[PATCH v2 5/5] drivers: firmware: psci: Announce support for OS initiated suspend mode

From: Ulf Hansson
Date: Wed Mar 13 2019 - 04:37:19 EST


PSCI firmware v1.0+, supports two different modes for CPU_SUSPEND. The
Platform Coordinated mode, which is the default and mandatory mode, while
support for the OS initiated (OSI) mode is optional.

In some cases it's interesting for the user/developer to know if the OSI
mode is supported by the PSCI FW. Therefore, let's print a message to the
log, if that is the case.

Cc: Lina Iyer <ilina@xxxxxxxxxxxxxx>
Co-developed-by: Lina Iyer <lina.iyer@xxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
---
drivers/firmware/psci/psci.c | 21 ++++++++++++++++++++-
include/uapi/linux/psci.h | 5 +++++
2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index e480e0af632c..eabd01383cd6 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -95,6 +95,11 @@ static inline bool psci_has_ext_power_state(void)
PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
}

+static inline bool psci_has_osi_support(void)
+{
+ return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
+}
+
static inline bool psci_power_state_loses_context(u32 state)
{
const u32 mask = psci_has_ext_power_state() ?
@@ -659,10 +664,24 @@ static int __init psci_0_1_init(struct device_node *np)
return 0;
}

+static int __init psci_1_0_init(struct device_node *np)
+{
+ int err;
+
+ err = psci_0_2_init(np);
+ if (err)
+ return err;
+
+ if (psci_has_osi_support())
+ pr_info("OSI mode supported.\n");
+
+ return 0;
+}
+
static const struct of_device_id psci_of_match[] __initconst = {
{ .compatible = "arm,psci", .data = psci_0_1_init},
{ .compatible = "arm,psci-0.2", .data = psci_0_2_init},
- { .compatible = "arm,psci-1.0", .data = psci_0_2_init},
+ { .compatible = "arm,psci-1.0", .data = psci_1_0_init},
{},
};

diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index b3bcabe380da..581f72085c33 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -49,6 +49,7 @@

#define PSCI_1_0_FN_PSCI_FEATURES PSCI_0_2_FN(10)
#define PSCI_1_0_FN_SYSTEM_SUSPEND PSCI_0_2_FN(14)
+#define PSCI_1_0_FN_SET_SUSPEND_MODE PSCI_0_2_FN(15)

#define PSCI_1_0_FN64_SYSTEM_SUSPEND PSCI_0_2_FN64(14)

@@ -97,6 +98,10 @@
#define PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK \
(0x1 << PSCI_1_0_FEATURES_CPU_SUSPEND_PF_SHIFT)

+#define PSCI_1_0_OS_INITIATED BIT(0)
+#define PSCI_1_0_SUSPEND_MODE_PC 0
+#define PSCI_1_0_SUSPEND_MODE_OSI 1
+
/* PSCI return values (inclusive of all PSCI versions) */
#define PSCI_RET_SUCCESS 0
#define PSCI_RET_NOT_SUPPORTED -1
--
2.17.1