Re: [PATCH v8 0/5] PCI: dwc: Add common pme_turn_off message by using outbound iATU

Frank Li
2024-05-02T19:18:02Z

On Thu, Apr 18, 2024 at 12:04:23PM -0400, Frank Li wrote:
> Involve an new and common mathod to send pme_turn_off() message. Previously
> pme_turn_off() implement by platform related special register to trigge
> it.
>
> But Yoshihiro give good idea by using iATU to send out message. Previously
> Yoshihiro provide patches to raise INTx message by dummy write to outbound
> iATU.
>
> Use similar mathod to send out pme_turn_off message.
>
> Previous two patches is picked from Yoshihiro' big patch serialise.
> PCI: dwc: Change arguments of dw_pcie_prog_outbound_atu()
> PCI: Add INTx Mechanism Messages macros
>
> PCI: Add PME_TURN_OFF message macro
> dt-bindings: PCI: dwc: Add 'msg" register region, Add "msg" region to use
> to map PCI msg.
>
> PCI: dwc: Add common pme_turn_off message method
> Using common pme_turn_off() message if platform have not define their.
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Lorenzo:

Could you please pick up these patches? All have been reviewed and
acked by Bjorn/Mani? If you have more comments, let me know.

Frank

> ---
> Changes in v8:
> - Total use devm_ manage msg_res. after read devres.c code to better
> understand release sequence. It use reverse order to release resource. So
> it is safe for msg_res.
> - Add Reviewed tag of Manivannan Sadhasivam in patch 4/5
> - Link to v7: https://lore.kernel.org/r/20240417-pme_msg-v7-0-9c6208cda90f@nxp.com
>
> Changes in v7:
> patch 4/5 add
> /* Power Management Messages; PCIe r6.0, sec 2.2.8.2 */
> patch 1/5 change comment to
> /* Message Routing (r[2:0]); PCIe r6.0, sec 2.2.8 */
> /* INTx Mechanism Messages; PCIe r6.0, sec 2.2.8.1 */
>
> order according to value.
> Add Acked-by: Bjorn Helgaas <bhelgaas@google.com> in patch 4/5
>
> patch 5/5
> Apply all mani's comments.
>
> - Link to v6: https://lore.kernel.org/r/20240415-pme_msg-v6-0-56dad968ad3a@nxp.com
>
> Changes in v6:
> - Move PCIE_MSG_CODE_PME_TURN_OFF ahead before INTx to keep the codes
> sorted.
> - Added reason why not alloc_resesource in commit messag.
> - Change title PCI: dwc: Add generic MSG TLP support for sending
> PME_Turn_Off when system suspend.
> - Rework commit message
> "Instead of relying on the vendor specific implementations to send the
> PME_Turn_Off message, let's introduce a generic way of sending the message using
> the MSG TLP.
>
> This is achieved by reserving a region for MSG TLP of size 'pci->region_align',
> at the end of the first IORESOURCE_MEM window of the host bridge. And then
> sending the PME_Turn_Off message during system suspend with the help of iATU.
>
> It should be noted that this generic implementation is optional for the glue
> drivers and can be overridden by a custom 'pme_turn_off' callback.
>
> - using devm_request_resource()
> - using mani's suggest comments
>
> /*
> * Allocate the resource for MSG TLP before programming the iATU
> * outbound window in dw_pcie_setup_rc(). Since the allocation depends
> * on the value of 'region_align', this has to be done after
> * dw_pcie_iatu_detect().
> */
>
> - Add comments, about use_atu_msg, need glue driver set it.
>
> - m -> mem in dw_pcie_pme_turn_off()
>
> - remove redundant check() if (!atu.size) in dw_pcie_pme_turn_off().
>
> - The reason can't adjust windows->end
> This windows already reported to pci system before this function. It is
> not good to modify window-res-end. It just add child resource like below.
>
> windows is root resource, which will create may child when call
> request_resource.
> bridge -> windows
> child1 -> msg
> child2 -> pci ep1
> child3 -> pci_ep2.
> ...
>
> Although you see whole bridge window, 'msg' already used and put under root
> resource, new pci devices will never use 'msg' resource.
>
> If change windows->res->end here, I worry about it may broken resource
> tree.
>
> Detail below thread:
>
> - Link to v5: https://lore.kernel.org/r/20240319-pme_msg-v5-0-af9ffe57f432@nxp.com
>
> Changes in v5:
> - Default disable allocate TLP message memory windows. If driver need use
> this feature, need set use_atu_msg = true before call dw_host_init().
>
> - Link to v4: https://lore.kernel.org/r/20240213-pme_msg-v4-0-e2acd4d7a292@nxp.com
>
> Changes in v4:
> - Remove dt-binding patch. Needn't change any dts file and binding doc.
> Reserve a region at end of first IORESOURCE_MEM window by call
> request_resource(). So PCIe stack will not use this reserve region to any
> PCIe devices.
> I tested it by reserve at begin of IORESOURCE_MEM window. PCIe stack
> will skip it as expection.
>
> Fixed a issue, forget set iATU index when sent PME_turn_off.
>
> - Link to v3: https://lore.kernel.org/r/20240202-pme_msg-v3-0-ff2af57a02ad@nxp.com
>
> Changes in v3:
> - fix 'MSG"
> - Add pcie spec ref in head file
> - using function name dw_pci_pme_turn_off()
> - Using PCIE_ prefix macro
> - Link to v2: https://lore.kernel.org/r/20240201-pme_msg-v2-0-6767052fe6a4@nxp.com
>
> Changes in v2:
> - Add my sign off at PCI: dwc: Add outbound MSG TLPs support
> - Add Bjorn review tag at Add INTx Mechanism Messages macros
> - using PME_Turn_Off match PCIe spec
> - ref to pcie spec v6.1
> - using section number.
>
> - Link to v1: https://lore.kernel.org/r/20240130-pme_msg-v1-0-d52b0add5c7c@nxp.com
>
> ---
> Frank Li (2):
> PCI: Add PCIE_MSG_CODE_PME_TURN_OFF message macro
> PCI: dwc: Add generic MSG TLP support for sending PME_Turn_Off when system suspend
>
> Yoshihiro Shimoda (3):
> PCI: Add INTx Mechanism Messages macros
> PCI: dwc: Consolidate args of dw_pcie_prog_outbound_atu() into a structure
> PCI: dwc: Add outbound MSG TLPs support
>
> drivers/pci/controller/dwc/pcie-designware-ep.c | 21 ++--
> drivers/pci/controller/dwc/pcie-designware-host.c | 145 +++++++++++++++++++---
> drivers/pci/controller/dwc/pcie-designware.c | 54 ++++----
> drivers/pci/controller/dwc/pcie-designware.h | 22 +++-
> drivers/pci/pci.h | 21 ++++
> 5 files changed, 199 insertions(+), 64 deletions(-)
> ---
> base-commit: ef6a734484e939cf67bc41c45bc936a78ea210f0
> change-id: 20240130-pme_msg-dd2d81ee9886
>
> Best regards,
> ---
> Frank Li <Frank.Li@nxp.com>
>