staging: visorchipset driver to provide registration and other services

The visorchipset module receives device creation and destruction
events from the Command service partition of s-Par, as well as
controlling registration of shared device drivers with the s-Par
driver core. The events received are used to populate other s-Par
modules with their assigned shared devices. Visorchipset is required
for shared device drivers to function properly. Visorchipset also
stores information for handling dump disk device creation during
kdump.

In operation, the visorchipset module processes device creation and
destruction messages sent by s-Par's Command service partition through
a channel. These messages result in creation (or destruction) of each
virtual bus and virtual device. Each bus and device is also associated
with a communication channel, which is used to communicate with one or
more IO service partitions to perform device IO on behalf of the
guest.

Signed-off-by: Ken Cox <jkc@redhat.com>
Cc: Ben Romer <sparmaintainer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 209 insertions, 0 deletions

diff --git a/drivers/staging/unisys/common-spar/include/vbusdeviceinfo.h b/drivers/staging/unisys/common-spar/include/vbusdeviceinfo.h
new file mode 100644
index 000000000000..373677908915
--- /dev/null
+++ b/drivers/staging/unisys/common-spar/include/vbusdeviceinfo.h
@@ -0,0 +1,209 @@
+/* Copyright © 2010 - 2013 UNISYS CORPORATION
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ */
+
+#ifndef __VBUSDEVICEINFO_H__
+#define __VBUSDEVICEINFO_H__
+
+#include "commontypes.h"
+
+#pragma pack(push, 1)		/* both GCC and VC now allow this pragma */
+
+/* An array of this struct is present in the channel area for each vbus.
+ * (See vbuschannel.h.)
+ * It is filled in by the client side to provide info about the device
+ * and driver from the client's perspective.
+ */
+typedef struct _ULTRA_VBUS_DEVICEINFO {
+	U8 devType[16];		/* short string identifying the device type */
+	U8 drvName[16];		/* driver .sys file name */
+	U8 infoStrings[96];	/* sequence of tab-delimited id strings: */
+	/* <DRIVER_REV> <DRIVER_VERTAG> <DRIVER_COMPILETIME> */
+	U8 reserved[128];	/* pad size to 256 bytes */
+} ULTRA_VBUS_DEVICEINFO;
+
+#pragma pack(pop)
+
+/* Reads chars from the buffer at <src> for <srcmax> bytes, and writes to
+ * the buffer at <p>, which is <remain> bytes long, ensuring never to
+ * overflow the buffer at <p>, using the following rules:
+ * - printable characters are simply copied from the buffer at <src> to the
+ *   buffer at <p>
+ * - intervening streaks of non-printable characters in the buffer at <src>
+ *   are replaced with a single space in the buffer at <p>
+ * Note that we pay no attention to '\0'-termination.
+ * Returns the number of bytes written to <p>.
+ *
+ * Pass <p> == NULL and <remain> == 0 for this special behavior.  In this
+ * case, we simply return the number of bytes that WOULD HAVE been written
+ * to a buffer at <p>, had it been infinitely big.
+ */
+static inline int
+VBUSCHANNEL_sanitize_buffer(char *p, int remain, char *src, int srcmax)
+{
+	int chars = 0;
+	int nonprintable_streak = 0;
+	while (srcmax > 0) {
+		if ((*src >= ' ') && (*src < 0x7f)) {
+			if (nonprintable_streak) {
+				if (remain > 0) {
+					*p = ' ';
+					p++;
+					remain--;
+					chars++;
+				} else if (p == NULL)
+					chars++;
+				nonprintable_streak = 0;
+			}
+			if (remain > 0) {
+				*p = *src;
+				p++;
+				remain--;
+				chars++;
+			} else if (p == NULL)
+				chars++;
+		} else
+			nonprintable_streak = 1;
+		src++;
+		srcmax--;
+	}
+	return chars;
+}
+
+#define VBUSCHANNEL_ADDACHAR(ch, p, remain, chars) \
+	do {					   \
+		if (remain <= 0)		   \
+			break;			   \
+		*p = ch;			   \
+		p++;  chars++;  remain--;	   \
+	} while (0)
+
+/* Converts the non-negative value at <num> to an ascii decimal string
+ * at <p>, writing at most <remain> bytes.  Note there is NO '\0' termination
+ * written to <p>.
+ *
+ * Returns the number of bytes written to <p>.
+ *
+ * Note that we create this function because we need to do this operation in
+ * an environment-independent way (since we are in a common header file).
+ */
+static inline int
+VBUSCHANNEL_itoa(char *p, int remain, int num)
+{
+	int digits = 0;
+	char s[32];
+	int i;
+
+	if (num == 0) {
+		/* '0' is a special case */
+		if (remain <= 0)
+			return 0;
+		*p = '0';
+		return 1;
+	}
+	/* form a backwards decimal ascii string in <s> */
+	while (num > 0) {
+		if (digits >= (int) sizeof(s))
+			return 0;
+		s[digits++] = (num % 10) + '0';
+		num = num / 10;
+	}
+	if (remain < digits) {
+		/* not enough room left at <p> to hold number, so fill with
+		 * '?' */
+		for (i = 0; i < remain; i++, p++)
+			*p = '?';
+		return remain;
+	}
+	/* plug in the decimal ascii string representing the number, by */
+	/* reversing the string we just built in <s> */
+	i = digits;
+	while (i > 0) {
+		i--;
+		*p = s[i];
+		p++;
+	}
+	return digits;
+}
+
+/* Reads <devInfo>, and converts its contents to a printable string at <p>,
+ * writing at most <remain> bytes.  Note there is NO '\0' termination
+ * written to <p>.
+ *
+ * Pass <devix> >= 0 if you want a device index presented.
+ *
+ * Returns the number of bytes written to <p>.
+ */
+static inline int
+VBUSCHANNEL_devInfoToStringBuffer(ULTRA_VBUS_DEVICEINFO devInfo,
+				  char *p, int remain, int devix)
+{
+	char *psrc;
+	int nsrc, x, i, pad;
+	int chars = 0;
+
+	psrc = &(devInfo.devType[0]);
+	nsrc = sizeof(devInfo.devType);
+	if (VBUSCHANNEL_sanitize_buffer(NULL, 0, psrc, nsrc) <= 0)
+		return 0;
+
+	/* emit device index */
+	if (devix >= 0) {
+		VBUSCHANNEL_ADDACHAR('[', p, remain, chars);
+		x = VBUSCHANNEL_itoa(p, remain, devix);
+		p += x;
+		remain -= x;
+		chars += x;
+		VBUSCHANNEL_ADDACHAR(']', p, remain, chars);
+	} else {
+		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+	}
+
+	/* emit device type */
+	x = VBUSCHANNEL_sanitize_buffer(p, remain, psrc, nsrc);
+	p += x;
+	remain -= x;
+	chars += x;
+	pad = 15 - x;		/* pad device type to be exactly 15 chars */
+	for (i = 0; i < pad; i++)
+		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+	VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+
+	/* emit driver name */
+	psrc = &(devInfo.drvName[0]);
+	nsrc = sizeof(devInfo.drvName);
+	x = VBUSCHANNEL_sanitize_buffer(p, remain, psrc, nsrc);
+	p += x;
+	remain -= x;
+	chars += x;
+	pad = 15 - x;		/* pad driver name to be exactly 15 chars */
+	for (i = 0; i < pad; i++)
+		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+	VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
+
+	/* emit strings */
+	psrc = &(devInfo.infoStrings[0]);
+	nsrc = sizeof(devInfo.infoStrings);
+	x = VBUSCHANNEL_sanitize_buffer(p, remain, psrc, nsrc);
+	p += x;
+	remain -= x;
+	chars += x;
+	VBUSCHANNEL_ADDACHAR('\n', p, remain, chars);
+
+	return chars;
+}
+
+#endif