Re: [PATCH] [27/31] CPA: Change comments of external interfaces tokerneldoc format

From: Randy Dunlap
Date: Mon Jan 14 2008 - 17:52:22 EST


On Mon, 14 Jan 2008 23:17:00 +0100 (CET) Andi Kleen wrote:

>
> And clarify description a bit.
>
> Only for 64bit, but the interfaces are identical for 32bit and kerneldoc should
> merge them (?)

I doubt that kernel-doc will merge them.

Normally we just import (like with !I, !E, !F, etc.) one file that
contains the kernel-doc API notations.
Would that work for this case?


> Signed-off-by: Andi Kleen <ak@xxxxxxx>
>
> ---
> Documentation/DocBook/kernel-api.tmpl | 8 +++++
> arch/x86/mm/pageattr_64.c | 46 +++++++++++++++++++++++++---------
> 2 files changed, 42 insertions(+), 12 deletions(-)
>
> Index: linux/arch/x86/mm/pageattr_64.c
> ===================================================================
> --- linux.orig/arch/x86/mm/pageattr_64.c
> +++ linux/arch/x86/mm/pageattr_64.c
> @@ -269,19 +269,19 @@ __change_page_attr(unsigned long address
> return 0;
> }
>
> -/*
> - * Change the page attributes of an page in the linear mapping.
> - *
> - * This should be used when a page is mapped with a different caching policy
> - * than write-back somewhere - some CPUs do not like it when mappings with
> - * different caching policies exist. This changes the page attributes of the
> - * in kernel linear mapping too.
> +/**
> + * change_page_attr_addr - Change page table attributes in linear mapping
> + * @address: Virtual address in linear mapping.
> + * @numpages: Number of pages to change
> + * @prot: New page table attribute (PAGE_*)
> *
> - * The caller needs to ensure that there are no conflicting mappings elsewhere.
> - * This function only deals with the kernel linear map.
> - *
> - * Caller must call global_flush_tlb() after this.
> + * Change page attributes of a page in the direct mapping. This is a variant
> + * of change_page_attr() that also works on memory holes that do not have
> + * mem_map entry (pfn_valid() is false).
> + *
> + * See change_page_attr() documentation for more details.
> */
> +
> int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
> {
> int err = 0, kernel_map = 0;
> @@ -318,13 +318,35 @@ int change_page_attr_addr(unsigned long
> return err;
> }
>
> -/* Don't call this for MMIO areas that may not have a mem_map entry */
> +/**
> + * change_page_attr - Change page table attributes in the linear mapping.
> + * @page: First page to change
> + * @numpages: Number of pages to change
> + * @prot: New protection/caching type (PAGE_*)
> + *
> + * Returns 0 on success, otherwise a negated errno.
> + *
> + * This should be used when a page is mapped with a different caching policy
> + * than write-back somewhere - some CPUs do not like it when mappings with
> + * different caching policies exist. This changes the page attributes of the
> + * in kernel linear mapping too.
> + *
> + * Caller must call global_flush_tlb() later to make the changes active.
> + *
> + * The caller needs to ensure that there are no conflicting mappings elsewhere
> + * (e.g. in user space) * This function only deals with the kernel linear map.
> + *
> + * For MMIO areas without mem_map use change_page_attr_addr() instead.
> + */
> int change_page_attr(struct page *page, int numpages, pgprot_t prot)
> {
> unsigned long addr = (unsigned long)page_address(page);
> return change_page_attr_addr(addr, numpages, prot);
> }
>
> +/**
> + * global_flush_tlb - Flush linear mappings changed by change_page_attr()
> + */
> void global_flush_tlb(void)
> {
> struct page *pg, *next;
> Index: linux/Documentation/DocBook/kernel-api.tmpl
> ===================================================================
> --- linux.orig/Documentation/DocBook/kernel-api.tmpl
> +++ linux/Documentation/DocBook/kernel-api.tmpl
> @@ -726,4 +726,12 @@ X!Idrivers/video/console/fonts.c
> !Ffs/pipe.c
> </chapter>
>
> + <chapter id="pageattr">
> + <title>Kernel direct mapping paging attributes</title>
> + <para>
> + Changing the paging attributes of kernel direct mapping pages
> + on x86.
> + </para>
> +!Farch/x86/mm/pageattr_64.c
> + </chapter>
> </book>
> --

---
~Randy
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