Re: [PATCH 0/8 v2] PCI: Align return values of PCIe capability and PCI accessors
From: Bjorn Helgaas
Date: Fri Jun 26 2020 - 14:52:10 EST
On Mon, Jun 15, 2020 at 09:32:17AM +0200, refactormyself@xxxxxxxxx wrote:
> From: Bolarinwa Olayemi Saheed <refactormyself@xxxxxxxxx>
>
>
> PATCH 1/8 to 7/8:
> PCIBIOS_ error codes have positive values and they are passed down the
> call heirarchy from accessors. For functions which are meant to return
> only a negative value on failure, passing on this value is a bug.
> To mitigate this, call pcibios_err_to_errno() before passing on return
> value from PCIe capability accessors call heirarchy. This function
> converts any positive PCIBIOS_ error codes to negative generic error
> values.
>
> PATCH 8/8:
> The PCIe capability accessors can return 0, -EINVAL, or any PCIBIOS_ error
> code. The pci accessor on the other hand can only return 0 or any PCIBIOS_
> error code.This inconsistency among these accessor makes it harder for
> callers to check for errors.
> Return PCIBIOS_BAD_REGISTER_NUMBER instead of -EINVAL in all PCIe
> capability accessors.
>
> MERGING:
> These may all be merged via the PCI tree, since it is a collection of
> similar fixes. This way they all get merged at once.
>
> Version 2:
> * cc to maintainers and mailing lists
> * Edit the Subject to conform with previous style
> * reorder "Signed by" and "Suggested by"
> * made spelling corrections
> * fixed redundant initialisation in PATCH 3/8
> * include missing call to pcibios_err_to_errno() in PATCH 6/8 and 7/8
>
>
> Bolarinwa Olayemi Saheed (8):
> dmaengine: ioatdma: Convert PCIBIOS_* errors to generic -E* errors
> IB/hfi1: Convert PCIBIOS_* errors to generic -E* errors
> IB/hfi1: Convert PCIBIOS_* errors to generic -E* errors
> PCI: Convert PCIBIOS_* errors to generic -E* errors
> scsi: smartpqi: Convert PCIBIOS_* errors to generic -E* errors
> PCI/AER: Convert PCIBIOS_* errors to generic -E* errors
> PCI/AER: Convert PCIBIOS_* errors to generic -E* errors
> PCI: Align return values of PCIe capability and PCI accessorss
>
> drivers/dma/ioat/init.c | 4 ++--
> drivers/infiniband/hw/hfi1/pcie.c | 18 +++++++++++++-----
> drivers/pci/access.c | 8 ++++----
> drivers/pci/pci.c | 10 ++++++++--
> drivers/pci/pcie/aer.c | 12 ++++++++++--
> drivers/scsi/smartpqi/smartpqi_init.c | 6 +++++-
> 6 files changed, 42 insertions(+), 16 deletions(-)
Since these are really fixing a single PCI API problem, not individual
driver-related problems, I squashed the pcibios_err_to_errno() patches
together (except IB/hfi1, since Jason will take those separately) and
applied them to pci/misc, thanks!
The squashed patch as applied is:
commit d20df83b66cc ("PCI: Convert PCIe capability PCIBIOS errors to errno")
Author: Bolarinwa Olayemi Saheed <refactormyself@xxxxxxxxx>
Date: Mon Jun 15 09:32:18 2020 +0200
PCI: Convert PCIe capability PCIBIOS errors to errno
The PCI config accessors (pci_read_config_word(), et al) return
PCIBIOS_SUCCESSFUL (zero) or positive error values like
PCIBIOS_FUNC_NOT_SUPPORTED.
The PCIe capability accessors (pcie_capability_read_word(), et al)
similarly return PCIBIOS errors, but some callers assume they return
generic errno values like -EINVAL.
For example, the Myri-10G probe function returns a positive PCIBIOS error
if the pcie_capability_clear_and_set_word() in pcie_set_readrq() fails:
myri10ge_probe
status = pcie_set_readrq
return pcie_capability_clear_and_set_word
if (status)
return status
A positive return from a PCI driver probe function would cause a "Driver
probe function unexpectedly returned" warning from local_pci_probe()
instead of the desired probe failure.
Convert PCIBIOS errors to generic errno for all callers of:
pcie_capability_read_word
pcie_capability_read_dword
pcie_capability_write_word
pcie_capability_write_dword
pcie_capability_set_word
pcie_capability_set_dword
pcie_capability_clear_word
pcie_capability_clear_dword
pcie_capability_clear_and_set_word
pcie_capability_clear_and_set_dword
that check the return code for anything other than zero.
[bhelgaas: commit log, squash together]
Suggested-by: Bjorn Helgaas <bjorn@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200615073225.24061-1-refactormyself@xxxxxxxxx
Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index 58d13564f88b..9a6a9ec3cf48 100644
--- a/drivers/dma/ioat/init.c
+++ b/drivers/dma/ioat/init.c
@@ -1195,13 +1195,13 @@ static int ioat3_dma_probe(struct ioatdma_device *ioat_dma, int dca)
/* disable relaxed ordering */
err = pcie_capability_read_word(pdev, IOAT_DEVCTRL_OFFSET, &val16);
if (err)
- return err;
+ return pcibios_err_to_errno(err);
/* clear relaxed ordering enable */
val16 &= ~IOAT_DEVCTRL_ROE;
err = pcie_capability_write_word(pdev, IOAT_DEVCTRL_OFFSET, val16);
if (err)
- return err;
+ return pcibios_err_to_errno(err);
if (ioat_dma->cap & IOAT_CAP_DPS)
writeb(ioat_pending_level + 1,
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ce096272f52b..45c51aff9c03 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5688,6 +5688,7 @@ EXPORT_SYMBOL(pcie_get_readrq);
int pcie_set_readrq(struct pci_dev *dev, int rq)
{
u16 v;
+ int ret;
if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
return -EINVAL;
@@ -5706,8 +5707,10 @@ int pcie_set_readrq(struct pci_dev *dev, int rq)
v = (ffs(rq) - 8) << 12;
- return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
+ ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_READRQ, v);
+
+ return pcibios_err_to_errno(ret);
}
EXPORT_SYMBOL(pcie_set_readrq);
@@ -5738,6 +5741,7 @@ EXPORT_SYMBOL(pcie_get_mps);
int pcie_set_mps(struct pci_dev *dev, int mps)
{
u16 v;
+ int ret;
if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
return -EINVAL;
@@ -5747,8 +5751,10 @@ int pcie_set_mps(struct pci_dev *dev, int mps)
return -EINVAL;
v <<= 5;
- return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
+ ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_DEVCTL_PAYLOAD, v);
+
+ return pcibios_err_to_errno(ret);
}
EXPORT_SYMBOL(pcie_set_mps);
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 3acf56683915..2dbc1fd2910b 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -224,20 +224,25 @@ int pcie_aer_is_native(struct pci_dev *dev)
int pci_enable_pcie_error_reporting(struct pci_dev *dev)
{
+ int rc;
+
if (!pcie_aer_is_native(dev))
return -EIO;
- return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+ rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+ return pcibios_err_to_errno(rc);
}
EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
int pci_disable_pcie_error_reporting(struct pci_dev *dev)
{
+ int rc;
+
if (!pcie_aer_is_native(dev))
return -EIO;
- return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
- PCI_EXP_AER_FLAGS);
+ rc = pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+ return pcibios_err_to_errno(rc);
}
EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index cd157f11eb22..bd38c8cea56e 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -7423,8 +7423,12 @@ static int pqi_ctrl_init_resume(struct pqi_ctrl_info *ctrl_info)
static inline int pqi_set_pcie_completion_timeout(struct pci_dev *pci_dev,
u16 timeout)
{
- return pcie_capability_clear_and_set_word(pci_dev, PCI_EXP_DEVCTL2,
+ int rc;
+
+ rc = pcie_capability_clear_and_set_word(pci_dev, PCI_EXP_DEVCTL2,
PCI_EXP_DEVCTL2_COMP_TIMEOUT, timeout);
+
+ return pcibios_err_to_errno(rc);
}
static int pqi_pci_init(struct pqi_ctrl_info *ctrl_info)