cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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catas.c (8995B)


      1/*
      2 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
      3 * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
      4 *
      5 * This software is available to you under a choice of one of two
      6 * licenses.  You may choose to be licensed under the terms of the GNU
      7 * General Public License (GPL) Version 2, available from the file
      8 * COPYING in the main directory of this source tree, or the
      9 * OpenIB.org BSD license below:
     10 *
     11 *     Redistribution and use in source and binary forms, with or
     12 *     without modification, are permitted provided that the following
     13 *     conditions are met:
     14 *
     15 *      - Redistributions of source code must retain the above
     16 *        copyright notice, this list of conditions and the following
     17 *        disclaimer.
     18 *
     19 *      - Redistributions in binary form must reproduce the above
     20 *        copyright notice, this list of conditions and the following
     21 *        disclaimer in the documentation and/or other materials
     22 *        provided with the distribution.
     23 *
     24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
     28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
     29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     31 * SOFTWARE.
     32 */
     33
     34#include <linux/workqueue.h>
     35#include <linux/module.h>
     36
     37#include "mlx4.h"
     38
     39enum {
     40	MLX4_CATAS_POLL_INTERVAL	= 5 * HZ,
     41};
     42
     43
     44
     45int mlx4_internal_err_reset = 1;
     46module_param_named(internal_err_reset, mlx4_internal_err_reset,  int, 0644);
     47MODULE_PARM_DESC(internal_err_reset,
     48		 "Reset device on internal errors if non-zero (default 1)");
     49
     50static int read_vendor_id(struct mlx4_dev *dev)
     51{
     52	u16 vendor_id = 0;
     53	int ret;
     54
     55	ret = pci_read_config_word(dev->persist->pdev, 0, &vendor_id);
     56	if (ret) {
     57		mlx4_err(dev, "Failed to read vendor ID, ret=%d\n", ret);
     58		return ret;
     59	}
     60
     61	if (vendor_id == 0xffff) {
     62		mlx4_err(dev, "PCI can't be accessed to read vendor id\n");
     63		return -EINVAL;
     64	}
     65
     66	return 0;
     67}
     68
     69static int mlx4_reset_master(struct mlx4_dev *dev)
     70{
     71	int err = 0;
     72
     73	if (mlx4_is_master(dev))
     74		mlx4_report_internal_err_comm_event(dev);
     75
     76	if (!pci_channel_offline(dev->persist->pdev)) {
     77		err = read_vendor_id(dev);
     78		/* If PCI can't be accessed to read vendor ID we assume that its
     79		 * link was disabled and chip was already reset.
     80		 */
     81		if (err)
     82			return 0;
     83
     84		err = mlx4_reset(dev);
     85		if (err)
     86			mlx4_err(dev, "Fail to reset HCA\n");
     87	}
     88
     89	return err;
     90}
     91
     92static int mlx4_reset_slave(struct mlx4_dev *dev)
     93{
     94#define COM_CHAN_RST_REQ_OFFSET 0x10
     95#define COM_CHAN_RST_ACK_OFFSET 0x08
     96
     97	u32 comm_flags;
     98	u32 rst_req;
     99	u32 rst_ack;
    100	unsigned long end;
    101	struct mlx4_priv *priv = mlx4_priv(dev);
    102
    103	if (pci_channel_offline(dev->persist->pdev))
    104		return 0;
    105
    106	comm_flags = swab32(readl((__iomem char *)priv->mfunc.comm +
    107				  MLX4_COMM_CHAN_FLAGS));
    108	if (comm_flags == 0xffffffff) {
    109		mlx4_err(dev, "VF reset is not needed\n");
    110		return 0;
    111	}
    112
    113	if (!(dev->caps.vf_caps & MLX4_VF_CAP_FLAG_RESET)) {
    114		mlx4_err(dev, "VF reset is not supported\n");
    115		return -EOPNOTSUPP;
    116	}
    117
    118	rst_req = (comm_flags & (u32)(1 << COM_CHAN_RST_REQ_OFFSET)) >>
    119		COM_CHAN_RST_REQ_OFFSET;
    120	rst_ack = (comm_flags & (u32)(1 << COM_CHAN_RST_ACK_OFFSET)) >>
    121		COM_CHAN_RST_ACK_OFFSET;
    122	if (rst_req != rst_ack) {
    123		mlx4_err(dev, "Communication channel isn't sync, fail to send reset\n");
    124		return -EIO;
    125	}
    126
    127	rst_req ^= 1;
    128	mlx4_warn(dev, "VF is sending reset request to Firmware\n");
    129	comm_flags = rst_req << COM_CHAN_RST_REQ_OFFSET;
    130	__raw_writel((__force u32)cpu_to_be32(comm_flags),
    131		     (__iomem char *)priv->mfunc.comm + MLX4_COMM_CHAN_FLAGS);
    132
    133	end = msecs_to_jiffies(MLX4_COMM_TIME) + jiffies;
    134	while (time_before(jiffies, end)) {
    135		comm_flags = swab32(readl((__iomem char *)priv->mfunc.comm +
    136					  MLX4_COMM_CHAN_FLAGS));
    137		rst_ack = (comm_flags & (u32)(1 << COM_CHAN_RST_ACK_OFFSET)) >>
    138			COM_CHAN_RST_ACK_OFFSET;
    139
    140		/* Reading rst_req again since the communication channel can
    141		 * be reset at any time by the PF and all its bits will be
    142		 * set to zero.
    143		 */
    144		rst_req = (comm_flags & (u32)(1 << COM_CHAN_RST_REQ_OFFSET)) >>
    145			COM_CHAN_RST_REQ_OFFSET;
    146
    147		if (rst_ack == rst_req) {
    148			mlx4_warn(dev, "VF Reset succeed\n");
    149			return 0;
    150		}
    151		cond_resched();
    152	}
    153	mlx4_err(dev, "Fail to send reset over the communication channel\n");
    154	return -ETIMEDOUT;
    155}
    156
    157int mlx4_comm_internal_err(u32 slave_read)
    158{
    159	return (u32)COMM_CHAN_EVENT_INTERNAL_ERR ==
    160		(slave_read & (u32)COMM_CHAN_EVENT_INTERNAL_ERR) ? 1 : 0;
    161}
    162
    163void mlx4_enter_error_state(struct mlx4_dev_persistent *persist)
    164{
    165	int err;
    166	struct mlx4_dev *dev;
    167
    168	if (!mlx4_internal_err_reset)
    169		return;
    170
    171	mutex_lock(&persist->device_state_mutex);
    172	if (persist->state & MLX4_DEVICE_STATE_INTERNAL_ERROR)
    173		goto out;
    174
    175	dev = persist->dev;
    176	mlx4_err(dev, "device is going to be reset\n");
    177	if (mlx4_is_slave(dev)) {
    178		err = mlx4_reset_slave(dev);
    179	} else {
    180		mlx4_crdump_collect(dev);
    181		err = mlx4_reset_master(dev);
    182	}
    183
    184	if (!err) {
    185		mlx4_err(dev, "device was reset successfully\n");
    186	} else {
    187		/* EEH could have disabled the PCI channel during reset. That's
    188		 * recoverable and the PCI error flow will handle it.
    189		 */
    190		if (!pci_channel_offline(dev->persist->pdev))
    191			BUG_ON(1);
    192	}
    193	dev->persist->state |= MLX4_DEVICE_STATE_INTERNAL_ERROR;
    194	mutex_unlock(&persist->device_state_mutex);
    195
    196	/* At that step HW was already reset, now notify clients */
    197	mlx4_dispatch_event(dev, MLX4_DEV_EVENT_CATASTROPHIC_ERROR, 0);
    198	mlx4_cmd_wake_completions(dev);
    199	return;
    200
    201out:
    202	mutex_unlock(&persist->device_state_mutex);
    203}
    204
    205static void mlx4_handle_error_state(struct mlx4_dev_persistent *persist)
    206{
    207	int err = 0;
    208
    209	mlx4_enter_error_state(persist);
    210	mutex_lock(&persist->interface_state_mutex);
    211	if (persist->interface_state & MLX4_INTERFACE_STATE_UP &&
    212	    !(persist->interface_state & MLX4_INTERFACE_STATE_DELETION)) {
    213		err = mlx4_restart_one(persist->pdev);
    214		mlx4_info(persist->dev, "mlx4_restart_one was ended, ret=%d\n",
    215			  err);
    216	}
    217	mutex_unlock(&persist->interface_state_mutex);
    218}
    219
    220static void dump_err_buf(struct mlx4_dev *dev)
    221{
    222	struct mlx4_priv *priv = mlx4_priv(dev);
    223
    224	int i;
    225
    226	mlx4_err(dev, "Internal error detected:\n");
    227	for (i = 0; i < priv->fw.catas_size; ++i)
    228		mlx4_err(dev, "  buf[%02x]: %08x\n",
    229			 i, swab32(readl(priv->catas_err.map + i)));
    230}
    231
    232static void poll_catas(struct timer_list *t)
    233{
    234	struct mlx4_priv *priv = from_timer(priv, t, catas_err.timer);
    235	struct mlx4_dev *dev = &priv->dev;
    236	u32 slave_read;
    237
    238	if (mlx4_is_slave(dev)) {
    239		slave_read = swab32(readl(&priv->mfunc.comm->slave_read));
    240		if (mlx4_comm_internal_err(slave_read)) {
    241			mlx4_warn(dev, "Internal error detected on the communication channel\n");
    242			goto internal_err;
    243		}
    244	} else if (readl(priv->catas_err.map)) {
    245		dump_err_buf(dev);
    246		goto internal_err;
    247	}
    248
    249	if (dev->persist->state & MLX4_DEVICE_STATE_INTERNAL_ERROR) {
    250		mlx4_warn(dev, "Internal error mark was detected on device\n");
    251		goto internal_err;
    252	}
    253
    254	mod_timer(&priv->catas_err.timer,
    255		  round_jiffies(jiffies + MLX4_CATAS_POLL_INTERVAL));
    256	return;
    257
    258internal_err:
    259	if (mlx4_internal_err_reset)
    260		queue_work(dev->persist->catas_wq, &dev->persist->catas_work);
    261}
    262
    263static void catas_reset(struct work_struct *work)
    264{
    265	struct mlx4_dev_persistent *persist =
    266		container_of(work, struct mlx4_dev_persistent,
    267			     catas_work);
    268
    269	mlx4_handle_error_state(persist);
    270}
    271
    272void mlx4_start_catas_poll(struct mlx4_dev *dev)
    273{
    274	struct mlx4_priv *priv = mlx4_priv(dev);
    275	phys_addr_t addr;
    276
    277	INIT_LIST_HEAD(&priv->catas_err.list);
    278	timer_setup(&priv->catas_err.timer, poll_catas, 0);
    279	priv->catas_err.map = NULL;
    280
    281	if (!mlx4_is_slave(dev)) {
    282		addr = pci_resource_start(dev->persist->pdev,
    283					  priv->fw.catas_bar) +
    284					  priv->fw.catas_offset;
    285
    286		priv->catas_err.map = ioremap(addr, priv->fw.catas_size * 4);
    287		if (!priv->catas_err.map) {
    288			mlx4_warn(dev, "Failed to map internal error buffer at 0x%llx\n",
    289				  (unsigned long long)addr);
    290			return;
    291		}
    292	}
    293
    294	priv->catas_err.timer.expires  =
    295		round_jiffies(jiffies + MLX4_CATAS_POLL_INTERVAL);
    296	add_timer(&priv->catas_err.timer);
    297}
    298
    299void mlx4_stop_catas_poll(struct mlx4_dev *dev)
    300{
    301	struct mlx4_priv *priv = mlx4_priv(dev);
    302
    303	del_timer_sync(&priv->catas_err.timer);
    304
    305	if (priv->catas_err.map) {
    306		iounmap(priv->catas_err.map);
    307		priv->catas_err.map = NULL;
    308	}
    309
    310	if (dev->persist->interface_state & MLX4_INTERFACE_STATE_DELETION)
    311		flush_workqueue(dev->persist->catas_wq);
    312}
    313
    314int  mlx4_catas_init(struct mlx4_dev *dev)
    315{
    316	INIT_WORK(&dev->persist->catas_work, catas_reset);
    317	dev->persist->catas_wq = create_singlethread_workqueue("mlx4_health");
    318	if (!dev->persist->catas_wq)
    319		return -ENOMEM;
    320
    321	return 0;
    322}
    323
    324void mlx4_catas_end(struct mlx4_dev *dev)
    325{
    326	if (dev->persist->catas_wq) {
    327		destroy_workqueue(dev->persist->catas_wq);
    328		dev->persist->catas_wq = NULL;
    329	}
    330}