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rio_mport_cdev.c
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rio_mport_cdev.c
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/*
* RapidIO mport character device
*
* Copyright 2014-2015 Integrated Device Technology, Inc.
* Alexandre Bounine <[email protected]>
* Copyright 2014-2015 Prodrive Technologies
* Andre van Herk <[email protected]>
* Jerry Jacobs <[email protected]>
* Copyright (C) 2014 Texas Instruments Incorporated
* Aurelien Jacquiot <[email protected]>
*
* 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/cdev.h>
#include <linux/ioctl.h>
#include <linux/uaccess.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/net.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/kfifo.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mman.h>
#include <linux/dma-mapping.h>
#ifdef CONFIG_RAPIDIO_DMA_ENGINE
#include <linux/dmaengine.h>
#endif
#include <linux/rio.h>
#include <linux/rio_ids.h>
#include <linux/rio_drv.h>
#include <linux/rio_mport_cdev.h>
#include "../rio.h"
#define DRV_NAME "rio_mport"
#define DRV_PREFIX DRV_NAME ": "
#define DEV_NAME "rio_mport"
#define DRV_VERSION "1.0.0"
/* Debug output filtering masks */
enum {
DBG_NONE = 0,
DBG_INIT = BIT(0), /* driver init */
DBG_EXIT = BIT(1), /* driver exit */
DBG_MPORT = BIT(2), /* mport add/remove */
DBG_RDEV = BIT(3), /* RapidIO device add/remove */
DBG_DMA = BIT(4), /* DMA transfer messages */
DBG_MMAP = BIT(5), /* mapping messages */
DBG_IBW = BIT(6), /* inbound window */
DBG_EVENT = BIT(7), /* event handling messages */
DBG_OBW = BIT(8), /* outbound window messages */
DBG_DBELL = BIT(9), /* doorbell messages */
DBG_ALL = ~0,
};
#ifdef DEBUG
#define rmcd_debug(level, fmt, arg...) \
do { \
if (DBG_##level & dbg_level) \
pr_debug(DRV_PREFIX "%s: " fmt "\n", __func__, ##arg); \
} while (0)
#else
#define rmcd_debug(level, fmt, arg...) \
no_printk(KERN_DEBUG pr_fmt(DRV_PREFIX fmt "\n"), ##arg)
#endif
#define rmcd_warn(fmt, arg...) \
pr_warn(DRV_PREFIX "%s WARNING " fmt "\n", __func__, ##arg)
#define rmcd_error(fmt, arg...) \
pr_err(DRV_PREFIX "%s ERROR " fmt "\n", __func__, ##arg)
MODULE_AUTHOR("Jerry Jacobs <[email protected]>");
MODULE_AUTHOR("Aurelien Jacquiot <[email protected]>");
MODULE_AUTHOR("Alexandre Bounine <[email protected]>");
MODULE_AUTHOR("Andre van Herk <[email protected]>");
MODULE_DESCRIPTION("RapidIO mport character device driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
static int dma_timeout = 3000; /* DMA transfer timeout in msec */
module_param(dma_timeout, int, S_IRUGO);
MODULE_PARM_DESC(dma_timeout, "DMA Transfer Timeout in msec (default: 3000)");
#ifdef DEBUG
static u32 dbg_level = DBG_NONE;
module_param(dbg_level, uint, S_IWUSR | S_IWGRP | S_IRUGO);
MODULE_PARM_DESC(dbg_level, "Debugging output level (default 0 = none)");
#endif
/*
* An internal DMA coherent buffer
*/
struct mport_dma_buf {
void *ib_base;
dma_addr_t ib_phys;
u32 ib_size;
u64 ib_rio_base;
bool ib_map;
struct file *filp;
};
/*
* Internal memory mapping structure
*/
enum rio_mport_map_dir {
MAP_INBOUND,
MAP_OUTBOUND,
MAP_DMA,
};
struct rio_mport_mapping {
struct list_head node;
struct mport_dev *md;
enum rio_mport_map_dir dir;
u16 rioid;
u64 rio_addr;
dma_addr_t phys_addr; /* for mmap */
void *virt_addr; /* kernel address, for dma_free_coherent */
u64 size;
struct kref ref; /* refcount of vmas sharing the mapping */
struct file *filp;
};
struct rio_mport_dma_map {
int valid;
u64 length;
void *vaddr;
dma_addr_t paddr;
};
#define MPORT_MAX_DMA_BUFS 16
#define MPORT_EVENT_DEPTH 10
/*
* mport_dev driver-specific structure that represents mport device
* @active mport device status flag
* @node list node to maintain list of registered mports
* @cdev character device
* @dev associated device object
* @mport associated subsystem's master port device object
* @buf_mutex lock for buffer handling
* @file_mutex - lock for open files list
* @file_list - list of open files on given mport
* @properties properties of this mport
* @portwrites queue of inbound portwrites
* @pw_lock lock for port write queue
* @mappings queue for memory mappings
* @dma_chan DMA channels associated with this device
* @dma_ref:
* @comp:
*/
struct mport_dev {
atomic_t active;
struct list_head node;
struct cdev cdev;
struct device dev;
struct rio_mport *mport;
struct mutex buf_mutex;
struct mutex file_mutex;
struct list_head file_list;
struct rio_mport_properties properties;
struct list_head doorbells;
spinlock_t db_lock;
struct list_head portwrites;
spinlock_t pw_lock;
struct list_head mappings;
#ifdef CONFIG_RAPIDIO_DMA_ENGINE
struct dma_chan *dma_chan;
struct kref dma_ref;
struct completion comp;
#endif
};
/*
* mport_cdev_priv - data structure specific to individual file object
* associated with an open device
* @md master port character device object
* @async_queue - asynchronous notification queue
* @list - file objects tracking list
* @db_filters inbound doorbell filters for this descriptor
* @pw_filters portwrite filters for this descriptor
* @event_fifo event fifo for this descriptor
* @event_rx_wait wait queue for this descriptor
* @fifo_lock lock for event_fifo
* @event_mask event mask for this descriptor
* @dmach DMA engine channel allocated for specific file object
*/
struct mport_cdev_priv {
struct mport_dev *md;
struct fasync_struct *async_queue;
struct list_head list;
struct list_head db_filters;
struct list_head pw_filters;
struct kfifo event_fifo;
wait_queue_head_t event_rx_wait;
spinlock_t fifo_lock;
u32 event_mask; /* RIO_DOORBELL, RIO_PORTWRITE */
#ifdef CONFIG_RAPIDIO_DMA_ENGINE
struct dma_chan *dmach;
struct list_head async_list;
struct list_head pend_list;
spinlock_t req_lock;
struct mutex dma_lock;
struct kref dma_ref;
struct completion comp;
#endif
};
/*
* rio_mport_pw_filter - structure to describe a portwrite filter
* md_node node in mport device's list
* priv_node node in private file object's list
* priv reference to private data
* filter actual portwrite filter
*/
struct rio_mport_pw_filter {
struct list_head md_node;
struct list_head priv_node;
struct mport_cdev_priv *priv;
struct rio_pw_filter filter;
};
/*
* rio_mport_db_filter - structure to describe a doorbell filter
* @data_node reference to device node
* @priv_node node in private data
* @priv reference to private data
* @filter actual doorbell filter
*/
struct rio_mport_db_filter {
struct list_head data_node;
struct list_head priv_node;
struct mport_cdev_priv *priv;
struct rio_doorbell_filter filter;
};
static LIST_HEAD(mport_devs);
static DEFINE_MUTEX(mport_devs_lock);
#if (0) /* used by commented out portion of poll function : FIXME */
static DECLARE_WAIT_QUEUE_HEAD(mport_cdev_wait);
#endif
static struct class *dev_class;
static dev_t dev_number;
static struct workqueue_struct *dma_wq;
static void mport_release_mapping(struct kref *ref);
static int rio_mport_maint_rd(struct mport_cdev_priv *priv, void __user *arg,
int local)
{
struct rio_mport *mport = priv->md->mport;
struct rio_mport_maint_io maint_io;
u32 *buffer;
u32 offset;
size_t length;
int ret, i;
if (unlikely(copy_from_user(&maint_io, arg, sizeof(maint_io))))
return -EFAULT;
if ((maint_io.offset % 4) ||
(maint_io.length == 0) || (maint_io.length % 4) ||
(maint_io.length + maint_io.offset) > RIO_MAINT_SPACE_SZ)
return -EINVAL;
buffer = vmalloc(maint_io.length);
if (buffer == NULL)
return -ENOMEM;
length = maint_io.length/sizeof(u32);
offset = maint_io.offset;
for (i = 0; i < length; i++) {
if (local)
ret = __rio_local_read_config_32(mport,
offset, &buffer[i]);
else
ret = rio_mport_read_config_32(mport, maint_io.rioid,
maint_io.hopcount, offset, &buffer[i]);
if (ret)
goto out;
offset += 4;
}
if (unlikely(copy_to_user((void __user *)(uintptr_t)maint_io.buffer,
buffer, maint_io.length)))
ret = -EFAULT;
out:
vfree(buffer);
return ret;
}
static int rio_mport_maint_wr(struct mport_cdev_priv *priv, void __user *arg,
int local)
{
struct rio_mport *mport = priv->md->mport;
struct rio_mport_maint_io maint_io;
u32 *buffer;
u32 offset;
size_t length;
int ret = -EINVAL, i;
if (unlikely(copy_from_user(&maint_io, arg, sizeof(maint_io))))
return -EFAULT;
if ((maint_io.offset % 4) ||
(maint_io.length == 0) || (maint_io.length % 4) ||
(maint_io.length + maint_io.offset) > RIO_MAINT_SPACE_SZ)
return -EINVAL;
buffer = vmalloc(maint_io.length);
if (buffer == NULL)
return -ENOMEM;
length = maint_io.length;
if (unlikely(copy_from_user(buffer,
(void __user *)(uintptr_t)maint_io.buffer, length))) {
ret = -EFAULT;
goto out;
}
offset = maint_io.offset;
length /= sizeof(u32);
for (i = 0; i < length; i++) {
if (local)
ret = __rio_local_write_config_32(mport,
offset, buffer[i]);
else
ret = rio_mport_write_config_32(mport, maint_io.rioid,
maint_io.hopcount,
offset, buffer[i]);
if (ret)
goto out;
offset += 4;
}
out:
vfree(buffer);
return ret;
}
/*
* Inbound/outbound memory mapping functions
*/
static int
rio_mport_create_outbound_mapping(struct mport_dev *md, struct file *filp,
u16 rioid, u64 raddr, u32 size,
dma_addr_t *paddr)
{
struct rio_mport *mport = md->mport;
struct rio_mport_mapping *map;
int ret;
rmcd_debug(OBW, "did=%d ra=0x%llx sz=0x%x", rioid, raddr, size);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (map == NULL)
return -ENOMEM;
ret = rio_map_outb_region(mport, rioid, raddr, size, 0, paddr);
if (ret < 0)
goto err_map_outb;
map->dir = MAP_OUTBOUND;
map->rioid = rioid;
map->rio_addr = raddr;
map->size = size;
map->phys_addr = *paddr;
map->filp = filp;
map->md = md;
kref_init(&map->ref);
list_add_tail(&map->node, &md->mappings);
return 0;
err_map_outb:
kfree(map);
return ret;
}
static int
rio_mport_get_outbound_mapping(struct mport_dev *md, struct file *filp,
u16 rioid, u64 raddr, u32 size,
dma_addr_t *paddr)
{
struct rio_mport_mapping *map;
int err = -ENOMEM;
mutex_lock(&md->buf_mutex);
list_for_each_entry(map, &md->mappings, node) {
if (map->dir != MAP_OUTBOUND)
continue;
if (rioid == map->rioid &&
raddr == map->rio_addr && size == map->size) {
*paddr = map->phys_addr;
err = 0;
break;
} else if (rioid == map->rioid &&
raddr < (map->rio_addr + map->size - 1) &&
(raddr + size) > map->rio_addr) {
err = -EBUSY;
break;
}
}
/* If not found, create new */
if (err == -ENOMEM)
err = rio_mport_create_outbound_mapping(md, filp, rioid, raddr,
size, paddr);
mutex_unlock(&md->buf_mutex);
return err;
}
static int rio_mport_obw_map(struct file *filp, void __user *arg)
{
struct mport_cdev_priv *priv = filp->private_data;
struct mport_dev *data = priv->md;
struct rio_mmap map;
dma_addr_t paddr;
int ret;
if (unlikely(copy_from_user(&map, arg, sizeof(map))))
return -EFAULT;
rmcd_debug(OBW, "did=%d ra=0x%llx sz=0x%llx",
map.rioid, map.rio_addr, map.length);
ret = rio_mport_get_outbound_mapping(data, filp, map.rioid,
map.rio_addr, map.length, &paddr);
if (ret < 0) {
rmcd_error("Failed to set OBW err= %d", ret);
return ret;
}
map.handle = paddr;
if (unlikely(copy_to_user(arg, &map, sizeof(map))))
return -EFAULT;
return 0;
}
/*
* rio_mport_obw_free() - unmap an OutBound Window from RapidIO address space
*
* @priv: driver private data
* @arg: buffer handle returned by allocation routine
*/
static int rio_mport_obw_free(struct file *filp, void __user *arg)
{
struct mport_cdev_priv *priv = filp->private_data;
struct mport_dev *md = priv->md;
u64 handle;
struct rio_mport_mapping *map, *_map;
if (!md->mport->ops->unmap_outb)
return -EPROTONOSUPPORT;
if (copy_from_user(&handle, arg, sizeof(handle)))
return -EFAULT;
rmcd_debug(OBW, "h=0x%llx", handle);
mutex_lock(&md->buf_mutex);
list_for_each_entry_safe(map, _map, &md->mappings, node) {
if (map->dir == MAP_OUTBOUND && map->phys_addr == handle) {
if (map->filp == filp) {
rmcd_debug(OBW, "kref_put h=0x%llx", handle);
map->filp = NULL;
kref_put(&map->ref, mport_release_mapping);
}
break;
}
}
mutex_unlock(&md->buf_mutex);
return 0;
}
/*
* maint_hdid_set() - Set the host Device ID
* @priv: driver private data
* @arg: Device Id
*/
static int maint_hdid_set(struct mport_cdev_priv *priv, void __user *arg)
{
struct mport_dev *md = priv->md;
u16 hdid;
if (copy_from_user(&hdid, arg, sizeof(hdid)))
return -EFAULT;
md->mport->host_deviceid = hdid;
md->properties.hdid = hdid;
rio_local_set_device_id(md->mport, hdid);
rmcd_debug(MPORT, "Set host device Id to %d", hdid);
return 0;
}
/*
* maint_comptag_set() - Set the host Component Tag
* @priv: driver private data
* @arg: Component Tag
*/
static int maint_comptag_set(struct mport_cdev_priv *priv, void __user *arg)
{
struct mport_dev *md = priv->md;
u32 comptag;
if (copy_from_user(&comptag, arg, sizeof(comptag)))
return -EFAULT;
rio_local_write_config_32(md->mport, RIO_COMPONENT_TAG_CSR, comptag);
rmcd_debug(MPORT, "Set host Component Tag to %d", comptag);
return 0;
}
#ifdef CONFIG_RAPIDIO_DMA_ENGINE
struct mport_dma_req {
struct list_head node;
struct file *filp;
struct mport_cdev_priv *priv;
enum rio_transfer_sync sync;
struct sg_table sgt;
struct page **page_list;
unsigned int nr_pages;
struct rio_mport_mapping *map;
struct dma_chan *dmach;
enum dma_data_direction dir;
dma_cookie_t cookie;
enum dma_status status;
struct completion req_comp;
};
struct mport_faf_work {
struct work_struct work;
struct mport_dma_req *req;
};
static void mport_release_def_dma(struct kref *dma_ref)
{
struct mport_dev *md =
container_of(dma_ref, struct mport_dev, dma_ref);
rmcd_debug(EXIT, "DMA_%d", md->dma_chan->chan_id);
rio_release_dma(md->dma_chan);
md->dma_chan = NULL;
}
static void mport_release_dma(struct kref *dma_ref)
{
struct mport_cdev_priv *priv =
container_of(dma_ref, struct mport_cdev_priv, dma_ref);
rmcd_debug(EXIT, "DMA_%d", priv->dmach->chan_id);
complete(&priv->comp);
}
static void dma_req_free(struct mport_dma_req *req)
{
struct mport_cdev_priv *priv = req->priv;
unsigned int i;
dma_unmap_sg(req->dmach->device->dev,
req->sgt.sgl, req->sgt.nents, req->dir);
sg_free_table(&req->sgt);
if (req->page_list) {
for (i = 0; i < req->nr_pages; i++)
put_page(req->page_list[i]);
kfree(req->page_list);
}
if (req->map) {
mutex_lock(&req->map->md->buf_mutex);
kref_put(&req->map->ref, mport_release_mapping);
mutex_unlock(&req->map->md->buf_mutex);
}
kref_put(&priv->dma_ref, mport_release_dma);
kfree(req);
}
static void dma_xfer_callback(void *param)
{
struct mport_dma_req *req = (struct mport_dma_req *)param;
struct mport_cdev_priv *priv = req->priv;
req->status = dma_async_is_tx_complete(priv->dmach, req->cookie,
NULL, NULL);
complete(&req->req_comp);
}
static void dma_faf_cleanup(struct work_struct *_work)
{
struct mport_faf_work *work = container_of(_work,
struct mport_faf_work, work);
struct mport_dma_req *req = work->req;
dma_req_free(req);
kfree(work);
}
static void dma_faf_callback(void *param)
{
struct mport_dma_req *req = (struct mport_dma_req *)param;
struct mport_faf_work *work;
work = kmalloc(sizeof(*work), GFP_ATOMIC);
if (!work)
return;
INIT_WORK(&work->work, dma_faf_cleanup);
work->req = req;
queue_work(dma_wq, &work->work);
}
/*
* prep_dma_xfer() - Configure and send request to DMAengine to prepare DMA
* transfer object.
* Returns pointer to DMA transaction descriptor allocated by DMA driver on
* success or ERR_PTR (and/or NULL) if failed. Caller must check returned
* non-NULL pointer using IS_ERR macro.
*/
static struct dma_async_tx_descriptor
*prep_dma_xfer(struct dma_chan *chan, struct rio_transfer_io *transfer,
struct sg_table *sgt, int nents, enum dma_transfer_direction dir,
enum dma_ctrl_flags flags)
{
struct rio_dma_data tx_data;
tx_data.sg = sgt->sgl;
tx_data.sg_len = nents;
tx_data.rio_addr_u = 0;
tx_data.rio_addr = transfer->rio_addr;
if (dir == DMA_MEM_TO_DEV) {
switch (transfer->method) {
case RIO_EXCHANGE_NWRITE:
tx_data.wr_type = RDW_ALL_NWRITE;
break;
case RIO_EXCHANGE_NWRITE_R_ALL:
tx_data.wr_type = RDW_ALL_NWRITE_R;
break;
case RIO_EXCHANGE_NWRITE_R:
tx_data.wr_type = RDW_LAST_NWRITE_R;
break;
case RIO_EXCHANGE_DEFAULT:
tx_data.wr_type = RDW_DEFAULT;
break;
default:
return ERR_PTR(-EINVAL);
}
}
return rio_dma_prep_xfer(chan, transfer->rioid, &tx_data, dir, flags);
}
/* Request DMA channel associated with this mport device.
* Try to request DMA channel for every new process that opened given
* mport. If a new DMA channel is not available use default channel
* which is the first DMA channel opened on mport device.
*/
static int get_dma_channel(struct mport_cdev_priv *priv)
{
mutex_lock(&priv->dma_lock);
if (!priv->dmach) {
priv->dmach = rio_request_mport_dma(priv->md->mport);
if (!priv->dmach) {
/* Use default DMA channel if available */
if (priv->md->dma_chan) {
priv->dmach = priv->md->dma_chan;
kref_get(&priv->md->dma_ref);
} else {
rmcd_error("Failed to get DMA channel");
mutex_unlock(&priv->dma_lock);
return -ENODEV;
}
} else if (!priv->md->dma_chan) {
/* Register default DMA channel if we do not have one */
priv->md->dma_chan = priv->dmach;
kref_init(&priv->md->dma_ref);
rmcd_debug(DMA, "Register DMA_chan %d as default",
priv->dmach->chan_id);
}
kref_init(&priv->dma_ref);
init_completion(&priv->comp);
}
kref_get(&priv->dma_ref);
mutex_unlock(&priv->dma_lock);
return 0;
}
static void put_dma_channel(struct mport_cdev_priv *priv)
{
kref_put(&priv->dma_ref, mport_release_dma);
}
/*
* DMA transfer functions
*/
static int do_dma_request(struct mport_dma_req *req,
struct rio_transfer_io *xfer,
enum rio_transfer_sync sync, int nents)
{
struct mport_cdev_priv *priv;
struct sg_table *sgt;
struct dma_chan *chan;
struct dma_async_tx_descriptor *tx;
dma_cookie_t cookie;
unsigned long tmo = msecs_to_jiffies(dma_timeout);
enum dma_transfer_direction dir;
long wret;
int ret = 0;
priv = req->priv;
sgt = &req->sgt;
chan = priv->dmach;
dir = (req->dir == DMA_FROM_DEVICE) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
rmcd_debug(DMA, "%s(%d) uses %s for DMA_%s",
current->comm, task_pid_nr(current),
dev_name(&chan->dev->device),
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE");
/* Initialize DMA transaction request */
tx = prep_dma_xfer(chan, xfer, sgt, nents, dir,
DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
if (!tx) {
rmcd_debug(DMA, "prep error for %s A:0x%llx L:0x%llx",
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE",
xfer->rio_addr, xfer->length);
ret = -EIO;
goto err_out;
} else if (IS_ERR(tx)) {
ret = PTR_ERR(tx);
rmcd_debug(DMA, "prep error %d for %s A:0x%llx L:0x%llx", ret,
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE",
xfer->rio_addr, xfer->length);
goto err_out;
}
if (sync == RIO_TRANSFER_FAF)
tx->callback = dma_faf_callback;
else
tx->callback = dma_xfer_callback;
tx->callback_param = req;
req->dmach = chan;
req->sync = sync;
req->status = DMA_IN_PROGRESS;
init_completion(&req->req_comp);
cookie = dmaengine_submit(tx);
req->cookie = cookie;
rmcd_debug(DMA, "pid=%d DMA_%s tx_cookie = %d", task_pid_nr(current),
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE", cookie);
if (dma_submit_error(cookie)) {
rmcd_error("submit err=%d (addr:0x%llx len:0x%llx)",
cookie, xfer->rio_addr, xfer->length);
ret = -EIO;
goto err_out;
}
dma_async_issue_pending(chan);
if (sync == RIO_TRANSFER_ASYNC) {
spin_lock(&priv->req_lock);
list_add_tail(&req->node, &priv->async_list);
spin_unlock(&priv->req_lock);
return cookie;
} else if (sync == RIO_TRANSFER_FAF)
return 0;
wret = wait_for_completion_interruptible_timeout(&req->req_comp, tmo);
if (wret == 0) {
/* Timeout on wait occurred */
rmcd_error("%s(%d) timed out waiting for DMA_%s %d",
current->comm, task_pid_nr(current),
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE", cookie);
return -ETIMEDOUT;
} else if (wret == -ERESTARTSYS) {
/* Wait_for_completion was interrupted by a signal but DMA may
* be in progress
*/
rmcd_error("%s(%d) wait for DMA_%s %d was interrupted",
current->comm, task_pid_nr(current),
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE", cookie);
return -EINTR;
}
if (req->status != DMA_COMPLETE) {
/* DMA transaction completion was signaled with error */
rmcd_error("%s(%d) DMA_%s %d completed with status %d (ret=%d)",
current->comm, task_pid_nr(current),
(dir == DMA_DEV_TO_MEM)?"READ":"WRITE",
cookie, req->status, ret);
ret = -EIO;
}
err_out:
return ret;
}
/*
* rio_dma_transfer() - Perform RapidIO DMA data transfer to/from
* the remote RapidIO device
* @filp: file pointer associated with the call
* @transfer_mode: DMA transfer mode
* @sync: synchronization mode
* @dir: DMA transfer direction (DMA_MEM_TO_DEV = write OR
* DMA_DEV_TO_MEM = read)
* @xfer: data transfer descriptor structure
*/
static int
rio_dma_transfer(struct file *filp, u32 transfer_mode,
enum rio_transfer_sync sync, enum dma_data_direction dir,
struct rio_transfer_io *xfer)
{
struct mport_cdev_priv *priv = filp->private_data;
unsigned long nr_pages = 0;
struct page **page_list = NULL;
struct mport_dma_req *req;
struct mport_dev *md = priv->md;
struct dma_chan *chan;
int i, ret;
int nents;
if (xfer->length == 0)
return -EINVAL;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
ret = get_dma_channel(priv);
if (ret) {
kfree(req);
return ret;
}
/*
* If parameter loc_addr != NULL, we are transferring data from/to
* data buffer allocated in user-space: lock in memory user-space
* buffer pages and build an SG table for DMA transfer request
*
* Otherwise (loc_addr == NULL) contiguous kernel-space buffer is
* used for DMA data transfers: build single entry SG table using
* offset within the internal buffer specified by handle parameter.
*/
if (xfer->loc_addr) {
unsigned long offset;
long pinned;
offset = (unsigned long)(uintptr_t)xfer->loc_addr & ~PAGE_MASK;
nr_pages = PAGE_ALIGN(xfer->length + offset) >> PAGE_SHIFT;
page_list = kmalloc_array(nr_pages,
sizeof(*page_list), GFP_KERNEL);
if (page_list == NULL) {
ret = -ENOMEM;
goto err_req;
}
down_read(¤t->mm->mmap_sem);
pinned = get_user_pages(
(unsigned long)xfer->loc_addr & PAGE_MASK,
nr_pages, dir == DMA_FROM_DEVICE, 0,
page_list, NULL);
up_read(¤t->mm->mmap_sem);
if (pinned != nr_pages) {
if (pinned < 0) {
rmcd_error("get_user_pages err=%ld", pinned);
nr_pages = 0;
} else
rmcd_error("pinned %ld out of %ld pages",
pinned, nr_pages);
ret = -EFAULT;
goto err_pg;
}
ret = sg_alloc_table_from_pages(&req->sgt, page_list, nr_pages,
offset, xfer->length, GFP_KERNEL);
if (ret) {
rmcd_error("sg_alloc_table failed with err=%d", ret);
goto err_pg;
}
req->page_list = page_list;
req->nr_pages = nr_pages;
} else {
dma_addr_t baddr;
struct rio_mport_mapping *map;
baddr = (dma_addr_t)xfer->handle;
mutex_lock(&md->buf_mutex);
list_for_each_entry(map, &md->mappings, node) {
if (baddr >= map->phys_addr &&
baddr < (map->phys_addr + map->size)) {
kref_get(&map->ref);
req->map = map;
break;
}
}
mutex_unlock(&md->buf_mutex);
if (req->map == NULL) {
ret = -ENOMEM;
goto err_req;
}
if (xfer->length + xfer->offset > map->size) {
ret = -EINVAL;
goto err_req;
}
ret = sg_alloc_table(&req->sgt, 1, GFP_KERNEL);
if (unlikely(ret)) {
rmcd_error("sg_alloc_table failed for internal buf");
goto err_req;
}
sg_set_buf(req->sgt.sgl,
map->virt_addr + (baddr - map->phys_addr) +
xfer->offset, xfer->length);
}
req->dir = dir;
req->filp = filp;
req->priv = priv;
chan = priv->dmach;
nents = dma_map_sg(chan->device->dev,
req->sgt.sgl, req->sgt.nents, dir);
if (nents == -EFAULT) {
rmcd_error("Failed to map SG list");
return -EFAULT;
}
ret = do_dma_request(req, xfer, sync, nents);
if (ret >= 0) {
if (sync == RIO_TRANSFER_SYNC)
goto sync_out;
return ret; /* return ASYNC cookie */
}
if (ret == -ETIMEDOUT || ret == -EINTR) {
/*
* This can happen only in case of SYNC transfer.
* Do not free unfinished request structure immediately.
* Place it into pending list and deal with it later
*/
spin_lock(&priv->req_lock);
list_add_tail(&req->node, &priv->pend_list);
spin_unlock(&priv->req_lock);
return ret;
}
rmcd_debug(DMA, "do_dma_request failed with err=%d", ret);
sync_out:
dma_unmap_sg(chan->device->dev, req->sgt.sgl, req->sgt.nents, dir);
sg_free_table(&req->sgt);
err_pg:
if (page_list) {
for (i = 0; i < nr_pages; i++)
put_page(page_list[i]);
kfree(page_list);
}
err_req: