[PATCH v3 02/23] psci: Accessor for configured PSCI function IDs

From: David Brazdil <dbrazdil@google.com>
To: kvmarm@lists.cs.columbia.edu
Cc: Jonathan Corbet <corbet@lwn.net>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
	Christoph Lameter <cl@linux.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Sudeep Holla <sudeep.holla@arm.com>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
	David Brazdil <dbrazdil@google.com>
Subject: [PATCH v3 02/23] psci: Accessor for configured PSCI function IDs
Date: Thu, 26 Nov 2020 15:54:00 +0000	[thread overview]
Message-ID: <20201126155421.14901-3-dbrazdil@google.com> (raw)
In-Reply-To: <20201126155421.14901-1-dbrazdil@google.com>

Function IDs used by PSCI are configurable for v0.1 via DT/APCI. If the
host is using PSCI v0.1, KVM's host PSCI proxy needs to use the same IDs.
Expose the array holding the information with a read-only accessor.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 drivers/firmware/psci/psci.c | 16 ++++++++--------
 include/linux/psci.h         | 10 ++++++++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index 213c68418a65..40609564595e 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -58,16 +58,16 @@ typedef unsigned long (psci_fn)(unsigned long, unsigned long,
 				unsigned long, unsigned long);
 static psci_fn *invoke_psci_fn;
 
-enum psci_function {
-	PSCI_FN_CPU_SUSPEND,
-	PSCI_FN_CPU_ON,
-	PSCI_FN_CPU_OFF,
-	PSCI_FN_MIGRATE,
-	PSCI_FN_MAX,
-};
-
 static u32 psci_function_id[PSCI_FN_MAX];
 
+u32 psci_get_function_id(enum psci_function fn)
+{
+	if (WARN_ON_ONCE(fn < 0 || fn >= PSCI_FN_MAX))
+		return 0;
+
+	return psci_function_id[fn];
+}
+
 #define PSCI_0_2_POWER_STATE_MASK		\
 				(PSCI_0_2_POWER_STATE_ID_MASK | \
 				PSCI_0_2_POWER_STATE_TYPE_MASK | \
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 2a1bfb890e58..5b49a5c82d6f 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -21,6 +21,16 @@ bool psci_power_state_is_valid(u32 state);
 int psci_set_osi_mode(bool enable);
 bool psci_has_osi_support(void);
 
+enum psci_function {
+	PSCI_FN_CPU_SUSPEND,
+	PSCI_FN_CPU_ON,
+	PSCI_FN_CPU_OFF,
+	PSCI_FN_MIGRATE,
+	PSCI_FN_MAX,
+};
+
+u32 psci_get_function_id(enum psci_function fn);
+
 struct psci_operations {
 	u32 (*get_version)(void);
 	int (*cpu_suspend)(u32 state, unsigned long entry_point);
-- 
2.29.2.454.gaff20da3a2-goog

