cregit-Linux how code gets into the kernel

Release 4.11 drivers/input/mouse/vmmouse.c

/*
 * Driver for Virtual PS/2 Mouse on VMware and QEMU hypervisors.
 *
 * Copyright (C) 2014, VMware, Inc. 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 version 2 as published by
 * the Free Software Foundation.
 *
 * Twin device code is hugely inspired by the ALPS driver.
 * Authors:
 *   Dmitry Torokhov <dmitry.torokhov@gmail.com>
 *   Thomas Hellstrom <thellstrom@vmware.com>
 */

#include <linux/input.h>
#include <linux/serio.h>
#include <linux/libps2.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <asm/hypervisor.h>

#include "psmouse.h"
#include "vmmouse.h"


#define VMMOUSE_PROTO_MAGIC			0x564D5868U

#define VMMOUSE_PROTO_PORT			0x5658

/*
 * Main commands supported by the vmmouse hypervisor port.
 */

#define VMMOUSE_PROTO_CMD_GETVERSION		10

#define VMMOUSE_PROTO_CMD_ABSPOINTER_DATA	39

#define VMMOUSE_PROTO_CMD_ABSPOINTER_STATUS	40

#define VMMOUSE_PROTO_CMD_ABSPOINTER_COMMAND	41

#define VMMOUSE_PROTO_CMD_ABSPOINTER_RESTRICT   86

/*
 * Subcommands for VMMOUSE_PROTO_CMD_ABSPOINTER_COMMAND
 */

#define VMMOUSE_CMD_ENABLE			0x45414552U

#define VMMOUSE_CMD_DISABLE			0x000000f5U

#define VMMOUSE_CMD_REQUEST_RELATIVE		0x4c455252U

#define VMMOUSE_CMD_REQUEST_ABSOLUTE		0x53424152U


#define VMMOUSE_ERROR				0xffff0000U


#define VMMOUSE_VERSION_ID			0x3442554aU


#define VMMOUSE_RELATIVE_PACKET			0x00010000U


#define VMMOUSE_LEFT_BUTTON			0x20

#define VMMOUSE_RIGHT_BUTTON			0x10

#define VMMOUSE_MIDDLE_BUTTON			0x08

/*
 * VMMouse Restrict command
 */

#define VMMOUSE_RESTRICT_ANY                    0x00

#define VMMOUSE_RESTRICT_CPL0                   0x01

#define VMMOUSE_RESTRICT_IOPL                   0x02


#define VMMOUSE_MAX_X                           0xFFFF

#define VMMOUSE_MAX_Y                           0xFFFF


#define VMMOUSE_VENDOR "VMware"

#define VMMOUSE_NAME   "VMMouse"

/**
 * struct vmmouse_data - private data structure for the vmmouse driver
 *
 * @abs_dev: "Absolute" device used to report absolute mouse movement.
 * @phys: Physical path for the absolute device.
 * @dev_name: Name attribute name for the absolute device.
 */

struct vmmouse_data {
	
struct input_dev *abs_dev;
	
char phys[32];
	
char dev_name[128];
};

/**
 * Hypervisor-specific bi-directional communication channel
 * implementing the vmmouse protocol. Should never execute on
 * bare metal hardware.
 */

#define VMMOUSE_CMD(cmd, in1, out1, out2, out3, out4)	\
({                                                      \
        unsigned long __dummy1, __dummy2;               \
        __asm__ __volatile__ ("inl %%dx" :              \
                "=a"(out1),                             \
                "=b"(out2),                             \
                "=c"(out3),                             \
                "=d"(out4),                             \
                "=S"(__dummy1),                         \
                "=D"(__dummy2) :                        \
                "a"(VMMOUSE_PROTO_MAGIC),               \
                "b"(in1),                               \
                "c"(VMMOUSE_PROTO_CMD_##cmd),           \
                "d"(VMMOUSE_PROTO_PORT) :               \
                "memory");                              \
})

/**
 * vmmouse_report_button - report button state on the correct input device
 *
 * @psmouse:  Pointer to the psmouse struct
 * @abs_dev:  The absolute input device
 * @rel_dev:  The relative input device
 * @pref_dev: The preferred device for reporting
 * @code:     Button code
 * @value:    Button value
 *
 * Report @value and @code on @pref_dev, unless the button is already
 * pressed on the other device, in which case the state is reported on that
 * device.
 */

static void vmmouse_report_button(struct psmouse *psmouse, struct input_dev *abs_dev, struct input_dev *rel_dev, struct input_dev *pref_dev, unsigned int code, int value) { if (test_bit(code, abs_dev->key)) pref_dev = abs_dev; else if (test_bit(code, rel_dev->key)) pref_dev = rel_dev; input_report_key(pref_dev, code, value); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom73100.00%1100.00%
Total73100.00%1100.00%

/** * vmmouse_report_events - process events on the vmmouse communications channel * * @psmouse: Pointer to the psmouse struct * * This function pulls events from the vmmouse communications channel and * reports them on the correct (absolute or relative) input device. When the * communications channel is drained, or if we've processed more than 255 * psmouse commands, the function returns PSMOUSE_FULL_PACKET. If there is a * host- or synchronization error, the function returns PSMOUSE_BAD_DATA in * the hope that the caller will reset the communications channel. */
static psmouse_ret_t vmmouse_report_events(struct psmouse *psmouse) { struct input_dev *rel_dev = psmouse->dev; struct vmmouse_data *priv = psmouse->private; struct input_dev *abs_dev = priv->abs_dev; struct input_dev *pref_dev; u32 status, x, y, z; u32 dummy1, dummy2, dummy3; unsigned int queue_length; unsigned int count = 255; while (count--) { /* See if we have motion data. */ VMMOUSE_CMD(ABSPOINTER_STATUS, 0, status, dummy1, dummy2, dummy3); if ((status & VMMOUSE_ERROR) == VMMOUSE_ERROR) { psmouse_err(psmouse, "failed to fetch status data\n"); /* * After a few attempts this will result in * reconnect. */ return PSMOUSE_BAD_DATA; } queue_length = status & 0xffff; if (queue_length == 0) break; if (queue_length % 4) { psmouse_err(psmouse, "invalid queue length\n"); return PSMOUSE_BAD_DATA; } /* Now get it */ VMMOUSE_CMD(ABSPOINTER_DATA, 4, status, x, y, z); /* * And report what we've got. Prefer to report button * events on the same device where we report motion events. * This doesn't work well with the mouse wheel, though. See * below. Ideally we would want to report that on the * preferred device as well. */ if (status & VMMOUSE_RELATIVE_PACKET) { pref_dev = rel_dev; input_report_rel(rel_dev, REL_X, (s32)x); input_report_rel(rel_dev, REL_Y, -(s32)y); } else { pref_dev = abs_dev; input_report_abs(abs_dev, ABS_X, x); input_report_abs(abs_dev, ABS_Y, y); } /* Xorg seems to ignore wheel events on absolute devices */ input_report_rel(rel_dev, REL_WHEEL, -(s8)((u8) z)); vmmouse_report_button(psmouse, abs_dev, rel_dev, pref_dev, BTN_LEFT, status & VMMOUSE_LEFT_BUTTON); vmmouse_report_button(psmouse, abs_dev, rel_dev, pref_dev, BTN_RIGHT, status & VMMOUSE_RIGHT_BUTTON); vmmouse_report_button(psmouse, abs_dev, rel_dev, pref_dev, BTN_MIDDLE, status & VMMOUSE_MIDDLE_BUTTON); input_sync(abs_dev); input_sync(rel_dev); } return PSMOUSE_FULL_PACKET; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom308100.00%1100.00%
Total308100.00%1100.00%

/** * vmmouse_process_byte - process data on the ps/2 channel * * @psmouse: Pointer to the psmouse struct * * When the ps/2 channel indicates that there is vmmouse data available, * call vmmouse channel processing. Otherwise, continue to accept bytes. If * there is a synchronization or communication data error, return * PSMOUSE_BAD_DATA in the hope that the caller will reset the mouse. */
static psmouse_ret_t vmmouse_process_byte(struct psmouse *psmouse) { unsigned char *packet = psmouse->packet; switch (psmouse->pktcnt) { case 1: return (packet[0] & 0x8) == 0x8 ? PSMOUSE_GOOD_DATA : PSMOUSE_BAD_DATA; case 2: return PSMOUSE_GOOD_DATA; default: return vmmouse_report_events(psmouse); } }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom60100.00%1100.00%
Total60100.00%1100.00%

/** * vmmouse_disable - Disable vmmouse * * @psmouse: Pointer to the psmouse struct * * Tries to disable vmmouse mode. */
static void vmmouse_disable(struct psmouse *psmouse) { u32 status; u32 dummy1, dummy2, dummy3, dummy4; VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_DISABLE, dummy1, dummy2, dummy3, dummy4); VMMOUSE_CMD(ABSPOINTER_STATUS, 0, status, dummy1, dummy2, dummy3); if ((status & VMMOUSE_ERROR) != VMMOUSE_ERROR) psmouse_warn(psmouse, "failed to disable vmmouse device\n"); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom70100.00%1100.00%
Total70100.00%1100.00%

/** * vmmouse_enable - Enable vmmouse and request absolute mode. * * @psmouse: Pointer to the psmouse struct * * Tries to enable vmmouse mode. Performs basic checks and requests * absolute vmmouse mode. * Returns 0 on success, -ENODEV on failure. */
static int vmmouse_enable(struct psmouse *psmouse) { u32 status, version; u32 dummy1, dummy2, dummy3, dummy4; /* * Try enabling the device. If successful, we should be able to * read valid version ID back from it. */ VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_ENABLE, dummy1, dummy2, dummy3, dummy4); /* * See if version ID can be retrieved. */ VMMOUSE_CMD(ABSPOINTER_STATUS, 0, status, dummy1, dummy2, dummy3); if ((status & 0x0000ffff) == 0) { psmouse_dbg(psmouse, "empty flags - assuming no device\n"); return -ENXIO; } VMMOUSE_CMD(ABSPOINTER_DATA, 1 /* single item */, version, dummy1, dummy2, dummy3); if (version != VMMOUSE_VERSION_ID) { psmouse_dbg(psmouse, "Unexpected version value: %u vs %u\n", (unsigned) version, VMMOUSE_VERSION_ID); vmmouse_disable(psmouse); return -ENXIO; } /* * Restrict ioport access, if possible. */ VMMOUSE_CMD(ABSPOINTER_RESTRICT, VMMOUSE_RESTRICT_CPL0, dummy1, dummy2, dummy3, dummy4); VMMOUSE_CMD(ABSPOINTER_COMMAND, VMMOUSE_CMD_REQUEST_ABSOLUTE, dummy1, dummy2, dummy3, dummy4); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom161100.00%1100.00%
Total161100.00%1100.00%

/* * Array of supported hypervisors. */ static const struct hypervisor_x86 *vmmouse_supported_hypervisors[] = { &x86_hyper_vmware, #ifdef CONFIG_KVM_GUEST &x86_hyper_kvm, #endif }; /** * vmmouse_check_hypervisor - Check if we're running on a supported hypervisor */
static bool vmmouse_check_hypervisor(void) { int i; for (i = 0; i < ARRAY_SIZE(vmmouse_supported_hypervisors); i++) if (vmmouse_supported_hypervisors[i] == x86_hyper) return true; return false; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom42100.00%1100.00%
Total42100.00%1100.00%

/** * vmmouse_detect - Probe whether vmmouse is available * * @psmouse: Pointer to the psmouse struct * @set_properties: Whether to set psmouse name and vendor * * Returns 0 if vmmouse channel is available. Negative error code if not. */
int vmmouse_detect(struct psmouse *psmouse, bool set_properties) { u32 response, version, dummy1, dummy2; if (!vmmouse_check_hypervisor()) { psmouse_dbg(psmouse, "VMMouse not running on supported hypervisor.\n"); return -ENXIO; } /* Check if the device is present */ response = ~VMMOUSE_PROTO_MAGIC; VMMOUSE_CMD(GETVERSION, 0, version, response, dummy1, dummy2); if (response != VMMOUSE_PROTO_MAGIC || version == 0xffffffffU) return -ENXIO; if (set_properties) { psmouse->vendor = VMMOUSE_VENDOR; psmouse->name = VMMOUSE_NAME; psmouse->model = version; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom103100.00%1100.00%
Total103100.00%1100.00%

/** * vmmouse_disconnect - Take down vmmouse driver * * @psmouse: Pointer to the psmouse struct * * Takes down vmmouse driver and frees resources set up in vmmouse_init(). */
static void vmmouse_disconnect(struct psmouse *psmouse) { struct vmmouse_data *priv = psmouse->private; vmmouse_disable(psmouse); psmouse_reset(psmouse); input_unregister_device(priv->abs_dev); kfree(priv); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom42100.00%1100.00%
Total42100.00%1100.00%

/** * vmmouse_reconnect - Reset the ps/2 - and vmmouse connections * * @psmouse: Pointer to the psmouse struct * * Attempts to reset the mouse connections. Returns 0 on success and * -1 on failure. */
static int vmmouse_reconnect(struct psmouse *psmouse) { int error; psmouse_reset(psmouse); vmmouse_disable(psmouse); error = vmmouse_enable(psmouse); if (error) { psmouse_err(psmouse, "Unable to re-enable mouse when reconnecting, err: %d\n", error); return error; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom52100.00%1100.00%
Total52100.00%1100.00%

/** * vmmouse_init - Initialize the vmmouse driver * * @psmouse: Pointer to the psmouse struct * * Requests the device and tries to enable vmmouse mode. * If successful, sets up the input device for relative movement events. * It also allocates another input device and sets it up for absolute motion * events. Returns 0 on success and -1 on failure. */
int vmmouse_init(struct psmouse *psmouse) { struct vmmouse_data *priv; struct input_dev *rel_dev = psmouse->dev, *abs_dev; int error; psmouse_reset(psmouse); error = vmmouse_enable(psmouse); if (error) return error; priv = kzalloc(sizeof(*priv), GFP_KERNEL); abs_dev = input_allocate_device(); if (!priv || !abs_dev) { error = -ENOMEM; goto init_fail; } priv->abs_dev = abs_dev; psmouse->private = priv; /* Set up and register absolute device */ snprintf(priv->phys, sizeof(priv->phys), "%s/input1", psmouse->ps2dev.serio->phys); /* Mimic name setup for relative device in psmouse-base.c */ snprintf(priv->dev_name, sizeof(priv->dev_name), "%s %s %s", VMMOUSE_PSNAME, VMMOUSE_VENDOR, VMMOUSE_NAME); abs_dev->phys = priv->phys; abs_dev->name = priv->dev_name; abs_dev->id.bustype = BUS_I8042; abs_dev->id.vendor = 0x0002; abs_dev->id.product = PSMOUSE_VMMOUSE; abs_dev->id.version = psmouse->model; abs_dev->dev.parent = &psmouse->ps2dev.serio->dev; /* Set absolute device capabilities */ input_set_capability(abs_dev, EV_KEY, BTN_LEFT); input_set_capability(abs_dev, EV_KEY, BTN_RIGHT); input_set_capability(abs_dev, EV_KEY, BTN_MIDDLE); input_set_capability(abs_dev, EV_ABS, ABS_X); input_set_capability(abs_dev, EV_ABS, ABS_Y); input_set_abs_params(abs_dev, ABS_X, 0, VMMOUSE_MAX_X, 0, 0); input_set_abs_params(abs_dev, ABS_Y, 0, VMMOUSE_MAX_Y, 0, 0); error = input_register_device(priv->abs_dev); if (error) goto init_fail; /* Add wheel capability to the relative device */ input_set_capability(rel_dev, EV_REL, REL_WHEEL); psmouse->protocol_handler = vmmouse_process_byte; psmouse->disconnect = vmmouse_disconnect; psmouse->reconnect = vmmouse_reconnect; return 0; init_fail: vmmouse_disable(psmouse); psmouse_reset(psmouse); input_free_device(abs_dev); kfree(priv); psmouse->private = NULL; return error; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom33592.03%133.33%
Dmitry Torokhov267.14%133.33%
Sinclair Yeh30.82%133.33%
Total364100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Thomas Hellstrom144598.03%133.33%
Dmitry Torokhov261.76%133.33%
Sinclair Yeh30.20%133.33%
Total1474100.00%3100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.