Re: [RFC PATCH 2/2] arm: pcibios: move to generic PCI domains

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Mon, Nov 03, 2014 at 01:18:12AM +0000, Jingoo Han wrote:
> On Thursday, October 30, 2014 8:45 PM, Lorenzo Pieralisi wrote:
> >
> > Most if not all ARM PCI host controller device drivers either ignore the
> > domain field in the pci_sys_data structure or just increment it every
> > time a host controller is probed, using it as a domain counter.
> >
> > Therefore, instead of relying on pci_sys_data to stash the domain number
> > in a standard location, ARM pcibios code can be moved to the newly
> > introduced generic PCI domains code, implemented in commits:
> >
> > commit 41e5c0f81d3e676d671d96a0a1fafb27abfbd9
> > ("of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr()")
> >
> > commit 670ba0c8883b576d0aec28bd7a838358a4be1
> > ("PCI: Add generic domain handling")
> >
> > In order to assign a domain number dynamically, the ARM pcibios defines
> > the function, called by core PCI code:
> >
> > void pci_bus_assign_domain_nr(...)
> >
> > that relies on a DT property to define the domain number or falls back to
> > a counter; its usage replaces the current domain assignment code in PCI
> > host controllers present in the kernel.
> >
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Phil Edworthy <phil.edworthy@renesas.com>
> > Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
> > Cc: Jingoo Han <jg1.han@samsung.com>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Russell King <linux@arm.linux.org.uk>
> > Cc: Mohit Kumar <mohit.kumar@st.com>
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> 
> (+CC Richard Zhu, Lucas Stach, Kishon Vijay Abraham I, Murali Karicheri)
> 
> Acked-by: Jingoo Han <jg1.han@samsung.com>

Thank you Jingoo.

> For a long time, I have wanted the patch like this. Personally,
> I want to increase the build coverage and keep the same binary
> regardless of config options as possible; thus, I don't like
> #ifdef guards such as '#ifdef CONFIG_PCI_DOMAINS'. When I submitted
> the first patch for 'pcie-designware.c', I was not able to find
> a way to remove '#ifdef CONFIG_PCI_DOMAINS' from 'pcie-designware.c'.
> 
> This patch looks good and I think that this patch will not make
> the problem. However, I didn't test this patch with Exynos platform,
> due to some reasons. So, I hope that other engineers test this patch
> on other SoC platforms related to designware PCIe.
> 
> To Mohit Kumar (ST SPEAR13XX), Richard Zhu/Lucas Stach (IMX6)
>     Kishon Vijay Abraham I (TI DRA7XX), Murali Karicheri (TI KEYSTONE)
> 
> Would you test this patch and share the result?
> It would be very helpful. Thank you.

I am happy to wait for a week or two before asking to add this code to -next,
it would be definitely great to get more coverage on pcie-designware.

Thanks,
Lorenzo

> Best regards,
> Jingoo Han
> 
> > ---
> >  arch/arm/Kconfig                   |  3 +++
> >  arch/arm/include/asm/mach/pci.h    |  3 ---
> >  arch/arm/include/asm/pci.h         |  7 -------
> >  arch/arm/kernel/bios32.c           | 26 +++++++++++++++++++++++---
> >  drivers/pci/host/pci-mvebu.c       | 10 ++--------
> >  drivers/pci/host/pcie-designware.c |  3 ---
> >  drivers/pci/host/pcie-rcar.c       |  3 ---
> >  7 files changed, 28 insertions(+), 27 deletions(-)
> >
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index 89c4b5c..29544f0 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -1292,6 +1292,9 @@ config PCI_DOMAINS
> >       bool
> >       depends on PCI
> >
> > +config PCI_DOMAINS_GENERIC
> > +     def_bool PCI_DOMAINS
> > +
> >  config PCI_NANOENGINE
> >       bool "BSE nanoEngine PCI support"
> >       depends on SA1100_NANOENGINE
> > diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
> > index 7fc4278..f19f627 100644
> > --- a/arch/arm/include/asm/mach/pci.h
> > +++ b/arch/arm/include/asm/mach/pci.h
> > @@ -44,9 +44,6 @@ struct hw_pci {
> >   * Per-controller structure
> >   */
> >  struct pci_sys_data {
> > -#ifdef CONFIG_PCI_DOMAINS
> > -     int             domain;
> > -#endif
> >       struct list_head node;
> >       int             busnr;          /* primary bus number                   */
> >       u64             mem_offset;     /* bus->cpu memory mapping offset       */
> > diff --git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
> > index 7e95d85..585dc33 100644
> > --- a/arch/arm/include/asm/pci.h
> > +++ b/arch/arm/include/asm/pci.h
> > @@ -18,13 +18,6 @@ static inline int pcibios_assign_all_busses(void)
> >  }
> >
> >  #ifdef CONFIG_PCI_DOMAINS
> > -static inline int pci_domain_nr(struct pci_bus *bus)
> > -{
> > -     struct pci_sys_data *root = bus->sysdata;
> > -
> > -     return root->domain;
> > -}
> > -
> >  static inline int pci_proc_domain(struct pci_bus *bus)
> >  {
> >       return pci_domain_nr(bus);
> > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> > index 17a26c1..d8c2b4e 100644
> > --- a/arch/arm/kernel/bios32.c
> > +++ b/arch/arm/kernel/bios32.c
> > @@ -11,6 +11,8 @@
> >  #include <linux/slab.h>
> >  #include <linux/init.h>
> >  #include <linux/io.h>
> > +#include <linux/of.h>
> > +#include <linux/of_pci.h>
> >
> >  #include <asm/mach-types.h>
> >  #include <asm/mach/map.h>
> > @@ -468,9 +470,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
> >               if (!sys)
> >                       panic("PCI: unable to allocate sys data!");
> >
> > -#ifdef CONFIG_PCI_DOMAINS
> > -             sys->domain  = hw->domain;
> > -#endif
> >               sys->busnr   = busnr;
> >               sys->swizzle = hw->swizzle;
> >               sys->map_irq = hw->map_irq;
> > @@ -511,6 +510,27 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
> >       }
> >  }
> >
> > +#ifdef CONFIG_PCI_DOMAINS_GENERIC
> > +static bool dt_domain_found;
> > +
> > +void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
> > +{
> > +     int domain = of_get_pci_domain_nr(parent->of_node);
> > +
> > +     if (domain >= 0) {
> > +             dt_domain_found = true;
> > +     } else if (dt_domain_found == true) {
> > +             dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n",
> > +                     parent->of_node->full_name);
> > +             return;
> > +     } else {
> > +             domain = pci_get_new_domain_nr();
> > +     }
> > +
> > +     bus->domain_nr = domain;
> > +}
> > +#endif
> > +
> >  void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
> >  {
> >       struct pci_sys_data *sys;
> > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> > index b1315e1..2b4c1f2 100644
> > --- a/drivers/pci/host/pci-mvebu.c
> > +++ b/drivers/pci/host/pci-mvebu.c
> > @@ -722,17 +722,11 @@ static int mvebu_pcie_setup(int nr, struct pci_sys_data *sys)
> >  {
> >       struct mvebu_pcie *pcie = sys_to_pcie(sys);
> >       int i;
> > -     int domain = 0;
> >
> > -#ifdef CONFIG_PCI_DOMAINS
> > -     domain = sys->domain;
> > -#endif
> > -
> > -     snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x",
> > -              domain);
> > +     snprintf(pcie->mem_name, sizeof(pcie->mem_name), "PCI MEM %04x", nr);
> >       pcie->mem.name = pcie->mem_name;
> >
> > -     snprintf(pcie->io_name, sizeof(pcie->io_name), "PCI I/O %04x", domain);
> > +     snprintf(pcie->io_name, sizeof(pcie->io_name), "PCI I/O %04x", nr);
> >       pcie->realio.name = pcie->io_name;
> >
> >       if (request_resource(&iomem_resource, &pcie->mem))
> > diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
> > index dfed00a..6790b87 100644
> > --- a/drivers/pci/host/pcie-designware.c
> > +++ b/drivers/pci/host/pcie-designware.c
> > @@ -502,9 +502,6 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
> >       dw_pci.private_data = (void **)&pp;
> >
> >       pci_common_init_dev(pp->dev, &dw_pci);
> > -#ifdef CONFIG_PCI_DOMAINS
> > -     dw_pci.domain++;
> > -#endif
> >
> >       return 0;
> >  }
> > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> > index 61158e0..b6b859e 100644
> > --- a/drivers/pci/host/pcie-rcar.c
> > +++ b/drivers/pci/host/pcie-rcar.c
> > @@ -404,9 +404,6 @@ static void rcar_pcie_enable(struct rcar_pcie *pcie)
> >       rcar_pci.private_data = (void **)&pcie;
> >
> >       pci_common_init_dev(&pdev->dev, &rcar_pci);
> > -#ifdef CONFIG_PCI_DOMAINS
> > -     rcar_pci.domain++;
> > -#endif
> >  }
> >
> >  static int phy_wait_for_ack(struct rcar_pcie *pcie)
> > --
> > 2.1.2
> 
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