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[v9,1/6] PCI: Introduce generic bus config read helper function

Message ID 20250409034156.92686-2-18255117159@163.com (mailing list archive)
State New
Delegated to: Krzysztof WilczyƄski
Headers show
Series Refactor capability search into common macros | expand

Commit Message

Hans Zhang April 9, 2025, 3:41 a.m. UTC
The primary PCI config space accessors are tied to the size of the read
(byte/word/dword). Upcoming refactoring of PCI capability discovery logic
requires passing a config accessor function that must be able to perform
read with different sizes.

Add any size config space read accessor pci_bus_read_config() to allow
giving it as the config space accessor to the upcoming PCI capability
discovery macro.

Reconstructs the PCI function discovery logic to prepare for unified
configuration of access modes. No function changes are intended.

Signed-off-by: Hans Zhang <18255117159@163.com>
---
Changes since v8:
- The new split is patch 1/6.
- The patch commit message were modified.
---
 drivers/pci/access.c | 17 +++++++++++++++++
 drivers/pci/pci.h    |  2 ++
 2 files changed, 19 insertions(+)
diff mbox series

Patch

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index b123da16b63b..603332658ab3 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -85,6 +85,23 @@  EXPORT_SYMBOL(pci_bus_write_config_byte);
 EXPORT_SYMBOL(pci_bus_write_config_word);
 EXPORT_SYMBOL(pci_bus_write_config_dword);
 
+int pci_bus_read_config(void *priv, unsigned int devfn, int where, u32 size,
+			u32 *val)
+{
+	struct pci_bus *bus = priv;
+	int ret;
+
+	if (size == 1)
+		ret = pci_bus_read_config_byte(bus, devfn, where, (u8 *)val);
+	else if (size == 2)
+		ret = pci_bus_read_config_word(bus, devfn, where, (u16 *)val);
+	else
+		ret = pci_bus_read_config_dword(bus, devfn, where, val);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_bus_read_config);
+
 int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
 			    int where, int size, u32 *val)
 {
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b81e99cd4b62..5e1477d6e254 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -88,6 +88,8 @@  extern bool pci_early_dump;
 bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
 bool pcie_cap_has_lnkctl2(const struct pci_dev *dev);
 bool pcie_cap_has_rtctl(const struct pci_dev *dev);
+int pci_bus_read_config(void *priv, unsigned int devfn, int where, u32 size,
+			u32 *val);
 
 /* Functions internal to the PCI core code */