linux-kernel - [PATCH 10/15] x86/resctrl: Initialize ABMC counters bitmap

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Message-ID: <20231201005720.235639-11-babu.moger@amd.com>
Date:   Thu, 30 Nov 2023 18:57:15 -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>,
        <seanjc@...gle.com>, <kim.phillips@....com>, <babu.moger@....com>,
        <jmattson@...gle.com>, <ilpo.jarvinen@...ux.intel.com>,
        <jithu.joseph@...el.com>, <kan.liang@...ux.intel.com>,
        <nikunj@....com>, <daniel.sneddon@...ux.intel.com>,
        <pbonzini@...hat.com>, <rick.p.edgecombe@...el.com>,
        <rppt@...nel.org>, <maciej.wieczor-retman@...el.com>,
        <linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <eranian@...gle.com>, <peternewman@...gle.com>, <dhagiani@....com>
Subject: [PATCH 10/15] x86/resctrl: Initialize ABMC counters bitmap

AMD Hardware provides 32 ABMC(Bandwidth Monitoring Event Configuration)
counters when supported. These hardware counters are used to assign
(or pin) the RMID to the group.

Introduce the bitmap abmc_free_map to allocate and free counters.

Signed-off-by: Babu Moger <babu.moger@....com>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index edb679b22b7b..f72d6d8c12df 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 abmc_free_map;
+static u32 abmc_free_map_len;
+
+static void abmc_counters_init(void)
+{
+	struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_L3];
+
+	if (hw_res->abmc_counters > 64) {
+		hw_res->abmc_counters = 64;
+		WARN(1, "Cannot support more than 64 abmc counters\n");
+	}
+
+	abmc_free_map = BIT_MASK(hw_res->abmc_counters) - 1;
+	abmc_free_map_len = hw_res->abmc_counters;
+}
+
 /**
  * rdtgroup_mode_by_closid - Return mode of resource group with closid
  * @closid: closid if the resource group
@@ -2715,6 +2731,7 @@ static int rdt_get_tree(struct fs_context *fc)
 {
 	struct rdt_fs_context *ctx = rdt_fc2context(fc);
 	unsigned long flags = RFTYPE_CTRL_BASE;
+	struct rdt_hw_resource *hw_res;
 	struct rdt_domain *dom;
 	struct rdt_resource *r;
 	int ret;
@@ -2745,6 +2762,12 @@ static int rdt_get_tree(struct fs_context *fc)
 
 	closid_init();
 
+	r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+	hw_res = resctrl_to_arch_res(r);
+
+	if (r->abmc_capable && hw_res->abmc_enabled)
+		abmc_counters_init();
+
 	if (rdt_mon_capable)
 		flags |= RFTYPE_MON;
 
@@ -2789,7 +2812,6 @@ 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