Revision 6e474083f3daf3a3546737f5d7d502ad12eb257c authored by Wei Xu on 01 December 2017, 10:10:36 UTC, committed by David S. Miller on 03 December 2017, 02:31:03 UTC
Matthew found a roughly 40% tcp throughput regression with commit c67df11f(vhost_net: try batch dequing from skb array) as discussed in the following thread: https://www.mail-archive.com/netdev@vger.kernel.org/msg187936.html Eventually we figured out that it was a skb leak in handle_rx() when sending packets to the VM. This usually happens when a guest can not drain out vq as fast as vhost fills in, afterwards it sets off the traffic jam and leaks skb(s) which occurs as no headcount to send on the vq from vhost side. This can be avoided by making sure we have got enough headcount before actually consuming a skb from the batched rx array while transmitting, which is simply done by moving checking the zero headcount a bit ahead. Signed-off-by: Wei Xu <wexu@redhat.com> Reported-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent fa935ca
i2c-amd8111.c
/*
* SMBus 2.0 driver for AMD-8111 IO-Hub.
*
* Copyright (c) 2002 Vojtech Pavlik
*
* 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 version 2.
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/io.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR ("Vojtech Pavlik <vojtech@suse.cz>");
MODULE_DESCRIPTION("AMD8111 SMBus 2.0 driver");
struct amd_smbus {
struct pci_dev *dev;
struct i2c_adapter adapter;
int base;
int size;
};
static struct pci_driver amd8111_driver;
/*
* AMD PCI control registers definitions.
*/
#define AMD_PCI_MISC 0x48
#define AMD_PCI_MISC_SCI 0x04 /* deliver SCI */
#define AMD_PCI_MISC_INT 0x02 /* deliver PCI IRQ */
#define AMD_PCI_MISC_SPEEDUP 0x01 /* 16x clock speedup */
/*
* ACPI 2.0 chapter 13 PCI interface definitions.
*/
#define AMD_EC_DATA 0x00 /* data register */
#define AMD_EC_SC 0x04 /* status of controller */
#define AMD_EC_CMD 0x04 /* command register */
#define AMD_EC_ICR 0x08 /* interrupt control register */
#define AMD_EC_SC_SMI 0x04 /* smi event pending */
#define AMD_EC_SC_SCI 0x02 /* sci event pending */
#define AMD_EC_SC_BURST 0x01 /* burst mode enabled */
#define AMD_EC_SC_CMD 0x08 /* byte in data reg is command */
#define AMD_EC_SC_IBF 0x02 /* data ready for embedded controller */
#define AMD_EC_SC_OBF 0x01 /* data ready for host */
#define AMD_EC_CMD_RD 0x80 /* read EC */
#define AMD_EC_CMD_WR 0x81 /* write EC */
#define AMD_EC_CMD_BE 0x82 /* enable burst mode */
#define AMD_EC_CMD_BD 0x83 /* disable burst mode */
#define AMD_EC_CMD_QR 0x84 /* query EC */
/*
* ACPI 2.0 chapter 13 access of registers of the EC
*/
static int amd_ec_wait_write(struct amd_smbus *smbus)
{
int timeout = 500;
while ((inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_IBF) && --timeout)
udelay(1);
if (!timeout) {
dev_warn(&smbus->dev->dev,
"Timeout while waiting for IBF to clear\n");
return -ETIMEDOUT;
}
return 0;
}
static int amd_ec_wait_read(struct amd_smbus *smbus)
{
int timeout = 500;
while ((~inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_OBF) && --timeout)
udelay(1);
if (!timeout) {
dev_warn(&smbus->dev->dev,
"Timeout while waiting for OBF to set\n");
return -ETIMEDOUT;
}
return 0;
}
static int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
unsigned char *data)
{
int status;
status = amd_ec_wait_write(smbus);
if (status)
return status;
outb(AMD_EC_CMD_RD, smbus->base + AMD_EC_CMD);
status = amd_ec_wait_write(smbus);
if (status)
return status;
outb(address, smbus->base + AMD_EC_DATA);
status = amd_ec_wait_read(smbus);
if (status)
return status;
*data = inb(smbus->base + AMD_EC_DATA);
return 0;
}
static int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
unsigned char data)
{
int status;
status = amd_ec_wait_write(smbus);
if (status)
return status;
outb(AMD_EC_CMD_WR, smbus->base + AMD_EC_CMD);
status = amd_ec_wait_write(smbus);
if (status)
return status;
outb(address, smbus->base + AMD_EC_DATA);
status = amd_ec_wait_write(smbus);
if (status)
return status;
outb(data, smbus->base + AMD_EC_DATA);
return 0;
}
/*
* ACPI 2.0 chapter 13 SMBus 2.0 EC register model
*/
#define AMD_SMB_PRTCL 0x00 /* protocol, PEC */
#define AMD_SMB_STS 0x01 /* status */
#define AMD_SMB_ADDR 0x02 /* address */
#define AMD_SMB_CMD 0x03 /* command */
#define AMD_SMB_DATA 0x04 /* 32 data registers */
#define AMD_SMB_BCNT 0x24 /* number of data bytes */
#define AMD_SMB_ALRM_A 0x25 /* alarm address */
#define AMD_SMB_ALRM_D 0x26 /* 2 bytes alarm data */
#define AMD_SMB_STS_DONE 0x80
#define AMD_SMB_STS_ALRM 0x40
#define AMD_SMB_STS_RES 0x20
#define AMD_SMB_STS_STATUS 0x1f
#define AMD_SMB_STATUS_OK 0x00
#define AMD_SMB_STATUS_FAIL 0x07
#define AMD_SMB_STATUS_DNAK 0x10
#define AMD_SMB_STATUS_DERR 0x11
#define AMD_SMB_STATUS_CMD_DENY 0x12
#define AMD_SMB_STATUS_UNKNOWN 0x13
#define AMD_SMB_STATUS_ACC_DENY 0x17
#define AMD_SMB_STATUS_TIMEOUT 0x18
#define AMD_SMB_STATUS_NOTSUP 0x19
#define AMD_SMB_STATUS_BUSY 0x1A
#define AMD_SMB_STATUS_PEC 0x1F
#define AMD_SMB_PRTCL_WRITE 0x00
#define AMD_SMB_PRTCL_READ 0x01
#define AMD_SMB_PRTCL_QUICK 0x02
#define AMD_SMB_PRTCL_BYTE 0x04
#define AMD_SMB_PRTCL_BYTE_DATA 0x06
#define AMD_SMB_PRTCL_WORD_DATA 0x08
#define AMD_SMB_PRTCL_BLOCK_DATA 0x0a
#define AMD_SMB_PRTCL_PROC_CALL 0x0c
#define AMD_SMB_PRTCL_BLOCK_PROC_CALL 0x0d
#define AMD_SMB_PRTCL_I2C_BLOCK_DATA 0x4a
#define AMD_SMB_PRTCL_PEC 0x80
static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
unsigned short flags, char read_write, u8 command, int size,
union i2c_smbus_data * data)
{
struct amd_smbus *smbus = adap->algo_data;
unsigned char protocol, len, pec, temp[2];
int i, status;
protocol = (read_write == I2C_SMBUS_READ) ? AMD_SMB_PRTCL_READ
: AMD_SMB_PRTCL_WRITE;
pec = (flags & I2C_CLIENT_PEC) ? AMD_SMB_PRTCL_PEC : 0;
switch (size) {
case I2C_SMBUS_QUICK:
protocol |= AMD_SMB_PRTCL_QUICK;
read_write = I2C_SMBUS_WRITE;
break;
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_WRITE) {
status = amd_ec_write(smbus, AMD_SMB_CMD,
command);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE) {
status = amd_ec_write(smbus, AMD_SMB_DATA,
data->byte);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_BYTE_DATA;
break;
case I2C_SMBUS_WORD_DATA:
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE) {
status = amd_ec_write(smbus, AMD_SMB_DATA,
data->word & 0xff);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
data->word >> 8);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
break;
case I2C_SMBUS_BLOCK_DATA:
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE) {
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX);
status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
if (status)
return status;
for (i = 0; i < len; i++) {
status =
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
if (status)
return status;
}
}
protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE)
for (i = 0; i < len; i++) {
status =
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
break;
case I2C_SMBUS_PROC_CALL:
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_DATA,
data->word & 0xff);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
data->word >> 8);
if (status)
return status;
protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
read_write = I2C_SMBUS_READ;
break;
case I2C_SMBUS_BLOCK_PROC_CALL:
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX - 1);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
if (status)
return status;
for (i = 0; i < len; i++) {
status = amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
if (status)
return status;
}
protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
read_write = I2C_SMBUS_READ;
break;
default:
dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
return -EOPNOTSUPP;
}
status = amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
if (status)
return status;
status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
if (status)
return status;
if (~temp[0] & AMD_SMB_STS_DONE) {
udelay(500);
status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
if (status)
return status;
}
if (~temp[0] & AMD_SMB_STS_DONE) {
msleep(1);
status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
if (status)
return status;
}
if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
return -EIO;
if (read_write == I2C_SMBUS_WRITE)
return 0;
switch (size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
status = amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
if (status)
return status;
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
status = amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
if (status)
return status;
status = amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
if (status)
return status;
data->word = (temp[1] << 8) | temp[0];
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
status = amd_ec_read(smbus, AMD_SMB_BCNT, &len);
if (status)
return status;
len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
case I2C_SMBUS_I2C_BLOCK_DATA:
for (i = 0; i < len; i++) {
status = amd_ec_read(smbus, AMD_SMB_DATA + i,
data->block + i + 1);
if (status)
return status;
}
data->block[0] = len;
break;
}
return 0;
}
static u32 amd8111_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA |
I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_PEC;
}
static const struct i2c_algorithm smbus_algorithm = {
.smbus_xfer = amd8111_access,
.functionality = amd8111_func,
};
static const struct pci_device_id amd8111_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS2) },
{ 0, }
};
MODULE_DEVICE_TABLE (pci, amd8111_ids);
static int amd8111_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
struct amd_smbus *smbus;
int error;
if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
return -ENODEV;
smbus = kzalloc(sizeof(struct amd_smbus), GFP_KERNEL);
if (!smbus)
return -ENOMEM;
smbus->dev = dev;
smbus->base = pci_resource_start(dev, 0);
smbus->size = pci_resource_len(dev, 0);
error = acpi_check_resource_conflict(&dev->resource[0]);
if (error) {
error = -ENODEV;
goto out_kfree;
}
if (!request_region(smbus->base, smbus->size, amd8111_driver.name)) {
error = -EBUSY;
goto out_kfree;
}
smbus->adapter.owner = THIS_MODULE;
snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
"SMBus2 AMD8111 adapter at %04x", smbus->base);
smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
smbus->adapter.algo = &smbus_algorithm;
smbus->adapter.algo_data = smbus;
/* set up the sysfs linkage to our parent device */
smbus->adapter.dev.parent = &dev->dev;
pci_write_config_dword(smbus->dev, AMD_PCI_MISC, 0);
error = i2c_add_adapter(&smbus->adapter);
if (error)
goto out_release_region;
pci_set_drvdata(dev, smbus);
return 0;
out_release_region:
release_region(smbus->base, smbus->size);
out_kfree:
kfree(smbus);
return error;
}
static void amd8111_remove(struct pci_dev *dev)
{
struct amd_smbus *smbus = pci_get_drvdata(dev);
i2c_del_adapter(&smbus->adapter);
release_region(smbus->base, smbus->size);
kfree(smbus);
}
static struct pci_driver amd8111_driver = {
.name = "amd8111_smbus2",
.id_table = amd8111_ids,
.probe = amd8111_probe,
.remove = amd8111_remove,
};
module_pci_driver(amd8111_driver);
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