Because MPAM's pmg aren't identical to RDT's rmid, resctrl handles some
data structures by index. This allows x86 to map indexes to RMID, and MPAM
to map them to partid-and-pmg.
Add the helpers to do this.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
---
Changes since rfc:
Use ~0U instead of ~0 in lhs of left shift
Changes since v2:
Drop changes signed-off-by as reworked patch
Use multiply and add rather than shift to avoid holes
---
drivers/resctrl/mpam_resctrl.c | 16 ++++++++++++++++
include/linux/arm_mpam.h | 3 +++
2 files changed, 19 insertions(+)
diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index b6bbe73bc248..92b2a2d4b51d 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -126,6 +126,22 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *ignored)
return mpam_partid_max + 1;
}
+u32 resctrl_arch_system_num_rmid_idx(void)
+{
+ return (mpam_pmg_max + 1) * (mpam_partid_max + 1);
+}
+
+u32 resctrl_arch_rmid_idx_encode(u32 closid, u32 rmid)
+{
+ return closid * (mpam_pmg_max + 1) + rmid;
+}
+
+void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid)
+{
+ *closid = idx / (mpam_pmg_max + 1);
+ *rmid = idx % (mpam_pmg_max + 1);
+}
+
void resctrl_arch_sched_in(struct task_struct *tsk)
{
lockdep_assert_preemption_disabled();
diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h
index d329b1dc148b..7d23c90f077d 100644
--- a/include/linux/arm_mpam.h
+++ b/include/linux/arm_mpam.h
@@ -58,6 +58,9 @@ void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid, u32 rmid);
void resctrl_arch_sched_in(struct task_struct *tsk);
bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid);
bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 closid, u32 rmid);
+u32 resctrl_arch_rmid_idx_encode(u32 closid, u32 rmid);
+void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid);
+u32 resctrl_arch_system_num_rmid_idx(void);
/**
* mpam_register_requestor() - Register a requestor with the MPAM driver
--
2.43.0