linux_dsm_epyc7002/drivers/net/ethernet/mellanox/mlx4/cq.c
Eric Dumazet 01f0f42534 mlx4: do not fire tasklet unless necessary
All rx and rx netdev interrupts are handled by respectively
by mlx4_en_rx_irq() and mlx4_en_tx_irq() which simply schedule a NAPI.

But mlx4_eq_int() also fires a tasklet to service all items that were
queued via mlx4_add_cq_to_tasklet(), but this handler was not called
unless user cqe was handled.

This is very confusing, as "mpstat -I SCPU ..." show huge number of
tasklet invocations.

This patch saves this overhead, by carefully firing the tasklet directly
from mlx4_add_cq_to_tasklet(), removing four atomic operations per IRQ.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-17 10:55:22 -05:00

421 lines
12 KiB
C

/*
* Copyright (c) 2004, 2005 Topspin Communications. All rights reserved.
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
* Copyright (c) 2005, 2006, 2007 Cisco Systems, Inc. All rights reserved.
* Copyright (c) 2005, 2006, 2007, 2008 Mellanox Technologies. All rights reserved.
* Copyright (c) 2004 Voltaire, 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.
*/
#include <linux/hardirq.h>
#include <linux/export.h>
#include <linux/mlx4/cmd.h>
#include <linux/mlx4/cq.h>
#include "mlx4.h"
#include "icm.h"
#define MLX4_CQ_STATUS_OK ( 0 << 28)
#define MLX4_CQ_STATUS_OVERFLOW ( 9 << 28)
#define MLX4_CQ_STATUS_WRITE_FAIL (10 << 28)
#define MLX4_CQ_FLAG_CC ( 1 << 18)
#define MLX4_CQ_FLAG_OI ( 1 << 17)
#define MLX4_CQ_STATE_ARMED ( 9 << 8)
#define MLX4_CQ_STATE_ARMED_SOL ( 6 << 8)
#define MLX4_EQ_STATE_FIRED (10 << 8)
#define TASKLET_MAX_TIME 2
#define TASKLET_MAX_TIME_JIFFIES msecs_to_jiffies(TASKLET_MAX_TIME)
void mlx4_cq_tasklet_cb(unsigned long data)
{
unsigned long flags;
unsigned long end = jiffies + TASKLET_MAX_TIME_JIFFIES;
struct mlx4_eq_tasklet *ctx = (struct mlx4_eq_tasklet *)data;
struct mlx4_cq *mcq, *temp;
spin_lock_irqsave(&ctx->lock, flags);
list_splice_tail_init(&ctx->list, &ctx->process_list);
spin_unlock_irqrestore(&ctx->lock, flags);
list_for_each_entry_safe(mcq, temp, &ctx->process_list, tasklet_ctx.list) {
list_del_init(&mcq->tasklet_ctx.list);
mcq->tasklet_ctx.comp(mcq);
if (atomic_dec_and_test(&mcq->refcount))
complete(&mcq->free);
if (time_after(jiffies, end))
break;
}
if (!list_empty(&ctx->process_list))
tasklet_schedule(&ctx->task);
}
static void mlx4_add_cq_to_tasklet(struct mlx4_cq *cq)
{
struct mlx4_eq_tasklet *tasklet_ctx = cq->tasklet_ctx.priv;
unsigned long flags;
bool kick;
spin_lock_irqsave(&tasklet_ctx->lock, flags);
/* When migrating CQs between EQs will be implemented, please note
* that you need to sync this point. It is possible that
* while migrating a CQ, completions on the old EQs could
* still arrive.
*/
if (list_empty_careful(&cq->tasklet_ctx.list)) {
atomic_inc(&cq->refcount);
kick = list_empty(&tasklet_ctx->list);
list_add_tail(&cq->tasklet_ctx.list, &tasklet_ctx->list);
if (kick)
tasklet_schedule(&tasklet_ctx->task);
}
spin_unlock_irqrestore(&tasklet_ctx->lock, flags);
}
void mlx4_cq_completion(struct mlx4_dev *dev, u32 cqn)
{
struct mlx4_cq *cq;
rcu_read_lock();
cq = radix_tree_lookup(&mlx4_priv(dev)->cq_table.tree,
cqn & (dev->caps.num_cqs - 1));
rcu_read_unlock();
if (!cq) {
mlx4_dbg(dev, "Completion event for bogus CQ %08x\n", cqn);
return;
}
/* Acessing the CQ outside of rcu_read_lock is safe, because
* the CQ is freed only after interrupt handling is completed.
*/
++cq->arm_sn;
cq->comp(cq);
}
void mlx4_cq_event(struct mlx4_dev *dev, u32 cqn, int event_type)
{
struct mlx4_cq_table *cq_table = &mlx4_priv(dev)->cq_table;
struct mlx4_cq *cq;
rcu_read_lock();
cq = radix_tree_lookup(&cq_table->tree, cqn & (dev->caps.num_cqs - 1));
rcu_read_unlock();
if (!cq) {
mlx4_dbg(dev, "Async event for bogus CQ %08x\n", cqn);
return;
}
/* Acessing the CQ outside of rcu_read_lock is safe, because
* the CQ is freed only after interrupt handling is completed.
*/
cq->event(cq, event_type);
}
static int mlx4_SW2HW_CQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
int cq_num)
{
return mlx4_cmd(dev, mailbox->dma, cq_num, 0,
MLX4_CMD_SW2HW_CQ, MLX4_CMD_TIME_CLASS_A,
MLX4_CMD_WRAPPED);
}
static int mlx4_MODIFY_CQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
int cq_num, u32 opmod)
{
return mlx4_cmd(dev, mailbox->dma, cq_num, opmod, MLX4_CMD_MODIFY_CQ,
MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
}
static int mlx4_HW2SW_CQ(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox,
int cq_num)
{
return mlx4_cmd_box(dev, 0, mailbox ? mailbox->dma : 0,
cq_num, mailbox ? 0 : 1, MLX4_CMD_HW2SW_CQ,
MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
}
int mlx4_cq_modify(struct mlx4_dev *dev, struct mlx4_cq *cq,
u16 count, u16 period)
{
struct mlx4_cmd_mailbox *mailbox;
struct mlx4_cq_context *cq_context;
int err;
mailbox = mlx4_alloc_cmd_mailbox(dev);
if (IS_ERR(mailbox))
return PTR_ERR(mailbox);
cq_context = mailbox->buf;
cq_context->cq_max_count = cpu_to_be16(count);
cq_context->cq_period = cpu_to_be16(period);
err = mlx4_MODIFY_CQ(dev, mailbox, cq->cqn, 1);
mlx4_free_cmd_mailbox(dev, mailbox);
return err;
}
EXPORT_SYMBOL_GPL(mlx4_cq_modify);
int mlx4_cq_resize(struct mlx4_dev *dev, struct mlx4_cq *cq,
int entries, struct mlx4_mtt *mtt)
{
struct mlx4_cmd_mailbox *mailbox;
struct mlx4_cq_context *cq_context;
u64 mtt_addr;
int err;
mailbox = mlx4_alloc_cmd_mailbox(dev);
if (IS_ERR(mailbox))
return PTR_ERR(mailbox);
cq_context = mailbox->buf;
cq_context->logsize_usrpage = cpu_to_be32(ilog2(entries) << 24);
cq_context->log_page_size = mtt->page_shift - 12;
mtt_addr = mlx4_mtt_addr(dev, mtt);
cq_context->mtt_base_addr_h = mtt_addr >> 32;
cq_context->mtt_base_addr_l = cpu_to_be32(mtt_addr & 0xffffffff);
err = mlx4_MODIFY_CQ(dev, mailbox, cq->cqn, 0);
mlx4_free_cmd_mailbox(dev, mailbox);
return err;
}
EXPORT_SYMBOL_GPL(mlx4_cq_resize);
int __mlx4_cq_alloc_icm(struct mlx4_dev *dev, int *cqn)
{
struct mlx4_priv *priv = mlx4_priv(dev);
struct mlx4_cq_table *cq_table = &priv->cq_table;
int err;
*cqn = mlx4_bitmap_alloc(&cq_table->bitmap);
if (*cqn == -1)
return -ENOMEM;
err = mlx4_table_get(dev, &cq_table->table, *cqn, GFP_KERNEL);
if (err)
goto err_out;
err = mlx4_table_get(dev, &cq_table->cmpt_table, *cqn, GFP_KERNEL);
if (err)
goto err_put;
return 0;
err_put:
mlx4_table_put(dev, &cq_table->table, *cqn);
err_out:
mlx4_bitmap_free(&cq_table->bitmap, *cqn, MLX4_NO_RR);
return err;
}
static int mlx4_cq_alloc_icm(struct mlx4_dev *dev, int *cqn)
{
u64 out_param;
int err;
if (mlx4_is_mfunc(dev)) {
err = mlx4_cmd_imm(dev, 0, &out_param, RES_CQ,
RES_OP_RESERVE_AND_MAP, MLX4_CMD_ALLOC_RES,
MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
if (err)
return err;
else {
*cqn = get_param_l(&out_param);
return 0;
}
}
return __mlx4_cq_alloc_icm(dev, cqn);
}
void __mlx4_cq_free_icm(struct mlx4_dev *dev, int cqn)
{
struct mlx4_priv *priv = mlx4_priv(dev);
struct mlx4_cq_table *cq_table = &priv->cq_table;
mlx4_table_put(dev, &cq_table->cmpt_table, cqn);
mlx4_table_put(dev, &cq_table->table, cqn);
mlx4_bitmap_free(&cq_table->bitmap, cqn, MLX4_NO_RR);
}
static void mlx4_cq_free_icm(struct mlx4_dev *dev, int cqn)
{
u64 in_param = 0;
int err;
if (mlx4_is_mfunc(dev)) {
set_param_l(&in_param, cqn);
err = mlx4_cmd(dev, in_param, RES_CQ, RES_OP_RESERVE_AND_MAP,
MLX4_CMD_FREE_RES,
MLX4_CMD_TIME_CLASS_A, MLX4_CMD_WRAPPED);
if (err)
mlx4_warn(dev, "Failed freeing cq:%d\n", cqn);
} else
__mlx4_cq_free_icm(dev, cqn);
}
int mlx4_cq_alloc(struct mlx4_dev *dev, int nent,
struct mlx4_mtt *mtt, struct mlx4_uar *uar, u64 db_rec,
struct mlx4_cq *cq, unsigned vector, int collapsed,
int timestamp_en)
{
struct mlx4_priv *priv = mlx4_priv(dev);
struct mlx4_cq_table *cq_table = &priv->cq_table;
struct mlx4_cmd_mailbox *mailbox;
struct mlx4_cq_context *cq_context;
u64 mtt_addr;
int err;
if (vector >= dev->caps.num_comp_vectors)
return -EINVAL;
cq->vector = vector;
err = mlx4_cq_alloc_icm(dev, &cq->cqn);
if (err)
return err;
spin_lock(&cq_table->lock);
err = radix_tree_insert(&cq_table->tree, cq->cqn, cq);
spin_unlock(&cq_table->lock);
if (err)
goto err_icm;
mailbox = mlx4_alloc_cmd_mailbox(dev);
if (IS_ERR(mailbox)) {
err = PTR_ERR(mailbox);
goto err_radix;
}
cq_context = mailbox->buf;
cq_context->flags = cpu_to_be32(!!collapsed << 18);
if (timestamp_en)
cq_context->flags |= cpu_to_be32(1 << 19);
cq_context->logsize_usrpage =
cpu_to_be32((ilog2(nent) << 24) |
mlx4_to_hw_uar_index(dev, uar->index));
cq_context->comp_eqn = priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].eqn;
cq_context->log_page_size = mtt->page_shift - MLX4_ICM_PAGE_SHIFT;
mtt_addr = mlx4_mtt_addr(dev, mtt);
cq_context->mtt_base_addr_h = mtt_addr >> 32;
cq_context->mtt_base_addr_l = cpu_to_be32(mtt_addr & 0xffffffff);
cq_context->db_rec_addr = cpu_to_be64(db_rec);
err = mlx4_SW2HW_CQ(dev, mailbox, cq->cqn);
mlx4_free_cmd_mailbox(dev, mailbox);
if (err)
goto err_radix;
cq->cons_index = 0;
cq->arm_sn = 1;
cq->uar = uar;
atomic_set(&cq->refcount, 1);
init_completion(&cq->free);
cq->comp = mlx4_add_cq_to_tasklet;
cq->tasklet_ctx.priv =
&priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].tasklet_ctx;
INIT_LIST_HEAD(&cq->tasklet_ctx.list);
cq->irq = priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(vector)].irq;
return 0;
err_radix:
spin_lock(&cq_table->lock);
radix_tree_delete(&cq_table->tree, cq->cqn);
spin_unlock(&cq_table->lock);
err_icm:
mlx4_cq_free_icm(dev, cq->cqn);
return err;
}
EXPORT_SYMBOL_GPL(mlx4_cq_alloc);
void mlx4_cq_free(struct mlx4_dev *dev, struct mlx4_cq *cq)
{
struct mlx4_priv *priv = mlx4_priv(dev);
struct mlx4_cq_table *cq_table = &priv->cq_table;
int err;
err = mlx4_HW2SW_CQ(dev, NULL, cq->cqn);
if (err)
mlx4_warn(dev, "HW2SW_CQ failed (%d) for CQN %06x\n", err, cq->cqn);
spin_lock(&cq_table->lock);
radix_tree_delete(&cq_table->tree, cq->cqn);
spin_unlock(&cq_table->lock);
synchronize_irq(priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(cq->vector)].irq);
if (priv->eq_table.eq[MLX4_CQ_TO_EQ_VECTOR(cq->vector)].irq !=
priv->eq_table.eq[MLX4_EQ_ASYNC].irq)
synchronize_irq(priv->eq_table.eq[MLX4_EQ_ASYNC].irq);
if (atomic_dec_and_test(&cq->refcount))
complete(&cq->free);
wait_for_completion(&cq->free);
mlx4_cq_free_icm(dev, cq->cqn);
}
EXPORT_SYMBOL_GPL(mlx4_cq_free);
int mlx4_init_cq_table(struct mlx4_dev *dev)
{
struct mlx4_cq_table *cq_table = &mlx4_priv(dev)->cq_table;
int err;
spin_lock_init(&cq_table->lock);
INIT_RADIX_TREE(&cq_table->tree, GFP_ATOMIC);
if (mlx4_is_slave(dev))
return 0;
err = mlx4_bitmap_init(&cq_table->bitmap, dev->caps.num_cqs,
dev->caps.num_cqs - 1, dev->caps.reserved_cqs, 0);
if (err)
return err;
return 0;
}
void mlx4_cleanup_cq_table(struct mlx4_dev *dev)
{
if (mlx4_is_slave(dev))
return;
/* Nothing to do to clean up radix_tree */
mlx4_bitmap_cleanup(&mlx4_priv(dev)->cq_table.bitmap);
}