X86_FEATURE_BMEC) || rdt_cpu_has(X86_FEATURE_ABMC)) {

		/* Detect list of bandwidth sources that can be tracked */

		cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx);

		r->mon.mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS;

	}



	if (rdt_cpu_has(X86_FEATURE_ABMC)) {

		r->mon.mbm_cntr_assignable = true;

		cpuid_count(0x80000020, 5, &eax, &ebx, &ecx, &edx);

		r->mon.num_mbm_cntrs = (ebx & GENMASK(15, 0)) + 1;

	}



	r->mon_capable = true;



	return 0;

fs/resctrl/monitor.c

+7 −0
Original line number Diff line number Diff line
@@ -922,6 +922,13 @@ int resctrl_mon_resource_init(void) 
	else if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID))

		mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID;



	if (r->mon.mbm_cntr_assignable) {

		if (!resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID))

			resctrl_enable_mon_event(QOS_L3_MBM_TOTAL_EVENT_ID);

		if (!resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID))

			resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID);

	}



	return 0;

}

include/linux/resctrl.h

+4 −0
Original line number Diff line number Diff line
@@ -260,10 +260,14 @@ enum resctrl_schema_fmt { 
 * @num_rmid:		Number of RMIDs available.

 * @mbm_cfg_mask:	Memory transactions that can be tracked when bandwidth

 *			monitoring events can be configured.

 * @num_mbm_cntrs:	Number of assignable counters.

 * @mbm_cntr_assignable:Is system capable of supporting counter assignment?

 */

struct resctrl_mon {

	int			num_rmid;

	unsigned int		mbm_cfg_mask;

	int			num_mbm_cntrs;

	bool			mbm_cntr_assignable;

};



/**