[PATCH v12 0/8] PCI: qcom: Fix higher MSI vectors handling

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

I have replied with my Tested-by to the patch at [2], which has landed
in the linux-next as the commit 20f1bfb8dd62 ("PCI: qcom:
Add support for handling MSIs from 8 endpoints"). However lately I
noticed that during the tests I still had 'pcie_pme=nomsi', so the
device was not forced to use higher MSI vectors.

After removing this option I noticed that hight MSI vectors are not
delivered on tested platforms. After additional research I stumbled upon
a patch in msm-4.14 ([1]), which describes that each group of MSI
vectors is mapped to the separate interrupt. Implement corresponding
mapping.

The first patch in the series is a revert of  [2] (landed in pci-next).
Either both patches should be applied or both should be dropped.

Patchseries dependecies: [3] (for the schema change).

Changes since v11 (suggested by Johan):
 - Added back reporting errors for the "msi0" interrupt,
 - Stopped overriding num_vectors field if it is less than the amount of
   MSI vectors deduced from interrupt list,
 - Added a warning (and an override) if the host specifies more MSI
   vectors than available,
 - Moved has_split_msi_irq variable to the patch where it is used.

Changes since v10:
 - Remove has_split_msi_irqs flag. Trust DT and use split MSI IRQs if
   they are described in the DT. This removes the need for the
   pcie-qcom.c changes (everything is handled by the core (suggested by
   Johan).
 - Rebased on top of Lorenzo's DWC branch

Changes since v9:
 - Relax requirements and stop validating the DT. If the has_split_msi
   was specified, parse as many msiN irqs as specified in DT. If there
   are none, fallback to the single "msi" IRQ.

Changes since v8:
 - Fix typos noted by Bjorn Helgaas
 - Add missing links to the patch 1 (revert)
 - Fix sm8250 interrupt-names (Johan)
 - Specify num_vectors in qcom configuration data (Johan)
 - Rework parsing of MSI IRQs (Johan)

Changes since v7:
 - Move code back to the dwc core driver (as required by Rob),
 - Change dt schema to require either a single "msi" interrupt or an
   array of "msi0", "msi1", ... "msi7" IRQs. Disallow specifying a
   part of the array (the DT should specify the exact amount of MSI IRQs
   allowing fallback to a single "msi" IRQ),
 - Fix in the DWC init code for the dma_mapping_error() return value.

Changes since v6:
 - Fix indentation of the arguments as requested by Stanimir

Changes since v5:
 - Fixed commit subject and in-comment code according to Bjorn's
   suggestion,
 - Changed variable idx to i to follow dw_handle_msi_irq() style.

Changes since v4:
 - Fix the minItems/maxItems properties in the YAML schema.

Changes since v3:
 - Reimplement MSI handling scheme in the Qualcomm host controller
   driver.

Changes since v2:
 - Fix and rephrase commit message for patch 2.

Changes since v1:
 - Split a huge patch into three patches as suggested by Bjorn Helgaas
 - snps,dw-pcie removal is now part of [3]

[1] https://git.codelinaro.org/clo/la/kernel/msm-4.14/-/commit/671a3d5f129f4bfe477152292ada2194c8440d22
[2] https://lore.kernel.org/linux-arm-msm/20211214101319.25258-1-manivannan.sadhasivam@linaro.org/
[3] https://lore.kernel.org/linux-arm-msm/20220422211002.2012070-1-dmitry.baryshkov@linaro.org/


Dmitry Baryshkov (8):
  PCI: qcom: Revert "PCI: qcom: Add support for handling MSIs from 8
    endpoints"
  PCI: dwc: Correct msi_irq condition in dw_pcie_free_msi()
  PCI: dwc: Convert msi_irq to the array
  PCI: dwc: split MSI IRQ parsing/allocation to a separate function
  PCI: dwc: Handle MSIs routed to multiple GIC interrupts
  PCI: dwc: Implement special ISR handler for split MSI IRQ setup
  dt-bindings: PCI: qcom: Support additional MSI interrupts
  arm64: dts: qcom: sm8250: provide additional MSI interrupts

 .../devicetree/bindings/pci/qcom,pcie.yaml    |  53 +++-
 arch/arm64/boot/dts/qcom/sm8250.dtsi          |  12 +-
 drivers/pci/controller/dwc/pci-dra7xx.c       |   2 +-
 drivers/pci/controller/dwc/pci-exynos.c       |   2 +-
 .../pci/controller/dwc/pcie-designware-host.c | 243 +++++++++++++-----
 drivers/pci/controller/dwc/pcie-designware.h  |   2 +-
 drivers/pci/controller/dwc/pcie-keembay.c     |   2 +-
 drivers/pci/controller/dwc/pcie-qcom.c        |   1 -
 drivers/pci/controller/dwc/pcie-spear13xx.c   |   2 +-
 drivers/pci/controller/dwc/pcie-tegra194.c    |   2 +-
 10 files changed, 246 insertions(+), 75 deletions(-)

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2.35.1