9 files changed, 309 insertions, 27 deletions

diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile
index f3c325207445..17821a026c9c 100644
--- a/drivers/s390/char/Makefile
+++ b/drivers/s390/char/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-y += ctrlchar.o keyboard.o defkeymap.o sclp.o sclp_rw.o sclp_quiesce.o \
-	 sclp_cmd.o sclp_config.o sclp_cpi_sys.o sclp_ocf.o
+	 sclp_cmd.o sclp_config.o sclp_cpi_sys.o sclp_ocf.o sclp_ctl.o
 
 obj-$(CONFIG_TN3270) += raw3270.o
 obj-$(CONFIG_TN3270_CONSOLE) += con3270.o
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index bd6871bf545a..3e4fb4e858da 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -50,11 +50,42 @@ static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
 /* Suspend request */
 static DECLARE_COMPLETION(sclp_request_queue_flushed);
 
+/* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */
+int sclp_console_pages = SCLP_CONSOLE_PAGES;
+/* Flag to indicate if buffer pages are dropped on buffer full condition */
+int sclp_console_drop = 0;
+/* Number of times the console dropped buffer pages */
+unsigned long sclp_console_full;
+
 static void sclp_suspend_req_cb(struct sclp_req *req, void *data)
 {
 	complete(&sclp_request_queue_flushed);
 }
 
+static int __init sclp_setup_console_pages(char *str)
+{
+	int pages, rc;
+
+	rc = kstrtoint(str, 0, &pages);
+	if (!rc && pages >= SCLP_CONSOLE_PAGES)
+		sclp_console_pages = pages;
+	return 1;
+}
+
+__setup("sclp_con_pages=", sclp_setup_console_pages);
+
+static int __init sclp_setup_console_drop(char *str)
+{
+	int drop, rc;
+
+	rc = kstrtoint(str, 0, &drop);
+	if (!rc && drop)
+		sclp_console_drop = 1;
+	return 1;
+}
+
+__setup("sclp_con_drop=", sclp_setup_console_drop);
+
 static struct sclp_req sclp_suspend_req;
 
 /* Timer for request retries. */
@@ -117,14 +148,19 @@ static int sclp_init(void);
 int
 sclp_service_call(sclp_cmdw_t command, void *sccb)
 {
-	int cc;
+	int cc = 4; /* Initialize for program check handling */
 
 	asm volatile(
-		"	.insn	rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
-		"	ipm	%0\n"
-		"	srl	%0,28"
-		: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
+		"0:	.insn	rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
+		"1:	ipm	%0\n"
+		"	srl	%0,28\n"
+		"2:\n"
+		EX_TABLE(0b, 2b)
+		EX_TABLE(1b, 2b)
+		: "+&d" (cc) : "d" (command), "a" (__pa(sccb))
 		: "cc", "memory");
+	if (cc == 4)
+		return -EINVAL;
 	if (cc == 3)
 		return -EIO;
 	if (cc == 2)
@@ -1013,11 +1049,47 @@ static const struct dev_pm_ops sclp_pm_ops = {
 	.restore	= sclp_restore,
 };
 
+static ssize_t sclp_show_console_pages(struct device_driver *dev, char *buf)
+{
+	return sprintf(buf, "%i\n", sclp_console_pages);
+}
+
+static DRIVER_ATTR(con_pages, S_IRUSR, sclp_show_console_pages, NULL);
+
+static ssize_t sclp_show_con_drop(struct device_driver *dev, char *buf)
+{
+	return sprintf(buf, "%i\n", sclp_console_drop);
+}
+
+static DRIVER_ATTR(con_drop, S_IRUSR, sclp_show_con_drop, NULL);
+
+static ssize_t sclp_show_console_full(struct device_driver *dev, char *buf)
+{
+	return sprintf(buf, "%lu\n", sclp_console_full);
+}
+
+static DRIVER_ATTR(con_full, S_IRUSR, sclp_show_console_full, NULL);
+
+static struct attribute *sclp_drv_attrs[] = {
+	&driver_attr_con_pages.attr,
+	&driver_attr_con_drop.attr,
+	&driver_attr_con_full.attr,
+	NULL,
+};
+static struct attribute_group sclp_drv_attr_group = {
+	.attrs = sclp_drv_attrs,
+};
+static const struct attribute_group *sclp_drv_attr_groups[] = {
+	&sclp_drv_attr_group,
+	NULL,
+};
+
 static struct platform_driver sclp_pdrv = {
 	.driver = {
 		.name	= "sclp",
 		.owner	= THIS_MODULE,
 		.pm	= &sclp_pm_ops,
+		.groups = sclp_drv_attr_groups,
 	},
 };
 
@@ -1096,10 +1168,12 @@ static __init int sclp_initcall(void)
 	rc = platform_driver_register(&sclp_pdrv);
 	if (rc)
 		return rc;
+
 	sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0);
-	rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0;
+	rc = PTR_RET(sclp_pdev);
 	if (rc)
 		goto fail_platform_driver_unregister;
+
 	rc = atomic_notifier_chain_register(&panic_notifier_list,
 					    &sclp_on_panic_nb);
 	if (rc)
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index 25bcd4c0ed82..40d1406289ed 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -15,7 +15,7 @@
 
 /* maximum number of pages concerning our own memory management */
 #define MAX_KMEM_PAGES (sizeof(unsigned long) << 3)
-#define MAX_CONSOLE_PAGES	6
+#define SCLP_CONSOLE_PAGES	6
 
 #define EVTYP_OPCMD		0x01
 #define EVTYP_MSG		0x02
@@ -171,10 +171,15 @@ int sclp_remove_processed(struct sccb_header *sccb);
 int sclp_deactivate(void);
 int sclp_reactivate(void);
 int sclp_service_call(sclp_cmdw_t command, void *sccb);
+int sclp_sync_request(sclp_cmdw_t command, void *sccb);
 
 int sclp_sdias_init(void);
 void sclp_sdias_exit(void);
 
+extern int sclp_console_pages;
+extern int sclp_console_drop;
+extern unsigned long sclp_console_full;
+
 /* useful inlines */
 
 /* VM uses EBCDIC 037, LPAR+native(SE+HMC) use EBCDIC 500 */
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index bf07c3a188d4..8cd34bf644b3 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -195,7 +195,7 @@ static void sclp_sync_callback(struct sclp_req *req, void *data)
 	complete(completion);
 }
 
-static int do_sync_request(sclp_cmdw_t cmd, void *sccb)
+int sclp_sync_request(sclp_cmdw_t cmd, void *sccb)
 {
 	struct completion completion;
 	struct sclp_req *request;
@@ -270,7 +270,7 @@ int sclp_get_cpu_info(struct sclp_cpu_info *info)
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = sizeof(*sccb);
-	rc = do_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
+	rc = sclp_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
 	if (rc)
 		goto out;
 	if (sccb->header.response_code != 0x0010) {
@@ -304,7 +304,7 @@ static int do_cpu_configure(sclp_cmdw_t cmd)
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = sizeof(*sccb);
-	rc = do_sync_request(cmd, sccb);
+	rc = sclp_sync_request(cmd, sccb);
 	if (rc)
 		goto out;
 	switch (sccb->header.response_code) {
@@ -374,7 +374,7 @@ static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
 		return -ENOMEM;
 	sccb->header.length = PAGE_SIZE;
 	sccb->rn = rn;
-	rc = do_sync_request(cmd, sccb);
+	rc = sclp_sync_request(cmd, sccb);
 	if (rc)
 		goto out;
 	switch (sccb->header.response_code) {
@@ -429,7 +429,7 @@ static int sclp_attach_storage(u8 id)
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = PAGE_SIZE;
-	rc = do_sync_request(0x00080001 | id << 8, sccb);
+	rc = sclp_sync_request(0x00080001 | id << 8, sccb);
 	if (rc)
 		goto out;
 	switch (sccb->header.response_code) {
@@ -627,7 +627,7 @@ static int __init sclp_detect_standby_memory(void)
 	for (id = 0; id <= sclp_max_storage_id; id++) {
 		memset(sccb, 0, PAGE_SIZE);
 		sccb->header.length = PAGE_SIZE;
-		rc = do_sync_request(0x00040001 | id << 8, sccb);
+		rc = sclp_sync_request(0x00040001 | id << 8, sccb);
 		if (rc)
 			goto out;
 		switch (sccb->header.response_code) {
@@ -668,7 +668,7 @@ static int __init sclp_detect_standby_memory(void)
 	if (rc)
 		goto out;
 	sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0);
-	rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0;
+	rc = PTR_RET(sclp_pdev);
 	if (rc)
 		goto out_driver;
 	sclp_add_standby_memory();
@@ -714,7 +714,7 @@ static int do_pci_configure(sclp_cmdw_t cmd, u32 fid)
 	sccb->header.length = PAGE_SIZE;
 	sccb->atype = SCLP_RECONFIG_PCI_ATPYE;
 	sccb->aid = fid;
-	rc = do_sync_request(cmd, sccb);
+	rc = sclp_sync_request(cmd, sccb);
 	if (rc)
 		goto out;
 	switch (sccb->header.response_code) {
@@ -771,7 +771,7 @@ static int do_chp_configure(sclp_cmdw_t cmd)
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = sizeof(*sccb);
-	rc = do_sync_request(cmd, sccb);
+	rc = sclp_sync_request(cmd, sccb);
 	if (rc)
 		goto out;
 	switch (sccb->header.response_code) {
@@ -846,7 +846,7 @@ int sclp_chp_read_info(struct sclp_chp_info *info)
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = sizeof(*sccb);
-	rc = do_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
+	rc = sclp_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb);
 	if (rc)
 		goto out;
 	if (sccb->header.response_code != 0x0010) {
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
index ecf45c54f8c4..5880def98fc1 100644
--- a/drivers/s390/char/sclp_con.c
+++ b/drivers/s390/char/sclp_con.c
@@ -130,6 +130,31 @@ sclp_console_timeout(unsigned long data)
 }
 
 /*
+ * Drop oldest console buffer if sclp_con_drop is set
+ */
+static int
+sclp_console_drop_buffer(void)
+{
+	struct list_head *list;
+	struct sclp_buffer *buffer;
+	void *page;
+
+	if (!sclp_console_drop)
+		return 0;
+	list = sclp_con_outqueue.next;
+	if (sclp_con_queue_running)
+		/* The first element is in I/O */
+		list = list->next;
+	if (list == &sclp_con_outqueue)
+		return 0;
+	list_del(list);
+	buffer = list_entry(list, struct sclp_buffer, list);
+	page = sclp_unmake_buffer(buffer);
+	list_add_tail((struct list_head *) page, &sclp_con_pages);
+	return 1;
+}
+
+/*
  * Writes the given message to S390 system console
  */
 static void
@@ -150,9 +175,13 @@ sclp_console_write(struct console *console, const char *message,
 	do {
 		/* make sure we have a console output buffer */
 		if (sclp_conbuf == NULL) {
+			if (list_empty(&sclp_con_pages))
+				sclp_console_full++;
 			while (list_empty(&sclp_con_pages)) {
 				if (sclp_con_suspended)
 					goto out;
+				if (sclp_console_drop_buffer())
+					break;
 				spin_unlock_irqrestore(&sclp_con_lock, flags);
 				sclp_sync_wait();
 				spin_lock_irqsave(&sclp_con_lock, flags);
@@ -297,7 +326,7 @@ sclp_console_init(void)
 		return rc;
 	/* Allocate pages for output buffering */
 	INIT_LIST_HEAD(&sclp_con_pages);
-	for (i = 0; i < MAX_CONSOLE_PAGES; i++) {
+	for (i = 0; i < sclp_console_pages; i++) {
 		page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 		list_add_tail(page, &sclp_con_pages);
 	}
diff --git a/drivers/s390/char/sclp_ctl.c b/drivers/s390/char/sclp_ctl.c
new file mode 100644
index 000000000000..648cb86afd42
--- /dev/null
+++ b/drivers/s390/char/sclp_ctl.c
@@ -0,0 +1,144 @@
+/*
+ * IOCTL interface for SCLP
+ *
+ * Copyright IBM Corp. 2012
+ *
+ * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <linux/compat.h>
+#include <linux/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <asm/compat.h>
+#include <asm/sclp_ctl.h>
+#include <asm/sclp.h>
+
+#include "sclp.h"
+
+/*
+ * Supported command words
+ */
+static unsigned int sclp_ctl_sccb_wlist[] = {
+	0x00400002,
+	0x00410002,
+};
+
+/*
+ * Check if command word is supported
+ */
+static int sclp_ctl_cmdw_supported(unsigned int cmdw)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) {
+		if (cmdw == sclp_ctl_sccb_wlist[i])
+			return 1;
+	}
+	return 0;
+}
+
+static void __user *u64_to_uptr(u64 value)
+{
+	if (is_compat_task())
+		return compat_ptr(value);
+	else
+		return (void __user *)(unsigned long)value;
+}
+
+/*
+ * Start SCLP request
+ */
+static int sclp_ctl_ioctl_sccb(void __user *user_area)
+{
+	struct sclp_ctl_sccb ctl_sccb;
+	struct sccb_header *sccb;
+	int rc;
+
+	if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb)))
+		return -EFAULT;
+	if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw))
+		return -EOPNOTSUPP;
+	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!sccb)
+		return -ENOMEM;
+	if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sizeof(*sccb))) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+	if (sccb->length > PAGE_SIZE || sccb->length < 8)
+		return -EINVAL;
+	if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sccb->length)) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+	rc = sclp_sync_request(ctl_sccb.cmdw, sccb);
+	if (rc)
+		goto out_free;
+	if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length))
+		rc = -EFAULT;
+out_free:
+	free_page((unsigned long) sccb);
+	return rc;
+}
+
+/*
+ * SCLP SCCB ioctl function
+ */
+static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd,
+			   unsigned long arg)
+{
+	void __user *argp;
+
+	if (is_compat_task())
+		argp = compat_ptr(arg);
+	else
+		argp = (void __user *) arg;
+	switch (cmd) {
+	case SCLP_CTL_SCCB:
+		return sclp_ctl_ioctl_sccb(argp);
+	default: /* unknown ioctl number */
+		return -ENOTTY;
+	}
+}
+
+/*
+ * File operations
+ */
+static const struct file_operations sclp_ctl_fops = {
+	.owner = THIS_MODULE,
+	.open = nonseekable_open,
+	.unlocked_ioctl = sclp_ctl_ioctl,
+	.compat_ioctl = sclp_ctl_ioctl,
+	.llseek = no_llseek,
+};
+
+/*
+ * Misc device definition
+ */
+static struct miscdevice sclp_ctl_device = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "sclp",
+	.fops = &sclp_ctl_fops,
+};
+
+/*
+ * Register sclp_ctl misc device
+ */
+static int __init sclp_ctl_init(void)
+{
+	return misc_register(&sclp_ctl_device);
+}
+module_init(sclp_ctl_init);
+
+/*
+ * Deregister sclp_ctl misc device
+ */
+static void __exit sclp_ctl_exit(void)
+{
+	misc_deregister(&sclp_ctl_device);
+}
+module_exit(sclp_ctl_exit);
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index 5aaaa2ec8df4..4eed38cd0af6 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -362,6 +362,31 @@ sclp_vt220_timeout(unsigned long data)
 
 #define BUFFER_MAX_DELAY	HZ/20
 
+/*
+ * Drop oldest console buffer if sclp_con_drop is set
+ */
+static int
+sclp_vt220_drop_buffer(void)
+{
+	struct list_head *list;
+	struct sclp_vt220_request *request;
+	void *page;
+
+	if (!sclp_console_drop)
+		return 0;
+	list = sclp_vt220_outqueue.next;
+	if (sclp_vt220_queue_running)
+		/* The first element is in I/O */
+		list = list->next;
+	if (list == &sclp_vt220_outqueue)
+		return 0;
+	list_del(list);
+	request = list_entry(list, struct sclp_vt220_request, list);
+	page = request->sclp_req.sccb;
+	list_add_tail((struct list_head *) page, &sclp_vt220_empty);
+	return 1;
+}
+
 /* 
  * Internal implementation of the write function. Write COUNT bytes of data
  * from memory at BUF
@@ -390,12 +415,16 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
 	do {
 		/* Create an sclp output buffer if none exists yet */
 		if (sclp_vt220_current_request == NULL) {
+			if (list_empty(&sclp_vt220_empty))
+				sclp_console_full++;
 			while (list_empty(&sclp_vt220_empty)) {
-				spin_unlock_irqrestore(&sclp_vt220_lock, flags);
 				if (may_fail || sclp_vt220_suspended)
 					goto out;
-				else
-					sclp_sync_wait();
+				if (sclp_vt220_drop_buffer())
+					break;
+				spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+
+				sclp_sync_wait();
 				spin_lock_irqsave(&sclp_vt220_lock, flags);
 			}
 			page = (void *) sclp_vt220_empty.next;
@@ -428,8 +457,8 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
 		sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY;
 		add_timer(&sclp_vt220_timer);
 	}
-	spin_unlock_irqrestore(&sclp_vt220_lock, flags);
 out:
+	spin_unlock_irqrestore(&sclp_vt220_lock, flags);
 	return overall_written;
 }
 
@@ -803,7 +832,7 @@ sclp_vt220_con_init(void)
 
 	if (!CONSOLE_IS_SCLP)
 		return 0;
-	rc = __sclp_vt220_init(MAX_CONSOLE_PAGES);
+	rc = __sclp_vt220_init(sclp_console_pages);
 	if (rc)
 		return rc;
 	/* Attach linux console */
diff --git a/drivers/s390/char/tape_class.c b/drivers/s390/char/tape_class.c
index 54b3c79203f5..91c3c642c76e 100644
--- a/drivers/s390/char/tape_class.c
+++ b/drivers/s390/char/tape_class.c
@@ -77,7 +77,7 @@ struct tape_class_device *register_tape_dev(
 	tcd->class_device = device_create(tape_class, device,
 					  tcd->char_device->dev, NULL,
 					  "%s", tcd->device_name);
-	rc = IS_ERR(tcd->class_device) ? PTR_ERR(tcd->class_device) : 0;
+	rc = PTR_RET(tcd->class_device);
 	if (rc)
 		goto fail_with_cdev;
 	rc = sysfs_create_link(
diff --git a/drivers/s390/char/vmwatchdog.c b/drivers/s390/char/vmwatchdog.c
index e9b72311e254..d5eac985976b 100644
--- a/drivers/s390/char/vmwatchdog.c
+++ b/drivers/s390/char/vmwatchdog.c
@@ -112,7 +112,8 @@ static int vmwdt_keepalive(void)
 
 static int vmwdt_disable(void)
 {
-	int ret = __diag288(wdt_cancel, 0, "", 0);
+	char cmd[] = {'\0'};
+	int ret = __diag288(wdt_cancel, 0, cmd, 0);
 	WARN_ON(ret != 0);
 	clear_bit(VMWDT_RUNNING, &vmwdt_is_open);
 	return ret;
@@ -124,7 +125,7 @@ static int __init vmwdt_probe(void)
 	 * so we try initializing it with a NOP command ("BEGIN")
 	 * that won't cause any harm even if the following disable
 	 * fails for some reason */
-	static char __initdata ebc_begin[] = {
+	char ebc_begin[] = {
 		194, 197, 199, 201, 213
 	};
 	if (__diag288(wdt_init, 15, ebc_begin, sizeof(ebc_begin)) != 0)