[PATCH v7 29/49] x86/resctrl: Move get_config_index() to a header

James Morse
2025-02-28T20:01:44Z

get_config_index() is used by the architecture specific code to map a
CLOSID+type pair to an index in the configuration arrays.

MPAM needs to do this too to preserve the ABI to user-space, there is
no reason to do it differently.

Move the helper to a header file to allow all architectures that either
use or emulate CDP to use the same pattern of CLOSID values. Moving
this to a header file means it must be marked inline, which matches
the existing compiler choice for this static function.

Co-developed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
Changes since v6:
* Expanded the last paragraph of the commit message.

Changes since v1:
* Reindent resctrl_get_config_index() as per coding-style.rst rules.
---
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 19 +++----------------
include/linux/resctrl.h | 15 +++++++++++++++
2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 1ecc93282b7d..0a0ac5f6112e 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -287,25 +287,12 @@ static int parse_line(char *line, struct resctrl_schema *s,
return -EINVAL;
}

-static u32 get_config_index(u32 closid, enum resctrl_conf_type type)
-{
- switch (type) {
- default:
- case CDP_NONE:
- return closid;
- case CDP_CODE:
- return closid * 2 + 1;
- case CDP_DATA:
- return closid * 2;
- }
-}
-
int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
u32 closid, enum resctrl_conf_type t, u32 cfg_val)
{
struct rdt_hw_ctrl_domain *hw_dom = resctrl_to_arch_ctrl_dom(d);
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
- u32 idx = get_config_index(closid, t);
+ u32 idx = resctrl_get_config_index(closid, t);
struct msr_param msr_param;

if (!cpumask_test_cpu(smp_processor_id(), &d->hdr.cpu_mask))
@@ -342,7 +329,7 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
if (!cfg->have_new_ctrl)
continue;

- idx = get_config_index(closid, t);
+ idx = resctrl_get_config_index(closid, t);
if (cfg->new_ctrl == hw_dom->ctrl_val[idx])
continue;
hw_dom->ctrl_val[idx] = cfg->new_ctrl;
@@ -462,7 +449,7 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
u32 closid, enum resctrl_conf_type type)
{
struct rdt_hw_ctrl_domain *hw_dom = resctrl_to_arch_ctrl_dom(d);
- u32 idx = get_config_index(closid, type);
+ u32 idx = resctrl_get_config_index(closid, type);

return hw_dom->ctrl_val[idx];
}
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 226cc5c0d765..880351ca3dfc 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -384,6 +384,21 @@ void resctrl_arch_mon_event_config_write(void *config_info);
*/
void resctrl_arch_mon_event_config_read(void *config_info);

+/* For use by arch code to remap resctrl's smaller CDP CLOSID range */
+static inline u32 resctrl_get_config_index(u32 closid,
+ enum resctrl_conf_type type)
+{
+ switch (type) {
+ default:
+ case CDP_NONE:
+ return closid;
+ case CDP_CODE:
+ return closid * 2 + 1;
+ case CDP_DATA:
+ return closid * 2;
+ }
+}
+
/*
* Update the ctrl_val and apply this config right now.
* Must be called on one of the domain's CPUs.
--
2.39.5