[PATCH v10 02/12] arm,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 x86 and MPAM
architecture headers. 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 x86
asm header, fragmenting the ERDT code into a header where it does not belong.

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>
Tested-by: Hongyu Ning <hongyu.ning@xxxxxxxxxxxxxxx>
Acked-by: Ben Horgan <ben.horgan@xxxxxxx>
---
Changes since v9:
- Move this patch from the middle of the series to patch 2, right after
  the x86/topology change, so that MPAM maintainers only need to review
  this patch. (Reinette Chatre)
- Change the subject prefix from "x86,fs/resctrl:" to
  "arm,x86,fs/resctrl:" to draw the attention of MPAM maintainers.
  (Reinette Chatre)
- Changelog: say "x86 and MPAM architecture headers" and "x86 asm
  header", and state that keeping the function inline would place ERDT
  code in a header where it does not belong. (Reinette Chatre)
- Since the patch is now ahead of the SNC change, the new function is
  placed after snc_get_config() instead of after the dropped
  resctrl_arch_update_snc(). No code change.
- Add Ben Horgan's Acked-by.

 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 3838e0a13d36..97fc60c23958 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -416,6 +416,15 @@ static __init int snc_get_config(void)
 	return ret;
 }
 
+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 5468367776e2..3576dde8608e 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 002f56e15362..f8fcdc7e7a63 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 10dfdca7f4bf..aa0d41f22293 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);
-- 
2.25.1