[PATCH 02/22] PCI: Unify PCI error response checking
From: Naveen Naidu <hidden>
Date: 2021-10-11 17:39:04
Also in:
linux-pci, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
An MMIO read from a PCI device that doesn't exist or doesn't respond causes a PCI error. There's no real data to return to satisfy the CPU read, so most hardware fabricates ~0 data. Use SET_PCI_ERROR_RESPONSE() to set the error response and RESPONSE_IS_PCI_ERROR() to check the error response during hardware read. These definitions make error checks consistent and easier to find. Signed-off-by: Naveen Naidu <redacted> --- drivers/pci/access.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 46935695cfb9..e1954bbbd137 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c@@ -81,7 +81,7 @@ int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn, addr = bus->ops->map_bus(bus, devfn, where); if (!addr) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; }
@@ -123,7 +123,7 @@ int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn, addr = bus->ops->map_bus(bus, devfn, where & ~0x3); if (!addr) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; }
@@ -411,10 +411,10 @@ int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val) ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val); /* * Reset *val to 0 if pci_read_config_word() fails, it may - * have been written as 0xFFFF if hardware error happens - * during pci_read_config_word(). + * have been written as 0xFFFF (PCI_ERROR_RESPONSE) if hardware error + * happens during pci_read_config_word(). */ - if (ret) + if (RESPONSE_IS_PCI_ERROR(val)) *val = 0; return ret; }
@@ -446,10 +446,10 @@ int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val) ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val); /* * Reset *val to 0 if pci_read_config_dword() fails, it may - * have been written as 0xFFFFFFFF if hardware error happens - * during pci_read_config_dword(). + * have been written as 0xFFFFFFFF (PCI_ERROR_RESPONSE) if hardware + * error happens during pci_read_config_dword(). */ - if (ret) + if (RESPONSE_IS_PCI_ERROR(val)) *val = 0; return ret; }
@@ -523,7 +523,7 @@ EXPORT_SYMBOL(pcie_capability_clear_and_set_dword); int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val) { if (pci_dev_is_disconnected(dev)) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; } return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
@@ -533,7 +533,7 @@ EXPORT_SYMBOL(pci_read_config_byte); int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val) { if (pci_dev_is_disconnected(dev)) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; } return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
@@ -544,7 +544,7 @@ int pci_read_config_dword(const struct pci_dev *dev, int where, u32 *val) { if (pci_dev_is_disconnected(dev)) { - *val = ~0; + SET_PCI_ERROR_RESPONSE(val); return PCIBIOS_DEVICE_NOT_FOUND; } return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
--
2.25.1
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