From 5f485a66f4d0693a535e4ab38ffc3538716d2c2b Mon Sep 17 00:00:00 2001
From: Nathan Lynch <nathanl@linux.ibm.com>
Date: Mon, 7 Dec 2020 15:51:37 -0600
Subject: [PATCH] powerpc/rtas: add rtas_activate_firmware()

References: bsc#1181674 ltc#189159
Patch-mainline: v5.11-rc1
Git-commit: 5f485a66f4d0693a535e4ab38ffc3538716d2c2b

Provide a documented wrapper function for the ibm,activate-firmware
service, which must be called after a partition migration or
hibernation.

If the function is absent or the call fails, the OS will continue to
run normally with the current firmware, so there is no need to perform
any recovery. Just log it and continue.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-6-nathanl@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/include/asm/rtas.h |  1 +
 arch/powerpc/kernel/rtas.c      | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index b43165fc6c2a..fdefe6a974eb 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -247,6 +247,7 @@ extern void __noreturn rtas_restart(char *cmd);
 extern void rtas_power_off(void);
 extern void __noreturn rtas_halt(void);
 extern void rtas_os_term(char *str);
+void rtas_activate_firmware(void);
 extern int rtas_get_sensor(int sensor, int index, int *state);
 extern int rtas_get_sensor_fast(int sensor, int index, int *state);
 extern int rtas_get_power_level(int powerdomain, int *level);
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 8a618a3c4beb..3a740ae933f8 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -798,6 +798,36 @@ void rtas_os_term(char *str)
 		printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
 }
 
+/**
+ * rtas_activate_firmware() - Activate a new version of firmware.
+ *
+ * Activate a new version of partition firmware. The OS must call this
+ * after resuming from a partition hibernation or migration in order
+ * to maintain the ability to perform live firmware updates. It's not
+ * catastrophic for this method to be absent or to fail; just log the
+ * condition in that case.
+ *
+ * Context: This function may sleep.
+ */
+void rtas_activate_firmware(void)
+{
+	int token;
+	int fwrc;
+
+	token = rtas_token("ibm,activate-firmware");
+	if (token == RTAS_UNKNOWN_SERVICE) {
+		pr_notice("ibm,activate-firmware method unavailable\n");
+		return;
+	}
+
+	do {
+		fwrc = rtas_call(token, 0, 1, NULL);
+	} while (rtas_busy_delay(fwrc));
+
+	if (fwrc)
+		pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
+}
+
 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
 #ifdef CONFIG_PPC_PSERIES
 static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
-- 
2.26.2