android_kernel_xiaomi_sm8350/drivers/infiniband/hw/ipath/ipath_diag.c
Bryan O'Sullivan 755e4ca4a9 IB/ipath: fix race with exposing reset file
We were accidentally exposing the "reset" sysfs file more than once
per device.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01 12:14:11 -07:00

369 lines
9.6 KiB
C

/*
* Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/*
* This file contains support for diagnostic functions. It is accessed by
* opening the ipath_diag device, normally minor number 129. Diagnostic use
* of the InfiniPath chip may render the chip or board unusable until the
* driver is unloaded, or in some cases, until the system is rebooted.
*
* Accesses to the chip through this interface are not similar to going
* through the /sys/bus/pci resource mmap interface.
*/
#include <linux/pci.h>
#include <asm/uaccess.h>
#include "ipath_common.h"
#include "ipath_kernel.h"
#include "ips_common.h"
#include "ipath_layer.h"
int ipath_diag_inuse;
static int diag_set_link;
static int ipath_diag_open(struct inode *in, struct file *fp);
static int ipath_diag_release(struct inode *in, struct file *fp);
static ssize_t ipath_diag_read(struct file *fp, char __user *data,
size_t count, loff_t *off);
static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
size_t count, loff_t *off);
static struct file_operations diag_file_ops = {
.owner = THIS_MODULE,
.write = ipath_diag_write,
.read = ipath_diag_read,
.open = ipath_diag_open,
.release = ipath_diag_release
};
static struct cdev *diag_cdev;
static struct class_device *diag_class_dev;
int ipath_diag_init(void)
{
return ipath_cdev_init(IPATH_DIAG_MINOR, "ipath_diag",
&diag_file_ops, &diag_cdev, &diag_class_dev);
}
void ipath_diag_cleanup(void)
{
ipath_cdev_cleanup(&diag_cdev, &diag_class_dev);
}
/**
* ipath_read_umem64 - read a 64-bit quantity from the chip into user space
* @dd: the infinipath device
* @uaddr: the location to store the data in user memory
* @caddr: the source chip address (full pointer, not offset)
* @count: number of bytes to copy (multiple of 32 bits)
*
* This function also localizes all chip memory accesses.
* The copy should be written such that we read full cacheline packets
* from the chip. This is usually used for a single qword
*
* NOTE: This assumes the chip address is 64-bit aligned.
*/
static int ipath_read_umem64(struct ipath_devdata *dd, void __user *uaddr,
const void __iomem *caddr, size_t count)
{
const u64 __iomem *reg_addr = caddr;
const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
int ret;
/* not very efficient, but it works for now */
if (reg_addr < dd->ipath_kregbase ||
reg_end > dd->ipath_kregend) {
ret = -EINVAL;
goto bail;
}
while (reg_addr < reg_end) {
u64 data = readq(reg_addr);
if (copy_to_user(uaddr, &data, sizeof(u64))) {
ret = -EFAULT;
goto bail;
}
reg_addr++;
uaddr++;
}
ret = 0;
bail:
return ret;
}
/**
* ipath_write_umem64 - write a 64-bit quantity to the chip from user space
* @dd: the infinipath device
* @caddr: the destination chip address (full pointer, not offset)
* @uaddr: the source of the data in user memory
* @count: the number of bytes to copy (multiple of 32 bits)
*
* This is usually used for a single qword
* NOTE: This assumes the chip address is 64-bit aligned.
*/
static int ipath_write_umem64(struct ipath_devdata *dd, void __iomem *caddr,
const void __user *uaddr, size_t count)
{
u64 __iomem *reg_addr = caddr;
const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
int ret;
/* not very efficient, but it works for now */
if (reg_addr < dd->ipath_kregbase ||
reg_end > dd->ipath_kregend) {
ret = -EINVAL;
goto bail;
}
while (reg_addr < reg_end) {
u64 data;
if (copy_from_user(&data, uaddr, sizeof(data))) {
ret = -EFAULT;
goto bail;
}
writeq(data, reg_addr);
reg_addr++;
uaddr++;
}
ret = 0;
bail:
return ret;
}
/**
* ipath_read_umem32 - read a 32-bit quantity from the chip into user space
* @dd: the infinipath device
* @uaddr: the location to store the data in user memory
* @caddr: the source chip address (full pointer, not offset)
* @count: number of bytes to copy
*
* read 32 bit values, not 64 bit; for memories that only
* support 32 bit reads; usually a single dword.
*/
static int ipath_read_umem32(struct ipath_devdata *dd, void __user *uaddr,
const void __iomem *caddr, size_t count)
{
const u32 __iomem *reg_addr = caddr;
const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
int ret;
if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
reg_end > (u32 __iomem *) dd->ipath_kregend) {
ret = -EINVAL;
goto bail;
}
/* not very efficient, but it works for now */
while (reg_addr < reg_end) {
u32 data = readl(reg_addr);
if (copy_to_user(uaddr, &data, sizeof(data))) {
ret = -EFAULT;
goto bail;
}
reg_addr++;
uaddr++;
}
ret = 0;
bail:
return ret;
}
/**
* ipath_write_umem32 - write a 32-bit quantity to the chip from user space
* @dd: the infinipath device
* @caddr: the destination chip address (full pointer, not offset)
* @uaddr: the source of the data in user memory
* @count: number of bytes to copy
*
* write 32 bit values, not 64 bit; for memories that only
* support 32 bit write; usually a single dword.
*/
static int ipath_write_umem32(struct ipath_devdata *dd, void __iomem *caddr,
const void __user *uaddr, size_t count)
{
u32 __iomem *reg_addr = caddr;
const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
int ret;
if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
reg_end > (u32 __iomem *) dd->ipath_kregend) {
ret = -EINVAL;
goto bail;
}
while (reg_addr < reg_end) {
u32 data;
if (copy_from_user(&data, uaddr, sizeof(data))) {
ret = -EFAULT;
goto bail;
}
writel(data, reg_addr);
reg_addr++;
uaddr++;
}
ret = 0;
bail:
return ret;
}
static int ipath_diag_open(struct inode *in, struct file *fp)
{
struct ipath_devdata *dd;
int unit = 0; /* XXX this is bogus */
unsigned long flags;
int ret;
dd = ipath_lookup(unit);
mutex_lock(&ipath_mutex);
spin_lock_irqsave(&ipath_devs_lock, flags);
if (ipath_diag_inuse) {
ret = -EBUSY;
goto bail;
}
list_for_each_entry(dd, &ipath_dev_list, ipath_list) {
/*
* we need at least one infinipath device to be present
* (don't use INITTED, because we want to be able to open
* even if device is in freeze mode, which cleared INITTED).
* There is a small amount of risk to this, which is why we
* also verify kregbase is set.
*/
if (!(dd->ipath_flags & IPATH_PRESENT) ||
!dd->ipath_kregbase)
continue;
ipath_diag_inuse = 1;
diag_set_link = 0;
ret = 0;
goto bail;
}
ret = -ENODEV;
bail:
spin_unlock_irqrestore(&ipath_devs_lock, flags);
/* Only expose a way to reset the device if we
make it into diag mode. */
if (ret == 0)
ipath_expose_reset(&dd->pcidev->dev);
mutex_unlock(&ipath_mutex);
return ret;
}
static int ipath_diag_release(struct inode *i, struct file *f)
{
mutex_lock(&ipath_mutex);
ipath_diag_inuse = 0;
mutex_unlock(&ipath_mutex);
return 0;
}
static ssize_t ipath_diag_read(struct file *fp, char __user *data,
size_t count, loff_t *off)
{
int unit = 0; /* XXX provide for reads on other units some day */
struct ipath_devdata *dd;
void __iomem *kreg_base;
ssize_t ret;
dd = ipath_lookup(unit);
if (!dd) {
ret = -ENODEV;
goto bail;
}
kreg_base = dd->ipath_kregbase;
if (count == 0)
ret = 0;
else if ((count % 4) || (*off % 4))
/* address or length is not 32-bit aligned, hence invalid */
ret = -EINVAL;
else if ((count % 8) || (*off % 8))
/* address or length not 64-bit aligned; do 32-bit reads */
ret = ipath_read_umem32(dd, data, kreg_base + *off, count);
else
ret = ipath_read_umem64(dd, data, kreg_base + *off, count);
if (ret >= 0) {
*off += count;
ret = count;
}
bail:
return ret;
}
static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
size_t count, loff_t *off)
{
int unit = 0; /* XXX this is bogus */
struct ipath_devdata *dd;
void __iomem *kreg_base;
ssize_t ret;
dd = ipath_lookup(unit);
if (!dd) {
ret = -ENODEV;
goto bail;
}
kreg_base = dd->ipath_kregbase;
if (count == 0)
ret = 0;
else if ((count % 4) || (*off % 4))
/* address or length is not 32-bit aligned, hence invalid */
ret = -EINVAL;
else if ((count % 8) || (*off % 8))
/* address or length not 64-bit aligned; do 32-bit writes */
ret = ipath_write_umem32(dd, kreg_base + *off, data, count);
else
ret = ipath_write_umem64(dd, kreg_base + *off, data, count);
if (ret >= 0) {
*off += count;
ret = count;
}
bail:
return ret;
}