linux/drivers/spi/pxa2xx_spi_pci.c
Sebastian Andrzej Siewior 0f3e1d27a7 spi/pxa2xx pci: fix the release - remove race
Right now the platform device and its platform data is included in one big
struct which requires its custom ->release function. The problem with the
release function within the driver is that it might be called after the
driver was removed because someone was holding a reference to it and it
was not called right after platform_device_unregister(). So we also free
the platform device memory to which one might hold a reference.

This patch uses the normal pdev functions so this kind of race does not
occur.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-02-15 13:25:36 -07:00

183 lines
4.0 KiB
C

/*
* CE4100's SPI device is more or less the same one as found on PXA
*
*/
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/spi/pxa2xx_spi.h>
struct ce4100_info {
struct ssp_device ssp;
struct platform_device *spi_pdev;
};
static DEFINE_MUTEX(ssp_lock);
static LIST_HEAD(ssp_list);
struct ssp_device *pxa_ssp_request(int port, const char *label)
{
struct ssp_device *ssp = NULL;
mutex_lock(&ssp_lock);
list_for_each_entry(ssp, &ssp_list, node) {
if (ssp->port_id == port && ssp->use_count == 0) {
ssp->use_count++;
ssp->label = label;
break;
}
}
mutex_unlock(&ssp_lock);
if (&ssp->node == &ssp_list)
return NULL;
return ssp;
}
EXPORT_SYMBOL_GPL(pxa_ssp_request);
void pxa_ssp_free(struct ssp_device *ssp)
{
mutex_lock(&ssp_lock);
if (ssp->use_count) {
ssp->use_count--;
ssp->label = NULL;
} else
dev_err(&ssp->pdev->dev, "device already free\n");
mutex_unlock(&ssp_lock);
}
EXPORT_SYMBOL_GPL(pxa_ssp_free);
static int __devinit ce4100_spi_probe(struct pci_dev *dev,
const struct pci_device_id *ent)
{
int ret;
resource_size_t phys_beg;
resource_size_t phys_len;
struct ce4100_info *spi_info;
struct platform_device *pdev;
struct pxa2xx_spi_master spi_pdata;
struct ssp_device *ssp;
ret = pci_enable_device(dev);
if (ret)
return ret;
phys_beg = pci_resource_start(dev, 0);
phys_len = pci_resource_len(dev, 0);
if (!request_mem_region(phys_beg, phys_len,
"CE4100 SPI")) {
dev_err(&dev->dev, "Can't request register space.\n");
ret = -EBUSY;
return ret;
}
pdev = platform_device_alloc("pxa2xx-spi", dev->devfn);
spi_info = kzalloc(sizeof(*spi_info), GFP_KERNEL);
if (!pdev || !spi_info ) {
ret = -ENOMEM;
goto err_nomem;
}
memset(&spi_pdata, 0, sizeof(spi_pdata));
spi_pdata.num_chipselect = dev->devfn;
ret = platform_device_add_data(pdev, &spi_pdata, sizeof(spi_pdata));
if (ret)
goto err_nomem;
pdev->dev.parent = &dev->dev;
#ifdef CONFIG_OF
pdev->dev.of_node = dev->dev.of_node;
#endif
ssp = &spi_info->ssp;
ssp->phys_base = pci_resource_start(dev, 0);
ssp->mmio_base = ioremap(phys_beg, phys_len);
if (!ssp->mmio_base) {
dev_err(&pdev->dev, "failed to ioremap() registers\n");
ret = -EIO;
goto err_nomem;
}
ssp->irq = dev->irq;
ssp->port_id = pdev->id;
ssp->type = PXA25x_SSP;
mutex_lock(&ssp_lock);
list_add(&ssp->node, &ssp_list);
mutex_unlock(&ssp_lock);
pci_set_drvdata(dev, spi_info);
ret = platform_device_add(pdev);
if (ret)
goto err_dev_add;
return ret;
err_dev_add:
pci_set_drvdata(dev, NULL);
mutex_lock(&ssp_lock);
list_del(&ssp->node);
mutex_unlock(&ssp_lock);
iounmap(ssp->mmio_base);
err_nomem:
release_mem_region(phys_beg, phys_len);
platform_device_put(pdev);
kfree(spi_info);
return ret;
}
static void __devexit ce4100_spi_remove(struct pci_dev *dev)
{
struct ce4100_info *spi_info;
struct ssp_device *ssp;
spi_info = pci_get_drvdata(dev);
ssp = &spi_info->ssp;
platform_device_unregister(spi_info->spi_pdev);
iounmap(ssp->mmio_base);
release_mem_region(pci_resource_start(dev, 0),
pci_resource_len(dev, 0));
mutex_lock(&ssp_lock);
list_del(&ssp->node);
mutex_unlock(&ssp_lock);
pci_set_drvdata(dev, NULL);
pci_disable_device(dev);
kfree(spi_info);
}
static struct pci_device_id ce4100_spi_devices[] __devinitdata = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2e6a) },
{ },
};
MODULE_DEVICE_TABLE(pci, ce4100_spi_devices);
static struct pci_driver ce4100_spi_driver = {
.name = "ce4100_spi",
.id_table = ce4100_spi_devices,
.probe = ce4100_spi_probe,
.remove = __devexit_p(ce4100_spi_remove),
};
static int __init ce4100_spi_init(void)
{
return pci_register_driver(&ce4100_spi_driver);
}
module_init(ce4100_spi_init);
static void __exit ce4100_spi_exit(void)
{
pci_unregister_driver(&ce4100_spi_driver);
}
module_exit(ce4100_spi_exit);
MODULE_DESCRIPTION("CE4100 PCI-SPI glue code for PXA's driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>");