Re: [PATCH 0/8 v2] PCI: Align return values of PCIe capability and PCI accessors
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2020-06-26 18:52:08
Also in:
dmaengine, linux-kernel-mentees, linux-pci, linux-rdma, linux-scsi, lkml
Subsystem:
dma generic offload engine subsystem, intel i/oat dma driver, microsemi smart array smartpqi driver (smartpqi), pci enhanced error handling (eeh) for powerpc, pci subsystem, scsi subsystem, the rest · Maintainers:
Vinod Koul, Dave Jiang, Don Brace, Mahesh J Salgaonkar, Bjorn Helgaas, "James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
On Mon, Jun 15, 2020 at 09:32:17AM +0200, refactormyself@gmail.com wrote:
From: Bolarinwa Olayemi Saheed <redacted> 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 [off-list ref]
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 [off-list ref]
Link: https://lore.kernel.org/r/20200615073225.24061-1-refactormyself@gmail.com (local)
Signed-off-by: Bolarinwa Olayemi Saheed [off-list ref]
Signed-off-by: Bjorn Helgaas [off-list ref]
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)