Re: [PATCH v5 1/4] resource: Move reparent_resources() to kernel/resource.c and make it public

Baoquan He
2018-06-12T03:34:55Z

On 06/12/18 at 11:28am, Baoquan He 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. Later its code also need be updated using list_head
> to replace singly linked list.
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Cc: Michal Simek <monstr@monstr.eu>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> ---
> v4->v5:
> Fix several code bugs reported by test robot on ARCH powerpc and
> microblaze.

Oops, I mistakenly added the patch change log of the current patch 0002
here. This patch is a newly added one.

>
> v3->v4:
> Fix several bugs test robot reported. And change patch log.
>
> 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.
>
> arch/microblaze/pci/pci-common.c | 37 -------------------------------------
> arch/powerpc/kernel/pci-common.c | 35 -----------------------------------
> include/linux/ioport.h | 1 +
> kernel/resource.c | 36 ++++++++++++++++++++++++++++++++++++
> 4 files changed, 37 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..5e7c56d5d838 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -983,6 +983,42 @@ int adjust_resource(struct resource *res, resource_size_t start,
> }
> EXPORT_SYMBOL(adjust_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;
> +}
> +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
>