/*
 * UIO Hilscher CIF card driver
 *
 * (C) 2007 Hans J. Koch <hjk@hansjkoch.de>
 * Original code (C) 2005 Benedikt Spranger <b.spranger@linutronix.de>
 *
 * Licensed under GPL version 2 only.
 *
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/uio_driver.h>

#include <asm/io.h>

#define PLX9030_INTCSR		0x4C
#define INTSCR_INT1_ENABLE	0x01
#define INTSCR_INT1_STATUS	0x04
#define INT1_ENABLED_AND_ACTIVE	(INTSCR_INT1_ENABLE | INTSCR_INT1_STATUS)

#define PCI_SUBVENDOR_ID_PEP	0x1518
#define CIF_SUBDEVICE_PROFIBUS	0x430
#define CIF_SUBDEVICE_DEVICENET	0x432


static irqreturn_t hilscher_handler(int irq, struct uio_info *dev_info)
{
	void __iomem *plx_intscr = dev_info->mem[0].internal_addr
					+ PLX9030_INTCSR;

	if ((ioread8(plx_intscr) & INT1_ENABLED_AND_ACTIVE)
	    != INT1_ENABLED_AND_ACTIVE)
		return IRQ_NONE;

	/* Disable interrupt */
	iowrite8(ioread8(plx_intscr) & ~INTSCR_INT1_ENABLE, plx_intscr);
	return IRQ_HANDLED;
}

static int hilscher_pci_probe(struct pci_dev *dev,
					const struct pci_device_id *id)
{
	struct uio_info *info;

	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	if (pci_enable_device(dev))
		goto out_free;

	if (pci_request_regions(dev, "hilscher"))
		goto out_disable;

	info->mem[0].addr = pci_resource_start(dev, 0);
	if (!info->mem[0].addr)
		goto out_release;
	info->mem[0].internal_addr = pci_ioremap_bar(dev, 0);
	if (!info->mem[0].internal_addr)
		goto out_release;

	info->mem[0].size = pci_resource_len(dev, 0);
	info->mem[0].memtype = UIO_MEM_PHYS;
	info->mem[1].addr = pci_resource_start(dev, 2);
	info->mem[1].size = pci_resource_len(dev, 2);
	info->mem[1].memtype = UIO_MEM_PHYS;
	switch (id->subdevice) {
		case CIF_SUBDEVICE_PROFIBUS:
			info->name = "CIF_Profibus";
			break;
		case CIF_SUBDEVICE_DEVICENET:
			info->name = "CIF_Devicenet";
			break;
		default:
			info->name = "CIF_???";
	}
	info->version = "0.0.1";
	info->irq = dev->irq;
	info->irq_flags = IRQF_SHARED;
	info->handler = hilscher_handler;

	if (uio_register_device(&dev->dev, info))
		goto out_unmap;

	pci_set_drvdata(dev, info);

	return 0;
out_unmap:
	iounmap(info->mem[0].internal_addr);
out_release:
	pci_release_regions(dev);
out_disable:
	pci_disable_device(dev);
out_free:
	kfree (info);
	return -ENODEV;
}

static void hilscher_pci_remove(struct pci_dev *dev)
{
	struct uio_info *info = pci_get_drvdata(dev);

	uio_unregister_device(info);
	pci_release_regions(dev);
	pci_disable_device(dev);
	iounmap(info->mem[0].internal_addr);

	kfree (info);
}

static struct pci_device_id hilscher_pci_ids[] = {
	{
		.vendor =	PCI_VENDOR_ID_PLX,
		.device =	PCI_DEVICE_ID_PLX_9030,
		.subvendor =	PCI_SUBVENDOR_ID_PEP,
		.subdevice =	CIF_SUBDEVICE_PROFIBUS,
	},
	{
		.vendor =	PCI_VENDOR_ID_PLX,
		.device =	PCI_DEVICE_ID_PLX_9030,
		.subvendor =	PCI_SUBVENDOR_ID_PEP,
		.subdevice =	CIF_SUBDEVICE_DEVICENET,
	},
	{ 0, }
};

static struct pci_driver hilscher_pci_driver = {
	.name = "hilscher",
	.id_table = hilscher_pci_ids,
	.probe = hilscher_pci_probe,
	.remove = hilscher_pci_remove,
};

module_pci_driver(hilscher_pci_driver);
MODULE_DEVICE_TABLE(pci, hilscher_pci_ids);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Hans J. Koch, Benedikt Spranger");
</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Iago Abal &lt;mail@iagoabal.eu&gt;</td><td class='right'>2017-01-11 14:00:21 +0100</td></tr>
<tr><th>committer</th><td>Vinod Koul &lt;vinod.koul@intel.com&gt;</td><td class='right'>2017-01-25 15:35:11 +0530</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/unix/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/unix/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>960f5ca6342ad20837aff18aad6e8ecd7da32fd6</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/unix/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>net/unix/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/unix/Kconfig?id=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>6610d0edf6dc7ee97e46ab3a538a565c79d26199</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/unix/Kconfig?id=91539eb1fda2d530d3b268eef542c5414e54bf1a&amp;id2=6610d0edf6dc7ee97e46ab3a538a565c79d26199'>diff</a>)</td></tr></table>
<div class='commit-subject'>dmaengine: pl330: fix double lock</div><div class='commit-msg'>The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:

    Double lock:
    1. spin_lock_irqsave(pch-&gt;lock, flags) at pl330_free_chan_resources:2236;
    2. call to function `pl330_release_channel' immediately after;
    3. call to function `dma_pl330_rqcb' in line 1753;
    4. spin_lock_irqsave(pch-&gt;lock, flags) at dma_pl330_rqcb:1505.

I have fixed it as suggested by Marek Szyprowski.

First, I have replaced `pch-&gt;lock' with `pl330-&gt;lock' in functions
`pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids
the double-lock by acquiring a different lock than `dma_pl330_rqcb'.

NOTE that, as a result, `pl330_free_chan_resources' executes
`list_splice_tail_init' on `pch-&gt;work_list' under lock `pl330-&gt;lock',
whereas in the rest of the code `pch-&gt;work_list' is protected by
`pch-&gt;lock'. I don't know if this may cause race conditions. Similarly
`pch-&gt;cyclic' is written by `pl330_alloc_chan_resources' under
`pl330-&gt;lock' but read by `pl330_tx_submit' under `pch-&gt;lock'.

Second, I have removed locking from `pl330_request_channel' and
`pl330_release_channel' functions. Function `pl330_request_channel' is
only called from `pl330_alloc_chan_resources', so the lock is already
held. Function `pl330_release_channel' is called from
`pl330_free_chan_resources', which already holds the lock, and from
`pl330_del'. Function `pl330_del' is called in an error path of
`pl330_probe' and at the end of `pl330_remove', but I assume that there
cannot be concurrent accesses to the protected data at those points.

Signed-off-by: Iago Abal &lt;mail@iagoabal.eu&gt;
Reviewed-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>Diffstat</a> (limited to 'net/unix/Kconfig')</div><table summary='diffstat' class='diffstat'>