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| author | Naveen Naidu <naveennaidu479@gmail.com> | 2021-11-18 15:03:12 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2021-11-18 20:36:55 +0100 |
| commit | f4f7eb43c5238fd2636a8e310394ed9920627ab3 (patch) | |
| tree | f4c217546186901a72dc93feb6ea060041d48344 /drivers/pci/access.c | |
| parent | PCI: Add PCI_ERROR_RESPONSE and related definitions (diff) | |
| download | linux-f4f7eb43c5238fd2636a8e310394ed9920627ab3.tar.xz linux-f4f7eb43c5238fd2636a8e310394ed9920627ab3.zip | |
PCI: Set error response data when config read fails
When a PCI config read fails, most PCI host bridges fabricate ~0 data to
complete the CPU read. But some host bridges do not; their drivers may
only return an error from the pci_ops.read() method.
In PCI_OP_READ() and PCI_USER_READ_CONFIG(), use PCI_SET_ERROR_RESPONSE()
to set the data value to indicate an error when pci_ops.read() fails.
This means the host bridge driver no longer needs to fabricate error data
when they detect errors.
This makes error response fabrication consistent and helps in removal of a
lot of repeated code.
Suggested-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/4188fc5465631ce0d472d1423de3d9fb2f09b8ff.1637243717.git.naveennaidu479@gmail.com
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Pali Rohár <pali@kernel.org>
Diffstat (limited to 'drivers/pci/access.c')
| -rw-r--r-- | drivers/pci/access.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 46935695cfb9..eac0765d8bed 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -42,7 +42,10 @@ int noinline pci_bus_read_config_##size \ if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ pci_lock_config(flags); \ res = bus->ops->read(bus, devfn, pos, len, &data); \ - *value = (type)data; \ + if (res) \ + PCI_SET_ERROR_RESPONSE(value); \ + else \ + *value = (type)data; \ pci_unlock_config(flags); \ return res; \ } @@ -228,7 +231,10 @@ int pci_user_read_config_##size \ ret = dev->bus->ops->read(dev->bus, dev->devfn, \ pos, sizeof(type), &data); \ raw_spin_unlock_irq(&pci_lock); \ - *val = (type)data; \ + if (ret) \ + PCI_SET_ERROR_RESPONSE(val); \ + else \ + *val = (type)data; \ return pcibios_err_to_errno(ret); \ } \ EXPORT_SYMBOL_GPL(pci_user_read_config_##size); |