[PATCH] s390: sclp driver.

Add error recovery for sclp failures. Fix endless loop in sclp_process_evbufs.

drivers/s390/char/Makefile

@@ -2,7 +2,7 @@
 # S/390 character devices
 #
 
-export-objs := sclp_rw.o tape_core.o tape_devmap.o tape_std.o
+export-objs := sclp.o tape_core.o tape_devmap.o tape_std.o
 
 tub3270-objs := tuball.o tubfs.o tubtty.o \
                      tubttyaid.o tubttybld.o tubttyscl.o \
@@ -10,8 +10,8 @@ tub3270-objs := tuball.o tubfs.o tubtty.o \
 
 obj-y += ctrlchar.o
 obj-$(CONFIG_TN3215) += con3215.o
-obj-$(CONFIG_SCLP) += sclp.o
-obj-$(CONFIG_SCLP_TTY) += sclp_rw.o sclp_tty.o
+obj-$(CONFIG_SCLP) += sclp.o sclp_rw.o
+obj-$(CONFIG_SCLP_TTY) += sclp_tty.o
 obj-$(CONFIG_SCLP_CONSOLE) += sclp_con.o
 obj-$(CONFIG_SCLP_CPI) += sclp_cpi.o
 obj-$(CONFIG_TN3270) += tub3270.o

drivers/s390/char/sclp.h

@@ -45,10 +45,6 @@
 #define LnTpFlgs_EndText	0x1000
 #define LnTpFlgs_PromptText	0x0800
 
-#define SCLP_COMMAND_INITIATED	0
-#define SCLP_BUSY		2
-#define SCLP_NOT_OPERATIONAL	3
-
 typedef unsigned int sclp_cmdw_t;
 
 #define SCLP_CMDW_READDATA	0x00770005
@@ -129,6 +125,7 @@ void sclp_add_request(struct sclp_req *req);
 void sclp_sync_wait(void);
 int sclp_register(struct sclp_register *reg);
 void sclp_unregister(struct sclp_register *reg);
+char *sclp_error_message(u16 response_code);
 
 /* useful inlines */
 

drivers/s390/char/sclp_con.c

@@ -51,13 +51,14 @@ sclp_conbuf_callback(struct sclp_buffer *buffer, int rc)
 	struct sclp_buffer *next;
 	void *page;
 
-	/* FIXME: what if rc != 0x0020 */
+	/* Ignore return code - because console-writes aren't critical,
+	   we do without a sophisticated error recovery mechanism.  */
 	page = sclp_unmake_buffer(buffer);
 	spin_lock_irqsave(&sclp_con_lock, flags);
-	list_add_tail((struct list_head *) page, &sclp_con_pages);
-	sclp_con_buffer_count--;
 	/* Remove buffer from outqueue */
 	list_del(&buffer->list);
+	sclp_con_buffer_count--;
+	list_add_tail((struct list_head *) page, &sclp_con_pages);
 	/* Check if there is a pending buffer on the out queue. */
 	next = NULL;
 	if (!list_empty(&sclp_con_outqueue))
@@ -104,7 +105,7 @@ sclp_console_write(struct console *console, const char *message,
 	void *page;
 	int written;
 
-	if (count <= 0)
+	if (count == 0)
 		return;
 	spin_lock_irqsave(&sclp_con_lock, flags);
 	/*
@@ -125,7 +126,8 @@ sclp_console_write(struct console *console, const char *message,
 						       sclp_con_width_htab);
 		}
 		/* try to write the string to the current output buffer */
-		written = sclp_write(sclp_conbuf, message, count, 0);
+		written = sclp_write(sclp_conbuf, (const unsigned char *)
+				     message, count, 0);
 		if (written == -EFAULT || written == count)
 			break;
 		/*
@@ -232,6 +234,6 @@ sclp_console_init(void)
 		sclp_con_columns = 80;
 	sclp_con_width_htab = 8;
 
-	/* enable printks access to this driver */
+	/* enable printk-access to this driver */
 	register_console(&sclp_console);
 }

drivers/s390/char/sclp_cpi.c

@@ -130,7 +130,7 @@ cpi_prepare_req(void)
 	req = (struct sclp_req *) kmalloc(sizeof(struct sclp_req), GFP_KERNEL);
 	if (req == NULL)
 		return ERR_PTR(-ENOMEM);
-	sccb = (struct cpi_sccb *) get_free_page(GFP_KERNEL);
+	sccb = (struct cpi_sccb *) __get_free_page(GFP_KERNEL);
 	if (sccb == NULL) {
 		kfree(req);
 		return ERR_PTR(-ENOMEM);
@@ -227,6 +227,7 @@ cpi_module_init(void)
 		rc = 0;
 
 	cpi_free_req(req);
+	sclp_unregister(&sclp_cpi_event);
 
 	return rc;
 }

drivers/s390/char/sclp_rw.h

@@ -11,6 +11,9 @@
 #ifndef __SCLP_RW_H__
 #define __SCLP_RW_H__
 
+#include <linux/list.h>
+#include <linux/timer.h>
+
 struct mto {
 	u16 length;
 	u16 type;
@@ -70,6 +73,8 @@ struct sclp_buffer {
 	struct write_sccb *sccb;
 	char *current_line;
 	int current_length;
+	int retry_count;
+	struct timer_list retry_timer;
 	/* output format settings */
 	unsigned short columns;
 	unsigned short htab;
@@ -84,8 +89,7 @@ int sclp_rw_init(void);
 struct sclp_buffer *sclp_make_buffer(void *, unsigned short, unsigned short);
 void *sclp_unmake_buffer(struct sclp_buffer *);
 int sclp_buffer_space(struct sclp_buffer *);
-int sclp_write(struct sclp_buffer *buffer, const char *, int, int);
-void sclp_move_current_line(struct sclp_buffer *, struct sclp_buffer *);
+int sclp_write(struct sclp_buffer *buffer, const unsigned char *, int, int);
 void sclp_emit_buffer(struct sclp_buffer *,void (*)(struct sclp_buffer *,int));
 void sclp_set_columns(struct sclp_buffer *, unsigned short);
 void sclp_set_htab(struct sclp_buffer *, unsigned short);

drivers/s390/char/sclp_tty.c

@@ -32,7 +32,7 @@
 #define SCLP_TTY_BUF_SIZE 512
 
 /*
- * There is excatly one SCLP terminal, so we can keep things simple
+ * There is exactly one SCLP terminal, so we can keep things simple
  * and allocate all variables statically.
  */
 
@@ -265,13 +265,14 @@ sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 	struct sclp_buffer *next;
 	void *page;
 
-	/* FIXME: what if rc != 0x0020 */
+	/* Ignore return code - because tty-writes aren't critical,
+	   we do without a sophisticated error recovery mechanism.  */
 	page = sclp_unmake_buffer(buffer);
 	spin_lock_irqsave(&sclp_tty_lock, flags);
-	list_add_tail((struct list_head *) page, &sclp_tty_pages);
-	sclp_tty_buffer_count--;
 	/* Remove buffer from outqueue */
 	list_del(&buffer->list);
+	sclp_tty_buffer_count--;
+	list_add_tail((struct list_head *) page, &sclp_tty_pages);
 	/* Check if there is a pending buffer on the out queue. */
 	next = NULL;
 	if (!list_empty(&sclp_tty_outqueue))
@@ -489,8 +490,8 @@ void sclp_tty_input(unsigned char* buf, unsigned int count)
 		/* send (normal) input to line discipline */
 		memcpy(sclp_tty->flip.char_buf_ptr, buf, count);
 		if (count < 2 ||
-		    strncmp (buf + count - 2, "^n", 2) ||
-		    strncmp (buf + count - 2, "\0252n", 2)) {
+		    strncmp ((const char *) buf + count - 2, "^n", 2) ||
+		    strncmp ((const char *) buf + count - 2, "\0252n", 2)) {
 			sclp_tty->flip.char_buf_ptr[count] = '\n';
 			count++;
 		} else
@@ -558,7 +559,7 @@ sclp_switch_cases(unsigned char *buf, int count,
 }
 
 static void
-sclp_get_input(char *start, char *end)
+sclp_get_input(unsigned char *start, unsigned char *end)
 {
 	int count;
 
@@ -572,7 +573,7 @@ sclp_get_input(char *start, char *end)
 
 	/*
 	 * if set in ioctl find out characters in lower or upper case
-	 * (depends on current case) seperated by a special character,
+	 * (depends on current case) separated by a special character,
 	 * works on EBCDIC
 	 */
 	if (sclp_ioctls.delim)
@@ -625,8 +626,8 @@ sclp_eval_selfdeftextmsg(struct gds_subvector *start,
 		subvec = find_gds_subvector(subvec, end, 0x30);
 		if (!subvec)
 			break;
-		sclp_get_input((void *)(subvec + 1),
-			       (void *) subvec + subvec->length);
+		sclp_get_input((unsigned char *)(subvec + 1),
+			       (unsigned char *) subvec + subvec->length);
 		(void *) subvec += subvec->length;
 	}
 }

drivers/s390/char/sclp_tty.h

@@ -18,9 +18,9 @@ struct sclp_ioctls {
 	unsigned short htab;
 	unsigned char echo;
 	unsigned short columns;
-	signed char final_nl;
+	unsigned char final_nl;
 	unsigned short max_sccb;
-	unsigned short kmem_sccb;	/* cant be modified at run time */
+	unsigned short kmem_sccb;	/* can't be modified at run time */
 	unsigned char tolower;
 	unsigned char delim;
 };