[PATCH v9 06/12] x86,fs/resctrl: Move resctrl_arch_round_mon_val() out of line

[Chen Yu]

resctrl_arch_round_mon_val() is an inline function in the architecture
header. It is only called during resctrl initialization and when user space
writes "max_threshold_occupancy", neither of which is a hot path that
benefits from inlining.

Upcoming ERDT support needs resctrl_arch_round_mon_val() to consult
ERDT-specific state. Keeping it inline would force ERDT prototypes into the
architecture header, fragmenting the ERDT code across files.

Move resctrl_arch_round_mon_val() into monitor.c and declare it in
include/linux/resctrl.h alongside the other resctrl_arch_*() calls. Move the
MPAM stub from arm_mpam.h into mpam_resctrl.c accordingly.

No functional change.

Suggested-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
Changes since v8:
- New patch. v8 added erdt_get_scale() and erdt_cpu_has() prototypes to
  asm/resctrl.h only to keep resctrl_arch_round_mon_val() inline, which
  fragmented the ERDT code. Move the function out of line instead so the
  ERDT prototypes can stay in the resctrl internal header.
  (Reinette Chatre)

 arch/x86/include/asm/resctrl.h        | 9 ---------
 arch/x86/kernel/cpu/resctrl/monitor.c | 9 +++++++++
 drivers/resctrl/mpam_resctrl.c        | 5 +++++
 include/linux/arm_mpam.h              | 5 -----
 include/linux/resctrl.h               | 1 +
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index 8f6edcdcfd87..738de74235bd 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -130,15 +130,6 @@ static inline void __resctrl_sched_in(struct task_struct *tsk)
 	}
 }
 
-static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
-{
-	unsigned int scale = boot_cpu_data.x86_cache_occ_scale;
-
-	/* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
-	val /= scale;
-	return val * scale;
-}
-
 static inline void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid,
 							    u32 rmid)
 {
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 6e46f10d8640..e42ee2769a39 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -421,6 +421,15 @@ __init void resctrl_arch_update_snc(void)
 	snc_nodes_per_l3_cache = snc_get_config();
 }
 
+unsigned int resctrl_arch_round_mon_val(unsigned int val)
+{
+	unsigned int scale = boot_cpu_data.x86_cache_occ_scale;
+
+	/* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
+	val /= scale;
+	return val * scale;
+}
+
 int __init rdt_get_l3_mon_config(struct rdt_resource *r)
 {
 	unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 9d223057953a..5799c6bd4f98 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -143,6 +143,11 @@ void resctrl_arch_pre_mount(void)
 {
 }
 
+unsigned int resctrl_arch_round_mon_val(unsigned int val)
+{
+	return val;
+}
+
 bool resctrl_arch_get_cdp_enabled(enum resctrl_res_level rid)
 {
 	return mpam_resctrl_controls[rid].cdp_enabled;
diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h
index f92a36187a52..4c639e9c8e5b 100644
--- a/include/linux/arm_mpam.h
+++ b/include/linux/arm_mpam.h
@@ -76,11 +76,6 @@ static inline void resctrl_arch_disable_mon(void) { }
 static inline void resctrl_arch_enable_alloc(void) { }
 static inline void resctrl_arch_disable_alloc(void) { }
 
-static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
-{
-	return val;
-}
-
 /**
  * mpam_register_requestor() - Register a requestor with the MPAM driver
  * @partid_max:		The maximum PARTID value the requestor can generate.
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index dd09c2ce9a0f..c99561b19e7a 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -418,6 +418,7 @@ static inline u32 resctrl_get_default_ctrl(struct rdt_resource *r)
 u32 resctrl_arch_get_num_closid(struct rdt_resource *r);
 u32 resctrl_arch_system_num_rmid_idx(void);
 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
+unsigned int resctrl_arch_round_mon_val(unsigned int val);
 
 bool resctrl_enable_mon_event(enum resctrl_event_id eventid, bool any_cpu,
 			      unsigned int binary_bits, void *arch_priv);
-- 
2.43.0