psci: add features/reset2 support

Adds support for:
* PSCI_FEATURES, which was introduced in PSCI 1.0. This provides API
that allows discovering whether a specific PSCI function is implemented
and its features.
* SYSTEM_RESET2, which was introduced in PSCI 1.1, which extends existing
SYSTEM_RESET. It provides support for vendor-specific resets, providing
reset_type as an additional param.

For additional details visit [1].

Implementations of some functions were borrowed from Linux PSCI driver
code [2].

[1] https://developer.arm.com/documentation/den0022/latest/
[2] drivers/firmware/psci/psci.c

Signed-off-by: Igor Opaniuk <igor.opaniuk@foundries.io>

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 68953cc4f4e20b08517101e53cb1538cc9a479bb..be57552aba00ee8d3d63e9a6f740141428f1e536 100644 (file)
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -13,6 +13,7 @@
 #include <log.h>
 #include <dm/lists.h>
 #include <efi_loader.h>
+#include <sysreset.h>
 #include <linux/delay.h>
 #include <linux/libfdt.h>
 #include <linux/arm-smccc.h>
@@ -26,6 +27,18 @@
 #define PSCI_METHOD_HVC 1
 #define PSCI_METHOD_SMC 2
 
+/*
+ * While a 64-bit OS can make calls with SMC32 calling conventions, for some
+ * calls it is necessary to use SMC64 to pass or return 64-bit values.
+ * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
+ * (native-width) function ID.
+ */
+#if defined(CONFIG_ARM64)
+#define PSCI_FN_NATIVE(version, name)  PSCI_##version##_FN64_##name
+#else
+#define PSCI_FN_NATIVE(version, name)  PSCI_##version##_FN_##name
+#endif
+
 #if CONFIG_IS_ENABLED(EFI_LOADER)
 int __efi_runtime_data psci_method;
 #else
@@ -53,6 +66,34 @@ unsigned long __efi_runtime invoke_psci_fn
        return res.a0;
 }
 
+static int psci_features(u32 psci_func_id)
+{
+       return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
+                             psci_func_id, 0, 0);
+}
+
+static u32 psci_0_2_get_version(void)
+{
+       return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+}
+
+static bool psci_is_system_reset2_supported(void)
+{
+       int ret;
+       u32 ver;
+
+       ver = psci_0_2_get_version();
+
+       if (PSCI_VERSION_MAJOR(ver) >= 1) {
+               ret = psci_features(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2));
+
+               if (ret != PSCI_RET_NOT_SUPPORTED)
+                       return true;
+       }
+
+       return false;
+}
+
 static int psci_bind(struct udevice *dev)
 {
        /* No SYSTEM_RESET support for PSCI 0.1 */
@@ -141,6 +182,33 @@ void reset_misc(void)
 }
 #endif /* CONFIG_PSCI_RESET */
 
+void psci_sys_reset(u32 type)
+{
+       bool reset2_supported;
+
+       do_psci_probe();
+
+       reset2_supported = psci_is_system_reset2_supported();
+
+       if (type == SYSRESET_WARM && reset2_supported) {
+               /*
+                * reset_type[31] = 0 (architectural)
+                * 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);
+       } else {
+               invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+       }
+}
+
+void psci_sys_poweroff(void)
+{
+       do_psci_probe();
+
+       invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+}
+
 #ifdef CONFIG_CMD_POWEROFF
 int do_poweroff(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {

diff --git a/include/linux/psci.h b/include/linux/psci.h
index 38edde31370043805e40466c76637071364adcaa..c78c1079a826ee338e9d82a59246b3d1aac0e432 100644 (file)
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -118,6 +118,9 @@
 #ifdef CONFIG_ARM_PSCI_FW
 unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
                             unsigned long a2, unsigned long a3);
+void psci_sys_reset(u32 type);
+void psci_sys_poweroff(void);
+
 #else
 static inline unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
                                           unsigned long a2, unsigned long a3)