Re: [PATCH v3] PCI/AER: Use pci_clear_and_set_config_dword() to simplify mask updates

[Hans Zhang]

On 2025/8/17 04:25, Lukas Wunner wrote:
On Sun, Aug 17, 2025 at 12:17:43AM +0800, Hans Zhang wrote:
Replace manual read-modify-write sequences in multiple functions with
pci_clear_and_set_config_dword() helper to reduce code duplication.

None of the occurrences you're replacing is clearing *and* setting
bits at the same time.  They all either clear or set bits, but not both.

For the PCIe Capability, there are pcie_capability_clear_dword()
and pcie_capability_set_dword() helpers.

It would arguably be clearer and less confusing to introduce similar
pci_clear_config_dword() and pci_set_config_dword() helpers and use
those, instead of using pci_clear_and_set_config_dword() and setting
one argument to 0.


Dear Lukas,

Thank you very much for your reply and suggestions.

In the next version, I will introduce two helper functions, 
pci_clear_config_dword() and pci_set_config_dword().

Best regards,
Hans


Thanks,

Lukas

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index e286c197d716..3d37e2b7e412 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -176,14 +176,13 @@ static int enable_ecrc_checking(struct pci_dev *dev)
  static int disable_ecrc_checking(struct pci_dev *dev)
  {
        int aer = dev->aer_cap;
-       u32 reg32;
  
  	if (!aer)
                return -ENODEV;
  
-	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
-       reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
-       pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
+       pci_clear_and_set_config_dword(dev, aer + PCI_ERR_CAP,
+                                      PCI_ERR_CAP_ECRC_GENE |
+                                      PCI_ERR_CAP_ECRC_CHKE, 0);
  
  	return 0;
  }
@@ -1102,15 +1101,12 @@ static bool find_source_device(struct pci_dev *parent,
  static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
  {
        int aer = dev->aer_cap;
-       u32 mask;
  
-	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
-       mask &= ~PCI_ERR_UNC_INTN;
-       pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, mask);
+       pci_clear_and_set_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
+                                      PCI_ERR_UNC_INTN, 0);
  
-	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
-       mask &= ~PCI_ERR_COR_INTERNAL;
-       pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, mask);
+       pci_clear_and_set_config_dword(dev, aer + PCI_ERR_COR_MASK,
+                                      PCI_ERR_COR_INTERNAL, 0);
  }
  
  static bool is_cxl_mem_dev(struct pci_dev *dev)
@@ -1556,23 +1552,19 @@ static irqreturn_t aer_irq(int irq, void *context)
  static void aer_enable_irq(struct pci_dev *pdev)
  {
        int aer = pdev->aer_cap;
-       u32 reg32;
  
  	/* Enable Root Port's interrupt in response to error messages */
-       pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
-       reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
-       pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+       pci_clear_and_set_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND,
+                                      0, ROOT_PORT_INTR_ON_MESG_MASK);
  }
  
  static void aer_disable_irq(struct pci_dev *pdev)
  {
        int aer = pdev->aer_cap;
-       u32 reg32;
  
  	/* Disable Root Port's interrupt in response to error messages */
-       pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
-       reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
-       pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+       pci_clear_and_set_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND,
+                                      ROOT_PORT_INTR_ON_MESG_MASK, 0);
  }
  
  /**