[RFC] drivers: firmware: psci: Add function to support SYSTEM_RESET2

[Elliot Berman <eberman@codeaurora.org>]

Make SYSTEM_RESET2 command part of its own function which client drivers
may also invoke to support vendor-specific reset types.

Signed-off-by: Elliot Berman <eberman@codeaurora.org>
---
 drivers/firmware/psci/psci.c | 16 +++++++++++++++-
 include/linux/psci.h         |  3 +++
 include/uapi/linux/psci.h    |  8 ++++++++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index b3b6c15..338e4be 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -220,6 +220,15 @@ static unsigned long psci_migrate_info_up_cpu(void)
 			      0, 0, 0);
 }
 
+int psci_system_reset2(const u32 reset_type, const unsigned long cookie)
+{
+	if (!psci_system_reset2_supported)
+		return -EOPNOTSUPP;
+	return invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), reset_type,
+			      cookie, 0);
+}
+EXPORT_SYMBOL_GPL(psci_system_reset2);
+
 static void set_conduit(enum arm_smccc_conduit conduit)
 {
 	switch (conduit) {
@@ -267,7 +276,12 @@ static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
 		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
 		 * cookie = 0 (ignored by the implementation)
 		 */
-		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
+		psci_system_reset2(
+			PSCI_1_1_SYSTEM_RESET2_SYSTEM_WARM_RESET |
+			(PSCI_1_1_SYSTEM_RESET2_TYPE_ARCHITECTURE <<
+			PSCI_1_1_SYSTEM_RESET2_SHIFT),
+			0
+		);
 	} else {
 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
 	}
diff --git a/include/linux/psci.h b/include/linux/psci.h
index ebe0a88..9479952 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -41,8 +41,11 @@ extern struct psci_operations psci_ops;
 
 #if defined(CONFIG_ARM_PSCI_FW)
 int __init psci_dt_init(void);
+int psci_system_reset2(const u32 reset_type, const unsigned long cookie);
 #else
 static inline int psci_dt_init(void) { return 0; }
+static inline int psci_system_reset2(const u32 reset_type,
+	const unsigned long cookie) { return -ENODEV; }
 #endif
 
 #if defined(CONFIG_ARM_PSCI_FW) && defined(CONFIG_ACPI)
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index 2fcad1d..42edbd7 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -72,6 +72,14 @@
 #define PSCI_1_0_EXT_POWER_STATE_TYPE_MASK	\
 				(0x1 << PSCI_1_0_EXT_POWER_STATE_TYPE_SHIFT)
 
+/* PSCI SYSTEM_RESET2 reset_type argument */
+#define PSCI_1_1_SYSTEM_RESET2_SYSTEM_WARM_RESET	0x0
+#define PSCI_1_1_SYSTEM_RESET2_TYPE_VENDOR		1
+#define PSCI_1_1_SYSTEM_RESET2_TYPE_ARCHITECTURE	0
+#define PSCI_1_1_SYSTEM_RESET2_TYPE_SHIFT		30
+#define PSCI_1_1_SYSTEM_RESET2_TYPE_MASK		\
+				(0x1 << PSCI_1_1_SYSTEM_RESET2_TYPE_SHIFT)
+
 /* PSCI v0.2 affinity level state returned by AFFINITY_INFO */
 #define PSCI_0_2_AFFINITY_LEVEL_ON		0
 #define PSCI_0_2_AFFINITY_LEVEL_OFF		1
-- 
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