[PATCH v6 0/4] resource: Use list_head to link sibling resource

[PATCH v6 0/4] resource: Use list_head to link sibling resource

[Baoquan He]

This patchset is doing:
1) Replace struct resource's sibling list from singly linked list to
list_head. Clearing out those pointer operation within singly linked
list for better code readability.
2) Based on list_head replacement, add a new function
walk_system_ram_res_rev() which can does reversed iteration on
iomem_resource's siblings.
3) Change kexec_file loading to search system RAM top down for kernel
loadin, using walk_system_ram_res_rev().

Note:
This patchset only passed testing on  x86_64 arch with network
enabling. The thing we need pay attetion to is that a root resource's
child member need be initialized specifically with LIST_HEAD_INIT() if
statically defined or INIT_LIST_HEAD() for dynamically definition. Here
Just like we do for iomem_resource/ioport_resource, or the change in
get_pci_domain_busn_res().

v5:
http://lkml.kernel.org/r/20180612032831.29747-1-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org

v4:
http://lkml.kernel.org/r/20180507063224.24229-1-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org

v3:
http://lkml.kernel.org/r/20180419001848.3041-1-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org

v2:
http://lkml.kernel.org/r/20180408024724.16812-1-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org

v1:
http://lkml.kernel.org/r/20180322033722.9279-1-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org

Changelog:
v5->v6:
  Fix code style problems in reparent_resources() and use existing
  error codes, according to Andy's suggestion.

  Fix bugs test robot reported.
  
v4->v5:
  Add new patch 0001 to move duplicated reparent_resources() to
  kernel/resource.c to make it be shared by different ARCH-es.

  Fix several code bugs reported by test robot on ARCH powerpc and
  microblaze.
v3->v4:
  Fix several bugs test robot reported. Rewrite cover letter and patch
  log according to reviewer's comment.

v2->v3:
  Rename resource functions first_child() and sibling() to
  resource_first_chils() and resource_sibling(). Dan suggested this.

  Move resource_first_chils() and resource_sibling() to linux/ioport.h
  and make them as inline function. Rob suggested this. Accordingly add
  linux/list.h including in linux/ioport.h, please help review if this
  bring efficiency degradation or code redundancy.

  The change on struct resource {} bring two pointers of size increase,
  mention this in git log to make it more specifically, Rob suggested
  this.

v1->v2:
  Use list_head instead to link resource siblings. This is suggested by
  Andrew.

  Rewrite walk_system_ram_res_rev() after list_head is taken to link
  resouce siblings.



Baoquan He (4):
  resource: Move reparent_resources() to kernel/resource.c and make it
    public
  resource: Use list_head to link sibling resource
  resource: add walk_system_ram_res_rev()
  kexec_file: Load kernel at top of system RAM if required

 arch/arm/plat-samsung/pm-check.c            |   6 +-
 arch/microblaze/pci/pci-common.c            |  41 +----
 arch/powerpc/kernel/pci-common.c            |  39 +----
 arch/sparc/kernel/ioport.c                  |   2 +-
 arch/xtensa/include/asm/pci-bridge.h        |   4 +-
 drivers/eisa/eisa-bus.c                     |   2 +
 drivers/gpu/drm/drm_memory.c                |   3 +-
 drivers/gpu/drm/gma500/gtt.c                |   5 +-
 drivers/hv/vmbus_drv.c                      |  52 +++---
 drivers/input/joystick/iforce/iforce-main.c |   4 +-
 drivers/nvdimm/namespace_devs.c             |   6 +-
 drivers/nvdimm/nd.h                         |   5 +-
 drivers/of/address.c                        |   4 +-
 drivers/parisc/lba_pci.c                    |   4 +-
 drivers/pci/controller/vmd.c                |   8 +-
 drivers/pci/probe.c                         |   2 +
 drivers/pci/setup-bus.c                     |   2 +-
 include/linux/ioport.h                      |  21 ++-
 kernel/kexec_file.c                         |   2 +
 kernel/resource.c                           | 263 ++++++++++++++++++----------
 20 files changed, 248 insertions(+), 227 deletions(-)

-- 
2.13.6

[PATCH v6 1/4] resource: Move reparent_resources() to kernel/resource.c and make it public

[Baoquan He]

reparent_resources() is duplicated in arch/microblaze/pci/pci-common.c
and arch/powerpc/kernel/pci-common.c, so move it to kernel/resource.c
so that it's shared.

Signed-off-by: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 arch/microblaze/pci/pci-common.c | 37 -------------------------------------
 arch/powerpc/kernel/pci-common.c | 35 -----------------------------------
 include/linux/ioport.h           |  1 +
 kernel/resource.c                | 39 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 40 insertions(+), 72 deletions(-)

diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index f34346d56095..7899bafab064 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -619,43 +619,6 @@ int pcibios_add_device(struct pci_dev *dev)
 EXPORT_SYMBOL(pcibios_add_device);
 
 /*
- * Reparent resource children of pr that conflict with res
- * under res, and make res replace those children.
- */
-static int __init reparent_resources(struct resource *parent,
-				     struct resource *res)
-{
-	struct resource *p, **pp;
-	struct resource **firstpp = NULL;
-
-	for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
-		if (p->end < res->start)
-			continue;
-		if (res->end < p->start)
-			break;
-		if (p->start < res->start || p->end > res->end)
-			return -1;	/* not completely contained */
-		if (firstpp == NULL)
-			firstpp = pp;
-	}
-	if (firstpp == NULL)
-		return -1;	/* didn't find any conflicting entries? */
-	res->parent = parent;
-	res->child = *firstpp;
-	res->sibling = *pp;
-	*firstpp = res;
-	*pp = NULL;
-	for (p = res->child; p != NULL; p = p->sibling) {
-		p->parent = res;
-		pr_debug("PCI: Reparented %s [%llx..%llx] under %s\n",
-			 p->name,
-			 (unsigned long long)p->start,
-			 (unsigned long long)p->end, res->name);
-	}
-	return 0;
-}
-
-/*
  *  Handle resources of PCI devices.  If the world were perfect, we could
  *  just allocate all the resource regions and do nothing more.  It isn't.
  *  On the other hand, we cannot just re-allocate all devices, as it would
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index fe9733ffffaa..926035bb378d 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1088,41 +1088,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
 EXPORT_SYMBOL(pcibios_align_resource);
 
 /*
- * Reparent resource children of pr that conflict with res
- * under res, and make res replace those children.
- */
-static int reparent_resources(struct resource *parent,
-				     struct resource *res)
-{
-	struct resource *p, **pp;
-	struct resource **firstpp = NULL;
-
-	for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
-		if (p->end < res->start)
-			continue;
-		if (res->end < p->start)
-			break;
-		if (p->start < res->start || p->end > res->end)
-			return -1;	/* not completely contained */
-		if (firstpp == NULL)
-			firstpp = pp;
-	}
-	if (firstpp == NULL)
-		return -1;	/* didn't find any conflicting entries? */
-	res->parent = parent;
-	res->child = *firstpp;
-	res->sibling = *pp;
-	*firstpp = res;
-	*pp = NULL;
-	for (p = res->child; p != NULL; p = p->sibling) {
-		p->parent = res;
-		pr_debug("PCI: Reparented %s %pR under %s\n",
-			 p->name, p, res->name);
-	}
-	return 0;
-}
-
-/*
  *  Handle resources of PCI devices.  If the world were perfect, we could
  *  just allocate all the resource regions and do nothing more.  It isn't.
  *  On the other hand, we cannot just re-allocate all devices, as it would
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index da0ebaec25f0..dfdcd0bfe54e 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -192,6 +192,7 @@ extern int allocate_resource(struct resource *root, struct resource *new,
 struct resource *lookup_resource(struct resource *root, resource_size_t start);
 int adjust_resource(struct resource *res, resource_size_t start,
 		    resource_size_t size);
+int reparent_resources(struct resource *parent, struct resource *res);
 resource_size_t resource_alignment(struct resource *res);
 static inline resource_size_t resource_size(const struct resource *res)
 {
diff --git a/kernel/resource.c b/kernel/resource.c
index 30e1bc68503b..d1cbf4b50e17 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -983,6 +983,45 @@ int adjust_resource(struct resource *res, resource_size_t start,
 }
 EXPORT_SYMBOL(adjust_resource);
 
+/*
+ * reparent_resources - reparent resource children of parent that res covers
+ * @parent: parent resource descriptor
+ * @res: resource descriptor desired by caller
+ *
+ * Reparent resource children of 'parent' that conflict with 'res'
+ * under 'res', and make 'res' replace those children.
+ */
+int reparent_resources(struct resource *parent, struct resource *res)
+{
+	struct resource *p, **pp;
+	struct resource **firstpp = NULL;
+
+	for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
+		if (p->end < res->start)
+			continue;
+		if (res->end < p->start)
+			break;
+		if (p->start < res->start || p->end > res->end)
+			return -ENOTSUPP;	/* not completely contained */
+		if (firstpp == NULL)
+			firstpp = pp;
+	}
+	if (firstpp == NULL)
+		return -ECANCELED; /* didn't find any conflicting entries? */
+	res->parent = parent;
+	res->child = *firstpp;
+	res->sibling = *pp;
+	*firstpp = res;
+	*pp = NULL;
+	for (p = res->child; p != NULL; p = p->sibling) {
+		p->parent = res;
+		pr_debug("PCI: Reparented %s %pR under %s\n",
+			 p->name, p, res->name);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(reparent_resources);
+
 static void __init __reserve_region_with_split(struct resource *root,
 		resource_size_t start, resource_size_t end,
 		const char *name)
-- 
2.13.6

Re: [PATCH v6 1/4] resource: Move reparent_resources() to kernel/resource.c and make it public

[Andy Shevchenko]

On Wed, Jul 4, 2018 at 7:10 AM, Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> reparent_resources() is duplicated in arch/microblaze/pci/pci-common.c
> and arch/powerpc/kernel/pci-common.c, so move it to kernel/resource.c
> so that it's shared.

With couple of comments below,

Reviewed-by: Andy Shevchenko <andy.shevchenko-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

P.S. In some commit message in this series you used 'likt' instead of 'like'.

>
> Signed-off-by: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  arch/microblaze/pci/pci-common.c | 37 -------------------------------------
>  arch/powerpc/kernel/pci-common.c | 35 -----------------------------------
>  include/linux/ioport.h           |  1 +
>  kernel/resource.c                | 39 +++++++++++++++++++++++++++++++++++++++
>  4 files changed, 40 insertions(+), 72 deletions(-)
>
> diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
> index f34346d56095..7899bafab064 100644
> --- a/arch/microblaze/pci/pci-common.c
> +++ b/arch/microblaze/pci/pci-common.c
> @@ -619,43 +619,6 @@ int pcibios_add_device(struct pci_dev *dev)
>  EXPORT_SYMBOL(pcibios_add_device);
>
>  /*
> - * Reparent resource children of pr that conflict with res
> - * under res, and make res replace those children.
> - */
> -static int __init reparent_resources(struct resource *parent,
> -                                    struct resource *res)
> -{
> -       struct resource *p, **pp;
> -       struct resource **firstpp = NULL;
> -
> -       for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
> -               if (p->end < res->start)
> -                       continue;
> -               if (res->end < p->start)
> -                       break;
> -               if (p->start < res->start || p->end > res->end)
> -                       return -1;      /* not completely contained */
> -               if (firstpp == NULL)
> -                       firstpp = pp;
> -       }
> -       if (firstpp == NULL)
> -               return -1;      /* didn't find any conflicting entries? */
> -       res->parent = parent;
> -       res->child = *firstpp;
> -       res->sibling = *pp;
> -       *firstpp = res;
> -       *pp = NULL;
> -       for (p = res->child; p != NULL; p = p->sibling) {
> -               p->parent = res;
> -               pr_debug("PCI: Reparented %s [%llx..%llx] under %s\n",
> -                        p->name,
> -                        (unsigned long long)p->start,
> -                        (unsigned long long)p->end, res->name);
> -       }
> -       return 0;
> -}
> -
> -/*
>   *  Handle resources of PCI devices.  If the world were perfect, we could
>   *  just allocate all the resource regions and do nothing more.  It isn't.
>   *  On the other hand, we cannot just re-allocate all devices, as it would
> diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> index fe9733ffffaa..926035bb378d 100644
> --- a/arch/powerpc/kernel/pci-common.c
> +++ b/arch/powerpc/kernel/pci-common.c
> @@ -1088,41 +1088,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
>  EXPORT_SYMBOL(pcibios_align_resource);
>
>  /*
> - * Reparent resource children of pr that conflict with res
> - * under res, and make res replace those children.
> - */
> -static int reparent_resources(struct resource *parent,
> -                                    struct resource *res)
> -{
> -       struct resource *p, **pp;
> -       struct resource **firstpp = NULL;
> -
> -       for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
> -               if (p->end < res->start)
> -                       continue;
> -               if (res->end < p->start)
> -                       break;
> -               if (p->start < res->start || p->end > res->end)
> -                       return -1;      /* not completely contained */
> -               if (firstpp == NULL)
> -                       firstpp = pp;
> -       }
> -       if (firstpp == NULL)
> -               return -1;      /* didn't find any conflicting entries? */
> -       res->parent = parent;
> -       res->child = *firstpp;
> -       res->sibling = *pp;
> -       *firstpp = res;
> -       *pp = NULL;
> -       for (p = res->child; p != NULL; p = p->sibling) {
> -               p->parent = res;
> -               pr_debug("PCI: Reparented %s %pR under %s\n",
> -                        p->name, p, res->name);
> -       }
> -       return 0;
> -}
> -
> -/*
>   *  Handle resources of PCI devices.  If the world were perfect, we could
>   *  just allocate all the resource regions and do nothing more.  It isn't.
>   *  On the other hand, we cannot just re-allocate all devices, as it would
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index da0ebaec25f0..dfdcd0bfe54e 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -192,6 +192,7 @@ extern int allocate_resource(struct resource *root, struct resource *new,
>  struct resource *lookup_resource(struct resource *root, resource_size_t start);
>  int adjust_resource(struct resource *res, resource_size_t start,
>                     resource_size_t size);
> +int reparent_resources(struct resource *parent, struct resource *res);
>  resource_size_t resource_alignment(struct resource *res);
>  static inline resource_size_t resource_size(const struct resource *res)
>  {
> diff --git a/kernel/resource.c b/kernel/resource.c
> index 30e1bc68503b..d1cbf4b50e17 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -983,6 +983,45 @@ int adjust_resource(struct resource *res, resource_size_t start,
>  }
>  EXPORT_SYMBOL(adjust_resource);
>
> +/*

/** ?

> + * reparent_resources - reparent resource children of parent that res covers
> + * @parent: parent resource descriptor
> + * @res: resource descriptor desired by caller
> + *
> + * Reparent resource children of 'parent' that conflict with 'res'
> + * under 'res', and make 'res' replace those children.

Describe error codes, please.

> + */
> +int reparent_resources(struct resource *parent, struct resource *res)
> +{
> +       struct resource *p, **pp;
> +       struct resource **firstpp = NULL;
> +
> +       for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
> +               if (p->end < res->start)
> +                       continue;
> +               if (res->end < p->start)
> +                       break;
> +               if (p->start < res->start || p->end > res->end)
> +                       return -ENOTSUPP;       /* not completely contained */
> +               if (firstpp == NULL)
> +                       firstpp = pp;
> +       }
> +       if (firstpp == NULL)
> +               return -ECANCELED; /* didn't find any conflicting entries? */
> +       res->parent = parent;
> +       res->child = *firstpp;
> +       res->sibling = *pp;
> +       *firstpp = res;
> +       *pp = NULL;
> +       for (p = res->child; p != NULL; p = p->sibling) {
> +               p->parent = res;
> +               pr_debug("PCI: Reparented %s %pR under %s\n",
> +                        p->name, p, res->name);
> +       }
> +       return 0;
> +}
> +EXPORT_SYMBOL(reparent_resources);
> +
>  static void __init __reserve_region_with_split(struct resource *root,
>                 resource_size_t start, resource_size_t end,
>                 const char *name)
> --
> 2.13.6
>



-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v6 1/4] resource: Move reparent_resources() to kernel/resource.c and make it public

[Baoquan He]

On 07/04/18 at 07:46pm, Andy Shevchenko wrote:
> On Wed, Jul 4, 2018 at 7:10 AM, Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> > reparent_resources() is duplicated in arch/microblaze/pci/pci-common.c
> > and arch/powerpc/kernel/pci-common.c, so move it to kernel/resource.c
> > so that it's shared.
> 
> With couple of comments below,

Sure, will fix these and repost with your reviewed-by, thanks. Should be
after I reproduce and fix those issues reported by test robot.

> 
> Reviewed-by: Andy Shevchenko <andy.shevchenko-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> 
> P.S. In some commit message in this series you used 'likt' instead of 'like'.
> 
> >
> > Signed-off-by: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> > ---
> >  arch/microblaze/pci/pci-common.c | 37 -------------------------------------
> >  arch/powerpc/kernel/pci-common.c | 35 -----------------------------------
> >  include/linux/ioport.h           |  1 +
> >  kernel/resource.c                | 39 +++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 40 insertions(+), 72 deletions(-)
> >
> > diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
> > index f34346d56095..7899bafab064 100644
> > --- a/arch/microblaze/pci/pci-common.c
> > +++ b/arch/microblaze/pci/pci-common.c
> > @@ -619,43 +619,6 @@ int pcibios_add_device(struct pci_dev *dev)
> >  EXPORT_SYMBOL(pcibios_add_device);
> >
> >  /*
> > - * Reparent resource children of pr that conflict with res
> > - * under res, and make res replace those children.
> > - */
> > -static int __init reparent_resources(struct resource *parent,
> > -                                    struct resource *res)
> > -{
> > -       struct resource *p, **pp;
> > -       struct resource **firstpp = NULL;
> > -
> > -       for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
> > -               if (p->end < res->start)
> > -                       continue;
> > -               if (res->end < p->start)
> > -                       break;
> > -               if (p->start < res->start || p->end > res->end)
> > -                       return -1;      /* not completely contained */
> > -               if (firstpp == NULL)
> > -                       firstpp = pp;
> > -       }
> > -       if (firstpp == NULL)
> > -               return -1;      /* didn't find any conflicting entries? */
> > -       res->parent = parent;
> > -       res->child = *firstpp;
> > -       res->sibling = *pp;
> > -       *firstpp = res;
> > -       *pp = NULL;
> > -       for (p = res->child; p != NULL; p = p->sibling) {
> > -               p->parent = res;
> > -               pr_debug("PCI: Reparented %s [%llx..%llx] under %s\n",
> > -                        p->name,
> > -                        (unsigned long long)p->start,
> > -                        (unsigned long long)p->end, res->name);
> > -       }
> > -       return 0;
> > -}
> > -
> > -/*
> >   *  Handle resources of PCI devices.  If the world were perfect, we could
> >   *  just allocate all the resource regions and do nothing more.  It isn't.
> >   *  On the other hand, we cannot just re-allocate all devices, as it would
> > diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> > index fe9733ffffaa..926035bb378d 100644
> > --- a/arch/powerpc/kernel/pci-common.c
> > +++ b/arch/powerpc/kernel/pci-common.c
> > @@ -1088,41 +1088,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
> >  EXPORT_SYMBOL(pcibios_align_resource);
> >
> >  /*
> > - * Reparent resource children of pr that conflict with res
> > - * under res, and make res replace those children.
> > - */
> > -static int reparent_resources(struct resource *parent,
> > -                                    struct resource *res)
> > -{
> > -       struct resource *p, **pp;
> > -       struct resource **firstpp = NULL;
> > -
> > -       for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
> > -               if (p->end < res->start)
> > -                       continue;
> > -               if (res->end < p->start)
> > -                       break;
> > -               if (p->start < res->start || p->end > res->end)
> > -                       return -1;      /* not completely contained */
> > -               if (firstpp == NULL)
> > -                       firstpp = pp;
> > -       }
> > -       if (firstpp == NULL)
> > -               return -1;      /* didn't find any conflicting entries? */
> > -       res->parent = parent;
> > -       res->child = *firstpp;
> > -       res->sibling = *pp;
> > -       *firstpp = res;
> > -       *pp = NULL;
> > -       for (p = res->child; p != NULL; p = p->sibling) {
> > -               p->parent = res;
> > -               pr_debug("PCI: Reparented %s %pR under %s\n",
> > -                        p->name, p, res->name);
> > -       }
> > -       return 0;
> > -}
> > -
> > -/*
> >   *  Handle resources of PCI devices.  If the world were perfect, we could
> >   *  just allocate all the resource regions and do nothing more.  It isn't.
> >   *  On the other hand, we cannot just re-allocate all devices, as it would
> > diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> > index da0ebaec25f0..dfdcd0bfe54e 100644
> > --- a/include/linux/ioport.h
> > +++ b/include/linux/ioport.h
> > @@ -192,6 +192,7 @@ extern int allocate_resource(struct resource *root, struct resource *new,
> >  struct resource *lookup_resource(struct resource *root, resource_size_t start);
> >  int adjust_resource(struct resource *res, resource_size_t start,
> >                     resource_size_t size);
> > +int reparent_resources(struct resource *parent, struct resource *res);
> >  resource_size_t resource_alignment(struct resource *res);
> >  static inline resource_size_t resource_size(const struct resource *res)
> >  {
> > diff --git a/kernel/resource.c b/kernel/resource.c
> > index 30e1bc68503b..d1cbf4b50e17 100644
> > --- a/kernel/resource.c
> > +++ b/kernel/resource.c
> > @@ -983,6 +983,45 @@ int adjust_resource(struct resource *res, resource_size_t start,
> >  }
> >  EXPORT_SYMBOL(adjust_resource);
> >
> > +/*
> 
> /** ?
> 
> > + * reparent_resources - reparent resource children of parent that res covers
> > + * @parent: parent resource descriptor
> > + * @res: resource descriptor desired by caller
> > + *
> > + * Reparent resource children of 'parent' that conflict with 'res'
> > + * under 'res', and make 'res' replace those children.
> 
> Describe error codes, please.
> 
> > + */
> > +int reparent_resources(struct resource *parent, struct resource *res)
> > +{
> > +       struct resource *p, **pp;
> > +       struct resource **firstpp = NULL;
> > +
> > +       for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
> > +               if (p->end < res->start)
> > +                       continue;
> > +               if (res->end < p->start)
> > +                       break;
> > +               if (p->start < res->start || p->end > res->end)
> > +                       return -ENOTSUPP;       /* not completely contained */
> > +               if (firstpp == NULL)
> > +                       firstpp = pp;
> > +       }
> > +       if (firstpp == NULL)
> > +               return -ECANCELED; /* didn't find any conflicting entries? */
> > +       res->parent = parent;
> > +       res->child = *firstpp;
> > +       res->sibling = *pp;
> > +       *firstpp = res;
> > +       *pp = NULL;
> > +       for (p = res->child; p != NULL; p = p->sibling) {
> > +               p->parent = res;
> > +               pr_debug("PCI: Reparented %s %pR under %s\n",
> > +                        p->name, p, res->name);
> > +       }
> > +       return 0;
> > +}
> > +EXPORT_SYMBOL(reparent_resources);
> > +
> >  static void __init __reserve_region_with_split(struct resource *root,
> >                 resource_size_t start, resource_size_t end,
> >                 const char *name)
> > --
> > 2.13.6
> >
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko

[PATCH v6 2/4] resource: Use list_head to link sibling resource

[Baoquan He]

The struct resource uses singly linked list to link siblings, implemented
by pointer operation. Replace it with list_head for better code readability.

Based on this list_head replacement, it will be very easy to do reverse
iteration on iomem_resource's sibling list in later patch.

Besides, type of member variables of struct resource, sibling and child, are
changed from 'struct resource *' to 'struct list_head'. This brings two
pointers of size increase.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: David Airlie <airlied@linux.ie>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Jonathan Derrick <jonathan.derrick@intel.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: devel@linuxdriverproject.org
Cc: linux-input@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: devicetree@vger.kernel.org
Cc: linux-pci@vger.kernel.org
---
 arch/arm/plat-samsung/pm-check.c            |   6 +-
 arch/microblaze/pci/pci-common.c            |   4 +-
 arch/powerpc/kernel/pci-common.c            |   4 +-
 arch/sparc/kernel/ioport.c                  |   2 +-
 arch/xtensa/include/asm/pci-bridge.h        |   4 +-
 drivers/eisa/eisa-bus.c                     |   2 +
 drivers/gpu/drm/drm_memory.c                |   3 +-
 drivers/gpu/drm/gma500/gtt.c                |   5 +-
 drivers/hv/vmbus_drv.c                      |  52 +++----
 drivers/input/joystick/iforce/iforce-main.c |   4 +-
 drivers/nvdimm/namespace_devs.c             |   6 +-
 drivers/nvdimm/nd.h                         |   5 +-
 drivers/of/address.c                        |   4 +-
 drivers/parisc/lba_pci.c                    |   4 +-
 drivers/pci/controller/vmd.c                |   8 +-
 drivers/pci/probe.c                         |   2 +
 drivers/pci/setup-bus.c                     |   2 +-
 include/linux/ioport.h                      |  17 ++-
 kernel/resource.c                           | 208 ++++++++++++++--------------
 19 files changed, 175 insertions(+), 167 deletions(-)

diff --git a/arch/arm/plat-samsung/pm-check.c b/arch/arm/plat-samsung/pm-check.c
index cd2c02c68bc3..5494355b1c49 100644
--- a/arch/arm/plat-samsung/pm-check.c
+++ b/arch/arm/plat-samsung/pm-check.c
@@ -46,8 +46,8 @@ typedef u32 *(run_fn_t)(struct resource *ptr, u32 *arg);
 static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
 {
 	while (ptr != NULL) {
-		if (ptr->child != NULL)
-			s3c_pm_run_res(ptr->child, fn, arg);
+		if (!list_empty(&ptr->child))
+			s3c_pm_run_res(resource_first_child(&ptr->child), fn, arg);
 
 		if ((ptr->flags & IORESOURCE_SYSTEM_RAM)
 				== IORESOURCE_SYSTEM_RAM) {
@@ -57,7 +57,7 @@ static void s3c_pm_run_res(struct resource *ptr, run_fn_t fn, u32 *arg)
 			arg = (fn)(ptr, arg);
 		}
 
-		ptr = ptr->sibling;
+		ptr = resource_sibling(ptr);
 	}
 }
 
diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index 7899bafab064..2bf73e27e231 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -533,7 +533,9 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 			res->flags = range.flags;
 			res->start = range.cpu_addr;
 			res->end = range.cpu_addr + range.size - 1;
-			res->parent = res->child = res->sibling = NULL;
+			res->parent = NULL;
+			INIT_LIST_HEAD(&res->child);
+			INIT_LIST_HEAD(&res->sibling);
 		}
 	}
 
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 926035bb378d..28fbe83c9daf 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -761,7 +761,9 @@ void pci_process_bridge_OF_ranges(struct pci_controller *hose,
 			res->flags = range.flags;
 			res->start = range.cpu_addr;
 			res->end = range.cpu_addr + range.size - 1;
-			res->parent = res->child = res->sibling = NULL;
+			res->parent = NULL;
+			INIT_LIST_HEAD(&res->child);
+			INIT_LIST_HEAD(&res->sibling);
 		}
 	}
 }
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index cca9134cfa7d..99efe4e98b16 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -669,7 +669,7 @@ static int sparc_io_proc_show(struct seq_file *m, void *v)
 	struct resource *root = m->private, *r;
 	const char *nm;
 
-	for (r = root->child; r != NULL; r = r->sibling) {
+	list_for_each_entry(r, &root->child, sibling) {
 		if ((nm = r->name) == NULL) nm = "???";
 		seq_printf(m, "%016llx-%016llx: %s\n",
 				(unsigned long long)r->start,
diff --git a/arch/xtensa/include/asm/pci-bridge.h b/arch/xtensa/include/asm/pci-bridge.h
index 0b68c76ec1e6..f487b06817df 100644
--- a/arch/xtensa/include/asm/pci-bridge.h
+++ b/arch/xtensa/include/asm/pci-bridge.h
@@ -71,8 +71,8 @@ static inline void pcibios_init_resource(struct resource *res,
 	res->flags = flags;
 	res->name = name;
 	res->parent = NULL;
-	res->sibling = NULL;
-	res->child = NULL;
+	INIT_LIST_HEAD(&res->child);
+	INIT_LIST_HEAD(&res->sibling);
 }
 
 
diff --git a/drivers/eisa/eisa-bus.c b/drivers/eisa/eisa-bus.c
index 1e8062f6dbfc..dba78f75fd06 100644
--- a/drivers/eisa/eisa-bus.c
+++ b/drivers/eisa/eisa-bus.c
@@ -408,6 +408,8 @@ static struct resource eisa_root_res = {
 	.start = 0,
 	.end   = 0xffffffff,
 	.flags = IORESOURCE_IO,
+	.sibling = LIST_HEAD_INIT(eisa_root_res.sibling),
+	.child  = LIST_HEAD_INIT(eisa_root_res.child),
 };
 
 static int eisa_bus_count;
diff --git a/drivers/gpu/drm/drm_memory.c b/drivers/gpu/drm/drm_memory.c
index d69e4fc1ee77..33baa7fa5e41 100644
--- a/drivers/gpu/drm/drm_memory.c
+++ b/drivers/gpu/drm/drm_memory.c
@@ -155,9 +155,8 @@ u64 drm_get_max_iomem(void)
 	struct resource *tmp;
 	resource_size_t max_iomem = 0;
 
-	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
+	list_for_each_entry(tmp, &iomem_resource.child, sibling)
 		max_iomem = max(max_iomem,  tmp->end);
-	}
 
 	return max_iomem;
 }
diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index 3949b0990916..addd3bc009af 100644
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -565,7 +565,7 @@ int psb_gtt_init(struct drm_device *dev, int resume)
 int psb_gtt_restore(struct drm_device *dev)
 {
 	struct drm_psb_private *dev_priv = dev->dev_private;
-	struct resource *r = dev_priv->gtt_mem->child;
+	struct resource *r;
 	struct gtt_range *range;
 	unsigned int restored = 0, total = 0, size = 0;
 
@@ -573,14 +573,13 @@ int psb_gtt_restore(struct drm_device *dev)
 	mutex_lock(&dev_priv->gtt_mutex);
 	psb_gtt_init(dev, 1);
 
-	while (r != NULL) {
+	list_for_each_entry(r, &dev_priv->gtt_mem->child, sibling) {
 		range = container_of(r, struct gtt_range, resource);
 		if (range->pages) {
 			psb_gtt_insert(dev, range, 1);
 			size += range->resource.end - range->resource.start;
 			restored++;
 		}
-		r = r->sibling;
 		total++;
 	}
 	mutex_unlock(&dev_priv->gtt_mutex);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index b10fe26c4891..d87ec5a1bc4c 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1412,9 +1412,8 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 {
 	resource_size_t start = 0;
 	resource_size_t end = 0;
-	struct resource *new_res;
+	struct resource *new_res, *tmp;
 	struct resource **old_res = &hyperv_mmio;
-	struct resource **prev_res = NULL;
 
 	switch (res->type) {
 
@@ -1461,44 +1460,36 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 	/*
 	 * If two ranges are adjacent, merge them.
 	 */
-	do {
-		if (!*old_res) {
-			*old_res = new_res;
-			break;
-		}
-
-		if (((*old_res)->end + 1) == new_res->start) {
-			(*old_res)->end = new_res->end;
+	if (!*old_res) {
+		*old_res = new_res;
+		return AE_OK;
+	}
+	tmp = *old_res;
+	list_for_each_entry_from(tmp, &tmp->parent->child, sibling) {
+		if ((tmp->end + 1) == new_res->start) {
+			tmp->end = new_res->end;
 			kfree(new_res);
 			break;
 		}
 
-		if ((*old_res)->start == new_res->end + 1) {
-			(*old_res)->start = new_res->start;
+		if (tmp->start == new_res->end + 1) {
+			tmp->start = new_res->start;
 			kfree(new_res);
 			break;
 		}
 
-		if ((*old_res)->start > new_res->end) {
-			new_res->sibling = *old_res;
-			if (prev_res)
-				(*prev_res)->sibling = new_res;
-			*old_res = new_res;
+		if (tmp->start > new_res->end) {
+			list_add(&new_res->sibling, tmp->sibling.prev);
 			break;
 		}
-
-		prev_res = old_res;
-		old_res = &(*old_res)->sibling;
-
-	} while (1);
+	}
 
 	return AE_OK;
 }
 
 static int vmbus_acpi_remove(struct acpi_device *device)
 {
-	struct resource *cur_res;
-	struct resource *next_res;
+	struct resource *res;
 
 	if (hyperv_mmio) {
 		if (fb_mmio) {
@@ -1507,10 +1498,9 @@ static int vmbus_acpi_remove(struct acpi_device *device)
 			fb_mmio = NULL;
 		}
 
-		for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
-			next_res = cur_res->sibling;
-			kfree(cur_res);
-		}
+		res = hyperv_mmio;
+		list_for_each_entry_from(res, &res->parent->child, sibling)
+			kfree(res);
 	}
 
 	return 0;
@@ -1596,7 +1586,8 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 		}
 	}
 
-	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
+	iter = hyperv_mmio;
+	list_for_each_entry_from(iter, &iter->parent->child, sibling) {
 		if ((iter->start >= max) || (iter->end <= min))
 			continue;
 
@@ -1639,7 +1630,8 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size)
 	struct resource *iter;
 
 	down(&hyperv_mmio_lock);
-	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
+	iter = hyperv_mmio;
+	list_for_each_entry_from(iter, &iter->parent->child, sibling) {
 		if ((iter->start >= start + size) || (iter->end <= start))
 			continue;
 
diff --git a/drivers/input/joystick/iforce/iforce-main.c b/drivers/input/joystick/iforce/iforce-main.c
index daeeb4c7e3b0..5c0be27b33ff 100644
--- a/drivers/input/joystick/iforce/iforce-main.c
+++ b/drivers/input/joystick/iforce/iforce-main.c
@@ -305,8 +305,8 @@ int iforce_init_device(struct iforce *iforce)
 	iforce->device_memory.end = 200;
 	iforce->device_memory.flags = IORESOURCE_MEM;
 	iforce->device_memory.parent = NULL;
-	iforce->device_memory.child = NULL;
-	iforce->device_memory.sibling = NULL;
+	INIT_LIST_HEAD(&iforce->device_memory.child);
+	INIT_LIST_HEAD(&iforce->device_memory.sibling);
 
 /*
  * Wait until device ready - until it sends its first response.
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 28afdd668905..f53d410d9981 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -637,7 +637,7 @@ static resource_size_t scan_allocate(struct nd_region *nd_region,
  retry:
 	first = 0;
 	for_each_dpa_resource(ndd, res) {
-		struct resource *next = res->sibling, *new_res = NULL;
+		struct resource *next = resource_sibling(res), *new_res = NULL;
 		resource_size_t allocate, available = 0;
 		enum alloc_loc loc = ALLOC_ERR;
 		const char *action;
@@ -763,7 +763,7 @@ static resource_size_t scan_allocate(struct nd_region *nd_region,
 	 * an initial "pmem-reserve pass".  Only do an initial BLK allocation
 	 * when none of the DPA space is reserved.
 	 */
-	if ((is_pmem || !ndd->dpa.child) && n == to_allocate)
+	if ((is_pmem || list_empty(&ndd->dpa.child)) && n == to_allocate)
 		return init_dpa_allocation(label_id, nd_region, nd_mapping, n);
 	return n;
 }
@@ -779,7 +779,7 @@ static int merge_dpa(struct nd_region *nd_region,
  retry:
 	for_each_dpa_resource(ndd, res) {
 		int rc;
-		struct resource *next = res->sibling;
+		struct resource *next = resource_sibling(res);
 		resource_size_t end = res->start + resource_size(res);
 
 		if (!next || strcmp(res->name, label_id->id) != 0
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 32e0364b48b9..da7da15e03e7 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -102,11 +102,10 @@ unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd);
 		(unsigned long long) (res ? res->start : 0), ##arg)
 
 #define for_each_dpa_resource(ndd, res) \
-	for (res = (ndd)->dpa.child; res; res = res->sibling)
+	list_for_each_entry(res, &(ndd)->dpa.child, sibling)
 
 #define for_each_dpa_resource_safe(ndd, res, next) \
-	for (res = (ndd)->dpa.child, next = res ? res->sibling : NULL; \
-			res; res = next, next = next ? next->sibling : NULL)
+	list_for_each_entry_safe(res, next, &(ndd)->dpa.child, sibling)
 
 struct nd_percpu_lane {
 	int count;
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 53349912ac75..e2e25719ab52 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -330,7 +330,9 @@ int of_pci_range_to_resource(struct of_pci_range *range,
 {
 	int err;
 	res->flags = range->flags;
-	res->parent = res->child = res->sibling = NULL;
+	res->parent = NULL;
+	INIT_LIST_HEAD(&res->child);
+	INIT_LIST_HEAD(&res->sibling);
 	res->name = np->full_name;
 
 	if (res->flags & IORESOURCE_IO) {
diff --git a/drivers/parisc/lba_pci.c b/drivers/parisc/lba_pci.c
index 69bd98421eb1..7482bdfd1959 100644
--- a/drivers/parisc/lba_pci.c
+++ b/drivers/parisc/lba_pci.c
@@ -170,8 +170,8 @@ lba_dump_res(struct resource *r, int d)
 	for (i = d; i ; --i) printk(" ");
 	printk(KERN_DEBUG "%p [%lx,%lx]/%lx\n", r,
 		(long)r->start, (long)r->end, r->flags);
-	lba_dump_res(r->child, d+2);
-	lba_dump_res(r->sibling, d);
+	lba_dump_res(resource_first_child(&r->child), d+2);
+	lba_dump_res(resource_sibling(r), d);
 }
 
 
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 942b64fc7f1f..e3ace20345c7 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -542,14 +542,14 @@ static struct pci_ops vmd_ops = {
 
 static void vmd_attach_resources(struct vmd_dev *vmd)
 {
-	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
-	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
+	list_add(&vmd->resources[1].sibling, &vmd->dev->resource[VMD_MEMBAR1].child);
+	list_add(&vmd->resources[2].sibling, &vmd->dev->resource[VMD_MEMBAR2].child);
 }
 
 static void vmd_detach_resources(struct vmd_dev *vmd)
 {
-	vmd->dev->resource[VMD_MEMBAR1].child = NULL;
-	vmd->dev->resource[VMD_MEMBAR2].child = NULL;
+	INIT_LIST_HEAD(&vmd->dev->resource[VMD_MEMBAR1].child);
+	INIT_LIST_HEAD(&vmd->dev->resource[VMD_MEMBAR2].child);
 }
 
 /*
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ac876e32de4b..9624dd1dfd49 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -59,6 +59,8 @@ static struct resource *get_pci_domain_busn_res(int domain_nr)
 	r->res.start = 0;
 	r->res.end = 0xff;
 	r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED;
+	INIT_LIST_HEAD(&r->res.child);
+	INIT_LIST_HEAD(&r->res.sibling);
 
 	list_add_tail(&r->list, &pci_domain_busn_res_list);
 
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 79b1824e83b4..8e685af8938d 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -2107,7 +2107,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
 				continue;
 
 			/* Ignore BARs which are still in use */
-			if (res->child)
+			if (!list_empty(&res->child))
 				continue;
 
 			ret = add_to_list(&saved, bridge, res, 0, 0);
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index dfdcd0bfe54e..b7456ae889dd 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -12,6 +12,7 @@
 #ifndef __ASSEMBLY__
 #include <linux/compiler.h>
 #include <linux/types.h>
+#include <linux/list.h>
 /*
  * Resources are tree-like, allowing
  * nesting etc..
@@ -22,7 +23,8 @@ struct resource {
 	const char *name;
 	unsigned long flags;
 	unsigned long desc;
-	struct resource *parent, *sibling, *child;
+	struct list_head child, sibling;
+	struct resource *parent;
 };
 
 /*
@@ -216,7 +218,6 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2)
 	return r1->start <= r2->start && r1->end >= r2->end;
 }
 
-
 /* Convenience shorthand with allocation */
 #define request_region(start,n,name)		__request_region(&ioport_resource, (start), (n), (name), 0)
 #define request_muxed_region(start,n,name)	__request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)
@@ -287,6 +288,18 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2)
        return (r1->start <= r2->end && r1->end >= r2->start);
 }
 
+static inline struct resource *resource_sibling(struct resource *res)
+{
+	if (res->parent && !list_is_last(&res->sibling, &res->parent->child))
+		return list_next_entry(res, sibling);
+	return NULL;
+}
+
+static inline struct resource *resource_first_child(struct list_head *head)
+{
+	return list_first_entry_or_null(head, struct resource, sibling);
+}
+
 
 #endif /* __ASSEMBLY__ */
 #endif	/* _LINUX_IOPORT_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index d1cbf4b50e17..6d647a3824b1 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -31,6 +31,8 @@ struct resource ioport_resource = {
 	.start	= 0,
 	.end	= IO_SPACE_LIMIT,
 	.flags	= IORESOURCE_IO,
+	.sibling = LIST_HEAD_INIT(ioport_resource.sibling),
+	.child  = LIST_HEAD_INIT(ioport_resource.child),
 };
 EXPORT_SYMBOL(ioport_resource);
 
@@ -39,6 +41,8 @@ struct resource iomem_resource = {
 	.start	= 0,
 	.end	= -1,
 	.flags	= IORESOURCE_MEM,
+	.sibling = LIST_HEAD_INIT(iomem_resource.sibling),
+	.child  = LIST_HEAD_INIT(iomem_resource.child),
 };
 EXPORT_SYMBOL(iomem_resource);
 
@@ -57,20 +61,20 @@ static DEFINE_RWLOCK(resource_lock);
  * by boot mem after the system is up. So for reusing the resource entry
  * we need to remember the resource.
  */
-static struct resource *bootmem_resource_free;
+static struct list_head bootmem_resource_free = LIST_HEAD_INIT(bootmem_resource_free);
 static DEFINE_SPINLOCK(bootmem_resource_lock);
 
 static struct resource *next_resource(struct resource *p, bool sibling_only)
 {
 	/* Caller wants to traverse through siblings only */
 	if (sibling_only)
-		return p->sibling;
+		return resource_sibling(p);
 
-	if (p->child)
-		return p->child;
-	while (!p->sibling && p->parent)
+	if (!list_empty(&p->child))
+		return resource_first_child(&p->child);
+	while (!resource_sibling(p) && p->parent)
 		p = p->parent;
-	return p->sibling;
+	return resource_sibling(p);
 }
 
 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
@@ -90,7 +94,7 @@ static void *r_start(struct seq_file *m, loff_t *pos)
 	struct resource *p = PDE_DATA(file_inode(m->file));
 	loff_t l = 0;
 	read_lock(&resource_lock);
-	for (p = p->child; p && l < *pos; p = r_next(m, p, &l))
+	for (p = resource_first_child(&p->child); p && l < *pos; p = r_next(m, p, &l))
 		;
 	return p;
 }
@@ -153,8 +157,7 @@ static void free_resource(struct resource *res)
 
 	if (!PageSlab(virt_to_head_page(res))) {
 		spin_lock(&bootmem_resource_lock);
-		res->sibling = bootmem_resource_free;
-		bootmem_resource_free = res;
+		list_add(&res->sibling, &bootmem_resource_free);
 		spin_unlock(&bootmem_resource_lock);
 	} else {
 		kfree(res);
@@ -166,10 +169,9 @@ static struct resource *alloc_resource(gfp_t flags)
 	struct resource *res = NULL;
 
 	spin_lock(&bootmem_resource_lock);
-	if (bootmem_resource_free) {
-		res = bootmem_resource_free;
-		bootmem_resource_free = res->sibling;
-	}
+	res = resource_first_child(&bootmem_resource_free);
+	if (res)
+		list_del(&res->sibling);
 	spin_unlock(&bootmem_resource_lock);
 
 	if (res)
@@ -177,6 +179,8 @@ static struct resource *alloc_resource(gfp_t flags)
 	else
 		res = kzalloc(sizeof(struct resource), flags);
 
+	INIT_LIST_HEAD(&res->child);
+	INIT_LIST_HEAD(&res->sibling);
 	return res;
 }
 
@@ -185,7 +189,7 @@ static struct resource * __request_resource(struct resource *root, struct resour
 {
 	resource_size_t start = new->start;
 	resource_size_t end = new->end;
-	struct resource *tmp, **p;
+	struct resource *tmp;
 
 	if (end < start)
 		return root;
@@ -193,64 +197,62 @@ static struct resource * __request_resource(struct resource *root, struct resour
 		return root;
 	if (end > root->end)
 		return root;
-	p = &root->child;
-	for (;;) {
-		tmp = *p;
-		if (!tmp || tmp->start > end) {
-			new->sibling = tmp;
-			*p = new;
+
+	if (list_empty(&root->child)) {
+		list_add(&new->sibling, &root->child);
+		new->parent = root;
+		INIT_LIST_HEAD(&new->child);
+		return NULL;
+	}
+
+	list_for_each_entry(tmp, &root->child, sibling) {
+		if (tmp->start > end) {
+			list_add(&new->sibling, tmp->sibling.prev);
 			new->parent = root;
+			INIT_LIST_HEAD(&new->child);
 			return NULL;
 		}
-		p = &tmp->sibling;
 		if (tmp->end < start)
 			continue;
 		return tmp;
 	}
+
+	list_add_tail(&new->sibling, &root->child);
+	new->parent = root;
+	INIT_LIST_HEAD(&new->child);
+	return NULL;
 }
 
 static int __release_resource(struct resource *old, bool release_child)
 {
-	struct resource *tmp, **p, *chd;
+	struct resource *tmp, *next, *chd;
 
-	p = &old->parent->child;
-	for (;;) {
-		tmp = *p;
-		if (!tmp)
-			break;
+	list_for_each_entry_safe(tmp, next, &old->parent->child, sibling) {
 		if (tmp == old) {
-			if (release_child || !(tmp->child)) {
-				*p = tmp->sibling;
+			if (release_child || list_empty(&tmp->child)) {
+				list_del(&tmp->sibling);
 			} else {
-				for (chd = tmp->child;; chd = chd->sibling) {
+				list_for_each_entry(chd, &tmp->child, sibling)
 					chd->parent = tmp->parent;
-					if (!(chd->sibling))
-						break;
-				}
-				*p = tmp->child;
-				chd->sibling = tmp->sibling;
+				list_splice(&tmp->child, tmp->sibling.prev);
+				list_del(&tmp->sibling);
 			}
+
 			old->parent = NULL;
 			return 0;
 		}
-		p = &tmp->sibling;
 	}
 	return -EINVAL;
 }
 
 static void __release_child_resources(struct resource *r)
 {
-	struct resource *tmp, *p;
+	struct resource *tmp, *next;
 	resource_size_t size;
 
-	p = r->child;
-	r->child = NULL;
-	while (p) {
-		tmp = p;
-		p = p->sibling;
-
+	list_for_each_entry_safe(tmp, next, &r->child, sibling) {
 		tmp->parent = NULL;
-		tmp->sibling = NULL;
+		list_del_init(&tmp->sibling);
 		__release_child_resources(tmp);
 
 		printk(KERN_DEBUG "release child resource %pR\n", tmp);
@@ -259,6 +261,8 @@ static void __release_child_resources(struct resource *r)
 		tmp->start = 0;
 		tmp->end = size - 1;
 	}
+
+	INIT_LIST_HEAD(&tmp->child);
 }
 
 void release_child_resources(struct resource *r)
@@ -343,7 +347,8 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,
 
 	read_lock(&resource_lock);
 
-	for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
+	for (p = resource_first_child(&iomem_resource.child); p;
+			p = next_resource(p, sibling_only)) {
 		if ((p->flags & res->flags) != res->flags)
 			continue;
 		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
@@ -532,7 +537,7 @@ int region_intersects(resource_size_t start, size_t size, unsigned long flags,
 	struct resource *p;
 
 	read_lock(&resource_lock);
-	for (p = iomem_resource.child; p ; p = p->sibling) {
+	list_for_each_entry(p, &iomem_resource.child, sibling) {
 		bool is_type = (((p->flags & flags) == flags) &&
 				((desc == IORES_DESC_NONE) ||
 				 (desc == p->desc)));
@@ -586,7 +591,7 @@ static int __find_resource(struct resource *root, struct resource *old,
 			 resource_size_t  size,
 			 struct resource_constraint *constraint)
 {
-	struct resource *this = root->child;
+	struct resource *this = resource_first_child(&root->child);
 	struct resource tmp = *new, avail, alloc;
 
 	tmp.start = root->start;
@@ -596,7 +601,7 @@ static int __find_resource(struct resource *root, struct resource *old,
 	 */
 	if (this && this->start == root->start) {
 		tmp.start = (this == old) ? old->start : this->end + 1;
-		this = this->sibling;
+		this = resource_sibling(this);
 	}
 	for(;;) {
 		if (this)
@@ -632,7 +637,7 @@ next:		if (!this || this->end == root->end)
 
 		if (this != old)
 			tmp.start = this->end + 1;
-		this = this->sibling;
+		this = resource_sibling(this);
 	}
 	return -EBUSY;
 }
@@ -676,7 +681,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
 		goto out;
 	}
 
-	if (old->child) {
+	if (!list_empty(&old->child)) {
 		err = -EBUSY;
 		goto out;
 	}
@@ -757,7 +762,7 @@ struct resource *lookup_resource(struct resource *root, resource_size_t start)
 	struct resource *res;
 
 	read_lock(&resource_lock);
-	for (res = root->child; res; res = res->sibling) {
+	list_for_each_entry(res, &root->child, sibling) {
 		if (res->start == start)
 			break;
 	}
@@ -790,32 +795,27 @@ static struct resource * __insert_resource(struct resource *parent, struct resou
 			break;
 	}
 
-	for (next = first; ; next = next->sibling) {
+	for (next = first; ; next = resource_sibling(next)) {
 		/* Partial overlap? Bad, and unfixable */
 		if (next->start < new->start || next->end > new->end)
 			return next;
-		if (!next->sibling)
+		if (!resource_sibling(next))
 			break;
-		if (next->sibling->start > new->end)
+		if (resource_sibling(next)->start > new->end)
 			break;
 	}
-
 	new->parent = parent;
-	new->sibling = next->sibling;
-	new->child = first;
+	list_add(&new->sibling, &next->sibling);
+	INIT_LIST_HEAD(&new->child);
 
-	next->sibling = NULL;
-	for (next = first; next; next = next->sibling)
+	/*
+	 * From first to next, they all fall into new's region, so change them
+	 * as new's children.
+	 */
+	list_cut_position(&new->child, first->sibling.prev, &next->sibling);
+	list_for_each_entry(next, &new->child, sibling)
 		next->parent = new;
 
-	if (parent->child == first) {
-		parent->child = new;
-	} else {
-		next = parent->child;
-		while (next->sibling != first)
-			next = next->sibling;
-		next->sibling = new;
-	}
 	return NULL;
 }
 
@@ -937,19 +937,17 @@ static int __adjust_resource(struct resource *res, resource_size_t start,
 	if ((start < parent->start) || (end > parent->end))
 		goto out;
 
-	if (res->sibling && (res->sibling->start <= end))
+	if (resource_sibling(res) && (resource_sibling(res)->start <= end))
 		goto out;
 
-	tmp = parent->child;
-	if (tmp != res) {
-		while (tmp->sibling != res)
-			tmp = tmp->sibling;
+	if (res->sibling.prev != &parent->child) {
+		tmp = list_prev_entry(res, sibling);
 		if (start <= tmp->end)
 			goto out;
 	}
 
 skip:
-	for (tmp = res->child; tmp; tmp = tmp->sibling)
+	list_for_each_entry(tmp, &res->child, sibling)
 		if ((tmp->start < start) || (tmp->end > end))
 			goto out;
 
@@ -993,28 +991,31 @@ EXPORT_SYMBOL(adjust_resource);
  */
 int reparent_resources(struct resource *parent, struct resource *res)
 {
-	struct resource *p, **pp;
-	struct resource **firstpp = NULL;
+	struct resource *p, *first = NULL;
 
-	for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
+	list_for_each_entry(p, &parent->child, sibling) {
 		if (p->end < res->start)
 			continue;
 		if (res->end < p->start)
 			break;
 		if (p->start < res->start || p->end > res->end)
 			return -ENOTSUPP;	/* not completely contained */
-		if (firstpp == NULL)
-			firstpp = pp;
+		if (first == NULL)
+			first = p;
 	}
-	if (firstpp == NULL)
+	if (first == NULL)
 		return -ECANCELED; /* didn't find any conflicting entries? */
 	res->parent = parent;
-	res->child = *firstpp;
-	res->sibling = *pp;
-	*firstpp = res;
-	*pp = NULL;
-	for (p = res->child; p != NULL; p = p->sibling) {
-		p->parent = res;
+	list_add(&res->sibling, p->sibling.prev);
+	INIT_LIST_HEAD(&res->child);
+
+	/*
+	 * From first to p's previous sibling, they all fall into
+	 * res's region, change them as res's children.
+	 */
+	list_cut_position(&res->child, first->sibling.prev, res->sibling.prev);
+	list_for_each_entry(p, &res->child, sibling) {
+                p->parent = res;
 		pr_debug("PCI: Reparented %s %pR under %s\n",
 			 p->name, p, res->name);
 	}
@@ -1213,34 +1214,32 @@ EXPORT_SYMBOL(__request_region);
 void __release_region(struct resource *parent, resource_size_t start,
 			resource_size_t n)
 {
-	struct resource **p;
+	struct resource *res;
 	resource_size_t end;
 
-	p = &parent->child;
+	res = resource_first_child(&parent->child);
 	end = start + n - 1;
 
 	write_lock(&resource_lock);
 
 	for (;;) {
-		struct resource *res = *p;
-
 		if (!res)
 			break;
 		if (res->start <= start && res->end >= end) {
 			if (!(res->flags & IORESOURCE_BUSY)) {
-				p = &res->child;
+				res = resource_first_child(&res->child);
 				continue;
 			}
 			if (res->start != start || res->end != end)
 				break;
-			*p = res->sibling;
+			list_del(&res->sibling);
 			write_unlock(&resource_lock);
 			if (res->flags & IORESOURCE_MUXED)
 				wake_up(&muxed_resource_wait);
 			free_resource(res);
 			return;
 		}
-		p = &res->sibling;
+		res = resource_sibling(res);
 	}
 
 	write_unlock(&resource_lock);
@@ -1275,9 +1274,7 @@ EXPORT_SYMBOL(__release_region);
 int release_mem_region_adjustable(struct resource *parent,
 			resource_size_t start, resource_size_t size)
 {
-	struct resource **p;
-	struct resource *res;
-	struct resource *new_res;
+	struct resource *res, *new_res;
 	resource_size_t end;
 	int ret = -EINVAL;
 
@@ -1288,16 +1285,16 @@ int release_mem_region_adjustable(struct resource *parent,
 	/* The alloc_resource() result gets checked later */
 	new_res = alloc_resource(GFP_KERNEL);
 
-	p = &parent->child;
+	res = resource_first_child(&parent->child);
 	write_lock(&resource_lock);
 
-	while ((res = *p)) {
+	while ((res)) {
 		if (res->start >= end)
 			break;
 
 		/* look for the next resource if it does not fit into */
 		if (res->start > start || res->end < end) {
-			p = &res->sibling;
+			res = resource_sibling(res);
 			continue;
 		}
 
@@ -1305,14 +1302,14 @@ int release_mem_region_adjustable(struct resource *parent,
 			break;
 
 		if (!(res->flags & IORESOURCE_BUSY)) {
-			p = &res->child;
+			res = resource_first_child(&res->child);
 			continue;
 		}
 
 		/* found the target resource; let's adjust accordingly */
 		if (res->start == start && res->end == end) {
 			/* free the whole entry */
-			*p = res->sibling;
+			list_del(&res->sibling);
 			free_resource(res);
 			ret = 0;
 		} else if (res->start == start && res->end != end) {
@@ -1335,14 +1332,13 @@ int release_mem_region_adjustable(struct resource *parent,
 			new_res->flags = res->flags;
 			new_res->desc = res->desc;
 			new_res->parent = res->parent;
-			new_res->sibling = res->sibling;
-			new_res->child = NULL;
+			INIT_LIST_HEAD(&new_res->child);
 
 			ret = __adjust_resource(res, res->start,
 						start - res->start);
 			if (ret)
 				break;
-			res->sibling = new_res;
+			list_add(&new_res->sibling, &res->sibling);
 			new_res = NULL;
 		}
 
@@ -1523,7 +1519,7 @@ static int __init reserve_setup(char *str)
 			res->end = io_start + io_num - 1;
 			res->flags |= IORESOURCE_BUSY;
 			res->desc = IORES_DESC_NONE;
-			res->child = NULL;
+			INIT_LIST_HEAD(&res->child);
 			if (request_resource(parent, res) == 0)
 				reserved = x+1;
 		}
@@ -1543,7 +1539,7 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 	loff_t l;
 
 	read_lock(&resource_lock);
-	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+	for (p = resource_first_child(&p->child); p; p = r_next(NULL, p, &l)) {
 		/*
 		 * We can probably skip the resources without
 		 * IORESOURCE_IO attribute?
@@ -1599,7 +1595,7 @@ bool iomem_is_exclusive(u64 addr)
 	addr = addr & PAGE_MASK;
 
 	read_lock(&resource_lock);
-	for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+	for (p = resource_first_child(&p->child); p; p = r_next(NULL, p, &l)) {
 		/*
 		 * We can probably skip the resources without
 		 * IORESOURCE_IO attribute?
-- 
2.13.6

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Re: [PATCH v6 2/4] resource: Use list_head to link sibling resource

[kbuild test robot]

Hi Baoquan,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.18-rc3 next-20180704]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180704-121402
config: ia64-allnoconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 8.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=8.1.0 make.cross ARCH=ia64 

All errors (new ones prefixed by >>):

   arch/ia64/sn/kernel/io_init.c: In function 'sn_io_slot_fixup':
>> arch/ia64/sn/kernel/io_init.c:195:19: error: invalid operands to binary && (have 'int' and 'struct list_head')
      if (res->parent && res->parent->child)
          ~~~~~~~~~~~ ^~ ~~~~~~~~~~~~~~~~~~

vim +195 arch/ia64/sn/kernel/io_init.c

^1da177e Linus Torvalds  2005-04-16  142  
3ec829b6 John Keller     2005-11-29  143  /*
6f09a925 John Keller     2007-01-30  144   * sn_io_slot_fixup() -   We are not running with an ACPI capable PROM,
8ea6091f John Keller     2006-10-04  145   *			  and need to convert the pci_dev->resource
8ea6091f John Keller     2006-10-04  146   *			  'start' and 'end' addresses to mapped addresses,
8ea6091f John Keller     2006-10-04  147   *			  and setup the pci_controller->window array entries.
^1da177e Linus Torvalds  2005-04-16  148   */
8ea6091f John Keller     2006-10-04  149  void
6f09a925 John Keller     2007-01-30  150  sn_io_slot_fixup(struct pci_dev *dev)
^1da177e Linus Torvalds  2005-04-16  151  {
^1da177e Linus Torvalds  2005-04-16  152  	int idx;
ab97b8cc Bjorn Helgaas   2016-03-02  153  	struct resource *res;
18c25526 Matt Fleming    2016-05-04  154  	unsigned long size;
6f09a925 John Keller     2007-01-30  155  	struct pcidev_info *pcidev_info;
6f09a925 John Keller     2007-01-30  156  	struct sn_irq_info *sn_irq_info;
6f09a925 John Keller     2007-01-30  157  	int status;
6f09a925 John Keller     2007-01-30  158  
6f09a925 John Keller     2007-01-30  159  	pcidev_info = kzalloc(sizeof(struct pcidev_info), GFP_KERNEL);
6f09a925 John Keller     2007-01-30  160  	if (!pcidev_info)
d4ed8084 Harvey Harrison 2008-03-04  161  		panic("%s: Unable to alloc memory for pcidev_info", __func__);
6f09a925 John Keller     2007-01-30  162  
6f09a925 John Keller     2007-01-30  163  	sn_irq_info = kzalloc(sizeof(struct sn_irq_info), GFP_KERNEL);
6f09a925 John Keller     2007-01-30  164  	if (!sn_irq_info)
d4ed8084 Harvey Harrison 2008-03-04  165  		panic("%s: Unable to alloc memory for sn_irq_info", __func__);
6f09a925 John Keller     2007-01-30  166  
6f09a925 John Keller     2007-01-30  167  	/* Call to retrieve pci device information needed by kernel. */
6f09a925 John Keller     2007-01-30  168  	status = sal_get_pcidev_info((u64) pci_domain_nr(dev),
6f09a925 John Keller     2007-01-30  169  		(u64) dev->bus->number,
6f09a925 John Keller     2007-01-30  170  		dev->devfn,
6f09a925 John Keller     2007-01-30  171  		(u64) __pa(pcidev_info),
6f09a925 John Keller     2007-01-30  172  		(u64) __pa(sn_irq_info));
6f09a925 John Keller     2007-01-30  173  
80a03e29 Stoyan Gaydarov 2009-03-10  174  	BUG_ON(status); /* Cannot get platform pci device information */
6f09a925 John Keller     2007-01-30  175  
3ec829b6 John Keller     2005-11-29  176  
^1da177e Linus Torvalds  2005-04-16  177  	/* Copy over PIO Mapped Addresses */
^1da177e Linus Torvalds  2005-04-16  178  	for (idx = 0; idx <= PCI_ROM_RESOURCE; idx++) {
ab97b8cc Bjorn Helgaas   2016-03-02  179  		if (!pcidev_info->pdi_pio_mapped_addr[idx])
^1da177e Linus Torvalds  2005-04-16  180  			continue;
^1da177e Linus Torvalds  2005-04-16  181  
ab97b8cc Bjorn Helgaas   2016-03-02  182  		res = &dev->resource[idx];
ab97b8cc Bjorn Helgaas   2016-03-02  183  
ab97b8cc Bjorn Helgaas   2016-03-02  184  		size = res->end - res->start;
ab97b8cc Bjorn Helgaas   2016-03-02  185  		if (size == 0)
3ec829b6 John Keller     2005-11-29  186  			continue;
ab97b8cc Bjorn Helgaas   2016-03-02  187  
240504ad Bjorn Helgaas   2016-03-02  188  		res->start = pcidev_info->pdi_pio_mapped_addr[idx];
18c25526 Matt Fleming    2016-05-04  189  		res->end = res->start + size;
64715725 Bernhard Walle  2007-03-18  190  
64715725 Bernhard Walle  2007-03-18  191  		/*
64715725 Bernhard Walle  2007-03-18  192  		 * if it's already in the device structure, remove it before
64715725 Bernhard Walle  2007-03-18  193  		 * inserting
64715725 Bernhard Walle  2007-03-18  194  		 */
ab97b8cc Bjorn Helgaas   2016-03-02 @195  		if (res->parent && res->parent->child)
ab97b8cc Bjorn Helgaas   2016-03-02  196  			release_resource(res);
64715725 Bernhard Walle  2007-03-18  197  
ab97b8cc Bjorn Helgaas   2016-03-02  198  		if (res->flags & IORESOURCE_IO)
ab97b8cc Bjorn Helgaas   2016-03-02  199  			insert_resource(&ioport_resource, res);
^1da177e Linus Torvalds  2005-04-16  200  		else
ab97b8cc Bjorn Helgaas   2016-03-02  201  			insert_resource(&iomem_resource, res);
d7ad2254 John Keller     2007-07-09  202  		/*
240504ad Bjorn Helgaas   2016-03-02  203  		 * If ROM, mark as shadowed in PROM.
d7ad2254 John Keller     2007-07-09  204  		 */
d7ad2254 John Keller     2007-07-09  205  		if (idx == PCI_ROM_RESOURCE) {
240504ad Bjorn Helgaas   2016-03-02  206  			pci_disable_rom(dev);
240504ad Bjorn Helgaas   2016-03-02  207  			res->flags = IORESOURCE_MEM | IORESOURCE_ROM_SHADOW |
240504ad Bjorn Helgaas   2016-03-02  208  				     IORESOURCE_PCI_FIXED;
d7ad2254 John Keller     2007-07-09  209  		}
^1da177e Linus Torvalds  2005-04-16  210  	}
6f09a925 John Keller     2007-01-30  211  
6f09a925 John Keller     2007-01-30  212  	sn_pci_fixup_slot(dev, pcidev_info, sn_irq_info);
^1da177e Linus Torvalds  2005-04-16  213  }
6f09a925 John Keller     2007-01-30  214  EXPORT_SYMBOL(sn_io_slot_fixup);
6f09a925 John Keller     2007-01-30  215  

:::::: The code at line 195 was first introduced by commit
:::::: ab97b8cc560eabfd8139dd97924a09e46a3c9632 ia64/PCI: Use temporary struct resource * to avoid repetition

:::::: TO: Bjorn Helgaas <bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
:::::: CC: Bjorn Helgaas <bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Re: [PATCH v6 2/4] resource: Use list_head to link sibling resource

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 2540 bytes --]

Hi Baoquan,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.18-rc3 next-20180704]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180704-121402
config: mips-rb532_defconfig (attached as .config)
compiler: mipsel-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.2.0 make.cross ARCH=mips 

All error/warnings (new ones prefixed by >>):

>> arch/mips/pci/pci-rc32434.c:57:11: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
     .child = &rc32434_res_pci_mem2
              ^
   arch/mips/pci/pci-rc32434.c:57:11: note: (near initialization for 'rc32434_res_pci_mem1.child.next')
>> arch/mips/pci/pci-rc32434.c:51:47: warning: missing braces around initializer [-Wmissing-braces]
    static struct resource rc32434_res_pci_mem1 = {
                                                  ^
   arch/mips/pci/pci-rc32434.c:60:47: warning: missing braces around initializer [-Wmissing-braces]
    static struct resource rc32434_res_pci_mem2 = {
                                                  ^
   cc1: some warnings being treated as errors

vim +57 arch/mips/pci/pci-rc32434.c

73b4390f Ralf Baechle 2008-07-16  50  
73b4390f Ralf Baechle 2008-07-16 @51  static struct resource rc32434_res_pci_mem1 = {
73b4390f Ralf Baechle 2008-07-16  52  	.name = "PCI MEM1",
73b4390f Ralf Baechle 2008-07-16  53  	.start = 0x50000000,
73b4390f Ralf Baechle 2008-07-16  54  	.end = 0x5FFFFFFF,
73b4390f Ralf Baechle 2008-07-16  55  	.flags = IORESOURCE_MEM,
73b4390f Ralf Baechle 2008-07-16  56  	.sibling = NULL,
73b4390f Ralf Baechle 2008-07-16 @57  	.child = &rc32434_res_pci_mem2
73b4390f Ralf Baechle 2008-07-16  58  };
73b4390f Ralf Baechle 2008-07-16  59  

:::::: The code at line 57 was first introduced by commit
:::::: 73b4390fb23456964201abda79f1210fe337d01a [MIPS] Routerboard 532: Support for base system

:::::: TO: Ralf Baechle <ralf@linux-mips.org>
:::::: CC: Ralf Baechle <ralf@linux-mips.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 14130 bytes --]

Re: [PATCH v6 2/4] resource: Use list_head to link sibling resource

[Baoquan He]

Hi,

On 07/05/18 at 01:00am, kbuild test robot wrote:
> Hi Baoquan,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on linus/master]
> [also build test ERROR on v4.18-rc3 next-20180704]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

Thanks for telling. 

I cloned 0day-ci/linut to my local pc.
https://github.com/0day-ci/linux.git

However, I didn't find below branch. And tried to open it in web
broswer, also failed.


> url:    https://github.com/0day-ci/linux/commits/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180704-121402
> config: mips-rb532_defconfig (attached as .config)
> compiler: mipsel-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=7.2.0 make.cross ARCH=mips 

I did find a old one which is for the old version 5 post.

[bhe@linux]$ git remote -v
0day-ci	https://github.com/0day-ci/linux.git (fetch)
0day-ci	https://github.com/0day-ci/linux.git (push)
[bhe@dhcp-128-28 linux]$ git branch -a| grep Baoquan| grep resource
  remotes/0day-ci/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180612-113600

Could you help have a look at this?

Thanks
Baoquan

> 
> All error/warnings (new ones prefixed by >>):
> 
> >> arch/mips/pci/pci-rc32434.c:57:11: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
>      .child = &rc32434_res_pci_mem2
>               ^
>    arch/mips/pci/pci-rc32434.c:57:11: note: (near initialization for 'rc32434_res_pci_mem1.child.next')
> >> arch/mips/pci/pci-rc32434.c:51:47: warning: missing braces around initializer [-Wmissing-braces]
>     static struct resource rc32434_res_pci_mem1 = {
>                                                   ^
>    arch/mips/pci/pci-rc32434.c:60:47: warning: missing braces around initializer [-Wmissing-braces]
>     static struct resource rc32434_res_pci_mem2 = {
>                                                   ^
>    cc1: some warnings being treated as errors
> 
> vim +57 arch/mips/pci/pci-rc32434.c
> 
> 73b4390f Ralf Baechle 2008-07-16  50  
> 73b4390f Ralf Baechle 2008-07-16 @51  static struct resource rc32434_res_pci_mem1 = {
> 73b4390f Ralf Baechle 2008-07-16  52  	.name = "PCI MEM1",
> 73b4390f Ralf Baechle 2008-07-16  53  	.start = 0x50000000,
> 73b4390f Ralf Baechle 2008-07-16  54  	.end = 0x5FFFFFFF,
> 73b4390f Ralf Baechle 2008-07-16  55  	.flags = IORESOURCE_MEM,
> 73b4390f Ralf Baechle 2008-07-16  56  	.sibling = NULL,
> 73b4390f Ralf Baechle 2008-07-16 @57  	.child = &rc32434_res_pci_mem2
> 73b4390f Ralf Baechle 2008-07-16  58  };
> 73b4390f Ralf Baechle 2008-07-16  59  
> 
> :::::: The code at line 57 was first introduced by commit
> :::::: 73b4390fb23456964201abda79f1210fe337d01a [MIPS] Routerboard 532: Support for base system
> 
> :::::: TO: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> :::::: CC: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Re: [PATCH v6 2/4] resource: Use list_head to link sibling resource

[Andy Shevchenko]

On Sun, Jul 8, 2018 at 5:59 AM, Baoquan He <bhe@redhat.com> wrote:
> On 07/05/18 at 01:00am, kbuild test robot wrote:

> However, I didn't find below branch. And tried to open it in web
> broswer, also failed.

While this is kinda valid point...

> Could you help have a look at this?

...isn't obvious that you didn't change the file mentioned in a report?
Just take latest linux-next and you will see.


>> All error/warnings (new ones prefixed by >>):
>>
>> >> arch/mips/pci/pci-rc32434.c:57:11: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
>>      .child = &rc32434_res_pci_mem2
>>               ^
>>    arch/mips/pci/pci-rc32434.c:57:11: note: (near initialization for 'rc32434_res_pci_mem1.child.next')
>> >> arch/mips/pci/pci-rc32434.c:51:47: warning: missing braces around initializer [-Wmissing-braces]
>>     static struct resource rc32434_res_pci_mem1 = {
>>                                                   ^
>>    arch/mips/pci/pci-rc32434.c:60:47: warning: missing braces around initializer [-Wmissing-braces]
>>     static struct resource rc32434_res_pci_mem2 = {
>>                                                   ^
>>    cc1: some warnings being treated as errors
>>
>> vim +57 arch/mips/pci/pci-rc32434.c
>>
>> 73b4390f Ralf Baechle 2008-07-16  50
>> 73b4390f Ralf Baechle 2008-07-16 @51  static struct resource rc32434_res_pci_mem1 = {
>> 73b4390f Ralf Baechle 2008-07-16  52          .name = "PCI MEM1",
>> 73b4390f Ralf Baechle 2008-07-16  53          .start = 0x50000000,
>> 73b4390f Ralf Baechle 2008-07-16  54          .end = 0x5FFFFFFF,
>> 73b4390f Ralf Baechle 2008-07-16  55          .flags = IORESOURCE_MEM,
>> 73b4390f Ralf Baechle 2008-07-16  56          .sibling = NULL,
>> 73b4390f Ralf Baechle 2008-07-16 @57          .child = &rc32434_res_pci_mem2
>> 73b4390f Ralf Baechle 2008-07-16  58  };
>> 73b4390f Ralf Baechle 2008-07-16  59
>>
>> :::::: The code at line 57 was first introduced by commit
>> :::::: 73b4390fb23456964201abda79f1210fe337d01a [MIPS] Routerboard 532: Support for base system
>>
>> :::::: TO: Ralf Baechle <ralf@linux-mips.org>
>> :::::: CC: Ralf Baechle <ralf@linux-mips.org>
>>
>> ---
>> 0-DAY kernel test infrastructure                Open Source Technology Center
>> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
>
>



-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v6 2/4] resource: Use list_head to link sibling resource

[Baoquan He]

On 07/08/18 at 08:48pm, Andy Shevchenko wrote:
> On Sun, Jul 8, 2018 at 5:59 AM, Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> > On 07/05/18 at 01:00am, kbuild test robot wrote:
> 
> > However, I didn't find below branch. And tried to open it in web
> > broswer, also failed.
> 
> While this is kinda valid point...
> 
> > Could you help have a look at this?
> 
> ...isn't obvious that you didn't change the file mentioned in a report?
> Just take latest linux-next and you will see.

Yes, it's clear to me. Just want to use the way to cross compile them on
ia64 and mips, hope I can find out all missed places on these ARCHes.
Now I think I can apply patches on linux-next, and use the config
attached to compile. Thanks.

> 
> 
> >> All error/warnings (new ones prefixed by >>):
> >>
> >> >> arch/mips/pci/pci-rc32434.c:57:11: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
> >>      .child = &rc32434_res_pci_mem2
> >>               ^
> >>    arch/mips/pci/pci-rc32434.c:57:11: note: (near initialization for 'rc32434_res_pci_mem1.child.next')
> >> >> arch/mips/pci/pci-rc32434.c:51:47: warning: missing braces around initializer [-Wmissing-braces]
> >>     static struct resource rc32434_res_pci_mem1 = {
> >>                                                   ^
> >>    arch/mips/pci/pci-rc32434.c:60:47: warning: missing braces around initializer [-Wmissing-braces]
> >>     static struct resource rc32434_res_pci_mem2 = {
> >>                                                   ^
> >>    cc1: some warnings being treated as errors
> >>
> >> vim +57 arch/mips/pci/pci-rc32434.c
> >>
> >> 73b4390f Ralf Baechle 2008-07-16  50
> >> 73b4390f Ralf Baechle 2008-07-16 @51  static struct resource rc32434_res_pci_mem1 = {
> >> 73b4390f Ralf Baechle 2008-07-16  52          .name = "PCI MEM1",
> >> 73b4390f Ralf Baechle 2008-07-16  53          .start = 0x50000000,
> >> 73b4390f Ralf Baechle 2008-07-16  54          .end = 0x5FFFFFFF,
> >> 73b4390f Ralf Baechle 2008-07-16  55          .flags = IORESOURCE_MEM,
> >> 73b4390f Ralf Baechle 2008-07-16  56          .sibling = NULL,
> >> 73b4390f Ralf Baechle 2008-07-16 @57          .child = &rc32434_res_pci_mem2
> >> 73b4390f Ralf Baechle 2008-07-16  58  };
> >> 73b4390f Ralf Baechle 2008-07-16  59
> >>
> >> :::::: The code at line 57 was first introduced by commit
> >> :::::: 73b4390fb23456964201abda79f1210fe337d01a [MIPS] Routerboard 532: Support for base system
> >>
> >> :::::: TO: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> >> :::::: CC: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> >>
> >> ---
> >> 0-DAY kernel test infrastructure                Open Source Technology Center
> >> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
> >
> >
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko

Re: [kbuild-all] [PATCH v6 2/4] resource: Use list_head to link sibling resource

[Ye Xiaolong]

Hi,

On 07/08, Baoquan He wrote:
>Hi,
>
>On 07/05/18 at 01:00am, kbuild test robot wrote:
>> Hi Baoquan,
>> 
>> I love your patch! Yet something to improve:
>> 
>> [auto build test ERROR on linus/master]
>> [also build test ERROR on v4.18-rc3 next-20180704]
>> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
>Thanks for telling. 
>
>I cloned 0day-ci/linut to my local pc.
>https://github.com/0day-ci/linux.git
>
>However, I didn't find below branch. And tried to open it in web
>broswer, also failed.
>

Sorry for the inconvenience, 0day bot didn't push the branch to github successfully,
Just push it manually, you can have a try again.

Thanks,
Xiaolong


>
>> url:    https://github.com/0day-ci/linux/commits/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180704-121402
>> config: mips-rb532_defconfig (attached as .config)
>> compiler: mipsel-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
>> reproduce:
>>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>>         chmod +x ~/bin/make.cross
>>         # save the attached .config to linux build tree
>>         GCC_VERSION=7.2.0 make.cross ARCH=mips 
>
>I did find a old one which is for the old version 5 post.
>
>[bhe@linux]$ git remote -v
>0day-ci	https://github.com/0day-ci/linux.git (fetch)
>0day-ci	https://github.com/0day-ci/linux.git (push)
>[bhe@dhcp-128-28 linux]$ git branch -a| grep Baoquan| grep resource
>  remotes/0day-ci/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180612-113600
>
>Could you help have a look at this?
>
>Thanks
>Baoquan
>
>> 
>> All error/warnings (new ones prefixed by >>):
>> 
>> >> arch/mips/pci/pci-rc32434.c:57:11: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
>>      .child = &rc32434_res_pci_mem2
>>               ^
>>    arch/mips/pci/pci-rc32434.c:57:11: note: (near initialization for 'rc32434_res_pci_mem1.child.next')
>> >> arch/mips/pci/pci-rc32434.c:51:47: warning: missing braces around initializer [-Wmissing-braces]
>>     static struct resource rc32434_res_pci_mem1 = {
>>                                                   ^
>>    arch/mips/pci/pci-rc32434.c:60:47: warning: missing braces around initializer [-Wmissing-braces]
>>     static struct resource rc32434_res_pci_mem2 = {
>>                                                   ^
>>    cc1: some warnings being treated as errors
>> 
>> vim +57 arch/mips/pci/pci-rc32434.c
>> 
>> 73b4390f Ralf Baechle 2008-07-16  50  
>> 73b4390f Ralf Baechle 2008-07-16 @51  static struct resource rc32434_res_pci_mem1 = {
>> 73b4390f Ralf Baechle 2008-07-16  52  	.name = "PCI MEM1",
>> 73b4390f Ralf Baechle 2008-07-16  53  	.start = 0x50000000,
>> 73b4390f Ralf Baechle 2008-07-16  54  	.end = 0x5FFFFFFF,
>> 73b4390f Ralf Baechle 2008-07-16  55  	.flags = IORESOURCE_MEM,
>> 73b4390f Ralf Baechle 2008-07-16  56  	.sibling = NULL,
>> 73b4390f Ralf Baechle 2008-07-16 @57  	.child = &rc32434_res_pci_mem2
>> 73b4390f Ralf Baechle 2008-07-16  58  };
>> 73b4390f Ralf Baechle 2008-07-16  59  
>> 
>> :::::: The code at line 57 was first introduced by commit
>> :::::: 73b4390fb23456964201abda79f1210fe337d01a [MIPS] Routerboard 532: Support for base system
>> 
>> :::::: TO: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
>> :::::: CC: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
>> 
>> ---
>> 0-DAY kernel test infrastructure                Open Source Technology Center
>> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
>
>
>_______________________________________________
>kbuild-all mailing list
>kbuild-all-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org
>https://lists.01.org/mailman/listinfo/kbuild-all

Re: [kbuild-all] [PATCH v6 2/4] resource: Use list_head to link sibling resource

[Baoquan He]

On 07/10/18 at 08:59am, Ye Xiaolong wrote:
> Hi,
> 
> On 07/08, Baoquan He wrote:
> >Hi,
> >
> >On 07/05/18 at 01:00am, kbuild test robot wrote:
> >> Hi Baoquan,
> >> 
> >> I love your patch! Yet something to improve:
> >> 
> >> [auto build test ERROR on linus/master]
> >> [also build test ERROR on v4.18-rc3 next-20180704]
> >> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> >
> >Thanks for telling. 
> >
> >I cloned 0day-ci/linut to my local pc.
> >https://github.com/0day-ci/linux.git
> >
> >However, I didn't find below branch. And tried to open it in web
> >broswer, also failed.
> >
> 
> Sorry for the inconvenience, 0day bot didn't push the branch to github successfully,
> Just push it manually, you can have a try again.

Thanks, Xiaolong, I have applied them on top of linux-next/master, and
copy the config file attached, and run the command to reproduce as
suggested. Now I have fixed all those issues reported, will repost.

> 
> >
> >> url:    https://github.com/0day-ci/linux/commits/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180704-121402
> >> config: mips-rb532_defconfig (attached as .config)
> >> compiler: mipsel-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
> >> reproduce:
> >>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >>         chmod +x ~/bin/make.cross
> >>         # save the attached .config to linux build tree
> >>         GCC_VERSION=7.2.0 make.cross ARCH=mips 
> >
> >I did find a old one which is for the old version 5 post.
> >
> >[bhe@linux]$ git remote -v
> >0day-ci	https://github.com/0day-ci/linux.git (fetch)
> >0day-ci	https://github.com/0day-ci/linux.git (push)
> >[bhe@dhcp-128-28 linux]$ git branch -a| grep Baoquan| grep resource
> >  remotes/0day-ci/Baoquan-He/resource-Use-list_head-to-link-sibling-resource/20180612-113600
> >
> >Could you help have a look at this?
> >
> >Thanks
> >Baoquan
> >
> >> 
> >> All error/warnings (new ones prefixed by >>):
> >> 
> >> >> arch/mips/pci/pci-rc32434.c:57:11: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
> >>      .child = &rc32434_res_pci_mem2
> >>               ^
> >>    arch/mips/pci/pci-rc32434.c:57:11: note: (near initialization for 'rc32434_res_pci_mem1.child.next')
> >> >> arch/mips/pci/pci-rc32434.c:51:47: warning: missing braces around initializer [-Wmissing-braces]
> >>     static struct resource rc32434_res_pci_mem1 = {
> >>                                                   ^
> >>    arch/mips/pci/pci-rc32434.c:60:47: warning: missing braces around initializer [-Wmissing-braces]
> >>     static struct resource rc32434_res_pci_mem2 = {
> >>                                                   ^
> >>    cc1: some warnings being treated as errors
> >> 
> >> vim +57 arch/mips/pci/pci-rc32434.c
> >> 
> >> 73b4390f Ralf Baechle 2008-07-16  50  
> >> 73b4390f Ralf Baechle 2008-07-16 @51  static struct resource rc32434_res_pci_mem1 = {
> >> 73b4390f Ralf Baechle 2008-07-16  52  	.name = "PCI MEM1",
> >> 73b4390f Ralf Baechle 2008-07-16  53  	.start = 0x50000000,
> >> 73b4390f Ralf Baechle 2008-07-16  54  	.end = 0x5FFFFFFF,
> >> 73b4390f Ralf Baechle 2008-07-16  55  	.flags = IORESOURCE_MEM,
> >> 73b4390f Ralf Baechle 2008-07-16  56  	.sibling = NULL,
> >> 73b4390f Ralf Baechle 2008-07-16 @57  	.child = &rc32434_res_pci_mem2
> >> 73b4390f Ralf Baechle 2008-07-16  58  };
> >> 73b4390f Ralf Baechle 2008-07-16  59  
> >> 
> >> :::::: The code at line 57 was first introduced by commit
> >> :::::: 73b4390fb23456964201abda79f1210fe337d01a [MIPS] Routerboard 532: Support for base system
> >> 
> >> :::::: TO: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> >> :::::: CC: Ralf Baechle <ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org>
> >> 
> >> ---
> >> 0-DAY kernel test infrastructure                Open Source Technology Center
> >> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
> >
> >
> >_______________________________________________
> >kbuild-all mailing list
> >kbuild-all-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org
> >https://lists.01.org/mailman/listinfo/kbuild-all

[PATCH v6 3/4] resource: add walk_system_ram_res_rev()

[Baoquan He]

This function, being a variant of walk_system_ram_res() introduced in
commit 8c86e70acead ("resource: provide new functions to walk through
resources"), walks through a list of all the resources of System RAM
in reversed order, i.e., from higher to lower.

It will be used in kexec_file code.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
---
 include/linux/ioport.h |  3 +++
 kernel/resource.c      | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index b7456ae889dd..066cc263e2cc 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -279,6 +279,9 @@ extern int
 walk_system_ram_res(u64 start, u64 end, void *arg,
 		    int (*func)(struct resource *, void *));
 extern int
+walk_system_ram_res_rev(u64 start, u64 end, void *arg,
+			int (*func)(struct resource *, void *));
+extern int
 walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end,
 		    void *arg, int (*func)(struct resource *, void *));
 
diff --git a/kernel/resource.c b/kernel/resource.c
index 6d647a3824b1..4c5fbef4ea24 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -23,6 +23,8 @@
 #include <linux/pfn.h>
 #include <linux/mm.h>
 #include <linux/resource_ext.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
 #include <asm/io.h>
 
 
@@ -443,6 +445,44 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
 }
 
 /*
+ * This function, being a variant of walk_system_ram_res(), calls the @func
+ * callback against all memory ranges of type System RAM which are marked as
+ * IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY in reversed order, i.e., from
+ * higher to lower.
+ */
+int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
+				int (*func)(struct resource *, void *))
+{
+	unsigned long flags;
+	struct resource *res;
+	int ret = -1;
+
+	flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+	read_lock(&resource_lock);
+	list_for_each_entry_reverse(res, &iomem_resource.child, sibling) {
+		if (start >= end)
+			break;
+		if ((res->flags & flags) != flags)
+			continue;
+		if (res->desc != IORES_DESC_NONE)
+			continue;
+		if (res->end < start)
+			break;
+
+		if ((res->end >= start) && (res->start < end)) {
+			ret = (*func)(res, arg);
+			if (ret)
+				break;
+		}
+		end = res->start - 1;
+
+	}
+	read_unlock(&resource_lock);
+	return ret;
+}
+
+/*
  * This function calls the @func callback against all memory ranges, which
  * are ranges marked as IORESOURCE_MEM and IORESOUCE_BUSY.
  */
-- 
2.13.6

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[PATCH v6 4/4] kexec_file: Load kernel at top of system RAM if required

[Baoquan He]

For kexec_file loading, if kexec_buf.top_down is 'true', the memory which
is used to load kernel/initrd/purgatory is supposed to be allocated from
top to down. This is what we have been doing all along in the old kexec
loading interface and the kexec loading is still default setting in some
distributions. However, the current kexec_file loading interface doesn't
do likt this. The function arch_kexec_walk_mem() it calls ignores checking
kexec_buf.top_down, but calls walk_system_ram_res() directly to go through
all resources of System RAM from bottom to up, to try to find memory region
which can contain the specific kexec buffer, then call locate_mem_hole_callback()
to allocate memory in that found memory region from top to down. This brings
confusion especially when KASLR is widely supported , users have to make clear
why kexec/kdump kernel loading position is different between these two
interfaces in order to exclude unnecessary noises. Hence these two interfaces
need be unified on behaviour.

Here add checking if kexec_buf.top_down is 'true' in arch_kexec_walk_mem(),
if yes, call the newly added walk_system_ram_res_rev() to find memory region
from top to down to load kernel.

Signed-off-by: Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Eric Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: Yinghai Lu <yinghai-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
---
 kernel/kexec_file.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index c6a3b6851372..75226c1d08ce 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -518,6 +518,8 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 					   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
 					   crashk_res.start, crashk_res.end,
 					   kbuf, func);
+	else if (kbuf->top_down)
+		return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func);
 	else
 		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
 }
-- 
2.13.6