[PATCH v3 05/12] x86/resctrl: Initialize supported kernel modes for PLZA

[Babu Moger]

Resctrl subsystem tracks which kernel-mode CLOSID/RMID policies the
platform can offer via struct resctrl_kmode_cfg and
resctrl_arch_get_kmode_support(). AMD PLZA (Privilege Level Zero
Association) is the x86 feature that allows kernel traffic to use an
assigned CLOSID alone or CLOSID and RMID together.

Report the available kernel-modes when x86 PLZA is enabled.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v3: New patch to report all the supported kernel mode by arch.
---
 arch/x86/kernel/cpu/resctrl/core.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 4a8717157e3e..699d8bb82875 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -894,6 +894,21 @@ bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)
 	}
 }
 
+/**
+ * resctrl_arch_get_kmode_support() - x86: record which kernel-mode policies hardware supports
+ * @kcfg:	Cumulative snapshot; OR bits into @kcfg->kmode (see &struct resctrl_kmode_cfg).
+ *
+ * When PLZA is present (CPUID X86_FEATURE_PLZA), the kernel may assign a CLOSID
+ * for kernel work alone or assign CLOSID and RMID together.  Advertise both
+ * assign-style modes in @kcfg->kmode using &enum resctrl_kernel_modes indices.
+ */
+void resctrl_arch_get_kmode_support(struct resctrl_kmode_cfg *kcfg)
+{
+	if (rdt_cpu_has(X86_FEATURE_PLZA))
+		kcfg->kmode |= BIT(GLOBAL_ASSIGN_CTRL_INHERIT_MON_PER_CPU) |
+				BIT(GLOBAL_ASSIGN_CTRL_ASSIGN_MON_PER_CPU);
+}
+
 static __init bool get_mem_config(void)
 {
 	struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_MBA];
-- 
2.43.0