Re: [PATCH v16 08/22] PCI: microchip: Change the argument of plda_pcie_setup_iomems()

Minda Chen
2024-05-23T01:10:02Z

>
> On Wed, May 22, 2024 at 01:50:57AM +0000, Minda Chen wrote:
> > > The patch is OK, but the subject line is not very informative. It
> > > should be useful all by itself even without the commit log.
> > > "Change the argument of X" doesn't say anything about why we would
> > > want to do that.
> > >
> > > On Thu, Mar 28, 2024 at 05:18:21PM +0800, Minda Chen wrote:
> > > > If other vendor do not select PCI_HOST_COMMON, the driver data is
> > > > not struct pci_host_bridge.
> > >
> > > Also, I don't think this is the real problem. Your
> > > PCIE_MICROCHIP_HOST Kconfig selects PCI_HOST_COMMON, and the
> driver
> > > calls pci_host_common_probe(), so the driver wouldn't even build
> > > without PCI_HOST_COMMON.
> > >
> > > This patch is already applied and ready to go, but if you can tell
> > > us what's really going on here, I'd like to update the commit log.
> > >
> > It is modified for Starfive code. Starfive JH7110 PCIe do not select
> > PCI_HOST_COMMON
> > plda_pcie_setup_iomems() will be changed to common plda code.
> >
> > I think I can modify the title and commit log like this.
> >
> > Title:
> > PCI: microchip: Get struct pci_host_bridge pointer from platform code
> >
> > Since plda_pcie_setup_iomems() will be a common PLDA core driver
> > function, but the argument0 is a struct platform_device pointer.
> > plda_pcie_setup_iomems() actually using struct pci_host_bridge pointer
> > other than platform_device pointer. Further more if a new PLDA core
> > PCIe driver do not select PCI_HOST_COMMON, the platform driver data is
> > not struct pci_host_bridge pointer. So get struct pci_host_bridge
> > pointer from platform code function
> > mc_platform_init() and make it to be an argument of
> > plda_pcie_setup_iomems().
>
> OK, I see what you're doing. This actually has nothing to do with whether
> PCI_HOST_COMMON is *enabled*. It has to do with whether drivers use
> pci_host_common_probe(). Here's what I propose:
>
> PCI: plda: Pass pci_host_bridge to plda_pcie_setup_iomems()
>
> plda_pcie_setup_iomems() needs the bridge->windows list from struct
> pci_host_bridge and is currently used only by pcie-microchip-host.c. This
> driver uses pci_host_common_probe(), which sets a pci_host_bridge as the
> drvdata, so plda_pcie_setup_iomems() used platform_get_drvdata() to find
> the pci_host_bridge.
>
> But we also want to use plda_pcie_setup_iomems() in the new pcie-starfive.c
> driver, which does not use pci_host_common_probe() and will have struct
> starfive_jh7110_pcie as its drvdata, so pass the pci_host_bridge directly
> to plda_pcie_setup_iomems() so it doesn't need platform_get_drvdata() to
> find it.
>
OK, Thanks.

I see PCIe 6.10 changed have been merged to main line.
Should I resend this patch set base on 6.10-rc1?

> > > > Move calling platform_get_drvdata() to mc_platform_init().
> > > >
> > > > Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
> > > > Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> > > > ---
> > > > drivers/pci/controller/plda/pcie-microchip-host.c | 6 +++---
> > > > 1 file changed, 3 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/drivers/pci/controller/plda/pcie-microchip-host.c
> > > > b/drivers/pci/controller/plda/pcie-microchip-host.c
> > > > index 9b367927cd32..805870aed61d 100644
> > > > --- a/drivers/pci/controller/plda/pcie-microchip-host.c
> > > > +++ b/drivers/pci/controller/plda/pcie-microchip-host.c
> > > > @@ -876,11 +876,10 @@ static void plda_pcie_setup_window(void
> > > > __iomem
> > > *bridge_base_addr, u32 index,
> > > > writel(0, bridge_base_addr + ATR0_PCIE_WIN0_SRC_ADDR); }
> > > >
> > > > -static int plda_pcie_setup_iomems(struct platform_device *pdev,
> > > > +static int plda_pcie_setup_iomems(struct pci_host_bridge *bridge,
> > > > struct plda_pcie_rp *port)
> > > > {
> > > > void __iomem *bridge_base_addr = port->bridge_addr;
> > > > - struct pci_host_bridge *bridge = platform_get_drvdata(pdev);
> > > > struct resource_entry *entry;
> > > > u64 pci_addr;
> > > > u32 index = 1;
> > > > @@ -1018,6 +1017,7 @@ static int mc_platform_init(struct
> > > > pci_config_window *cfg) {
> > > > struct device *dev = cfg->parent;
> > > > struct platform_device *pdev = to_platform_device(dev);
> > > > + struct pci_host_bridge *bridge = platform_get_drvdata(pdev);
> > > > void __iomem *bridge_base_addr =
> > > > port->axi_base_addr + MC_PCIE_BRIDGE_ADDR;
> > > > int ret;
> > > > @@ -1031,7 +1031,7 @@ static int mc_platform_init(struct
> > > pci_config_window *cfg)
> > > > mc_pcie_enable_msi(port, cfg->win);
> > > >
> > > > /* Configure non-config space outbound ranges */
> > > > - ret = plda_pcie_setup_iomems(pdev, &port->plda);
> > > > + ret = plda_pcie_setup_iomems(bridge, &port->plda);
> > > > if (ret)
> > > > return ret;
> > > >
> > > > --
> > > > 2.17.1
> > > >