[S390] cio: Channel-path configure function.

Add a new attribute to the channel-path sysfs directory through which
channel-path configure operations can be triggered. Also listen for
hardware events requesting channel-path configure operations and
process them accordingly.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/char/sclp_chp.c b/drivers/s390/char/sclp_chp.c
new file mode 100644
index 0000000..a66b914
--- /dev/null
+++ b/drivers/s390/char/sclp_chp.c
@@ -0,0 +1,196 @@
+/*
+ *  drivers/s390/char/sclp_chp.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/gfp.h>
+#include <linux/errno.h>
+#include <linux/completion.h>
+#include <asm/sclp.h>
+#include <asm/chpid.h>
+
+#include "sclp.h"
+
+#define TAG	"sclp_chp: "
+
+#define SCLP_CMDW_CONFIGURE_CHANNEL_PATH	0x000f0001
+#define SCLP_CMDW_DECONFIGURE_CHANNEL_PATH	0x000e0001
+#define SCLP_CMDW_READ_CHANNEL_PATH_INFORMATION	0x00030001
+
+static inline sclp_cmdw_t get_configure_cmdw(struct chp_id chpid)
+{
+	return SCLP_CMDW_CONFIGURE_CHANNEL_PATH | chpid.id << 8;
+}
+
+static inline sclp_cmdw_t get_deconfigure_cmdw(struct chp_id chpid)
+{
+	return SCLP_CMDW_DECONFIGURE_CHANNEL_PATH | chpid.id << 8;
+}
+
+static void chp_callback(struct sclp_req *req, void *data)
+{
+	struct completion *completion = data;
+
+	complete(completion);
+}
+
+struct chp_cfg_sccb {
+	struct sccb_header header;
+	u8 ccm;
+	u8 reserved[6];
+	u8 cssid;
+} __attribute__((packed));
+
+struct chp_cfg_data {
+	struct chp_cfg_sccb sccb;
+	struct sclp_req req;
+	struct completion completion;
+} __attribute__((packed));
+
+static int do_configure(sclp_cmdw_t cmd)
+{
+	struct chp_cfg_data *data;
+	int rc;
+
+	/* Prepare sccb. */
+	data = (struct chp_cfg_data *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!data)
+		return -ENOMEM;
+	data->sccb.header.length = sizeof(struct chp_cfg_sccb);
+	data->req.command = cmd;
+	data->req.sccb = &(data->sccb);
+	data->req.status = SCLP_REQ_FILLED;
+	data->req.callback = chp_callback;
+	data->req.callback_data = &(data->completion);
+	init_completion(&data->completion);
+
+	/* Perform sclp request. */
+	rc = sclp_add_request(&(data->req));
+	if (rc)
+		goto out;
+	wait_for_completion(&data->completion);
+
+	/* Check response .*/
+	if (data->req.status != SCLP_REQ_DONE) {
+		printk(KERN_WARNING TAG "configure channel-path request failed "
+		       "(status=0x%02x)\n", data->req.status);
+		rc = -EIO;
+		goto out;
+	}
+	switch (data->sccb.header.response_code) {
+	case 0x0020:
+	case 0x0120:
+	case 0x0440:
+	case 0x0450:
+		break;
+	default:
+		printk(KERN_WARNING TAG "configure channel-path failed "
+		       "(cmd=0x%08x, response=0x%04x)\n", cmd,
+		       data->sccb.header.response_code);
+		rc = -EIO;
+		break;
+	}
+out:
+	free_page((unsigned long) data);
+
+	return rc;
+}
+
+/**
+ * sclp_chp_configure - perform configure channel-path sclp command
+ * @chpid: channel-path ID
+ *
+ * Perform configure channel-path command sclp command for specified chpid.
+ * Return 0 after command successfully finished, non-zero otherwise.
+ */
+int sclp_chp_configure(struct chp_id chpid)
+{
+	return do_configure(get_configure_cmdw(chpid));
+}
+
+/**
+ * sclp_chp_deconfigure - perform deconfigure channel-path sclp command
+ * @chpid: channel-path ID
+ *
+ * Perform deconfigure channel-path command sclp command for specified chpid
+ * and wait for completion. On success return 0. Return non-zero otherwise.
+ */
+int sclp_chp_deconfigure(struct chp_id chpid)
+{
+	return do_configure(get_deconfigure_cmdw(chpid));
+}
+
+struct chp_info_sccb {
+	struct sccb_header header;
+	u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
+	u8 standby[SCLP_CHP_INFO_MASK_SIZE];
+	u8 configured[SCLP_CHP_INFO_MASK_SIZE];
+	u8 ccm;
+	u8 reserved[6];
+	u8 cssid;
+} __attribute__((packed));
+
+struct chp_info_data {
+	struct chp_info_sccb sccb;
+	struct sclp_req req;
+	struct completion completion;
+} __attribute__((packed));
+
+/**
+ * sclp_chp_read_info - perform read channel-path information sclp command
+ * @info: resulting channel-path information data
+ *
+ * Perform read channel-path information sclp command and wait for completion.
+ * On success, store channel-path information in @info and return 0. Return
+ * non-zero otherwise.
+ */
+int sclp_chp_read_info(struct sclp_chp_info *info)
+{
+	struct chp_info_data *data;
+	int rc;
+
+	/* Prepare sccb. */
+	data = (struct chp_info_data *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!data)
+		return -ENOMEM;
+	data->sccb.header.length = sizeof(struct chp_info_sccb);
+	data->req.command = SCLP_CMDW_READ_CHANNEL_PATH_INFORMATION;
+	data->req.sccb = &(data->sccb);
+	data->req.status = SCLP_REQ_FILLED;
+	data->req.callback = chp_callback;
+	data->req.callback_data = &(data->completion);
+	init_completion(&data->completion);
+
+	/* Perform sclp request. */
+	rc = sclp_add_request(&(data->req));
+	if (rc)
+		goto out;
+	wait_for_completion(&data->completion);
+
+	/* Check response .*/
+	if (data->req.status != SCLP_REQ_DONE) {
+		printk(KERN_WARNING TAG "read channel-path info request failed "
+		       "(status=0x%02x)\n", data->req.status);
+		rc = -EIO;
+		goto out;
+	}
+	if (data->sccb.header.response_code != 0x0010) {
+		printk(KERN_WARNING TAG "read channel-path info failed "
+		       "(response=0x%04x)\n", data->sccb.header.response_code);
+		rc = -EIO;
+		goto out;
+	}
+	memcpy(info->recognized, data->sccb.recognized,
+	       SCLP_CHP_INFO_MASK_SIZE);
+	memcpy(info->standby, data->sccb.standby,
+	       SCLP_CHP_INFO_MASK_SIZE);
+	memcpy(info->configured, data->sccb.configured,
+	       SCLP_CHP_INFO_MASK_SIZE);
+out:
+	free_page((unsigned long) data);
+
+	return rc;
+}