From 7441b0627e2251370902305a204e1330a696ca04 Mon Sep 17 00:00:00 2001
From: Jan Glauber <jang@linux.vnet.ibm.com>
Date: Thu, 29 Nov 2012 14:35:47 +0100
Subject: s390/pci: PCI hotplug support via SCLP

Add SCLP PCI configure/deconfigure and implement a PCI hotplug
controller (s390_pci_hpc). The hotplug controller creates a slot
for every PCI function in stand-by or configured state. The PCI
functions are named after the PCI function ID (fid). By writing to
the power attribute in /sys/bus/pci/slots/<fid>/power the PCI function
is moved to stand-by or configured state. If moved to the configured
state the device is automatically scanned by the s390 PCI layer.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/char/sclp_cmd.c | 64 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

(limited to 'drivers/s390/char/sclp_cmd.c')

diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 0dfa88a30118..c44d13f607bc 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright IBM Corp. 2007, 2009
+ * Copyright IBM Corp. 2007,2012
  *
  * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
  *	      Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
@@ -12,6 +12,7 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/mm.h>
@@ -700,6 +701,67 @@ __initcall(sclp_detect_standby_memory);
 
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
+/*
+ * PCI I/O adapter configuration related functions.
+ */
+#define SCLP_CMDW_CONFIGURE_PCI			0x001a0001
+#define SCLP_CMDW_DECONFIGURE_PCI		0x001b0001
+
+#define SCLP_RECONFIG_PCI_ATPYE			2
+
+struct pci_cfg_sccb {
+	struct sccb_header header;
+	u8 atype;		/* adapter type */
+	u8 reserved1;
+	u16 reserved2;
+	u32 aid;		/* adapter identifier */
+} __packed;
+
+static int do_pci_configure(sclp_cmdw_t cmd, u32 fid)
+{
+	struct pci_cfg_sccb *sccb;
+	int rc;
+
+	if (!SCLP_HAS_PCI_RECONFIG)
+		return -EOPNOTSUPP;
+
+	sccb = (struct pci_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!sccb)
+		return -ENOMEM;
+
+	sccb->header.length = PAGE_SIZE;
+	sccb->atype = SCLP_RECONFIG_PCI_ATPYE;
+	sccb->aid = fid;
+	rc = do_sync_request(cmd, sccb);
+	if (rc)
+		goto out;
+	switch (sccb->header.response_code) {
+	case 0x0020:
+	case 0x0120:
+		break;
+	default:
+		pr_warn("configure PCI I/O adapter failed: cmd=0x%08x  response=0x%04x\n",
+			cmd, sccb->header.response_code);
+		rc = -EIO;
+		break;
+	}
+out:
+	free_page((unsigned long) sccb);
+	return rc;
+}
+
+int sclp_pci_configure(u32 fid)
+{
+	return do_pci_configure(SCLP_CMDW_CONFIGURE_PCI, fid);
+}
+EXPORT_SYMBOL(sclp_pci_configure);
+
+int sclp_pci_deconfigure(u32 fid)
+{
+	return do_pci_configure(SCLP_CMDW_DECONFIGURE_PCI, fid);
+}
+EXPORT_SYMBOL(sclp_pci_deconfigure);
+
 /*
  * Channel path configuration related functions.
  */
-- 
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