diff mbox series

[v6,9/9] xen/asm-generic: introduce generic device.h

Message ID 55d6810e2f8b0f54261c504354bf879c5b887c40.1703072575.git.oleksii.kurochko@gmail.com (mailing list archive)
State Superseded
Headers show
Series Introduce generic headers | expand

Commit Message

Oleksii Dec. 20, 2023, 2:08 p.m. UTC
Arm, PPC and RISC-V use the same device.h thereby device.h
was moved to asm-generic. Arm's device.h was taken as a base with
the following changes:
 - #ifdef PCI related things.
 - #ifdef ACPI related things.
 - Rename #ifdef guards.
 - Add SPDX tag.
 - #ifdef CONFIG_HAS_DEVICE_TREE related things.
 - #ifdef-ing iommu related things with CONFIG_HAS_PASSTHROUGH.

Also Arm and PPC are switched to asm-generic version of device.h

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---

     Jan wrote the following:
       Overall I think there are too many changes done all in one go here.
       But it's mostly Arm which is affected, so I'll leave judging about that
       to the Arm maintainers.
     
     Arm maintainers, will it be fine for you to not split the patch?
---
Changes in V6:
 - Rebase only.
---
Changes in V5:
  - Removed generated file: xen/include/headers++.chk.new
  - Removed pointless #ifdef CONFIG_HAS_DEVICE_TREE ... #endif for PPC as
    CONFIG_HAS_DEVICE_TREE will be always used for PPC.
---
Changes in V4:
 - Updated the commit message
 - Switched Arm and PPC to asm-generic version of device.h
 - Replaced HAS_PCI with CONFIG_HAS_PCI
 - ifdef-ing iommu filed of dev_archdata struct with CONFIG_HAS_PASSTHROUGH
 - ifdef-ing iommu_fwspec of device struct with CONFIG_HAS_PASSTHROUGH
 - ifdef-ing DT related things with CONFIG_HAS_DEVICE_TREE
 - Updated the commit message ( remove a note with question about
   if device.h should be in asm-generic or not )
 - Replaced DEVICE_IC with DEVICE_INTERRUPT_CONTROLLER
 - Rationalized usage of CONFIG_HAS_* in device.h
 - Fixed indents for ACPI_DEVICE_START and ACPI_DEVICE_END
---
Changes in V3:
 - ifdef device tree related things.
 - update the commit message
---
Changes in V2:
	- take ( as common ) device.h from Arm as PPC and RISC-V use it as a base.
	- #ifdef PCI related things.
	- #ifdef ACPI related things.
	- rename DEVICE_GIC to DEVIC_IC.
	- rename #ifdef guards.
	- switch Arm and PPC to generic device.h
	- add SPDX tag
	- update the commit message

---
 xen/arch/arm/device.c                         |  15 ++-
 xen/arch/arm/domain_build.c                   |   2 +-
 xen/arch/arm/gic-v2.c                         |   4 +-
 xen/arch/arm/gic-v3.c                         |   6 +-
 xen/arch/arm/gic.c                            |   4 +-
 xen/arch/arm/include/asm/Makefile             |   1 +
 xen/arch/ppc/include/asm/Makefile             |   1 +
 xen/arch/ppc/include/asm/device.h             |  53 --------
 .../asm => include/asm-generic}/device.h      | 125 +++++++++++-------
 9 files changed, 102 insertions(+), 109 deletions(-)
 delete mode 100644 xen/arch/ppc/include/asm/device.h
 rename xen/{arch/arm/include/asm => include/asm-generic}/device.h (79%)

Comments

Julien Grall Dec. 21, 2023, 7:38 p.m. UTC | #1
Hi,

On 20/12/2023 14:08, Oleksii Kurochko wrote:
> Arm, PPC and RISC-V use the same device.h thereby device.h
> was moved to asm-generic. Arm's device.h was taken as a base with
> the following changes:
>   - #ifdef PCI related things.
>   - #ifdef ACPI related things.
>   - Rename #ifdef guards.
>   - Add SPDX tag.
>   - #ifdef CONFIG_HAS_DEVICE_TREE related things.
>   - #ifdef-ing iommu related things with CONFIG_HAS_PASSTHROUGH.
> 
> Also Arm and PPC are switched to asm-generic version of device.h
> 
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> ---
> 
>       Jan wrote the following:
>         Overall I think there are too many changes done all in one go here.
>         But it's mostly Arm which is affected, so I'll leave judging about that
>         to the Arm maintainers.
>       
>       Arm maintainers, will it be fine for you to not split the patch?

So in general I agree with Jan, patches should be kept small so they are 
easy to review.

Given the discussion has been on-going for a while (we are at v6),  I 
will give an attempt to review the patch as-is. But in the future, 
please try to split. The smaller it is, the easier to review. For code 
movement and refactoring, I tend to first have a few refactoring patches 
and then move the code in a separate patch. So it is easier to spot the 
differences.

> ---
> Changes in V6:
>   - Rebase only.
> ---
> Changes in V5:
>    - Removed generated file: xen/include/headers++.chk.new
>    - Removed pointless #ifdef CONFIG_HAS_DEVICE_TREE ... #endif for PPC as
>      CONFIG_HAS_DEVICE_TREE will be always used for PPC.
> ---
> Changes in V4:
>   - Updated the commit message
>   - Switched Arm and PPC to asm-generic version of device.h
>   - Replaced HAS_PCI with CONFIG_HAS_PCI
>   - ifdef-ing iommu filed of dev_archdata struct with CONFIG_HAS_PASSTHROUGH
>   - ifdef-ing iommu_fwspec of device struct with CONFIG_HAS_PASSTHROUGH
>   - ifdef-ing DT related things with CONFIG_HAS_DEVICE_TREE
>   - Updated the commit message ( remove a note with question about
>     if device.h should be in asm-generic or not )
>   - Replaced DEVICE_IC with DEVICE_INTERRUPT_CONTROLLER
>   - Rationalized usage of CONFIG_HAS_* in device.h
>   - Fixed indents for ACPI_DEVICE_START and ACPI_DEVICE_END
> ---
> Changes in V3:
>   - ifdef device tree related things.
>   - update the commit message
> ---
> Changes in V2:
> 	- take ( as common ) device.h from Arm as PPC and RISC-V use it as a base.
> 	- #ifdef PCI related things.
> 	- #ifdef ACPI related things.
> 	- rename DEVICE_GIC to DEVIC_IC.
> 	- rename #ifdef guards.
> 	- switch Arm and PPC to generic device.h
> 	- add SPDX tag
> 	- update the commit message
> 
> ---
>   xen/arch/arm/device.c                         |  15 ++-
>   xen/arch/arm/domain_build.c                   |   2 +-
>   xen/arch/arm/gic-v2.c                         |   4 +-
>   xen/arch/arm/gic-v3.c                         |   6 +-
>   xen/arch/arm/gic.c                            |   4 +-
>   xen/arch/arm/include/asm/Makefile             |   1 +
>   xen/arch/ppc/include/asm/Makefile             |   1 +
>   xen/arch/ppc/include/asm/device.h             |  53 --------
>   .../asm => include/asm-generic}/device.h      | 125 +++++++++++-------
>   9 files changed, 102 insertions(+), 109 deletions(-)
>   delete mode 100644 xen/arch/ppc/include/asm/device.h
>   rename xen/{arch/arm/include/asm => include/asm-generic}/device.h (79%)
> 
> diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
> index 1f631d3274..affbe79f9a 100644
> --- a/xen/arch/arm/device.c
> +++ b/xen/arch/arm/device.c
> @@ -16,7 +16,10 @@
>   #include <xen/lib.h>
>   
>   extern const struct device_desc _sdevice[], _edevice[];
> +
> +#ifdef CONFIG_ACPI
>   extern const struct acpi_device_desc _asdevice[], _aedevice[];
> +#endif
>   
>   int __init device_init(struct dt_device_node *dev, enum device_class class,
>                          const void *data)
> @@ -45,6 +48,7 @@ int __init device_init(struct dt_device_node *dev, enum device_class class,
>       return -EBADF;
>   }
>   
> +#ifdef CONFIG_ACPI
>   int __init acpi_device_init(enum device_class class, const void *data, int class_type)
>   {
>       const struct acpi_device_desc *desc;
> @@ -61,6 +65,7 @@ int __init acpi_device_init(enum device_class class, const void *data, int class
>   
>       return -EBADF;
>   }
> +#endif
>   
>   enum device_class device_get_class(const struct dt_device_node *dev)
>   {
> @@ -329,9 +334,13 @@ int handle_device(struct domain *d, struct dt_device_node *dev, p2m_type_t p2mt,
>       struct map_range_data mr_data = {
>           .d = d,
>           .p2mt = p2mt,
> -        .skip_mapping = !own_device ||
> -                        (is_pci_passthrough_enabled() &&
> -                        (device_get_class(dev) == DEVICE_PCI_HOSTBRIDGE)),
> +        .skip_mapping =
> +                        !own_device
> +#ifdef CONFIG_HAS_PCI
> +                        || (is_pci_passthrough_enabled() &&
> +                        (device_get_class(dev) == DEVICE_PCI_HOSTBRIDGE))
> +#endif

So the #ifdef is only here because DEVICE_PCI_HOSTBRIDGE is not defined. 
It is not clear what's the actual problem of keeping 
DEVICE_PCI_HOSTBRIDGE available for every build.

In fact, we have tried to get away from #ifdef in order to make ensure 
we can catch any build failure without a randconfig (see use of 
IS_ENABLED() which would not apply work here).

[...]

> diff --git a/xen/arch/ppc/include/asm/device.h b/xen/arch/ppc/include/asm/device.h
> deleted file mode 100644
> index 8253e61d51..0000000000
> --- a/xen/arch/ppc/include/asm/device.h
> +++ /dev/null
> @@ -1,53 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0-only */
> -#ifndef __ASM_PPC_DEVICE_H__
> -#define __ASM_PPC_DEVICE_H__
> -
> -enum device_type
> -{
> -    DEV_DT,
> -    DEV_PCI,
> -};
> -
> -struct device {
> -    enum device_type type;
> -#ifdef CONFIG_HAS_DEVICE_TREE
> -    struct dt_device_node *of_node; /* Used by drivers imported from Linux */
> -#endif
> -};
> -
> -enum device_class
> -{
> -    DEVICE_SERIAL,
> -    DEVICE_IOMMU,
> -    DEVICE_PCI_HOSTBRIDGE,
> -    /* Use for error */
> -    DEVICE_UNKNOWN,
> -};
> -
> -struct device_desc {
> -    /* Device name */
> -    const char *name;
> -    /* Device class */
> -    enum device_class class;
> -    /* List of devices supported by this driver */
> -    const struct dt_device_match *dt_match;
> -    /*
> -     * Device initialization.
> -     *
> -     * -EAGAIN is used to indicate that device probing is deferred.
> -     */
> -    int (*init)(struct dt_device_node *dev, const void *data);
> -};
> -
> -typedef struct device device_t;
> -
> -#define DT_DEVICE_START(name_, namestr_, class_)                    \
> -static const struct device_desc __dev_desc_##name_ __used           \
> -__section(".dev.info") = {                                          \
> -    .name = namestr_,                                               \
> -    .class = class_,                                                \
> -
> -#define DT_DEVICE_END                                               \
> -};
> -
> -#endif /* __ASM_PPC_DEVICE_H__ */
> diff --git a/xen/arch/arm/include/asm/device.h b/xen/include/asm-generic/device.h
> similarity index 79%
> rename from xen/arch/arm/include/asm/device.h
> rename to xen/include/asm-generic/device.h
> index b5d451e087..063c448c4e 100644
> --- a/xen/arch/arm/include/asm/device.h
> +++ b/xen/include/asm-generic/device.h
> @@ -1,14 +1,37 @@
> -#ifndef __ASM_ARM_DEVICE_H
> -#define __ASM_ARM_DEVICE_H
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef __ASM_GENERIC_DEVICE_H__
> +#define __ASM_GENERIC_DEVICE_H__
> +
> +#include <xen/stdbool.h>
>   
>   enum device_type
>   {
> +#ifdef CONFIG_HAS_DEVICE_TREE
>       DEV_DT,
> +#endif
> +
> +#ifdef CONFIG_HAS_PCI
>       DEV_PCI,
> +#endif
> +    DEV_TYPE_MAX,
Nobody is using it. AFAICT, this was introduced because enum may be 
empty if !HAS_DEVICE_TREE and !HAS_PCI. If so, can you add a comment 
explaining it on top?

The rest LGTM.

Cheers,
Oleksii Dec. 22, 2023, 1:16 p.m. UTC | #2
Hi Julien,

On Thu, 2023-12-21 at 19:38 +0000, Julien Grall wrote:
> Hi,
> 
> On 20/12/2023 14:08, Oleksii Kurochko wrote:
> > Arm, PPC and RISC-V use the same device.h thereby device.h
> > was moved to asm-generic. Arm's device.h was taken as a base with
> > the following changes:
> >   - #ifdef PCI related things.
> >   - #ifdef ACPI related things.
> >   - Rename #ifdef guards.
> >   - Add SPDX tag.
> >   - #ifdef CONFIG_HAS_DEVICE_TREE related things.
> >   - #ifdef-ing iommu related things with CONFIG_HAS_PASSTHROUGH.
> > 
> > Also Arm and PPC are switched to asm-generic version of device.h
> > 
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
> > ---
> > 
> >       Jan wrote the following:
> >         Overall I think there are too many changes done all in one
> > go here.
> >         But it's mostly Arm which is affected, so I'll leave
> > judging about that
> >         to the Arm maintainers.
> >       
> >       Arm maintainers, will it be fine for you to not split the
> > patch?
> 
> So in general I agree with Jan, patches should be kept small so they
> are 
> easy to review.
> 
> Given the discussion has been on-going for a while (we are at v6),  I
> will give an attempt to review the patch as-is. But in the future, 
> please try to split. The smaller it is, the easier to review. For
> code 
> movement and refactoring, I tend to first have a few refactoring
> patches 
> and then move the code in a separate patch. So it is easier to spot
> the 
> differences.
Thanks, I'll separate the patch.
> 
> > ---
> > Changes in V6:
> >   - Rebase only.
> > ---
> > Changes in V5:
> >    - Removed generated file: xen/include/headers++.chk.new
> >    - Removed pointless #ifdef CONFIG_HAS_DEVICE_TREE ... #endif for
> > PPC as
> >      CONFIG_HAS_DEVICE_TREE will be always used for PPC.
> > ---
> > Changes in V4:
> >   - Updated the commit message
> >   - Switched Arm and PPC to asm-generic version of device.h
> >   - Replaced HAS_PCI with CONFIG_HAS_PCI
> >   - ifdef-ing iommu filed of dev_archdata struct with
> > CONFIG_HAS_PASSTHROUGH
> >   - ifdef-ing iommu_fwspec of device struct with
> > CONFIG_HAS_PASSTHROUGH
> >   - ifdef-ing DT related things with CONFIG_HAS_DEVICE_TREE
> >   - Updated the commit message ( remove a note with question about
> >     if device.h should be in asm-generic or not )
> >   - Replaced DEVICE_IC with DEVICE_INTERRUPT_CONTROLLER
> >   - Rationalized usage of CONFIG_HAS_* in device.h
> >   - Fixed indents for ACPI_DEVICE_START and ACPI_DEVICE_END
> > ---
> > Changes in V3:
> >   - ifdef device tree related things.
> >   - update the commit message
> > ---
> > Changes in V2:
> > 	- take ( as common ) device.h from Arm as PPC and RISC-V
> > use it as a base.
> > 	- #ifdef PCI related things.
> > 	- #ifdef ACPI related things.
> > 	- rename DEVICE_GIC to DEVIC_IC.
> > 	- rename #ifdef guards.
> > 	- switch Arm and PPC to generic device.h
> > 	- add SPDX tag
> > 	- update the commit message
> > 
> > ---
> >   xen/arch/arm/device.c                         |  15 ++-
> >   xen/arch/arm/domain_build.c                   |   2 +-
> >   xen/arch/arm/gic-v2.c                         |   4 +-
> >   xen/arch/arm/gic-v3.c                         |   6 +-
> >   xen/arch/arm/gic.c                            |   4 +-
> >   xen/arch/arm/include/asm/Makefile             |   1 +
> >   xen/arch/ppc/include/asm/Makefile             |   1 +
> >   xen/arch/ppc/include/asm/device.h             |  53 --------
> >   .../asm => include/asm-generic}/device.h      | 125 +++++++++++--
> > -----
> >   9 files changed, 102 insertions(+), 109 deletions(-)
> >   delete mode 100644 xen/arch/ppc/include/asm/device.h
> >   rename xen/{arch/arm/include/asm => include/asm-generic}/device.h
> > (79%)
> > 
> > diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
> > index 1f631d3274..affbe79f9a 100644
> > --- a/xen/arch/arm/device.c
> > +++ b/xen/arch/arm/device.c
> > @@ -16,7 +16,10 @@
> >   #include <xen/lib.h>
> >   
> >   extern const struct device_desc _sdevice[], _edevice[];
> > +
> > +#ifdef CONFIG_ACPI
> >   extern const struct acpi_device_desc _asdevice[], _aedevice[];
> > +#endif
> >   
> >   int __init device_init(struct dt_device_node *dev, enum
> > device_class class,
> >                          const void *data)
> > @@ -45,6 +48,7 @@ int __init device_init(struct dt_device_node
> > *dev, enum device_class class,
> >       return -EBADF;
> >   }
> >   
> > +#ifdef CONFIG_ACPI
> >   int __init acpi_device_init(enum device_class class, const void
> > *data, int class_type)
> >   {
> >       const struct acpi_device_desc *desc;
> > @@ -61,6 +65,7 @@ int __init acpi_device_init(enum device_class
> > class, const void *data, int class
> >   
> >       return -EBADF;
> >   }
> > +#endif
> >   
> >   enum device_class device_get_class(const struct dt_device_node
> > *dev)
> >   {
> > @@ -329,9 +334,13 @@ int handle_device(struct domain *d, struct
> > dt_device_node *dev, p2m_type_t p2mt,
> >       struct map_range_data mr_data = {
> >           .d = d,
> >           .p2mt = p2mt,
> > -        .skip_mapping = !own_device ||
> > -                        (is_pci_passthrough_enabled() &&
> > -                        (device_get_class(dev) ==
> > DEVICE_PCI_HOSTBRIDGE)),
> > +        .skip_mapping =
> > +                        !own_device
> > +#ifdef CONFIG_HAS_PCI
> > +                        || (is_pci_passthrough_enabled() &&
> > +                        (device_get_class(dev) ==
> > DEVICE_PCI_HOSTBRIDGE))
> > +#endif
> 
> So the #ifdef is only here because DEVICE_PCI_HOSTBRIDGE is not
> defined. 
> It is not clear what's the actual problem of keeping 
> DEVICE_PCI_HOSTBRIDGE available for every build.
The only reason for that is that it seems to be used only in thecase when CONFIG_HAS_PCI is enabled ( probably not all archs will
have PCI support ). Generally,
I think it's okay not to use #ifdef DEVICE_PCI_HOSTBRIDGE to keep
the Arm code cleaner.

Does it make sense?
> 
> In fact, we have tried to get away from #ifdef in order to make
> ensure 
> we can catch any build failure without a randconfig (see use of 
> IS_ENABLED() which would not apply work here).
It would be nice to use IS_ENABLED but in this case still need to
something with definition of DEVICE_PCI_HOSTBRIDGE.

> 
> [...]
> 
> > diff --git a/xen/arch/ppc/include/asm/device.h
> > b/xen/arch/ppc/include/asm/device.h
> > deleted file mode 100644
> > index 8253e61d51..0000000000
> > --- a/xen/arch/ppc/include/asm/device.h
> > +++ /dev/null
> > @@ -1,53 +0,0 @@
> > -/* SPDX-License-Identifier: GPL-2.0-only */
> > -#ifndef __ASM_PPC_DEVICE_H__
> > -#define __ASM_PPC_DEVICE_H__
> > -
> > -enum device_type
> > -{
> > -    DEV_DT,
> > -    DEV_PCI,
> > -};
> > -
> > -struct device {
> > -    enum device_type type;
> > -#ifdef CONFIG_HAS_DEVICE_TREE
> > -    struct dt_device_node *of_node; /* Used by drivers imported
> > from Linux */
> > -#endif
> > -};
> > -
> > -enum device_class
> > -{
> > -    DEVICE_SERIAL,
> > -    DEVICE_IOMMU,
> > -    DEVICE_PCI_HOSTBRIDGE,
> > -    /* Use for error */
> > -    DEVICE_UNKNOWN,
> > -};
> > -
> > -struct device_desc {
> > -    /* Device name */
> > -    const char *name;
> > -    /* Device class */
> > -    enum device_class class;
> > -    /* List of devices supported by this driver */
> > -    const struct dt_device_match *dt_match;
> > -    /*
> > -     * Device initialization.
> > -     *
> > -     * -EAGAIN is used to indicate that device probing is
> > deferred.
> > -     */
> > -    int (*init)(struct dt_device_node *dev, const void *data);
> > -};
> > -
> > -typedef struct device device_t;
> > -
> > -#define DT_DEVICE_START(name_, namestr_,
> > class_)                    \
> > -static const struct device_desc __dev_desc_##name_
> > __used           \
> > -__section(".dev.info") =
> > {                                          \
> > -    .name =
> > namestr_,                                               \
> > -    .class =
> > class_,                                                \
> > -
> > -#define
> > DT_DEVICE_END                                               \
> > -};
> > -
> > -#endif /* __ASM_PPC_DEVICE_H__ */
> > diff --git a/xen/arch/arm/include/asm/device.h b/xen/include/asm-
> > generic/device.h
> > similarity index 79%
> > rename from xen/arch/arm/include/asm/device.h
> > rename to xen/include/asm-generic/device.h
> > index b5d451e087..063c448c4e 100644
> > --- a/xen/arch/arm/include/asm/device.h
> > +++ b/xen/include/asm-generic/device.h
> > @@ -1,14 +1,37 @@
> > -#ifndef __ASM_ARM_DEVICE_H
> > -#define __ASM_ARM_DEVICE_H
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ASM_GENERIC_DEVICE_H__
> > +#define __ASM_GENERIC_DEVICE_H__
> > +
> > +#include <xen/stdbool.h>
> >   
> >   enum device_type
> >   {
> > +#ifdef CONFIG_HAS_DEVICE_TREE
> >       DEV_DT,
> > +#endif
> > +
> > +#ifdef CONFIG_HAS_PCI
> >       DEV_PCI,
> > +#endif
> > +    DEV_TYPE_MAX,
> Nobody is using it. AFAICT, this was introduced because enum may be 
> empty if !HAS_DEVICE_TREE and !HAS_PCI. If so, can you add a comment 
> explaining it on top?
Sure, thanks. I'll add the comment.

> 
> The rest LGTM.
> 
> Cheers,
> 
~ Oleksii
Julien Grall Dec. 22, 2023, 2:15 p.m. UTC | #3
Hi Oleksii,

On 22/12/2023 13:16, Oleksii wrote:
> On Thu, 2023-12-21 at 19:38 +0000, Julien Grall wrote:
>> Hi,
>>
>> On 20/12/2023 14:08, Oleksii Kurochko wrote:
>>> Arm, PPC and RISC-V use the same device.h thereby device.h
>>> was moved to asm-generic. Arm's device.h was taken as a base with
>>> the following changes:
>>>    - #ifdef PCI related things.
>>>    - #ifdef ACPI related things.
>>>    - Rename #ifdef guards.
>>>    - Add SPDX tag.
>>>    - #ifdef CONFIG_HAS_DEVICE_TREE related things.
>>>    - #ifdef-ing iommu related things with CONFIG_HAS_PASSTHROUGH.
>>>
>>> Also Arm and PPC are switched to asm-generic version of device.h
>>>
>>> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
>>> ---
>>>
>>>        Jan wrote the following:
>>>          Overall I think there are too many changes done all in one
>>> go here.
>>>          But it's mostly Arm which is affected, so I'll leave
>>> judging about that
>>>          to the Arm maintainers.
>>>        
>>>        Arm maintainers, will it be fine for you to not split the
>>> patch?
>>
>> So in general I agree with Jan, patches should be kept small so they
>> are
>> easy to review.
>>
>> Given the discussion has been on-going for a while (we are at v6),  I
>> will give an attempt to review the patch as-is. But in the future,
>> please try to split. The smaller it is, the easier to review. For
>> code
>> movement and refactoring, I tend to first have a few refactoring
>> patches
>> and then move the code in a separate patch. So it is easier to spot
>> the
>> differences.
> Thanks, I'll separate the patch.
>>
>>> ---
>>> Changes in V6:
>>>    - Rebase only.
>>> ---
>>> Changes in V5:
>>>     - Removed generated file: xen/include/headers++.chk.new
>>>     - Removed pointless #ifdef CONFIG_HAS_DEVICE_TREE ... #endif for
>>> PPC as
>>>       CONFIG_HAS_DEVICE_TREE will be always used for PPC.
>>> ---
>>> Changes in V4:
>>>    - Updated the commit message
>>>    - Switched Arm and PPC to asm-generic version of device.h
>>>    - Replaced HAS_PCI with CONFIG_HAS_PCI
>>>    - ifdef-ing iommu filed of dev_archdata struct with
>>> CONFIG_HAS_PASSTHROUGH
>>>    - ifdef-ing iommu_fwspec of device struct with
>>> CONFIG_HAS_PASSTHROUGH
>>>    - ifdef-ing DT related things with CONFIG_HAS_DEVICE_TREE
>>>    - Updated the commit message ( remove a note with question about
>>>      if device.h should be in asm-generic or not )
>>>    - Replaced DEVICE_IC with DEVICE_INTERRUPT_CONTROLLER
>>>    - Rationalized usage of CONFIG_HAS_* in device.h
>>>    - Fixed indents for ACPI_DEVICE_START and ACPI_DEVICE_END
>>> ---
>>> Changes in V3:
>>>    - ifdef device tree related things.
>>>    - update the commit message
>>> ---
>>> Changes in V2:
>>> 	- take ( as common ) device.h from Arm as PPC and RISC-V
>>> use it as a base.
>>> 	- #ifdef PCI related things.
>>> 	- #ifdef ACPI related things.
>>> 	- rename DEVICE_GIC to DEVIC_IC.
>>> 	- rename #ifdef guards.
>>> 	- switch Arm and PPC to generic device.h
>>> 	- add SPDX tag
>>> 	- update the commit message
>>>
>>> ---
>>>    xen/arch/arm/device.c                         |  15 ++-
>>>    xen/arch/arm/domain_build.c                   |   2 +-
>>>    xen/arch/arm/gic-v2.c                         |   4 +-
>>>    xen/arch/arm/gic-v3.c                         |   6 +-
>>>    xen/arch/arm/gic.c                            |   4 +-
>>>    xen/arch/arm/include/asm/Makefile             |   1 +
>>>    xen/arch/ppc/include/asm/Makefile             |   1 +
>>>    xen/arch/ppc/include/asm/device.h             |  53 --------
>>>    .../asm => include/asm-generic}/device.h      | 125 +++++++++++--
>>> -----
>>>    9 files changed, 102 insertions(+), 109 deletions(-)
>>>    delete mode 100644 xen/arch/ppc/include/asm/device.h
>>>    rename xen/{arch/arm/include/asm => include/asm-generic}/device.h
>>> (79%)
>>>
>>> diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
>>> index 1f631d3274..affbe79f9a 100644
>>> --- a/xen/arch/arm/device.c
>>> +++ b/xen/arch/arm/device.c
>>> @@ -16,7 +16,10 @@
>>>    #include <xen/lib.h>
>>>    
>>>    extern const struct device_desc _sdevice[], _edevice[];
>>> +
>>> +#ifdef CONFIG_ACPI
>>>    extern const struct acpi_device_desc _asdevice[], _aedevice[];
>>> +#endif
>>>    
>>>    int __init device_init(struct dt_device_node *dev, enum
>>> device_class class,
>>>                           const void *data)
>>> @@ -45,6 +48,7 @@ int __init device_init(struct dt_device_node
>>> *dev, enum device_class class,
>>>        return -EBADF;
>>>    }
>>>    
>>> +#ifdef CONFIG_ACPI
>>>    int __init acpi_device_init(enum device_class class, const void
>>> *data, int class_type)
>>>    {
>>>        const struct acpi_device_desc *desc;
>>> @@ -61,6 +65,7 @@ int __init acpi_device_init(enum device_class
>>> class, const void *data, int class
>>>    
>>>        return -EBADF;
>>>    }
>>> +#endif
>>>    
>>>    enum device_class device_get_class(const struct dt_device_node
>>> *dev)
>>>    {
>>> @@ -329,9 +334,13 @@ int handle_device(struct domain *d, struct
>>> dt_device_node *dev, p2m_type_t p2mt,
>>>        struct map_range_data mr_data = {
>>>            .d = d,
>>>            .p2mt = p2mt,
>>> -        .skip_mapping = !own_device ||
>>> -                        (is_pci_passthrough_enabled() &&
>>> -                        (device_get_class(dev) ==
>>> DEVICE_PCI_HOSTBRIDGE)),
>>> +        .skip_mapping =
>>> +                        !own_device
>>> +#ifdef CONFIG_HAS_PCI
>>> +                        || (is_pci_passthrough_enabled() &&
>>> +                        (device_get_class(dev) ==
>>> DEVICE_PCI_HOSTBRIDGE))
>>> +#endif
>>
>> So the #ifdef is only here because DEVICE_PCI_HOSTBRIDGE is not
>> defined.
>> It is not clear what's the actual problem of keeping
>> DEVICE_PCI_HOSTBRIDGE available for every build.
> The only reason for that is that it seems to be used only in thecase when CONFIG_HAS_PCI is enabled ( probably not all archs will
> have PCI support ). 

Possibly yes. But you will always need some compat layer unless you 
manage to get rid of any use of PCI (or any feature you don't want) 
within "common" code.

Here, it is not clear to me what you are effectively trying to protect 
against. IOW, what could go wrong if PCI_HOSTBRIDGE is available for 
everyone?

I know it means we would never return DEVICE_PCI_HOSTBRIDGE even if the 
device is actually a hostbridge. But the same is true if Xen doesn't 
have a driver for the hostbridge (not everyone are using ECAM).

So at the end of the day this is a trade-off between keep the code 
readable (from my POV) and reducing the amount of symbols/defines exposed.

This is also matching my view on Jan's proposal to protect the static 
keyword for first_valid_mfn with #ifdef. There is a limit in the amount 
of #ifdef I will tolerate.

I'd like to hear the opinion from the others.

> Generally,
> I think it's okay not to use #ifdef DEVICE_PCI_HOSTBRIDGE to keep
> the Arm code cleaner.
> 
> Does it make sense?

I don't quite understand your last sentence. Are you saying you would be 
ok to remove #ifdef CONFIG_HAS_PCI around DEVICE_PCI_HOSTBRIDGE?

Cheers,
Oleksii Dec. 22, 2023, 4:24 p.m. UTC | #4
> 
> > Generally,
> > I think it's okay not to use #ifdef DEVICE_PCI_HOSTBRIDGE to keep
> > the Arm code cleaner.
> > 
> > Does it make sense?
> 
> I don't quite understand your last sentence. Are you saying you would
> be 
> ok to remove #ifdef CONFIG_HAS_PCI around DEVICE_PCI_HOSTBRIDGE?
Yes, that is what I meant.


~ Oleksii
diff mbox series

Patch

diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
index 1f631d3274..affbe79f9a 100644
--- a/xen/arch/arm/device.c
+++ b/xen/arch/arm/device.c
@@ -16,7 +16,10 @@ 
 #include <xen/lib.h>
 
 extern const struct device_desc _sdevice[], _edevice[];
+
+#ifdef CONFIG_ACPI
 extern const struct acpi_device_desc _asdevice[], _aedevice[];
+#endif
 
 int __init device_init(struct dt_device_node *dev, enum device_class class,
                        const void *data)
@@ -45,6 +48,7 @@  int __init device_init(struct dt_device_node *dev, enum device_class class,
     return -EBADF;
 }
 
+#ifdef CONFIG_ACPI
 int __init acpi_device_init(enum device_class class, const void *data, int class_type)
 {
     const struct acpi_device_desc *desc;
@@ -61,6 +65,7 @@  int __init acpi_device_init(enum device_class class, const void *data, int class
 
     return -EBADF;
 }
+#endif
 
 enum device_class device_get_class(const struct dt_device_node *dev)
 {
@@ -329,9 +334,13 @@  int handle_device(struct domain *d, struct dt_device_node *dev, p2m_type_t p2mt,
     struct map_range_data mr_data = {
         .d = d,
         .p2mt = p2mt,
-        .skip_mapping = !own_device ||
-                        (is_pci_passthrough_enabled() &&
-                        (device_get_class(dev) == DEVICE_PCI_HOSTBRIDGE)),
+        .skip_mapping =
+                        !own_device
+#ifdef CONFIG_HAS_PCI
+                        || (is_pci_passthrough_enabled() &&
+                        (device_get_class(dev) == DEVICE_PCI_HOSTBRIDGE))
+#endif
+                        ,
         .iomem_ranges = iomem_ranges,
         .irq_ranges = irq_ranges
     };
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 46161848dc..085d88671e 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1651,7 +1651,7 @@  static int __init handle_node(struct domain *d, struct kernel_info *kinfo,
      * Replace these nodes with our own. Note that the original may be
      * used_by DOMID_XEN so this check comes first.
      */
-    if ( device_get_class(node) == DEVICE_GIC )
+    if ( device_get_class(node) == DEVICE_INTERRUPT_CONTROLLER )
         return make_gic_node(d, kinfo->fdt, node);
     if ( dt_match_node(timer_matches, node) )
         return make_timer_node(kinfo);
diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index cf392bfd1c..5d6885e389 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -1366,7 +1366,7 @@  static const struct dt_device_match gicv2_dt_match[] __initconst =
     { /* sentinel */ },
 };
 
-DT_DEVICE_START(gicv2, "GICv2", DEVICE_GIC)
+DT_DEVICE_START(gicv2, "GICv2", DEVICE_INTERRUPT_CONTROLLER)
         .dt_match = gicv2_dt_match,
         .init = gicv2_dt_preinit,
 DT_DEVICE_END
@@ -1381,7 +1381,7 @@  static int __init gicv2_acpi_preinit(const void *data)
     return 0;
 }
 
-ACPI_DEVICE_START(agicv2, "GICv2", DEVICE_GIC)
+ACPI_DEVICE_START(agicv2, "GICv2", DEVICE_INTERRUPT_CONTROLLER)
         .class_type = ACPI_MADT_GIC_VERSION_V2,
         .init = gicv2_acpi_preinit,
 ACPI_DEVICE_END
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index 18289cd645..9e135aeb3d 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -1879,7 +1879,7 @@  static const struct dt_device_match gicv3_dt_match[] __initconst =
     { /* sentinel */ },
 };
 
-DT_DEVICE_START(gicv3, "GICv3", DEVICE_GIC)
+DT_DEVICE_START(gicv3, "GICv3", DEVICE_INTERRUPT_CONTROLLER)
         .dt_match = gicv3_dt_match,
         .init = gicv3_dt_preinit,
 DT_DEVICE_END
@@ -1894,12 +1894,12 @@  static int __init gicv3_acpi_preinit(const void *data)
     return 0;
 }
 
-ACPI_DEVICE_START(agicv3, "GICv3", DEVICE_GIC)
+ACPI_DEVICE_START(agicv3, "GICv3", DEVICE_INTERRUPT_CONTROLLER)
         .class_type = ACPI_MADT_GIC_VERSION_V3,
         .init = gicv3_acpi_preinit,
 ACPI_DEVICE_END
 
-ACPI_DEVICE_START(agicv4, "GICv4", DEVICE_GIC)
+ACPI_DEVICE_START(agicv4, "GICv4", DEVICE_INTERRUPT_CONTROLLER)
         .class_type = ACPI_MADT_GIC_VERSION_V4,
         .init = gicv3_acpi_preinit,
 ACPI_DEVICE_END
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index d922ea67aa..b5a9c8266c 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -234,7 +234,7 @@  static void __init gic_dt_preinit(void)
         if ( !dt_get_parent(node) )
             continue;
 
-        rc = device_init(node, DEVICE_GIC, NULL);
+        rc = device_init(node, DEVICE_INTERRUPT_CONTROLLER, NULL);
         if ( !rc )
         {
             /* NOTE: Only one GIC is supported */
@@ -262,7 +262,7 @@  static void __init gic_acpi_preinit(void)
 
     dist = container_of(header, struct acpi_madt_generic_distributor, header);
 
-    if ( acpi_device_init(DEVICE_GIC, NULL, dist->version) )
+    if ( acpi_device_init(DEVICE_INTERRUPT_CONTROLLER, NULL, dist->version) )
         panic("Unable to find compatible GIC in the ACPI table\n");
 }
 #else
diff --git a/xen/arch/arm/include/asm/Makefile b/xen/arch/arm/include/asm/Makefile
index a28cc5d1b1..c3f4291ee2 100644
--- a/xen/arch/arm/include/asm/Makefile
+++ b/xen/arch/arm/include/asm/Makefile
@@ -1,5 +1,6 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 generic-y += altp2m.h
+generic-y += device.h
 generic-y += hardirq.h
 generic-y += iocap.h
 generic-y += numa.h
diff --git a/xen/arch/ppc/include/asm/Makefile b/xen/arch/ppc/include/asm/Makefile
index efd72862c8..adb752b804 100644
--- a/xen/arch/ppc/include/asm/Makefile
+++ b/xen/arch/ppc/include/asm/Makefile
@@ -1,5 +1,6 @@ 
 # SPDX-License-Identifier: GPL-2.0-only
 generic-y += altp2m.h
+generic-y += device.h
 generic-y += div64.h
 generic-y += hardirq.h
 generic-y += hypercall.h
diff --git a/xen/arch/ppc/include/asm/device.h b/xen/arch/ppc/include/asm/device.h
deleted file mode 100644
index 8253e61d51..0000000000
--- a/xen/arch/ppc/include/asm/device.h
+++ /dev/null
@@ -1,53 +0,0 @@ 
-/* SPDX-License-Identifier: GPL-2.0-only */
-#ifndef __ASM_PPC_DEVICE_H__
-#define __ASM_PPC_DEVICE_H__
-
-enum device_type
-{
-    DEV_DT,
-    DEV_PCI,
-};
-
-struct device {
-    enum device_type type;
-#ifdef CONFIG_HAS_DEVICE_TREE
-    struct dt_device_node *of_node; /* Used by drivers imported from Linux */
-#endif
-};
-
-enum device_class
-{
-    DEVICE_SERIAL,
-    DEVICE_IOMMU,
-    DEVICE_PCI_HOSTBRIDGE,
-    /* Use for error */
-    DEVICE_UNKNOWN,
-};
-
-struct device_desc {
-    /* Device name */
-    const char *name;
-    /* Device class */
-    enum device_class class;
-    /* List of devices supported by this driver */
-    const struct dt_device_match *dt_match;
-    /*
-     * Device initialization.
-     *
-     * -EAGAIN is used to indicate that device probing is deferred.
-     */
-    int (*init)(struct dt_device_node *dev, const void *data);
-};
-
-typedef struct device device_t;
-
-#define DT_DEVICE_START(name_, namestr_, class_)                    \
-static const struct device_desc __dev_desc_##name_ __used           \
-__section(".dev.info") = {                                          \
-    .name = namestr_,                                               \
-    .class = class_,                                                \
-
-#define DT_DEVICE_END                                               \
-};
-
-#endif /* __ASM_PPC_DEVICE_H__ */
diff --git a/xen/arch/arm/include/asm/device.h b/xen/include/asm-generic/device.h
similarity index 79%
rename from xen/arch/arm/include/asm/device.h
rename to xen/include/asm-generic/device.h
index b5d451e087..063c448c4e 100644
--- a/xen/arch/arm/include/asm/device.h
+++ b/xen/include/asm-generic/device.h
@@ -1,14 +1,37 @@ 
-#ifndef __ASM_ARM_DEVICE_H
-#define __ASM_ARM_DEVICE_H
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_DEVICE_H__
+#define __ASM_GENERIC_DEVICE_H__
+
+#include <xen/stdbool.h>
 
 enum device_type
 {
+#ifdef CONFIG_HAS_DEVICE_TREE
     DEV_DT,
+#endif
+
+#ifdef CONFIG_HAS_PCI
     DEV_PCI,
+#endif
+    DEV_TYPE_MAX,
+};
+
+enum device_class
+{
+    DEVICE_SERIAL,
+    DEVICE_IOMMU,
+    DEVICE_INTERRUPT_CONTROLLER,
+#ifdef CONFIG_HAS_PCI
+    DEVICE_PCI_HOSTBRIDGE,
+#endif
+    /* Use for error */
+    DEVICE_UNKNOWN,
 };
 
 struct dev_archdata {
+#ifdef CONFIG_HAS_PASSTHROUGH
     void *iommu;    /* IOMMU private data */
+#endif
 };
 
 /* struct device - The basic device structure */
@@ -19,31 +42,65 @@  struct device
     struct dt_device_node *of_node; /* Used by drivers imported from Linux */
 #endif
     struct dev_archdata archdata;
+#ifdef CONFIG_HAS_PASSTHROUGH
     struct iommu_fwspec *iommu_fwspec; /* per-device IOMMU instance data */
+#endif
 };
 
 typedef struct device device_t;
 
+#ifdef CONFIG_HAS_DEVICE_TREE
+
 #include <xen/device_tree.h>
 
-#define dev_is_pci(dev) ((dev)->type == DEV_PCI)
 #define dev_is_dt(dev)  ((dev)->type == DEV_DT)
 
-enum device_class
-{
-    DEVICE_SERIAL,
-    DEVICE_IOMMU,
-    DEVICE_GIC,
-    DEVICE_PCI_HOSTBRIDGE,
-    /* Use for error */
-    DEVICE_UNKNOWN,
+/**
+ *  device_init - Initialize a device
+ *  @dev: device to initialize
+ *  @class: class of the device (serial, network...)
+ *  @data: specific data for initializing the device
+ *
+ *  Return 0 on success.
+ */
+int device_init(struct dt_device_node *dev, enum device_class class,
+                const void *data);
+
+/**
+ * device_get_type - Get the type of the device
+ * @dev: device to match
+ *
+ * Return the device type on success or DEVICE_ANY on failure
+ */
+enum device_class device_get_class(const struct dt_device_node *dev);
+
+#define DT_DEVICE_START(_name, _namestr, _class)                    \
+static const struct device_desc __dev_desc_##_name __used           \
+__section(".dev.info") = {                                          \
+    .name = _namestr,                                               \
+    .class = _class,                                                \
+
+#define DT_DEVICE_END                                               \
 };
 
+#else /* !CONFIG_HAS_DEVICE_TREE */
+#define dev_is_dt(dev) ((void)(dev), false)
+#endif /* CONFIG_HAS_DEVICE_TREE */
+
+#ifdef CONFIG_HAS_PCI
+#define dev_is_pci(dev) ((dev)->type == DEV_PCI)
+#else
+#define dev_is_pci(dev) ((void)(dev), false)
+#endif
+
 struct device_desc {
     /* Device name */
     const char *name;
     /* Device class */
     enum device_class class;
+
+#ifdef CONFIG_HAS_DEVICE_TREE
+
     /* List of devices supported by this driver */
     const struct dt_device_match *dt_match;
     /*
@@ -52,8 +109,12 @@  struct device_desc {
      * -EAGAIN is used to indicate that device probing is deferred.
      */
     int (*init)(struct dt_device_node *dev, const void *data);
+
+#endif
 };
 
+#ifdef CONFIG_ACPI
+
 struct acpi_device_desc {
     /* Device name */
     const char *name;
@@ -75,44 +136,18 @@  struct acpi_device_desc {
 int acpi_device_init(enum device_class class,
                      const void *data, int class_type);
 
-/**
- *  device_init - Initialize a device
- *  @dev: device to initialize
- *  @class: class of the device (serial, network...)
- *  @data: specific data for initializing the device
- *
- *  Return 0 on success.
- */
-int device_init(struct dt_device_node *dev, enum device_class class,
-                const void *data);
-
-/**
- * device_get_type - Get the type of the device
- * @dev: device to match
- *
- * Return the device type on success or DEVICE_ANY on failure
- */
-enum device_class device_get_class(const struct dt_device_node *dev);
+#define ACPI_DEVICE_START(_name, _namestr, _class)              \
+static const struct acpi_device_desc __dev_desc_##_name __used  \
+__section(".adev.info") = {                                     \
+    .name = _namestr,                                           \
+    .class = _class,                                            \
 
-#define DT_DEVICE_START(_name, _namestr, _class)                    \
-static const struct device_desc __dev_desc_##_name __used           \
-__section(".dev.info") = {                                          \
-    .name = _namestr,                                               \
-    .class = _class,                                                \
-
-#define DT_DEVICE_END                                               \
+#define ACPI_DEVICE_END                                         \
 };
 
-#define ACPI_DEVICE_START(_name, _namestr, _class)                    \
-static const struct acpi_device_desc __dev_desc_##_name __used           \
-__section(".adev.info") = {                       \
-    .name = _namestr,                                               \
-    .class = _class,                                                \
-
-#define ACPI_DEVICE_END                                               \
-};
+#endif /* CONFIG_ACPI */
 
-#endif /* __ASM_ARM_DEVICE_H */
+#endif /* __ASM_GENERIC_DEVICE_H__ */
 
 /*
  * Local variables: