[RFC PATCH 24/31] x86/resctrl: Attach ACPI ERDT information to ctrl domain on CPU online

[Chen Yu]

After the rdt_hw_ctrl_domain has been created during CPU online, attach
the pre-parsed ACPI ERDT table information to the rdt_hw_ctrl_domain
to facilitate MBA control programming via the MARC MMIO registers.

This mirrors the approach used by the monitoring domain
(rdt_hw_l3_mon_domain::d_info) where ERDT domain information is
attached during domain creation.

Add erdt_find_domain_info() to look up the erdt_domain_info for a given
CPU by matching against the CACD-derived cpu_mask in each domain.

Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/core.c     |  1 +
 arch/x86/kernel/cpu/resctrl/erdt.c     | 12 ++++++++++++
 arch/x86/kernel/cpu/resctrl/internal.h |  3 +++
 3 files changed, 16 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index b2c53eab7d8f..86d78107537e 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -575,6 +575,7 @@ static void domain_add_cpu_ctrl(int cpu, struct rdt_resource *r,
 	d->hdr.type = RESCTRL_CTRL_DOMAIN;
 	d->hdr.rid = r->rid;
 	cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
+	hw_dom->d_info = erdt_find_domain_info(cpu);
 
 	rdt_domain_reconfigure_cdp(r);
 
diff --git a/arch/x86/kernel/cpu/resctrl/erdt.c b/arch/x86/kernel/cpu/resctrl/erdt.c
index b61f75b63f37..38720c3b4a3d 100644
--- a/arch/x86/kernel/cpu/resctrl/erdt.c
+++ b/arch/x86/kernel/cpu/resctrl/erdt.c
@@ -261,6 +261,18 @@ int erdt_mon_read(struct rdt_domain_hdr *hdr, enum resctrl_event_id evtid, u32 r
 	return -EIO;
 }
 
+struct erdt_domain_info *erdt_find_domain_info(int cpu)
+{
+	struct erdt_domain_info *d;
+
+	list_for_each_entry(d, &domain_info_list, entry) {
+		if (cpumask_test_cpu(cpu, &d->cpu_mask))
+			return d;
+	}
+
+	return NULL;
+}
+
 static void marc_hw_update(struct hw_param *m)
 {
 }
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index f09583c95a62..e9602525e4bd 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -137,12 +137,14 @@ static inline struct resctrl_hw_ctrl *resctrl_to_arch_ctrl(struct resctrl_ctrl *
  *			       a resource for a control function
  * @d_resctrl:	Properties exposed to the resctrl file system
  * @ctrl_val:	array of cache or mem ctrl values (indexed by CLOSID)
+ * @d_info:	ERDT table information of this domain (read-only)
  *
  * Members of this structure are accessed via helpers that provide abstraction.
  */
 struct rdt_hw_ctrl_domain {
 	struct rdt_ctrl_domain		d_resctrl;
 	u32				*ctrl_val;
+	struct erdt_domain_info		*d_info;
 };
 
 /**
@@ -325,6 +327,7 @@ static inline void intel_aet_mon_domain_setup(int cpu, int id, struct rdt_resour
 static inline bool intel_handle_aet_option(bool force_off, char *tok) { return false; }
 #endif
 
+struct erdt_domain_info *erdt_find_domain_info(int cpu);
 bool erdt_support(int flag);
 bool erdt_cpu_has(int flag);
 bool erdt_enable_mon(void);
-- 
2.43.0