Re: [RFC Patch 17/19] resources: Move struct resource_list_entry from ACPI into resource core

From: Rafael J. Wysocki
Date: Tue Jan 20 2015 - 19:47:55 EST


On Thursday, January 08, 2015 10:33:04 AM Jiang Liu wrote:
> Currently ACPI, PCI and pnp all implement the same resource list
> management with different data structure. We need to transfer from
> one data structure into another when passing resources from one
> subsystem into another subsystem. Sp move struct resource_list_entry
> from ACPI into resource core, so it could be reused by different
> subystems and avoid the data structure conversion.
>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
> ---
> drivers/acpi/acpi_lpss.c | 6 +++---
> drivers/acpi/acpi_platform.c | 2 +-
> drivers/acpi/resource.c | 13 ++++--------
> drivers/dma/acpi-dma.c | 8 +++----
> include/linux/acpi.h | 6 ------
> include/linux/ioport.h | 25 ++++++++++++++++++++++
> kernel/resource.c | 48 ++++++++++++++++++++++++++++++++++++++++++
> 7 files changed, 85 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> index 4f3febf8a589..39b548dba70b 100644
> --- a/drivers/acpi/acpi_lpss.c
> +++ b/drivers/acpi/acpi_lpss.c
> @@ -333,12 +333,12 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
> goto err_out;
>
> list_for_each_entry(rentry, &resource_list, node)
> - if (resource_type(&rentry->res) == IORESOURCE_MEM) {
> + if (resource_type(rentry->res) == IORESOURCE_MEM) {
> if (dev_desc->prv_size_override)
> pdata->mmio_size = dev_desc->prv_size_override;
> else
> - pdata->mmio_size = resource_size(&rentry->res);
> - pdata->mmio_base = ioremap(rentry->res.start,
> + pdata->mmio_size = resource_size(rentry->res);
> + pdata->mmio_base = ioremap(rentry->res->start,
> pdata->mmio_size);
> break;
> }
> diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
> index 6ba8beb6b9d2..238e32b9cbb0 100644
> --- a/drivers/acpi/acpi_platform.c
> +++ b/drivers/acpi/acpi_platform.c
> @@ -71,7 +71,7 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
> }
> count = 0;
> list_for_each_entry(rentry, &resource_list, node)
> - resources[count++] = rentry->res;
> + resources[count++] = *rentry->res;
>
> acpi_dev_free_resource_list(&resource_list);
> }
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 8ea7c26d6915..c0dc038274d4 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -444,12 +444,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_resource_interrupt);
> */
> void acpi_dev_free_resource_list(struct list_head *list)
> {
> - struct resource_list_entry *rentry, *re;
> -
> - list_for_each_entry_safe(rentry, re, list, node) {
> - list_del(&rentry->node);
> - kfree(rentry);
> - }
> + resource_list_free_list(list);
> }
> EXPORT_SYMBOL_GPL(acpi_dev_free_resource_list);
>
> @@ -467,14 +462,14 @@ static acpi_status acpi_dev_new_resource_entry(struct resource *r,
> {
> struct resource_list_entry *rentry;
>
> - rentry = kmalloc(sizeof(*rentry), GFP_KERNEL);
> + rentry = resource_list_alloc(NULL, 0);
> if (!rentry) {
> c->error = -ENOMEM;
> return AE_NO_MEMORY;
> }
> - rentry->res = *r;
> + *rentry->res = *r;
> rentry->offset = offset;
> - list_add_tail(&rentry->node, c->list);
> + resource_list_insert(c->list, rentry, true);
> c->count++;
> return AE_OK;
> }
> diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c
> index de361a156b34..1ce84abe0924 100644
> --- a/drivers/dma/acpi-dma.c
> +++ b/drivers/dma/acpi-dma.c
> @@ -56,10 +56,10 @@ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp,
> return 0;
>
> list_for_each_entry(rentry, &resource_list, node) {
> - if (resource_type(&rentry->res) == IORESOURCE_MEM)
> - mem = rentry->res.start;
> - else if (resource_type(&rentry->res) == IORESOURCE_IRQ)
> - irq = rentry->res.start;
> + if (resource_type(rentry->res) == IORESOURCE_MEM)
> + mem = rentry->res->start;
> + else if (resource_type(rentry->res) == IORESOURCE_IRQ)
> + irq = rentry->res->start;
> }
>
> acpi_dev_free_resource_list(&resource_list);
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 1df4a0211ae5..6d7f7edca22c 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -297,12 +297,6 @@ unsigned long acpi_dev_irq_flags(u8 triggering, u8 polarity, u8 shareable);
> bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int index,
> struct resource *res);
>
> -struct resource_list_entry {
> - struct list_head node;
> - struct resource res;
> - resource_size_t offset;
> -};
> -
> void acpi_dev_free_resource_list(struct list_head *list);
> int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
> int (*preproc)(struct acpi_resource *, void *),
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index 2c5250222278..a6f4841ca40c 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -11,6 +11,7 @@
> #ifndef __ASSEMBLY__
> #include <linux/compiler.h>
> #include <linux/types.h>
> +
> /*
> * Resources are tree-like, allowing
> * nesting etc..
> @@ -255,6 +256,30 @@ static inline bool resource_overlaps(struct resource *r1, struct resource *r2)
> return (r1->start <= r2->end && r1->end >= r2->start);
> }
>
> +/*
> + * Common resource list management data structure and interfaces to support
> + * ACPI, PNP and PCI host bridge etc.
> + */
> +struct resource_list_entry {
> + struct list_head node;
> + struct resource *res; /* In master (CPU) address space */
> + resource_size_t offset; /* Translation offset for bridge */
> + struct resource __res; /* Default storage for res */
> +};
> +
> +extern struct resource_list_entry *resource_list_alloc(struct resource *res,
> + size_t extra_size);
> +extern void resource_list_free(struct resource_list_entry *entry);
> +extern void resource_list_insert(struct list_head *head,
> + struct resource_list_entry *entry, bool tail);
> +extern void resource_list_delete(struct resource_list_entry *entry);
> +extern void resource_list_free_list(struct list_head *head);
> +
> +#define resource_list_for_each_entry(entry, list) \
> + list_for_each_entry((entry), (list), node)
> +
> +#define resource_list_for_each_entry_safe(entry, tmp, list) \
> + list_for_each_entry_safe((entry), (tmp), (list), node)
>
> #endif /* __ASSEMBLY__ */
> #endif /* _LINUX_IOPORT_H */
> diff --git a/kernel/resource.c b/kernel/resource.c
> index 0bcebffc4e77..414183809383 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -1529,6 +1529,54 @@ int iomem_is_exclusive(u64 addr)
> return err;
> }
>
> +struct resource_list_entry *resource_list_alloc(struct resource *res,
> + size_t extra_size)

What about create_resource_list_entry()? Less confusing surely.

> +{
> + struct resource_list_entry *entry;
> +
> + entry = kzalloc(sizeof(*entry) + extra_size, GFP_KERNEL);
> + if (entry) {
> + INIT_LIST_HEAD(&entry->node);
> + entry->res = res ? res : &entry->__res;
> + }
> +
> + return entry;
> +}
> +EXPORT_SYMBOL(resource_list_alloc);
> +
> +void resource_list_free(struct resource_list_entry *entry)
> +{
> + kfree(entry);
> +}
> +EXPORT_SYMBOL(resource_list_free);

Well, I'm not sure I like this. The name suggests that it would free the
entire list and what's wrong with using kfree() directly on "entry" anyway?

> +
> +void resource_list_insert(struct list_head *head,
> + struct resource_list_entry *entry, bool tail)

I would call this resource_list_add() if anything.

Also it may be better to have two helpers, one for "add" and one for "add_tail"
(and perhaps define them as static inline?).

And why change the ordering between "head" and "entry". That's alomost
guaranteed to confuse people.

> +{
> + if (tail)
> + list_add_tail(&entry->node, head);
> + else
> + list_add(&entry->node, head);
> +}
> +EXPORT_SYMBOL(resource_list_insert);
> +
> +void resource_list_delete(struct resource_list_entry *entry)
> +{
> + list_del(&entry->node);
> +}
> +EXPORT_SYMBOL(resource_list_delete);

Couldn't this be a static inline)?

Or maybe we can combine the "list_del" with "kfree" in one function?

> +
> +void resource_list_free_list(struct list_head *head)
> +{
> + struct resource_list_entry *entry, *tmp;
> +
> + list_for_each_entry_safe(entry, tmp, head, node) {
> + list_del(&entry->node);
> + resource_list_free(entry);
> + }
> +}
> +EXPORT_SYMBOL(resource_list_free_list);
> +
> static int __init strict_iomem(char *str)
> {
> if (strstr(str, "relaxed"))
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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