From 0671cc1048744c9a6f1c896baa85966a5abc42a0 Mon Sep 17 00:00:00 2001
From: Harald Freudenberger <freude@linux.ibm.com>
Date: Mon, 27 Jul 2020 14:34:57 +0200
Subject: s390/sclp: Add support for SCLP AP adapter config/deconfig

Add support for AP bus adapter config and deconfig to the sclp
core code. The code is statically build into the kernel when
ZCRYPT is configured either as module or with static support.

This is the base functionality for having configure/deconfigure
support in the AP bus and card code. Another patch will exploit
this soon.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Suggested-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
 drivers/s390/char/Makefile  |  2 ++
 drivers/s390/char/sclp.h    |  2 +-
 drivers/s390/char/sclp_ap.c | 63 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 drivers/s390/char/sclp_ap.c

(limited to 'drivers/s390/char')

diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile
index 845e12ac5954..c6fdb81a068a 100644
--- a/drivers/s390/char/Makefile
+++ b/drivers/s390/char/Makefile
@@ -34,6 +34,8 @@ obj-$(CONFIG_SCLP_VT220_TTY) += sclp_vt220.o
 
 obj-$(CONFIG_PCI) += sclp_pci.o
 
+obj-$(subst m,y,$(CONFIG_ZCRYPT)) += sclp_ap.o
+
 obj-$(CONFIG_VMLOGRDR) += vmlogrdr.o
 obj-$(CONFIG_VMCP) += vmcp.o
 
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index ccc2d759c575..69d9cde9ff5a 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -229,7 +229,7 @@ static inline void sclp_fill_core_info(struct sclp_core_info *info,
 #define SCLP_HAS_CPU_INFO	(sclp.facilities & 0x0800000000000000ULL)
 #define SCLP_HAS_CPU_RECONFIG	(sclp.facilities & 0x0400000000000000ULL)
 #define SCLP_HAS_PCI_RECONFIG	(sclp.facilities & 0x0000000040000000ULL)
-
+#define SCLP_HAS_AP_RECONFIG	(sclp.facilities & 0x0000000100000000ULL)
 
 struct gds_subvector {
 	u8	length;
diff --git a/drivers/s390/char/sclp_ap.c b/drivers/s390/char/sclp_ap.c
new file mode 100644
index 000000000000..0dd1ca712795
--- /dev/null
+++ b/drivers/s390/char/sclp_ap.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * s390 crypto adapter related sclp functions.
+ *
+ * Copyright IBM Corp. 2020
+ */
+#define KMSG_COMPONENT "sclp_cmd"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <asm/sclp.h>
+#include "sclp.h"
+
+#define SCLP_CMDW_CONFIGURE_AP			0x001f0001
+#define SCLP_CMDW_DECONFIGURE_AP		0x001e0001
+
+struct ap_cfg_sccb {
+	struct sccb_header header;
+} __packed;
+
+static int do_ap_configure(sclp_cmdw_t cmd, u32 apid)
+{
+	struct ap_cfg_sccb *sccb;
+	int rc;
+
+	if (!SCLP_HAS_AP_RECONFIG)
+		return -EOPNOTSUPP;
+
+	sccb = (struct ap_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!sccb)
+		return -ENOMEM;
+
+	sccb->header.length = PAGE_SIZE;
+	cmd |= (apid & 0xFF) << 8;
+	rc = sclp_sync_request(cmd, sccb);
+	if (rc)
+		goto out;
+	switch (sccb->header.response_code) {
+	case 0x0020: case 0x0120: case 0x0440: case 0x0450:
+		break;
+	default:
+		pr_warn("configure AP adapter %u failed: cmd=0x%08x response=0x%04x\n",
+			apid, cmd, sccb->header.response_code);
+		rc = -EIO;
+		break;
+	}
+out:
+	free_page((unsigned long) sccb);
+	return rc;
+}
+
+int sclp_ap_configure(u32 apid)
+{
+	return do_ap_configure(SCLP_CMDW_CONFIGURE_AP, apid);
+}
+EXPORT_SYMBOL(sclp_ap_configure);
+
+int sclp_ap_deconfigure(u32 apid)
+{
+	return do_ap_configure(SCLP_CMDW_DECONFIGURE_AP, apid);
+}
+EXPORT_SYMBOL(sclp_ap_deconfigure);
-- 
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