Revision 9c29bcd189f4ab1644b7125713602532d0aefdb7 authored by Eric Dumazet on 21 September 2018, 22:27:48 UTC, committed by David S. Miller on 24 September 2018, 04:55:25 UTC
As diagnosed by Song Liu, ndo_poll_controller() can be very dangerous on loaded hosts, since the cpu calling ndo_poll_controller() might steal all NAPI contexts (for all RX/TX queues of the NIC). This capture can last for unlimited amount of time, since one cpu is generally not able to drain all the queues under load. mlx5 uses NAPI for TX completions, so we better let core networking stack call the napi->poll() to avoid the capture. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent a24b66c
crc8.c
/*
* Copyright (c) 2011 Broadcom Corporation
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/crc8.h>
#include <linux/printk.h>
/**
* crc8_populate_msb - fill crc table for given polynomial in reverse bit order.
*
* @table: table to be filled.
* @polynomial: polynomial for which table is to be filled.
*/
void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial)
{
int i, j;
const u8 msbit = 0x80;
u8 t = msbit;
table[0] = 0;
for (i = 1; i < CRC8_TABLE_SIZE; i *= 2) {
t = (t << 1) ^ (t & msbit ? polynomial : 0);
for (j = 0; j < i; j++)
table[i+j] = table[j] ^ t;
}
}
EXPORT_SYMBOL(crc8_populate_msb);
/**
* crc8_populate_lsb - fill crc table for given polynomial in regular bit order.
*
* @table: table to be filled.
* @polynomial: polynomial for which table is to be filled.
*/
void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial)
{
int i, j;
u8 t = 1;
table[0] = 0;
for (i = (CRC8_TABLE_SIZE >> 1); i; i >>= 1) {
t = (t >> 1) ^ (t & 1 ? polynomial : 0);
for (j = 0; j < CRC8_TABLE_SIZE; j += 2*i)
table[i+j] = table[j] ^ t;
}
}
EXPORT_SYMBOL(crc8_populate_lsb);
/**
* crc8 - calculate a crc8 over the given input data.
*
* @table: crc table used for calculation.
* @pdata: pointer to data buffer.
* @nbytes: number of bytes in data buffer.
* @crc: previous returned crc8 value.
*/
u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc)
{
/* loop over the buffer data */
while (nbytes-- > 0)
crc = table[(crc ^ *pdata++) & 0xff];
return crc;
}
EXPORT_SYMBOL(crc8);
MODULE_DESCRIPTION("CRC8 (by Williams, Ross N.) function");
MODULE_AUTHOR("Broadcom Corporation");
MODULE_LICENSE("Dual BSD/GPL");
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