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linux-next/drivers/dma/ioat/dma.h
Dan Williams da87ca4d4c ioat: fix tasklet tear down
Since commit 7787380336 "net_dma: mark broken" we no longer pin dma
engines active for the network-receive-offload use case.  As a result
the ->free_chan_resources() that occurs after the driver self test no
longer has a NET_DMA induced ->alloc_chan_resources() to back it up.  A
late firing irq can lead to ksoftirqd spinning indefinitely due to the
tasklet_disable() performed by ->free_chan_resources().  Only
->alloc_chan_resources() can clear this condition in affected kernels.

This problem has been present since commit 3e037454bc "I/OAT: Add
support for MSI and MSI-X" in 2.6.24, but is now exposed. Given the
NET_DMA use case is deprecated we can revisit moving the driver to use
threaded irqs.  For now, just tear down the irq and tasklet properly by:

1/ Disable the irq from triggering the tasklet

2/ Disable the irq from re-arming

3/ Flush inflight interrupts

4/ Flush the timer

5/ Flush inflight tasklets

References:
https://lkml.org/lkml/2014/1/27/282
https://lkml.org/lkml/2014/2/19/672

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Reported-by: Mike Galbraith <bitbucket@online.de>
Reported-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Tested-by: Mike Galbraith <bitbucket@online.de>
Tested-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-02-25 09:44:20 -08:00

364 lines
10 KiB
C

/*
* Copyright(c) 2004 - 2009 Intel Corporation. All rights reserved.
*
* 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; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The full GNU General Public License is included in this distribution in the
* file called COPYING.
*/
#ifndef IOATDMA_H
#define IOATDMA_H
#include <linux/dmaengine.h>
#include "hw.h"
#include "registers.h"
#include <linux/init.h>
#include <linux/dmapool.h>
#include <linux/cache.h>
#include <linux/pci_ids.h>
#include <net/tcp.h>
#define IOAT_DMA_VERSION "4.00"
#define IOAT_LOW_COMPLETION_MASK 0xffffffc0
#define IOAT_DMA_DCA_ANY_CPU ~0
#define to_ioatdma_device(dev) container_of(dev, struct ioatdma_device, common)
#define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node)
#define tx_to_ioat_desc(tx) container_of(tx, struct ioat_desc_sw, txd)
#define to_dev(ioat_chan) (&(ioat_chan)->device->pdev->dev)
#define to_pdev(ioat_chan) ((ioat_chan)->device->pdev)
#define chan_num(ch) ((int)((ch)->reg_base - (ch)->device->reg_base) / 0x80)
/*
* workaround for IOAT ver.3.0 null descriptor issue
* (channel returns error when size is 0)
*/
#define NULL_DESC_BUFFER_SIZE 1
enum ioat_irq_mode {
IOAT_NOIRQ = 0,
IOAT_MSIX,
IOAT_MSI,
IOAT_INTX
};
/**
* struct ioatdma_device - internal representation of a IOAT device
* @pdev: PCI-Express device
* @reg_base: MMIO register space base address
* @dma_pool: for allocating DMA descriptors
* @common: embedded struct dma_device
* @version: version of ioatdma device
* @msix_entries: irq handlers
* @idx: per channel data
* @dca: direct cache access context
* @intr_quirk: interrupt setup quirk (for ioat_v1 devices)
* @enumerate_channels: hw version specific channel enumeration
* @reset_hw: hw version specific channel (re)initialization
* @cleanup_fn: select between the v2 and v3 cleanup routines
* @timer_fn: select between the v2 and v3 timer watchdog routines
* @self_test: hardware version specific self test for each supported op type
*
* Note: the v3 cleanup routine supports raid operations
*/
struct ioatdma_device {
struct pci_dev *pdev;
void __iomem *reg_base;
struct pci_pool *dma_pool;
struct pci_pool *completion_pool;
#define MAX_SED_POOLS 5
struct dma_pool *sed_hw_pool[MAX_SED_POOLS];
struct dma_device common;
u8 version;
struct msix_entry msix_entries[4];
struct ioat_chan_common *idx[4];
struct dca_provider *dca;
enum ioat_irq_mode irq_mode;
u32 cap;
void (*intr_quirk)(struct ioatdma_device *device);
int (*enumerate_channels)(struct ioatdma_device *device);
int (*reset_hw)(struct ioat_chan_common *chan);
void (*cleanup_fn)(unsigned long data);
void (*timer_fn)(unsigned long data);
int (*self_test)(struct ioatdma_device *device);
};
struct ioat_chan_common {
struct dma_chan common;
void __iomem *reg_base;
dma_addr_t last_completion;
spinlock_t cleanup_lock;
unsigned long state;
#define IOAT_COMPLETION_PENDING 0
#define IOAT_COMPLETION_ACK 1
#define IOAT_RESET_PENDING 2
#define IOAT_KOBJ_INIT_FAIL 3
#define IOAT_RESHAPE_PENDING 4
#define IOAT_RUN 5
#define IOAT_CHAN_ACTIVE 6
struct timer_list timer;
#define COMPLETION_TIMEOUT msecs_to_jiffies(100)
#define IDLE_TIMEOUT msecs_to_jiffies(2000)
#define RESET_DELAY msecs_to_jiffies(100)
struct ioatdma_device *device;
dma_addr_t completion_dma;
u64 *completion;
struct tasklet_struct cleanup_task;
struct kobject kobj;
};
struct ioat_sysfs_entry {
struct attribute attr;
ssize_t (*show)(struct dma_chan *, char *);
};
/**
* struct ioat_dma_chan - internal representation of a DMA channel
*/
struct ioat_dma_chan {
struct ioat_chan_common base;
size_t xfercap; /* XFERCAP register value expanded out */
spinlock_t desc_lock;
struct list_head free_desc;
struct list_head used_desc;
int pending;
u16 desccount;
u16 active;
};
/**
* struct ioat_sed_ent - wrapper around super extended hardware descriptor
* @hw: hardware SED
* @sed_dma: dma address for the SED
* @list: list member
* @parent: point to the dma descriptor that's the parent
*/
struct ioat_sed_ent {
struct ioat_sed_raw_descriptor *hw;
dma_addr_t dma;
struct ioat_ring_ent *parent;
unsigned int hw_pool;
};
static inline struct ioat_chan_common *to_chan_common(struct dma_chan *c)
{
return container_of(c, struct ioat_chan_common, common);
}
static inline struct ioat_dma_chan *to_ioat_chan(struct dma_chan *c)
{
struct ioat_chan_common *chan = to_chan_common(c);
return container_of(chan, struct ioat_dma_chan, base);
}
/* wrapper around hardware descriptor format + additional software fields */
/**
* struct ioat_desc_sw - wrapper around hardware descriptor
* @hw: hardware DMA descriptor (for memcpy)
* @node: this descriptor will either be on the free list,
* or attached to a transaction list (tx_list)
* @txd: the generic software descriptor for all engines
* @id: identifier for debug
*/
struct ioat_desc_sw {
struct ioat_dma_descriptor *hw;
struct list_head node;
size_t len;
struct list_head tx_list;
struct dma_async_tx_descriptor txd;
#ifdef DEBUG
int id;
#endif
};
#ifdef DEBUG
#define set_desc_id(desc, i) ((desc)->id = (i))
#define desc_id(desc) ((desc)->id)
#else
#define set_desc_id(desc, i)
#define desc_id(desc) (0)
#endif
static inline void
__dump_desc_dbg(struct ioat_chan_common *chan, struct ioat_dma_descriptor *hw,
struct dma_async_tx_descriptor *tx, int id)
{
struct device *dev = to_dev(chan);
dev_dbg(dev, "desc[%d]: (%#llx->%#llx) cookie: %d flags: %#x"
" ctl: %#10.8x (op: %#x int_en: %d compl: %d)\n", id,
(unsigned long long) tx->phys,
(unsigned long long) hw->next, tx->cookie, tx->flags,
hw->ctl, hw->ctl_f.op, hw->ctl_f.int_en, hw->ctl_f.compl_write);
}
#define dump_desc_dbg(c, d) \
({ if (d) __dump_desc_dbg(&c->base, d->hw, &d->txd, desc_id(d)); 0; })
static inline void ioat_set_tcp_copy_break(unsigned long copybreak)
{
#ifdef CONFIG_NET_DMA
sysctl_tcp_dma_copybreak = copybreak;
#endif
}
static inline struct ioat_chan_common *
ioat_chan_by_index(struct ioatdma_device *device, int index)
{
return device->idx[index];
}
static inline u64 ioat_chansts_32(struct ioat_chan_common *chan)
{
u8 ver = chan->device->version;
u64 status;
u32 status_lo;
/* We need to read the low address first as this causes the
* chipset to latch the upper bits for the subsequent read
*/
status_lo = readl(chan->reg_base + IOAT_CHANSTS_OFFSET_LOW(ver));
status = readl(chan->reg_base + IOAT_CHANSTS_OFFSET_HIGH(ver));
status <<= 32;
status |= status_lo;
return status;
}
#if BITS_PER_LONG == 64
static inline u64 ioat_chansts(struct ioat_chan_common *chan)
{
u8 ver = chan->device->version;
u64 status;
/* With IOAT v3.3 the status register is 64bit. */
if (ver >= IOAT_VER_3_3)
status = readq(chan->reg_base + IOAT_CHANSTS_OFFSET(ver));
else
status = ioat_chansts_32(chan);
return status;
}
#else
#define ioat_chansts ioat_chansts_32
#endif
static inline void ioat_start(struct ioat_chan_common *chan)
{
u8 ver = chan->device->version;
writeb(IOAT_CHANCMD_START, chan->reg_base + IOAT_CHANCMD_OFFSET(ver));
}
static inline u64 ioat_chansts_to_addr(u64 status)
{
return status & IOAT_CHANSTS_COMPLETED_DESCRIPTOR_ADDR;
}
static inline u32 ioat_chanerr(struct ioat_chan_common *chan)
{
return readl(chan->reg_base + IOAT_CHANERR_OFFSET);
}
static inline void ioat_suspend(struct ioat_chan_common *chan)
{
u8 ver = chan->device->version;
writeb(IOAT_CHANCMD_SUSPEND, chan->reg_base + IOAT_CHANCMD_OFFSET(ver));
}
static inline void ioat_reset(struct ioat_chan_common *chan)
{
u8 ver = chan->device->version;
writeb(IOAT_CHANCMD_RESET, chan->reg_base + IOAT_CHANCMD_OFFSET(ver));
}
static inline bool ioat_reset_pending(struct ioat_chan_common *chan)
{
u8 ver = chan->device->version;
u8 cmd;
cmd = readb(chan->reg_base + IOAT_CHANCMD_OFFSET(ver));
return (cmd & IOAT_CHANCMD_RESET) == IOAT_CHANCMD_RESET;
}
static inline void ioat_set_chainaddr(struct ioat_dma_chan *ioat, u64 addr)
{
struct ioat_chan_common *chan = &ioat->base;
writel(addr & 0x00000000FFFFFFFF,
chan->reg_base + IOAT1_CHAINADDR_OFFSET_LOW);
writel(addr >> 32,
chan->reg_base + IOAT1_CHAINADDR_OFFSET_HIGH);
}
static inline bool is_ioat_active(unsigned long status)
{
return ((status & IOAT_CHANSTS_STATUS) == IOAT_CHANSTS_ACTIVE);
}
static inline bool is_ioat_idle(unsigned long status)
{
return ((status & IOAT_CHANSTS_STATUS) == IOAT_CHANSTS_DONE);
}
static inline bool is_ioat_halted(unsigned long status)
{
return ((status & IOAT_CHANSTS_STATUS) == IOAT_CHANSTS_HALTED);
}
static inline bool is_ioat_suspended(unsigned long status)
{
return ((status & IOAT_CHANSTS_STATUS) == IOAT_CHANSTS_SUSPENDED);
}
/* channel was fatally programmed */
static inline bool is_ioat_bug(unsigned long err)
{
return !!err;
}
int ioat_probe(struct ioatdma_device *device);
int ioat_register(struct ioatdma_device *device);
int ioat1_dma_probe(struct ioatdma_device *dev, int dca);
int ioat_dma_self_test(struct ioatdma_device *device);
void ioat_dma_remove(struct ioatdma_device *device);
struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase);
dma_addr_t ioat_get_current_completion(struct ioat_chan_common *chan);
void ioat_init_channel(struct ioatdma_device *device,
struct ioat_chan_common *chan, int idx);
enum dma_status ioat_dma_tx_status(struct dma_chan *c, dma_cookie_t cookie,
struct dma_tx_state *txstate);
bool ioat_cleanup_preamble(struct ioat_chan_common *chan,
dma_addr_t *phys_complete);
void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type);
void ioat_kobject_del(struct ioatdma_device *device);
int ioat_dma_setup_interrupts(struct ioatdma_device *device);
void ioat_stop(struct ioat_chan_common *chan);
extern const struct sysfs_ops ioat_sysfs_ops;
extern struct ioat_sysfs_entry ioat_version_attr;
extern struct ioat_sysfs_entry ioat_cap_attr;
#endif /* IOATDMA_H */