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dm-queue-length
===============

dm-queue-length is a path selector module for device-mapper targets,
which selects a path with the least number of in-flight I/Os.
The path selector name is 'queue-length'.

Table parameters for each path: [<repeat_count>]
	<repeat_count>: The number of I/Os to dispatch using the selected
			path before switching to the next path.
			If not given, internal default is used. To check
			the default value, see the activated table.

Status for each path: <status> <fail-count> <in-flight>
	<status>: 'A' if the path is active, 'F' if the path is failed.
	<fail-count>: The number of path failures.
	<in-flight>: The number of in-flight I/Os on the path.


Algorithm
=========

dm-queue-length increments/decrements 'in-flight' when an I/O is
dispatched/completed respectively.
dm-queue-length selects a path with the minimum 'in-flight'.


Examples
========
In case that 2 paths (sda and sdb) are used with repeat_count == 128.

# echo "0 10 multipath 0 0 1 1 queue-length 0 2 1 8:0 128 8:16 128" \
  dmsetup create test
#
# dmsetup table
test: 0 10 multipath 0 0 1 1 queue-length 0 2 1 8:0 128 8:16 128
#
# dmsetup status
test: 0 10 multipath 2 0 0 0 1 1 E 0 2 1 8:0 A 0 0 8:16 A 0 0
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-06 16:42:28 -0500
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/*
 * topic.h 1.8 1999/08/28 04:01:47
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License
 * at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and
 * limitations under the License. 
 *
 * The initial developer of the original code is David A. Hinds
 * <dahinds@users.sourceforge.net>.  Portions created by David A. Hinds
 * are Copyright (C) 1999 David A. Hinds.  All Rights Reserved.
 *
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License version 2 (the "GPL"), in which
 * case the provisions of the GPL are applicable instead of the
 * above.  If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use
 * your version of this file under the MPL, indicate your decision by
 * deleting the provisions above and replace them with the notice and
 * other provisions required by the GPL.  If you do not delete the
 * provisions above, a recipient may use your version of this file
 * under either the MPL or the GPL.
 * topic.h $Release$ 1999/08/28 04:01:47
 */

#ifndef _LINUX_TOPIC_H
#define _LINUX_TOPIC_H

/* Register definitions for Toshiba ToPIC95/97/100 controllers */

#define TOPIC_SOCKET_CONTROL		0x0090	/* 32 bit */
#define  TOPIC_SCR_IRQSEL		0x00000001

#define TOPIC_SLOT_CONTROL		0x00a0	/* 8 bit */
#define  TOPIC_SLOT_SLOTON		0x80
#define  TOPIC_SLOT_SLOTEN		0x40
#define  TOPIC_SLOT_ID_LOCK		0x20
#define  TOPIC_SLOT_ID_WP		0x10
#define  TOPIC_SLOT_PORT_MASK		0x0c
#define  TOPIC_SLOT_PORT_SHIFT		2
#define  TOPIC_SLOT_OFS_MASK		0x03

#define TOPIC_CARD_CONTROL		0x00a1	/* 8 bit */
#define  TOPIC_CCR_INTB			0x20
#define  TOPIC_CCR_INTA			0x10
#define  TOPIC_CCR_CLOCK		0x0c
#define  TOPIC_CCR_PCICLK		0x0c
#define  TOPIC_CCR_PCICLK_2		0x08
#define  TOPIC_CCR_CCLK			0x04

#define TOPIC97_INT_CONTROL		0x00a1	/* 8 bit */
#define  TOPIC97_ICR_INTB		0x20
#define  TOPIC97_ICR_INTA		0x10
#define  TOPIC97_ICR_STSIRQNP		0x04
#define  TOPIC97_ICR_IRQNP		0x02
#define  TOPIC97_ICR_IRQSEL		0x01

#define TOPIC_CARD_DETECT		0x00a3	/* 8 bit */
#define  TOPIC_CDR_MODE_PC32		0x80
#define  TOPIC_CDR_VS1			0x04
#define  TOPIC_CDR_VS2			0x02
#define  TOPIC_CDR_SW_DETECT		0x01

#define TOPIC_REGISTER_CONTROL		0x00a4	/* 32 bit */
#define  TOPIC_RCR_RESUME_RESET		0x80000000
#define  TOPIC_RCR_REMOVE_RESET		0x40000000
#define  TOPIC97_RCR_CLKRUN_ENA		0x20000000
#define  TOPIC97_RCR_TESTMODE		0x10000000
#define  TOPIC97_RCR_IOPLUP		0x08000000
#define  TOPIC_RCR_BUFOFF_PWROFF	0x02000000
#define  TOPIC_RCR_BUFOFF_SIGOFF	0x01000000
#define  TOPIC97_RCR_CB_DEV_MASK	0x0000f800
#define  TOPIC97_RCR_CB_DEV_SHIFT	11
#define  TOPIC97_RCR_RI_DISABLE		0x00000004
#define  TOPIC97_RCR_CAUDIO_OFF		0x00000002
#define  TOPIC_RCR_CAUDIO_INVERT	0x00000001

#define TOPIC97_MISC1			0x00ad  /* 8bit */
#define  TOPIC97_MISC1_CLOCKRUN_ENABLE	0x80
#define  TOPIC97_MISC1_CLOCKRUN_MODE	0x40
#define  TOPIC97_MISC1_DETECT_REQ_ENA	0x10
#define  TOPIC97_MISC1_SCK_CLEAR_DIS	0x04
#define  TOPIC97_MISC1_R2_LOW_ENABLE	0x10

#define TOPIC97_MISC2			0x00ae  /* 8 bit */
#define  TOPIC97_MISC2_SPWRCLK_MASK	0x70
#define  TOPIC97_MISC2_SPWRMOD		0x08
#define  TOPIC97_MISC2_SPWR_ENABLE	0x04
#define  TOPIC97_MISC2_ZV_MODE		0x02
#define  TOPIC97_MISC2_ZV_ENABLE	0x01

#define TOPIC97_ZOOM_VIDEO_CONTROL	0x009c  /* 8 bit */
#define  TOPIC97_ZV_CONTROL_ENABLE	0x01

#define TOPIC97_AUDIO_VIDEO_SWITCH	0x003c  /* 8 bit */
#define  TOPIC97_AVS_AUDIO_CONTROL	0x02
#define  TOPIC97_AVS_VIDEO_CONTROL	0x01

#define TOPIC_EXCA_IF_CONTROL		0x3e	/* 8 bit */
#define TOPIC_EXCA_IFC_33V_ENA		0x01

static void topic97_zoom_video(struct pcmcia_socket *sock, int onoff)
{
	struct yenta_socket *socket = container_of(sock, struct yenta_socket, socket);
	u8 reg_zv, reg;

	reg_zv = config_readb(socket, TOPIC97_ZOOM_VIDEO_CONTROL);
	if (onoff) {
		reg_zv |= TOPIC97_ZV_CONTROL_ENABLE;
		config_writeb(socket, TOPIC97_ZOOM_VIDEO_CONTROL, reg_zv);

		reg = config_readb(socket, TOPIC97_MISC2);
		reg |= TOPIC97_MISC2_ZV_ENABLE;
		config_writeb(socket, TOPIC97_MISC2, reg);

		/* not sure this is needed, doc is unclear */
#if 0
		reg = config_readb(socket, TOPIC97_AUDIO_VIDEO_SWITCH);
		reg |= TOPIC97_AVS_AUDIO_CONTROL | TOPIC97_AVS_VIDEO_CONTROL;
		config_writeb(socket, TOPIC97_AUDIO_VIDEO_SWITCH, reg);
#endif
	}
	else {
		reg_zv &= ~TOPIC97_ZV_CONTROL_ENABLE;
		config_writeb(socket, TOPIC97_ZOOM_VIDEO_CONTROL, reg_zv);
	}

}

static int topic97_override(struct yenta_socket *socket)
{
	/* ToPIC97/100 support ZV */
	socket->socket.zoom_video = topic97_zoom_video;
	return 0;
}


static int topic95_override(struct yenta_socket *socket)
{
	u8 fctrl;

	/* enable 3.3V support for 16bit cards */
	fctrl = exca_readb(socket, TOPIC_EXCA_IF_CONTROL);
	exca_writeb(socket, TOPIC_EXCA_IF_CONTROL, fctrl | TOPIC_EXCA_IFC_33V_ENA);

	/* tell yenta to use exca registers to power 16bit cards */
	socket->flags |= YENTA_16BIT_POWER_EXCA | YENTA_16BIT_POWER_DF;

	return 0;
}

#endif /* _LINUX_TOPIC_H */
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-06 16:42:27 -0500