x86/resctrl: Remove rdtgroup from update_cpu_closid_rmid()

update_cpu_closid_rmid() takes a struct rdtgroup as an argument, which it uses
to update the local CPUs default pqr values. This is a problem once the
resctrl parts move out to /fs/, as the arch code cannot poke around inside
struct rdtgroup.

Rename update_cpu_closid_rmid() as resctrl_arch_sync_cpus_defaults() to be
used as the target of an IPI, and pass the effective CLOSID and RMID in a new
struct.

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>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20250311183715.16445-11-james.morse@arm.com

1 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index d16dc960f1fc..31808b3ddecb 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -266,6 +266,28 @@ struct resctrl_schema {
 	u32				num_closid;
 };
 
+struct resctrl_cpu_defaults {
+	u32 closid;
+	u32 rmid;
+};
+
+/**
+ * resctrl_arch_sync_cpu_closid_rmid() - Refresh this CPU's CLOSID and RMID.
+ *					 Call via IPI.
+ * @info:	If non-NULL, a pointer to a struct resctrl_cpu_defaults
+ *		specifying the new CLOSID and RMID for tasks in the default
+ *		resctrl ctrl and mon group when running on this CPU.  If NULL,
+ *		this CPU is not re-assigned to a different default group.
+ *
+ * Propagates reassignment of CPUs and/or tasks to different resctrl groups
+ * when requested by the resctrl core code.
+ *
+ * This function records the per-cpu defaults specified by @info (if any),
+ * and then reconfigures the CPU's hardware CLOSID and RMID for subsequent
+ * execution based on @current, in the same way as during a task switch.
+ */
+void resctrl_arch_sync_cpu_closid_rmid(void *info);
+
 /**
  * resctrl_get_default_ctrl() - Return the default control value for this
  *                              resource.