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PCI: Add pci_status_get_and_clear_errors

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Several drivers use the following code sequence:
1. Read PCI_STATUS
2. Mask out non-error bits
3. Action based on error bits set
4. Write back set error bits to clear them

As this is a repeated pattern, add a helper to the PCI core.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Heiner Kallweit 2020-02-29 23:24:23 +01:00 committed by David S. Miller
parent d6e055e873
commit ec5d9e8784
2 changed files with 24 additions and 0 deletions
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23
drivers/pci/pci.c
View File

@ -173,6 +173,29 @@ unsigned char pci_bus_max_busnr(struct pci_bus *bus)
}
EXPORT_SYMBOL_GPL(pci_bus_max_busnr);
/**
* pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS
* @pdev: the PCI device
*
* Returns error bits set in PCI_STATUS and clears them.
*/
int pci_status_get_and_clear_errors(struct pci_dev *pdev)
{
u16 status;
int ret;
ret = pci_read_config_word(pdev, PCI_STATUS, &status);
if (ret != PCIBIOS_SUCCESSFUL)
return -EIO;
status &= PCI_STATUS_ERROR_BITS;
if (status)
pci_write_config_word(pdev, PCI_STATUS, status);
return status;
}
EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors);
#ifdef CONFIG_HAS_IOMEM
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
{

1
include/linux/pci.h
View File

@ -1210,6 +1210,7 @@ int pci_select_bars(struct pci_dev *dev, unsigned long flags);
bool pci_device_is_present(struct pci_dev *pdev);
void pci_ignore_hotplug(struct pci_dev *dev);
struct pci_dev *pci_real_dma_dev(struct pci_dev *dev);
int pci_status_get_and_clear_errors(struct pci_dev *pdev);
int __printf(6, 7) pci_request_irq(struct pci_dev *dev, unsigned int nr,
irq_handler_t handler, irq_handler_t thread_fn, void *dev_id,