linux-kernel - [PATCH v5 1/8] ACPI: CPPC: Add IS_OPTIONAL_CPC_REG macro to judge if a cpc

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Message-ID: <20250206131428.3261578-2-zhenglifeng1@huawei.com>
Date: Thu, 6 Feb 2025 21:14:21 +0800
From: Lifeng Zheng <zhenglifeng1@...wei.com>
To: <rafael@...nel.org>, <lenb@...nel.org>, <robert.moore@...el.com>,
	<viresh.kumar@...aro.org>, <mario.limonciello@....com>,
	<gautham.shenoy@....com>, <ray.huang@....com>, <pierre.gondois@....com>
CC: <acpica-devel@...ts.linux.dev>, <linux-acpi@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-pm@...r.kernel.org>,
	<linuxarm@...wei.com>, <yumpusamongus@...il.com>,
	<srinivas.pandruvada@...ux.intel.com>, <jonathan.cameron@...wei.com>,
	<zhanjie9@...ilicon.com>, <lihuisong@...wei.com>, <zhenglifeng1@...wei.com>,
	<hepeng68@...wei.com>, <fanghao11@...wei.com>
Subject: [PATCH v5 1/8] ACPI: CPPC: Add IS_OPTIONAL_CPC_REG macro to judge if a cpc_reg is optional

In ACPI 6.5, s8.4.6.1 _CPC (Continuous Performance Control), whether each
of the per-cpu cpc_regs[] is mendatory or optional is defined. Since the
CPC_SUPPORTED() check is only for optional cpc field, another macro to
check if the field is optional is needed.

Signed-off-by: Lifeng Zheng <zhenglifeng1@...wei.com>
---
 drivers/acpi/cppc_acpi.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index f193e713825a..39f019e265da 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -129,6 +129,20 @@ 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))
+
+/*
+ * Each bit indicates the optionality of the register in per-cpu
+ * cpc_regs[] with the corresponding index. 0 means mandatory and 1
+ * means optional.
+ */
+#define REG_OPTIONAL (0x1FC7D0)
+
+/*
+ * Use the index of the register in per-cpu cpc_regs[] to check if
+ * it's an optional one.
+ */
+#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