[PATCH v4 1/6] ACPI: CPPC: Add IS_OPTIONAL_CPC_REG macro

[Lifeng Zheng]

Add IS_OPTIONAL_CPC_REG macro to judge if a cpc_reg is an optional one.

Signed-off-by: Lifeng Zheng <zhenglifeng1@xxxxxxxxxx>
---
 drivers/acpi/cppc_acpi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index f193e713825a..6454b469338f 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -129,6 +129,12 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr);
 #define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ?		\
 				!!(cpc)->cpc_entry.int_value :		\
 				!IS_NULL_REG(&(cpc)->cpc_entry.reg))
+
+/* These indicate optional of the per-cpu cpc_regs[]. */
+#define REG_OPTIONAL (0b111111100011111010000)
+
+#define IS_OPTIONAL_CPC_REG(reg_idx) (REG_OPTIONAL & (1U << (reg_idx)))
+
 /*
  * Arbitrary Retries in case the remote processor is slow to respond
  * to PCC commands. Keeping it high enough to cover emulators where
-- 
2.33.0