[PATCH v7 27/49] x86/resctrl: Move RFTYPE flags to be managed by resctrl

James Morse
2025-02-28T20:01:37Z

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@arm.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
---
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 2c352938d18d..70421d52eceb 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -229,9 +229,6 @@ 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