[PATCH v8:for-boris 27/30] x86/resctrl: Move RFTYPE flags to be managed by resctrl

[James Morse]

resctrl_file_fflags_init() is called from the architecture specific code
to make the 'thread_throttle_mode' file visible. The architecture specific
code has already set the membw.throttle_mode in the rdt_resource.

This forces the RFTYPE flags used by resctrl to be exposed to the
architecture specific code.

This doesn't need to be specific to the architecture, the throttle_mode
can be used by resctrl to determine if the 'thread_throttle_mode' file
should be visible. This allows the RFTYPE flags to be private to resctrl.

Add thread_throttle_mode_init(), and use it to call
resctrl_file_fflags_init() from resctrl_init(). This avoids
publishing an extra function between the architecture and filesystem
code.

Signed-off-by: James Morse <james.morse@xxxxxxx>
Tested-by: Peter Newman <peternewman@xxxxxxxxxx>
Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Tested-by: Amit Singh Tomar <amitsinght@xxxxxxxxxxx> # arm64
Tested-by: Shanker Donthineni <sdonthineni@xxxxxxxxxx> # arm64
Tested-by: Babu Moger <babu.moger@xxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reviewed-by: Fenghua Yu <fenghuay@xxxxxxxxxx>
---
Changes since v6:
 * Refer to resctrl_init() in the commit message.
 * Remove a space.

Changes since v5:
 * Added checking for SMBA.
 * Added printing of undefined to rdt_thread_throttle_mode_show().
 * Major juggling around commit 2937f9c361f7 ("x86/resctrl: Introduce resctrl_file_fflags_init() to initialize fflags")
 * Dropped tags, split patch
---
 arch/x86/kernel/cpu/resctrl/core.c     |  3 ---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 ++++++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index b9b74f53b8ee..e590dd347fa7 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -227,9 +227,6 @@ static __init bool __get_mem_config_intel(struct rdt_resource *r)
 	else
 		r->membw.throttle_mode = THREAD_THROTTLE_MAX;
 
-	resctrl_file_fflags_init("thread_throttle_mode",
-				 RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
-
 	r->alloc_capable = true;
 
 	return true;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index e59271515a46..58feba3feefd 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2064,6 +2064,16 @@ static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
 	return NULL;
 }
 
+static void thread_throttle_mode_init(void)
+{
+	struct rdt_resource *r_mba;
+
+	r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+	if (r_mba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
+		resctrl_file_fflags_init("thread_throttle_mode",
+					 RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
+}
+
 void resctrl_file_fflags_init(const char *config, unsigned long fflags)
 {
 	struct rftype *rft;
@@ -4277,6 +4287,8 @@ int __init resctrl_init(void)
 
 	rdtgroup_setup_default();
 
+	thread_throttle_mode_init();
+
 	ret = resctrl_mon_resource_init();
 	if (ret)
 		return ret;
-- 
2.39.5