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@xxxxxxxxx>
---
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
