On Sat, Feb 29, 2020 at 11:24:23PM +0100, Heiner Kallweit wrote:

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

Nit: if you have any reason to revise this, I would prefer "pci_status_get_and_clear_errors()" (with parens) in the subject.

---

v4:

• improve commit description

---

drivers/pci/pci.c | 23 +++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 24 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d828ca835..c16b0ba2a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -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) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 101d71e0a..7beaf51e9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -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, -- 2.25.1