cregit-Linux how code gets into the kernel

Release 4.14 drivers/ntb/test/ntb_tool.c

Directory: drivers/ntb/test
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   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.
 *
 *   BSD LICENSE
 *
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *
 *   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 copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * PCIe NTB Debugging Tool Linux driver
 *
 * Contact Information:
 * Allen Hubbe <Allen.Hubbe@emc.com>
 */

/*
 * How to use this tool, by example.
 *
 * Assuming $DBG_DIR is something like:
 * '/sys/kernel/debug/ntb_tool/0000:00:03.0'
 *
 * Eg: check if clearing the doorbell mask generates an interrupt.
 *
 * # Check the link status
 * root@self# cat $DBG_DIR/link
 *
 * # Block until the link is up
 * root@self# echo Y > $DBG_DIR/link_event
 *
 * # Set the doorbell mask
 * root@self# echo 's 1' > $DBG_DIR/mask
 *
 * # Ring the doorbell from the peer
 * root@peer# echo 's 1' > $DBG_DIR/peer_db
 *
 * # Clear the doorbell mask
 * root@self# echo 'c 1' > $DBG_DIR/mask
 *
 * Observe debugging output in dmesg or your console.  You should see a
 * doorbell event triggered by clearing the mask.  If not, this may indicate an
 * issue with the hardware that needs to be worked around in the driver.
 *
 * Eg: read and write scratchpad registers
 *
 * root@peer# echo '0 0x01010101 1 0x7f7f7f7f' > $DBG_DIR/peer_spad
 *
 * root@self# cat $DBG_DIR/spad
 *
 * Observe that spad 0 and 1 have the values set by the peer.
 *
 * # Check the memory window translation info
 * cat $DBG_DIR/peer_trans0
 *
 * # Setup a 16k memory window buffer
 * echo 16384 > $DBG_DIR/peer_trans0
 *
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>

#include <linux/debugfs.h>
#include <linux/dma-mapping.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include <linux/ntb.h>


#define DRIVER_NAME			"ntb_tool"

#define DRIVER_DESCRIPTION		"PCIe NTB Debugging Tool"


#define DRIVER_LICENSE			"Dual BSD/GPL"

#define DRIVER_VERSION			"1.0"

#define DRIVER_RELDATE			"22 April 2015"

#define DRIVER_AUTHOR			"Allen Hubbe <Allen.Hubbe@emc.com>"


MODULE_LICENSE(DRIVER_LICENSE);

MODULE_VERSION(DRIVER_VERSION);

MODULE_AUTHOR(DRIVER_AUTHOR);

MODULE_DESCRIPTION(DRIVER_DESCRIPTION);

/* It is rare to have hadrware with greater than six MWs */

#define MAX_MWS	6
/* Only two-ports devices are supported */

#define PIDX	NTB_DEF_PEER_IDX


static struct dentry *tool_dbgfs;


struct tool_mw {
	
int idx;
	
struct tool_ctx *tc;
	
resource_size_t win_size;
	
resource_size_t size;
	
u8 __iomem *local;
	
u8 *peer;
	
dma_addr_t peer_dma;
	
struct dentry *peer_dbg_file;
};


struct tool_ctx {
	
struct ntb_dev *ntb;
	
struct dentry *dbgfs;
	
wait_queue_head_t link_wq;
	
int mw_count;
	
struct tool_mw mws[MAX_MWS];
};


#define SPAD_FNAME_SIZE 0x10

#define INT_PTR(x) ((void *)(unsigned long)x)

#define PTR_INT(x) ((int)(unsigned long)x)


#define TOOL_FOPS_RDWR(__name, __read, __write) \
	const struct file_operations __name = { \
                .owner = THIS_MODULE,           \
                .open = simple_open,            \
                .read = __read,                 \
                .write = __write,               \
        }


static void tool_link_event(void *ctx) { struct tool_ctx *tc = ctx; enum ntb_speed speed; enum ntb_width width; int up; up = ntb_link_is_up(tc->ntb, &speed, &width); dev_dbg(&tc->ntb->dev, "link is %s speed %d width %d\n", up ? "up" : "down", speed, width); wake_up(&tc->link_wq); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe5169.86%375.00%
Allen Hubbe2230.14%125.00%
Total73100.00%4100.00%


static void tool_db_event(void *ctx, int vec) { struct tool_ctx *tc = ctx; u64 db_bits, db_mask; db_mask = ntb_db_vector_mask(tc->ntb, vec); db_bits = ntb_db_read(tc->ntb); dev_dbg(&tc->ntb->dev, "doorbell vec %d mask %#llx bits %#llx\n", vec, db_mask, db_bits); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe4876.19%266.67%
Allen Hubbe1523.81%133.33%
Total63100.00%3100.00%

static const struct ntb_ctx_ops tool_ops = { .link_event = tool_link_event, .db_event = tool_db_event, };
static ssize_t tool_dbfn_read(struct tool_ctx *tc, char __user *ubuf, size_t size, loff_t *offp, u64 (*db_read_fn)(struct ntb_dev *)) { size_t buf_size; char *buf; ssize_t pos, rc; if (!db_read_fn) return -EINVAL; buf_size = min_t(size_t, size, 0x20); buf = kmalloc(buf_size, GFP_KERNEL); if (!buf) return -ENOMEM; pos = scnprintf(buf, buf_size, "%#llx\n", db_read_fn(tc->ntb)); rc = simple_read_from_buffer(ubuf, size, offp, buf, pos); kfree(buf); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe12196.80%266.67%
Allen Hubbe43.20%133.33%
Total125100.00%3100.00%


static ssize_t tool_dbfn_write(struct tool_ctx *tc, const char __user *ubuf, size_t size, loff_t *offp, int (*db_set_fn)(struct ntb_dev *, u64), int (*db_clear_fn)(struct ntb_dev *, u64)) { u64 db_bits; char *buf, cmd; ssize_t rc; int n; buf = kmalloc(size + 1, GFP_KERNEL); if (!buf) return -ENOMEM; rc = simple_write_to_buffer(buf, size, offp, ubuf, size); if (rc < 0) { kfree(buf); return rc; } buf[size] = 0; n = sscanf(buf, "%c %lli", &cmd, &db_bits); kfree(buf); if (n != 2) { rc = -EINVAL; } else if (cmd == 's') { if (!db_set_fn) rc = -EINVAL; else rc = db_set_fn(tc->ntb, db_bits); } else if (cmd == 'c') { if (!db_clear_fn) rc = -EINVAL; else rc = db_clear_fn(tc->ntb, db_bits); } else { rc = -EINVAL; } return rc ? : size; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe23099.14%266.67%
Allen Hubbe20.86%133.33%
Total232100.00%3100.00%


static ssize_t tool_spadfn_read(struct tool_ctx *tc, char __user *ubuf, size_t size, loff_t *offp, u32 (*spad_read_fn)(struct ntb_dev *, int)) { size_t buf_size; char *buf; ssize_t pos, rc; int i, spad_count; if (!spad_read_fn) return -EINVAL; spad_count = ntb_spad_count(tc->ntb); /* * We multiply the number of spads by 15 to get the buffer size * this is from 3 for the %d, 10 for the largest hex value * (0x00000000) and 2 for the tab and line feed. */ buf_size = min_t(size_t, size, spad_count * 15); buf = kmalloc(buf_size, GFP_KERNEL); if (!buf) return -ENOMEM; pos = 0; for (i = 0; i < spad_count; ++i) { pos += scnprintf(buf + pos, buf_size - pos, "%d\t%#x\n", i, spad_read_fn(tc->ntb, i)); } rc = simple_read_from_buffer(ubuf, size, offp, buf, pos); kfree(buf); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe171100.00%2100.00%
Total171100.00%2100.00%


static ssize_t tool_spadfn_write(struct tool_ctx *tc, const char __user *ubuf, size_t size, loff_t *offp, int (*spad_write_fn)(struct ntb_dev *, int, u32)) { int spad_idx; u32 spad_val; char *buf, *buf_ptr; int pos, n; ssize_t rc; if (!spad_write_fn) { dev_dbg(&tc->ntb->dev, "no spad write fn\n"); return -EINVAL; } buf = kmalloc(size + 1, GFP_KERNEL); if (!buf) return -ENOMEM; rc = simple_write_to_buffer(buf, size, offp, ubuf, size); if (rc < 0) { kfree(buf); return rc; } buf[size] = 0; buf_ptr = buf; n = sscanf(buf_ptr, "%d %i%n", &spad_idx, &spad_val, &pos); while (n == 2) { buf_ptr += pos; rc = spad_write_fn(tc->ntb, spad_idx, spad_val); if (rc) break; n = sscanf(buf_ptr, "%d %i%n", &spad_idx, &spad_val, &pos); } if (n < 0) rc = n; kfree(buf); return rc ? : size; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe232100.00%2100.00%
Total232100.00%2100.00%


static ssize_t tool_db_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_read(tc, ubuf, size, offp, tc->ntb->ops->db_read); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe52100.00%2100.00%
Total52100.00%2100.00%


static ssize_t tool_db_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_write(tc, ubuf, size, offp, tc->ntb->ops->db_set, tc->ntb->ops->db_clear); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe61100.00%2100.00%
Total61100.00%2100.00%

static TOOL_FOPS_RDWR(tool_db_fops, tool_db_read, tool_db_write);
static ssize_t tool_mask_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_read(tc, ubuf, size, offp, tc->ntb->ops->db_read_mask); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe52100.00%2100.00%
Total52100.00%2100.00%


static ssize_t tool_mask_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_write(tc, ubuf, size, offp, tc->ntb->ops->db_set_mask, tc->ntb->ops->db_clear_mask); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe61100.00%2100.00%
Total61100.00%2100.00%

static TOOL_FOPS_RDWR(tool_mask_fops, tool_mask_read, tool_mask_write);
static ssize_t tool_peer_db_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_read(tc, ubuf, size, offp, tc->ntb->ops->peer_db_read); }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe2751.92%133.33%
Logan Gunthorpe2548.08%266.67%
Total52100.00%3100.00%


static ssize_t tool_peer_db_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_write(tc, ubuf, size, offp, tc->ntb->ops->peer_db_set, tc->ntb->ops->peer_db_clear); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe5386.89%266.67%
Allen Hubbe813.11%133.33%
Total61100.00%3100.00%

static TOOL_FOPS_RDWR(tool_peer_db_fops, tool_peer_db_read, tool_peer_db_write);
static ssize_t tool_peer_mask_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_read(tc, ubuf, size, offp, tc->ntb->ops->peer_db_read_mask); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe4892.31%150.00%
Allen Hubbe47.69%150.00%
Total52100.00%2100.00%


static ssize_t tool_peer_mask_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_dbfn_write(tc, ubuf, size, offp, tc->ntb->ops->peer_db_set_mask, tc->ntb->ops->peer_db_clear_mask); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe4167.21%266.67%
Allen Hubbe2032.79%133.33%
Total61100.00%3100.00%

static TOOL_FOPS_RDWR(tool_peer_mask_fops, tool_peer_mask_read, tool_peer_mask_write);
static ssize_t tool_spad_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_spadfn_read(tc, ubuf, size, offp, tc->ntb->ops->spad_read); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe4280.77%150.00%
Allen Hubbe1019.23%150.00%
Total52100.00%2100.00%


static ssize_t tool_spad_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_spadfn_write(tc, ubuf, size, offp, tc->ntb->ops->spad_write); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe4992.45%266.67%
Allen Hubbe47.55%133.33%
Total53100.00%3100.00%

static TOOL_FOPS_RDWR(tool_spad_fops, tool_spad_read, tool_spad_write);
static u32 ntb_tool_peer_spad_read(struct ntb_dev *ntb, int sidx) { return ntb_peer_spad_read(ntb, PIDX, sidx); }

Contributors

PersonTokensPropCommitsCommitProp
Serge Semin24100.00%1100.00%
Total24100.00%1100.00%


static ssize_t tool_peer_spad_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_spadfn_read(tc, ubuf, size, offp, ntb_tool_peer_spad_read); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe4086.96%250.00%
Serge Semin48.70%125.00%
Allen Hubbe24.35%125.00%
Total46100.00%4100.00%


static int ntb_tool_peer_spad_write(struct ntb_dev *ntb, int sidx, u32 val) { return ntb_peer_spad_write(ntb, PIDX, sidx, val); }

Contributors

PersonTokensPropCommitsCommitProp
Serge Semin2586.21%150.00%
Allen Hubbe413.79%150.00%
Total29100.00%2100.00%


static ssize_t tool_peer_spad_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; return tool_spadfn_write(tc, ubuf, size, offp, ntb_tool_peer_spad_write); }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe2859.57%120.00%
Logan Gunthorpe1838.30%360.00%
Serge Semin12.13%120.00%
Total47100.00%5100.00%

static TOOL_FOPS_RDWR(tool_peer_spad_fops, tool_peer_spad_read, tool_peer_spad_write);
static ssize_t tool_link_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; char buf[3]; buf[0] = ntb_link_is_up(tc->ntb, NULL, NULL) ? 'Y' : 'N'; buf[1] = '\n'; buf[2] = '\0'; return simple_read_from_buffer(ubuf, size, offp, buf, 2); }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe86100.00%1100.00%
Total86100.00%1100.00%


static ssize_t tool_link_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; char buf[32]; size_t buf_size; bool val; int rc; buf_size = min(size, (sizeof(buf) - 1)); if (copy_from_user(buf, ubuf, buf_size)) return -EFAULT; buf[buf_size] = '\0'; rc = strtobool(buf, &val); if (rc) return rc; if (val) rc = ntb_link_enable(tc->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO); else rc = ntb_link_disable(tc->ntb); if (rc) return rc; return size; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe140100.00%1100.00%
Total140100.00%1100.00%

static TOOL_FOPS_RDWR(tool_link_fops, tool_link_read, tool_link_write);
static ssize_t tool_link_event_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_ctx *tc = filep->private_data; char buf[32]; size_t buf_size; bool val; int rc; buf_size = min(size, (sizeof(buf) - 1)); if (copy_from_user(buf, ubuf, buf_size)) return -EFAULT; buf[buf_size] = '\0'; rc = strtobool(buf, &val); if (rc) return rc; if (wait_event_interruptible(tc->link_wq, ntb_link_is_up(tc->ntb, NULL, NULL) == val)) return -ERESTART; return size; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe132100.00%1100.00%
Total132100.00%1100.00%

static TOOL_FOPS_RDWR(tool_link_event_fops, NULL, tool_link_event_write);
static ssize_t tool_mw_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_mw *mw = filep->private_data; ssize_t rc; loff_t pos = *offp; void *buf; if (mw->local == NULL) return -EIO; if (pos < 0) return -EINVAL; if (pos >= mw->win_size || !size) return 0; if (size > mw->win_size - pos) size = mw->win_size - pos; buf = kmalloc(size, GFP_KERNEL); if (!buf) return -ENOMEM; memcpy_fromio(buf, mw->local + pos, size); rc = copy_to_user(ubuf, buf, size); if (rc == size) { rc = -EFAULT; goto err_free; } size -= rc; *offp = pos + size; rc = size; err_free: kfree(buf); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe15283.52%266.67%
Allen Hubbe3016.48%133.33%
Total182100.00%3100.00%


static ssize_t tool_mw_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_mw *mw = filep->private_data; ssize_t rc; loff_t pos = *offp; void *buf; if (pos < 0) return -EINVAL; if (pos >= mw->win_size || !size) return 0; if (size > mw->win_size - pos) size = mw->win_size - pos; buf = kmalloc(size, GFP_KERNEL); if (!buf) return -ENOMEM; rc = copy_from_user(buf, ubuf, size); if (rc == size) { rc = -EFAULT; goto err_free; } size -= rc; *offp = pos + size; rc = size; memcpy_toio(mw->local + pos, buf, size); err_free: kfree(buf); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
Logan Gunthorpe14987.13%266.67%
Allen Hubbe2212.87%133.33%
Total171100.00%3100.00%

static TOOL_FOPS_RDWR(tool_mw_fops, tool_mw_read, tool_mw_write);
static ssize_t tool_peer_mw_read(struct file *filep, char __user *ubuf, size_t size, loff_t *offp) { struct tool_mw *mw = filep->private_data; if (!mw->peer) return -ENXIO; return simple_read_from_buffer(ubuf, size, offp, mw->peer, mw->size); }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe4167.21%150.00%
Logan Gunthorpe2032.79%150.00%
Total61100.00%2100.00%


static ssize_t tool_peer_mw_write(struct file *filep, const char __user *ubuf, size_t size, loff_t *offp) { struct tool_mw *mw = filep->private_data; if (!mw->peer) return -ENXIO; return simple_write_to_buffer(mw->peer, mw->size, offp, ubuf, size); }

Contributors

PersonTokensPropCommitsCommitProp
Allen Hubbe4064.52%150.00%
Logan Gunthorpe2235.48%150.00%
Total62100.00%2100.00%

static TOOL_FOPS_RDWR(tool_peer_mw_fops, tool_peer_mw_read, tool_peer_mw_write);
static int tool_setup_mw(struct tool_ctx *tc, int idx, size_t req_size) { int rc; struct tool_mw *mw = &tc->mws[idx]; resource_size_t size, align_addr, align_size; char buf[16]; if (mw->peer) return 0; rc = ntb_mw_get_align(tc->ntb, PIDX, idx, &align_addr, &align_size, &size); if (rc) return rc; mw->size = min_t(resource_size_t, req_size, size); mw->size = round_up(mw->size, align_addr); mw->size = round_up(mw->size, align_size); mw->peer = dma_alloc_coherent(&tc->ntb->pdev->dev, mw->size, &mw->peer_dma, GFP_KERNEL); if (!mw->peer || !IS_ALIGNED(mw->peer_dma, align_addr)) return -ENOMEM; rc = ntb_mw_set_trans(tc->ntb, PIDX, idx, mw->peer_dma, mw->size); if (rc) goto err_free_dma; snprintf(buf, sizeof(buf), "peer_mw%d", idx); mw->peer_dbg_file