linux-kernel - [PATCH v2 12/17] x86/resctrl: Initialize assignable counters bitmap

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Date: Fri, 19 Jan 2024 12:22:14 -0600
From: Babu Moger <babu.moger@....com>
To: <corbet@....net>, <fenghua.yu@...el.com>, <reinette.chatre@...el.com>,
	<tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>,
	<dave.hansen@...ux.intel.com>
CC: <x86@...nel.org>, <hpa@...or.com>, <paulmck@...nel.org>,
	<rdunlap@...radead.org>, <tj@...nel.org>, <peterz@...radead.org>,
	<yanjiewtw@...il.com>, <babu.moger@....com>, <kim.phillips@....com>,
	<lukas.bulwahn@...il.com>, <seanjc@...gle.com>, <jmattson@...gle.com>,
	<leitao@...ian.org>, <jpoimboe@...nel.org>, <rick.p.edgecombe@...el.com>,
	<kirill.shutemov@...ux.intel.com>, <jithu.joseph@...el.com>,
	<kai.huang@...el.com>, <kan.liang@...ux.intel.com>,
	<daniel.sneddon@...ux.intel.com>, <pbonzini@...hat.com>,
	<sandipan.das@....com>, <ilpo.jarvinen@...ux.intel.com>,
	<peternewman@...gle.com>, <maciej.wieczor-retman@...el.com>,
	<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<eranian@...gle.com>
Subject: [PATCH v2 12/17] x86/resctrl: Initialize assignable counters bitmap

AMD Hardware provides a set of ABMC counters when the feature is supported.
These hardware counters are used for assigning the RMIDs to the group.

Introduce the bitmap assignable_counter_free_map to allocate and free
counters.

Signed-off-by: Babu Moger <babu.moger@....com>
---
v2: Changed the bitmap name to assignable_counter_free_map from
    abmc_counter_free_map.
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 7cae6ac13954..19b0ebf4f435 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -164,6 +164,22 @@ static bool closid_allocated(unsigned int closid)
 	return (closid_free_map & (1 << closid)) == 0;
 }
 
+static u64 assignable_counter_free_map;
+static u32 assignable_counter_free_map_len;
+
+static void assignable_counters_init(void)
+{
+	struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_L3];
+
+	if (hw_res->mbm_assignable_counters > 64) {
+		hw_res->mbm_assignable_counters = 64;
+		WARN(1, "Cannot support more than 64 Assignable counters\n");
+	}
+
+	assignable_counter_free_map = BIT_MASK(hw_res->mbm_assignable_counters) - 1;
+	assignable_counter_free_map_len = hw_res->mbm_assignable_counters;
+}
+
 /**
  * rdtgroup_mode_by_closid - Return mode of resource group with closid
  * @closid: closid if the resource group
@@ -2777,6 +2793,10 @@ static int rdt_get_tree(struct fs_context *fc)
 
 	closid_init();
 
+	r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+	if (r->mbm_assign_capable)
+		assignable_counters_init();
+
 	if (rdt_mon_capable)
 		flags |= RFTYPE_MON;
 
@@ -2821,7 +2841,6 @@ static int rdt_get_tree(struct fs_context *fc)
 		static_branch_enable_cpuslocked(&rdt_enable_key);
 
 	if (is_mbm_enabled()) {
-		r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
 		list_for_each_entry(dom, &r->domains, list)
 			mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
 	}
-- 
2.34.1