From 701ba68342412ae9be99a7c7f3badebf95271403 Mon Sep 17 00:00:00 2001

From: Nathan Lynch <nathanl@linux.ibm.com>

Date: Mon, 7 Dec 2020 15:51:36 -0600

Subject: [PATCH] powerpc/rtas: add rtas_ibm_suspend_me()

References: bsc#1181674 ltc#189159

Patch-mainline: v5.11-rc1

Git-commit: 701ba68342412ae9be99a7c7f3badebf95271403

Now that the name is available, provide a simple wrapper for

ibm,suspend-me which returns both a Linux errno and optionally the

actual RTAS status to the caller.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20201207215200.1785968-5-nathanl@linux.ibm.com

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 arch/powerpc/include/asm/rtas.h |  1 +

 arch/powerpc/kernel/rtas.c      | 57 +++++++++++++++++++++++++++++++++

 2 files changed, 58 insertions(+)

diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h

--- a/arch/powerpc/include/asm/rtas.h

+++ b/arch/powerpc/include/asm/rtas.h

@@ -258,6 +258,7 @@ extern void rtas_progress(char *s, unsigned short hex);

 extern int rtas_suspend_cpu(struct rtas_suspend_me_data *data);

 extern int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data);

 int rtas_ibm_suspend_me_unsafe(u64 handle);

+int rtas_ibm_suspend_me(int *fw_status);

 struct rtc_time;

 extern unsigned long rtas_get_boot_time(void);

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c

index 0a8e5dc2c108..8a618a3c4beb 100644

--- a/arch/powerpc/kernel/rtas.c

+++ b/arch/powerpc/kernel/rtas.c

@@ -684,6 +684,63 @@ int rtas_set_indicator_fast(int indicator, int index, int new_value)

 	return rc;

 }

+/**

+ * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR.

+ *

+ * @fw_status: RTAS call status will be placed here if not NULL.

+ *

+ * rtas_ibm_suspend_me() should be called only on a CPU which has

+ * received H_CONTINUE from the H_JOIN hcall. All other active CPUs

+ * should be waiting to return from H_JOIN.

+ *

+ * rtas_ibm_suspend_me() may suspend execution of the OS

+ * indefinitely. Callers should take appropriate measures upon return, such as

+ * resetting watchdog facilities.

+ *

+ * Callers may choose to retry this call if @fw_status is

+ * %RTAS_THREADS_ACTIVE.

+ *

+ * Return:

+ * 0          - The partition has resumed from suspend, possibly after

+ *              migration to a different host.

+ * -ECANCELED - The operation was aborted.

+ * -EAGAIN    - There were other CPUs not in H_JOIN at the time of the call.

+ * -EBUSY     - Some other condition prevented the suspend from succeeding.

+ * -EIO       - Hardware/platform error.

+ */

+int rtas_ibm_suspend_me(int *fw_status)

+{

+	int fwrc;

+	int ret;

+

+	fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL);

+

+	switch (fwrc) {

+	case 0:

+		ret = 0;

+		break;

+	case RTAS_SUSPEND_ABORTED:

+		ret = -ECANCELED;

+		break;

+	case RTAS_THREADS_ACTIVE:

+		ret = -EAGAIN;

+		break;

+	case RTAS_NOT_SUSPENDABLE:

+	case RTAS_OUTSTANDING_COPROC:

+		ret = -EBUSY;

+		break;

+	case -1:

+	default:

+		ret = -EIO;

+		break;

+	}

+

+	if (fw_status)

+		*fw_status = fwrc;

+

+	return ret;

+}

+

 void __noreturn rtas_restart(char *cmd)

 {

 	if (rtas_flash_term_hook)

-- 

2.26.2