Re: [PATCH 2/2] x86/pci: Clean up usage of X86_DEV_DMA_OPS

From: Derrick, Jonathan
Date: Wed Apr 10 2019 - 18:04:06 EST


On Wed, 2019-04-10 at 16:45 -0500, Bjorn Helgaas wrote:
> [+cc Keith, Jonathan (VMD guys)]
>
> I'm OK with this from a PCI perspective. It would be nice if
>
> dma_domain_list
> dma_domain_list_lock
> add_dma_domain()
> del_dma_domain()
> set_dma_domain_ops()
>
> could all be moved to vmd.c, since they're really only used there.
>
> But we don't really have a good way to call host bridge-specific code
> like set_dma_domain_ops() except via pcibios_add_device(). Someday
> maybe pcibios_add_device() will become a host bridge method.
I think these could have been contained to vmd.c with the host bridge
add_device callback [1] but I can't seem to find whatever came about
that discussion

[1] https://marc.info/?l=linux-pci&m=153337765811720&w=2



Either way, this looks fine
Reviewed-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>


>
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
>
> On Wed, Apr 10, 2019 at 10:16:17AM +0200, Ingo Molnar wrote:
> > (+Cc. Patch quoted below. Acked-by from an x86 perspective.)
> >
> > * Christoph Hellwig <hch@xxxxxx> wrote:
> >
> > > We have supported per-device dma_map_ops in generic code for a
> > > long
> > > time, and this symbol just guards the inclusion of the
> > > dma_map_ops
> > > registry used for vmd. Stop enabling it for anything but vmd.
> > >
> > > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> > > ---
> > > arch/x86/Kconfig | 3 ---
> > > drivers/misc/mic/Kconfig | 4 ++--
> > > drivers/pci/controller/Kconfig | 1 +
> > > drivers/pci/controller/vmd.c | 7 -------
> > > 4 files changed, 3 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > > index 38c62ff8a3f0..d8e2e6519a61 100644
> > > --- a/arch/x86/Kconfig
> > > +++ b/arch/x86/Kconfig
> > > @@ -28,7 +28,6 @@ config X86_64
> > > select MODULES_USE_ELF_RELA
> > > select NEED_DMA_MAP_STATE
> > > select SWIOTLB
> > > - select X86_DEV_DMA_OPS
> > > select ARCH_HAS_SYSCALL_WRAPPER
> > >
> > > #
> > > @@ -703,7 +702,6 @@ config STA2X11
> > > bool "STA2X11 Companion Chip Support"
> > > depends on X86_32_NON_STANDARD && PCI
> > > select ARCH_HAS_PHYS_TO_DMA
> > > - select X86_DEV_DMA_OPS
> > > select SWIOTLB
> > > select MFD_STA2X11
> > > select GPIOLIB
> > > @@ -2877,7 +2875,6 @@ config HAVE_ATOMIC_IOMAP
> > >
> > > config X86_DEV_DMA_OPS
> > > bool
> > > - depends on X86_64 || STA2X11
> > >
> > > config HAVE_GENERIC_GUP
> > > def_bool y
> > > diff --git a/drivers/misc/mic/Kconfig b/drivers/misc/mic/Kconfig
> > > index 242dcee14689..6736f72cc14a 100644
> > > --- a/drivers/misc/mic/Kconfig
> > > +++ b/drivers/misc/mic/Kconfig
> > > @@ -4,7 +4,7 @@ comment "Intel MIC Bus Driver"
> > >
> > > config INTEL_MIC_BUS
> > > tristate "Intel MIC Bus Driver"
> > > - depends on 64BIT && PCI && X86 && X86_DEV_DMA_OPS
> > > + depends on 64BIT && PCI && X86
> > > help
> > > This option is selected by any driver which registers a
> > > device or driver on the MIC Bus, such as
> > > CONFIG_INTEL_MIC_HOST,
> > > @@ -21,7 +21,7 @@ comment "SCIF Bus Driver"
> > >
> > > config SCIF_BUS
> > > tristate "SCIF Bus Driver"
> > > - depends on 64BIT && PCI && X86 && X86_DEV_DMA_OPS
> > > + depends on 64BIT && PCI && X86
> > > help
> > > This option is selected by any driver which registers a
> > > device or driver on the SCIF Bus, such as
> > > CONFIG_INTEL_MIC_HOST
> > > diff --git a/drivers/pci/controller/Kconfig
> > > b/drivers/pci/controller/Kconfig
> > > index 6012f3059acd..011c57cae4b0 100644
> > > --- a/drivers/pci/controller/Kconfig
> > > +++ b/drivers/pci/controller/Kconfig
> > > @@ -267,6 +267,7 @@ config PCIE_TANGO_SMP8759
> > >
> > > config VMD
> > > depends on PCI_MSI && X86_64 && SRCU
> > > + select X86_DEV_DMA_OPS
> > > tristate "Intel Volume Management Device Driver"
> > > ---help---
> > > Adds support for the Intel Volume Management Device (VMD).
> > > VMD is a
> > > diff --git a/drivers/pci/controller/vmd.c
> > > b/drivers/pci/controller/vmd.c
> > > index cf6816b55b5e..999a5509e57e 100644
> > > --- a/drivers/pci/controller/vmd.c
> > > +++ b/drivers/pci/controller/vmd.c
> > > @@ -95,10 +95,8 @@ struct vmd_dev {
> > > struct irq_domain *irq_domain;
> > > struct pci_bus *bus;
> > >
> > > -#ifdef CONFIG_X86_DEV_DMA_OPS
> > > struct dma_map_ops dma_ops;
> > > struct dma_domain dma_domain;
> > > -#endif
> > > };
> > >
> > > static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
> > > @@ -293,7 +291,6 @@ static struct msi_domain_info
> > > vmd_msi_domain_info = {
> > > .chip = &vmd_msi_controller,
> > > };
> > >
> > > -#ifdef CONFIG_X86_DEV_DMA_OPS
> > > /*
> > > * VMD replaces the requester ID with its own. DMA mappings for
> > > devices in a
> > > * VMD domain need to be mapped for the VMD, not the device
> > > requiring
> > > @@ -438,10 +435,6 @@ static void vmd_setup_dma_ops(struct vmd_dev
> > > *vmd)
> > > add_dma_domain(domain);
> > > }
> > > #undef ASSIGN_VMD_DMA_OPS
> > > -#else
> > > -static void vmd_teardown_dma_ops(struct vmd_dev *vmd) {}
> > > -static void vmd_setup_dma_ops(struct vmd_dev *vmd) {}
> > > -#endif
> > >
> > > static char __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct
> > > pci_bus *bus,
> > > unsigned int devfn, int reg, int len)
> > > --
> > > 2.20.1
> > >

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