[PATCH v3 00/15] Forward MSI-X vector enable error code in pci_alloc_irq_vectors_affinity()

[PATCH v3 00/15] Forward MSI-X vector enable error code in pci_alloc_irq_vectors_affinity()

[Piotr Stankiewicz]

The primary objective of this patch series is to change the behaviour
of pci_alloc_irq_vectors_affinity() such that it forwards the MSI-X enable
error code when appropriate. In the process, though, it was pointed out
that there are multiple places in the kernel which check/ask for message
signalled interrupts (MSI or MSI-X), which spawned the first patch adding
PCI_IRQ_MSI_TYPES. Finally the rest of the chain converts all users to
take advantage of PCI_IRQ_MSI_TYPES or PCI_IRQ_ALL_TYPES, as
appropriate.

Piotr Stankiewicz (15):
  PCI/MSI: Forward MSI-X vector enable error code in
    pci_alloc_irq_vectors_affinity()
  PCI: Add macro for message signalled interrupt types
  PCI: Use PCI_IRQ_MSI_TYPES where appropriate
  ahci: Use PCI_IRQ_MSI_TYPES where appropriate
  crypto: inside-secure - Use PCI_IRQ_MSI_TYPES where appropriate
  dmaengine: dw-edma: Use PCI_IRQ_MSI_TYPES  where appropriate
  drm/amdgpu: Use PCI_IRQ_MSI_TYPES where appropriate
  IB/qib: Use PCI_IRQ_MSI_TYPES where appropriate
  media: ddbridge: Use PCI_IRQ_MSI_TYPES where appropriate
  vmw_vmci: Use PCI_IRQ_ALL_TYPES where appropriate
  mmc: sdhci: Use PCI_IRQ_MSI_TYPES where appropriate
  amd-xgbe: Use PCI_IRQ_MSI_TYPES where appropriate
  aquantia: atlantic: Use PCI_IRQ_ALL_TYPES where appropriate
  net: hns3: Use PCI_IRQ_MSI_TYPES where appropriate
  scsi: Use PCI_IRQ_MSI_TYPES and PCI_IRQ_ALL_TYPES where appropriate

 Documentation/PCI/msi-howto.rst               |  5 +++--
 drivers/ata/ahci.c                            |  2 +-
 drivers/crypto/inside-secure/safexcel.c       |  2 +-
 drivers/dma/dw-edma/dw-edma-pcie.c            |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c       | 11 +---------
 drivers/infiniband/hw/qib/qib_pcie.c          |  6 +++--
 drivers/media/pci/ddbridge/ddbridge-main.c    |  2 +-
 drivers/misc/vmw_vmci/vmci_guest.c            |  3 +--
 drivers/mmc/host/sdhci-pci-gli.c              |  3 +--
 drivers/mmc/host/sdhci-pci-o2micro.c          |  3 +--
 drivers/net/ethernet/amd/xgbe/xgbe-pci.c      |  2 +-
 .../ethernet/aquantia/atlantic/aq_pci_func.c  |  4 +---
 .../hisilicon/hns3/hns3pf/hclge_main.c        |  3 +--
 .../hisilicon/hns3/hns3vf/hclgevf_main.c      |  3 +--
 drivers/pci/msi.c                             | 22 ++++++++-----------
 drivers/pci/pcie/portdrv_core.c               |  4 ++--
 drivers/pci/switch/switchtec.c                |  3 +--
 drivers/scsi/ipr.c                            |  5 +++--
 drivers/scsi/vmw_pvscsi.c                     |  2 +-
 include/linux/pci.h                           |  4 ++--
 20 files changed, 37 insertions(+), 54 deletions(-)

-- 
2.17.2

[PATCH v3 02/15] PCI: Add macro for message signalled interrupt types

[Piotr Stankiewicz]

There are several places in the kernel which check/ask for MSI or MSI-X
interrupts. It would make sense to have a macro which defines all types
of message signalled interrupts, to use in such situations. Add
PCI_IRQ_MSI_TYPES, for this purpose.

Signed-off-by: Piotr Stankiewicz <piotr.stankiewicz@intel.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 Documentation/PCI/msi-howto.rst | 5 +++--
 include/linux/pci.h             | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Documentation/PCI/msi-howto.rst b/Documentation/PCI/msi-howto.rst
index aa2046af69f7..2800ff5aa395 100644
--- a/Documentation/PCI/msi-howto.rst
+++ b/Documentation/PCI/msi-howto.rst
@@ -105,7 +105,8 @@ if it can't meet the minimum number of vectors.
 The flags argument is used to specify which type of interrupt can be used
 by the device and the driver (PCI_IRQ_LEGACY, PCI_IRQ_MSI, PCI_IRQ_MSIX).
 A convenient short-hand (PCI_IRQ_ALL_TYPES) is also available to ask for
-any possible kind of interrupt.  If the PCI_IRQ_AFFINITY flag is set,
+any possible kind of interrupt, and (PCI_IRQ_MSI_TYPES) to ask for message
+signalled interrupts (MSI or MSI-X).  If the PCI_IRQ_AFFINITY flag is set,
 pci_alloc_irq_vectors() will spread the interrupts around the available CPUs.
 
 To get the Linux IRQ numbers passed to request_irq() and free_irq() and the
@@ -160,7 +161,7 @@ the single MSI mode for a device.  It could be done by passing two 1s as
 Some devices might not support using legacy line interrupts, in which case
 the driver can specify that only MSI or MSI-X is acceptable::
 
-	nvec = pci_alloc_irq_vectors(pdev, 1, nvec, PCI_IRQ_MSI | PCI_IRQ_MSIX);
+	nvec = pci_alloc_irq_vectors(pdev, 1, nvec, PCI_IRQ_MSI_TYPES);
 	if (nvec < 0)
 		goto out_err;
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c79d83304e52..a99094f17b21 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1431,8 +1431,8 @@ int pci_set_vga_state(struct pci_dev *pdev, bool decode,
  */
 #define PCI_IRQ_VIRTUAL		(1 << 4)
 
-#define PCI_IRQ_ALL_TYPES \
-	(PCI_IRQ_LEGACY | PCI_IRQ_MSI | PCI_IRQ_MSIX)
+#define PCI_IRQ_MSI_TYPES	(PCI_IRQ_MSI | PCI_IRQ_MSIX)
+#define PCI_IRQ_ALL_TYPES	(PCI_IRQ_LEGACY | PCI_IRQ_MSI_TYPES)
 
 /* kmem_cache style wrapper around pci_alloc_consistent() */
 
-- 
2.17.2

Re: [PATCH v3 02/15] PCI: Add macro for message signalled interrupt types

[Christoph Hellwig]

On Tue, Jun 09, 2020 at 06:22:40PM +0200, Piotr Stankiewicz wrote:
> There are several places in the kernel which check/ask for MSI or MSI-X
> interrupts. It would make sense to have a macro which defines all types
> of message signalled interrupts, to use in such situations. Add
> PCI_IRQ_MSI_TYPES, for this purpose.

To state my objection voices in patch 3 here again:

I think this is a very bad idea.  Everyone knows what MSI and MSI-X
mean and that directly maps to specification.  The new IMS interrupt
scheme from the Intel SIOV spec for example is a message signalled
interrupt type as well and should not be picked up automatically.

If we want to change anything in this area we should probably remove
PCI_IRQ_ALL_TYPES instead..

RE: [PATCH v3 02/15] PCI: Add macro for message signalled interrupt types

[Stankiewicz, Piotr]

> -----Original Message-----
> From: Christoph Hellwig <hch@infradead.org>
> Sent: Wednesday, June 10, 2020 9:08 AM
> 
> On Tue, Jun 09, 2020 at 06:22:40PM +0200, Piotr Stankiewicz wrote:
> > There are several places in the kernel which check/ask for MSI or
> > MSI-X interrupts. It would make sense to have a macro which defines
> > all types of message signalled interrupts, to use in such situations.
> > Add PCI_IRQ_MSI_TYPES, for this purpose.
> 
> To state my objection voices in patch 3 here again:
> 
> I think this is a very bad idea.  Everyone knows what MSI and MSI-X mean and
> that directly maps to specification.  The new IMS interrupt scheme from the Intel
> SIOV spec for example is a message signalled interrupt type as well and should
> not be picked up automatically.
> 
> If we want to change anything in this area we should probably remove
> PCI_IRQ_ALL_TYPES instead..

Thanks, I've resent only the first patch as v4 of the chain, and dropped the rest.