[PATCH v2 02/16] fs, x86/resctrl: Add architecture routines for kernel mode initialization

[Babu Moger]

Implement the resctrl kernel mode (kmode) arch initialization.

- Add resctrl_arch_get_kmode_cfg() to fill the default kernel mode
  (INHERIT_CTRL_AND_MON). This can be extended later (e.g. for PLZA) to set
  additional modes.

- Add global resctrl_kcfg and resctrl_kmode_init() to initialize default
  values.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v2: New patch to handle PLZA interfaces with /sys/fs/resctrl/info/ directory.
    https://lore.kernel.org/lkml/2ab556af-095b-422b-9396-f845c6fd0342@xxxxxxxxx/
---
 arch/x86/kernel/cpu/resctrl/core.c |  7 +++++++
 fs/resctrl/rdtgroup.c              | 10 ++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 7667cf7c4e94..4c3ab2d93909 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -892,6 +892,13 @@ bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
 	}
 }
 
+void resctrl_arch_get_kmode_cfg(struct resctrl_kmode_cfg *kcfg)
+{
+	kcfg->kmode = INHERIT_CTRL_AND_MON;
+	kcfg->kmode_cur = INHERIT_CTRL_AND_MON;
+	kcfg->k_rdtgrp = NULL;
+}
+
 static __init bool get_mem_config(void)
 {
 	struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_MBA];
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 5da305bd36c9..9d6d74af4874 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -76,6 +76,9 @@ static void rdtgroup_destroy_root(void);
 
 struct dentry *debugfs_resctrl;
 
+/* Current resctrl kernel mode config (kmode, kmode_cur, k_rdtgrp). */
+struct resctrl_kmode_cfg resctrl_kcfg;
+
 /*
  * Memory bandwidth monitoring event to use for the default CTRL_MON group
  * and each new CTRL_MON group created by the user.  Only relevant when
@@ -2204,6 +2207,11 @@ static void io_alloc_init(void)
 	}
 }
 
+static void resctrl_kmode_init(void)
+{
+	resctrl_arch_get_kmode_cfg(&resctrl_kcfg);
+}
+
 void resctrl_file_fflags_init(const char *config, unsigned long fflags)
 {
 	struct rftype *rft;
@@ -4554,6 +4562,8 @@ int resctrl_init(void)
 
 	io_alloc_init();
 
+	resctrl_kmode_init();
+
 	ret = resctrl_l3_mon_resource_init();
 	if (ret)
 		return ret;
-- 
2.43.0