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