cregit-Linux how code gets into the kernel

Release 4.14 drivers/mailbox/mailbox-test.c

Directory: drivers/mailbox
/*
 * Copyright (C) 2015 ST Microelectronics
 *
 * Author: Lee Jones <lee.jones@linaro.org>
 *
 * 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/debugfs.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/sched/signal.h>


#define MBOX_MAX_SIG_LEN	8

#define MBOX_MAX_MSG_LEN	128

#define MBOX_BYTES_PER_LINE	16

#define MBOX_HEXDUMP_LINE_LEN	((MBOX_BYTES_PER_LINE * 4) + 2)

#define MBOX_HEXDUMP_MAX_LEN	(MBOX_HEXDUMP_LINE_LEN *                \
                                 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))


static struct dentry *root_debugfs_dir;


struct mbox_test_device {
	
struct device		*dev;
	
void __iomem		*tx_mmio;
	
void __iomem		*rx_mmio;
	
struct mbox_chan	*tx_channel;
	
struct mbox_chan	*rx_channel;
	
char			*rx_buffer;
	
char			*signal;
	
char			*message;
	
spinlock_t		lock;
	
wait_queue_head_t	waitq;
	
struct fasync_struct	*async_queue;
};


static ssize_t mbox_test_signal_write(struct file *filp, const char __user *userbuf, size_t count, loff_t *ppos) { struct mbox_test_device *tdev = filp->private_data; if (!tdev->tx_channel) { dev_err(tdev->dev, "Channel cannot do Tx\n"); return -EINVAL; } if (count > MBOX_MAX_SIG_LEN) { dev_err(tdev->dev, "Signal length %zd greater than max allowed %d\n", count, MBOX_MAX_SIG_LEN); return -EINVAL; } /* Only allocate memory if we need to */ if (!tdev->signal) { tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL); if (!tdev->signal) return -ENOMEM; } if (copy_from_user(tdev->signal, userbuf, count)) { kfree(tdev->signal); tdev->signal = NULL; return -EFAULT; } return count; }

Contributors

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Lee Jones147100.00%4100.00%
Total147100.00%4100.00%

static const struct file_operations mbox_test_signal_ops = { .write = mbox_test_signal_write, .open = simple_open, .llseek = generic_file_llseek, };
static int mbox_test_message_fasync(int fd, struct file *filp, int on) { struct mbox_test_device *tdev = filp->private_data; return fasync_helper(fd, filp, on, &tdev->async_queue); }

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Sudeep Holla41100.00%1100.00%
Total41100.00%1100.00%


static ssize_t mbox_test_message_write(struct file *filp, const char __user *userbuf, size_t count, loff_t *ppos) { struct mbox_test_device *tdev = filp->private_data; void *data; int ret; if (!tdev->tx_channel) { dev_err(tdev->dev, "Channel cannot do Tx\n"); return -EINVAL; } if (count > MBOX_MAX_MSG_LEN) { dev_err(tdev->dev, "Message length %zd greater than max allowed %d\n", count, MBOX_MAX_MSG_LEN); return -EINVAL; } tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL); if (!tdev->message) return -ENOMEM; ret = copy_from_user(tdev->message, userbuf, count); if (ret) { ret = -EFAULT; goto out; } /* * A separate signal is only of use if there is * MMIO to subsequently pass the message through */ if (tdev->tx_mmio && tdev->signal) { print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS, tdev->signal, MBOX_MAX_SIG_LEN); data = tdev->signal; } else data = tdev->message; print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS, tdev->message, MBOX_MAX_MSG_LEN); ret = mbox_send_message(tdev->tx_channel, data); if (ret < 0) dev_err(tdev->dev, "Failed to send message via mailbox\n"); out: kfree(tdev->signal); kfree(tdev->message); tdev->signal = NULL; return ret < 0 ? ret : count; }

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Lee Jones23696.33%240.00%
Sudeep Holla93.67%360.00%
Total245100.00%5100.00%


static bool mbox_test_message_data_ready(struct mbox_test_device *tdev) { unsigned char data; unsigned long flags; spin_lock_irqsave(&tdev->lock, flags); data = tdev->rx_buffer[0]; spin_unlock_irqrestore(&tdev->lock, flags); if (data != '\0') return true; return false; }

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Sudeep Holla60100.00%1100.00%
Total60100.00%1100.00%


static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf, size_t count, loff_t *ppos) { struct mbox_test_device *tdev = filp->private_data; unsigned long flags; char *touser, *ptr; int l = 0; int ret; DECLARE_WAITQUEUE(wait, current); touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL); if (!touser) return -ENOMEM; if (!tdev->rx_channel) { ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n"); ret = simple_read_from_buffer(userbuf, count, ppos, touser, ret); goto kfree_err; } add_wait_queue(&tdev->waitq, &wait); do { __set_current_state(TASK_INTERRUPTIBLE); if (mbox_test_message_data_ready(tdev)) break; if (filp->f_flags & O_NONBLOCK) { ret = -EAGAIN; goto waitq_err; } if (signal_pending(current)) { ret = -ERESTARTSYS; goto waitq_err; } schedule(); } while (1); spin_lock_irqsave(&tdev->lock, flags); ptr = tdev->rx_buffer; while (l < MBOX_HEXDUMP_MAX_LEN) { hex_dump_to_buffer(ptr, MBOX_BYTES_PER_LINE, MBOX_BYTES_PER_LINE, 1, touser + l, MBOX_HEXDUMP_LINE_LEN, true); ptr += MBOX_BYTES_PER_LINE; l += MBOX_HEXDUMP_LINE_LEN; *(touser + (l - 1)) = '\n'; } *(touser + l) = '\0'; memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN); spin_unlock_irqrestore(&tdev->lock, flags); ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN); waitq_err: __set_current_state(TASK_RUNNING); remove_wait_queue(&tdev->waitq, &wait); kfree_err: kfree(touser); return ret; }

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Lee Jones24074.30%133.33%
Sudeep Holla8125.08%133.33%
Dan Carpenter20.62%133.33%
Total323100.00%3100.00%


static unsigned int mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait) { struct mbox_test_device *tdev = filp->private_data; poll_wait(filp, &tdev->waitq, wait); if (mbox_test_message_data_ready(tdev)) return POLLIN | POLLRDNORM; return 0; }

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Sudeep Holla53100.00%1100.00%
Total53100.00%1100.00%

static const struct file_operations mbox_test_message_ops = { .write = mbox_test_message_write, .read = mbox_test_message_read, .fasync = mbox_test_message_fasync, .poll = mbox_test_message_poll, .open = simple_open, .llseek = generic_file_llseek, };
static int mbox_test_add_debugfs(struct platform_device *pdev, struct mbox_test_device *tdev) { if (!debugfs_initialized()) return 0; root_debugfs_dir = debugfs_create_dir("mailbox", NULL); if (!root_debugfs_dir) { dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n"); return -EINVAL; } debugfs_create_file("message", 0600, root_debugfs_dir, tdev, &mbox_test_message_ops); debugfs_create_file("signal", 0200, root_debugfs_dir, tdev, &mbox_test_signal_ops); return 0; }

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Lee Jones86100.00%1100.00%
Total86100.00%1100.00%


static void mbox_test_receive_message(struct mbox_client *client, void *message) { struct mbox_test_device *tdev = dev_get_drvdata(client->dev); unsigned long flags; spin_lock_irqsave(&tdev->lock, flags); if (tdev->rx_mmio) { memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN); print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS, tdev->rx_buffer, MBOX_MAX_MSG_LEN); } else if (message) { print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS, message, MBOX_MAX_MSG_LEN); memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN); } spin_unlock_irqrestore(&tdev->lock, flags); wake_up_interruptible(&tdev->waitq); kill_fasync(&tdev->async_queue, SIGIO, POLL_IN); }

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Lee Jones9772.39%120.00%
Sudeep Holla2417.91%360.00%
Jassi Brar139.70%120.00%
Total134100.00%5100.00%


static void mbox_test_prepare_message(struct mbox_client *client, void *message) { struct mbox_test_device *tdev = dev_get_drvdata(client->dev); if (tdev->tx_mmio) { if (tdev->signal) memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN); else memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN); } }

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Lee Jones6395.45%266.67%
Sudeep Holla34.55%133.33%
Total66100.00%3100.00%


static void mbox_test_message_sent(struct mbox_client *client, void *message, int r) { if (r) dev_warn(client->dev, "Client: Message could not be sent: %d\n", r); else dev_info(client->dev, "Client: Message sent\n"); }

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Lee Jones43100.00%1100.00%
Total43100.00%1100.00%


static struct mbox_chan * mbox_test_request_channel(struct platform_device *pdev, const char *name) { struct mbox_client *client; struct mbox_chan *channel; client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL); if (!client) return ERR_PTR(-ENOMEM); client->dev = &pdev->dev; client->rx_callback = mbox_test_receive_message; client->tx_prepare = mbox_test_prepare_message; client->tx_done = mbox_test_message_sent; client->tx_block = true; client->knows_txdone = false; client->tx_tout = 500; channel = mbox_request_channel_byname(client, name); if (IS_ERR(channel)) { dev_warn(&pdev->dev, "Failed to request %s channel\n", name); return NULL; } return channel; }

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Lee Jones139100.00%1100.00%
Total139100.00%1100.00%


static int mbox_test_probe(struct platform_device *pdev) { struct mbox_test_device *tdev; struct resource *res; resource_size_t size; int ret; tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL); if (!tdev) return -ENOMEM; /* It's okay for MMIO to be NULL */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); size = resource_size(res); tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res); if (PTR_ERR(tdev->tx_mmio) == -EBUSY) /* if reserved area in SRAM, try just ioremap */ tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size); else if (IS_ERR(tdev->tx_mmio)) tdev->tx_mmio = NULL; /* If specified, second reg entry is Rx MMIO */ res = platform_get_resource(pdev, IORESOURCE_MEM, 1); size = resource_size(res); tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res); if (PTR_ERR(tdev->rx_mmio) == -EBUSY) tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size); else if (IS_ERR(tdev->rx_mmio)) tdev->rx_mmio = tdev->tx_mmio; tdev->tx_channel = mbox_test_request_channel(pdev, "tx"); tdev->rx_channel = mbox_test_request_channel(pdev, "rx"); if (!tdev->tx_channel && !tdev->rx_channel) return -EPROBE_DEFER; /* If Rx is not specified but has Rx MMIO, then Rx = Tx */ if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio)) tdev->rx_channel = tdev->tx_channel; tdev->dev = &pdev->dev; platform_set_drvdata(pdev, tdev); spin_lock_init(&tdev->lock); if (tdev->rx_channel) { tdev->rx_buffer = devm_kzalloc(&pdev->dev, MBOX_MAX_MSG_LEN, GFP_KERNEL); if (!tdev->rx_buffer) return -ENOMEM; } ret = mbox_test_add_debugfs(pdev, tdev); if (ret) return ret; init_waitqueue_head(&tdev->waitq); dev_info(&pdev->dev, "Successfully registered\n"); return 0; }

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PersonTokensPropCommitsCommitProp
Lee Jones21557.33%240.00%
Sudeep Holla16042.67%360.00%
Total375100.00%5100.00%


static int mbox_test_remove(struct platform_device *pdev) { struct mbox_test_device *tdev = platform_get_drvdata(pdev); debugfs_remove_recursive(root_debugfs_dir); if (tdev->tx_channel) mbox_free_channel(tdev->tx_channel); if (tdev->rx_channel) mbox_free_channel(tdev->rx_channel); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Lee Jones55100.00%1100.00%
Total55100.00%1100.00%

static const struct of_device_id mbox_test_match[] = { { .compatible = "mailbox-test" }, {}, }; MODULE_DEVICE_TABLE(of, mbox_test_match); static struct platform_driver mbox_test_driver = { .driver = { .name = "mailbox_test", .of_match_table = mbox_test_match, }, .probe = mbox_test_probe, .remove = mbox_test_remove, }; module_platform_driver(mbox_test_driver); MODULE_DESCRIPTION("Generic Mailbox Testing Facility"); MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org"); MODULE_LICENSE("GPL v2");

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Lee Jones153675.89%531.25%
Sudeep Holla46322.88%743.75%
Jassi Brar130.64%16.25%
Javier Martinez Canillas70.35%16.25%
Ingo Molnar30.15%16.25%
Dan Carpenter20.10%16.25%
Total2024100.00%16100.00%
Directory: drivers/mailbox
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