Re: [PATCH] powerpc/mm: Make k(un)map_atomic out of line

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Thu, 2009-06-18 at 13:39 +1000, Benjamin Herrenschmidt wrote:
> Those functions are way too big to be inline, besides, kmap_atomic()
> wants to call debug_kmap_atomic() which isn't exported for modules
> and causes module link failures.

Missing a quilt ref ... this one won't build.

Ben.

> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
> 
>  arch/powerpc/include/asm/highmem.h |   55 +--------------------------
>  arch/powerpc/mm/Makefile           |    1 
>  arch/powerpc/mm/highmem.c          |   75 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 80 insertions(+), 51 deletions(-)
> 
> --- linux-work.orig/arch/powerpc/include/asm/highmem.h	2009-06-18 11:34:42.000000000 +1000
> +++ linux-work/arch/powerpc/include/asm/highmem.h	2009-06-18 11:34:45.000000000 +1000
> @@ -62,6 +62,9 @@ extern pte_t *pkmap_page_table;
>  
>  extern void *kmap_high(struct page *page);
>  extern void kunmap_high(struct page *page);
> +extern void *kmap_atomic_prot(struct page *page, enum km_type type,
> +			      pgprot_t prot);
> +extern void kunmap_atomic(void *kvaddr, enum km_type type);
>  
>  static inline void *kmap(struct page *page)
>  {
> @@ -79,62 +82,11 @@ static inline void kunmap(struct page *p
>  	kunmap_high(page);
>  }
>  
> -/*
> - * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
> - * gives a more generic (and caching) interface. But kmap_atomic can
> - * be used in IRQ contexts, so in some (very limited) cases we need
> - * it.
> - */
> -static inline void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
> -{
> -	unsigned int idx;
> -	unsigned long vaddr;
> -
> -	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
> -	pagefault_disable();
> -	if (!PageHighMem(page))
> -		return page_address(page);
> -
> -	debug_kmap_atomic(type);
> -	idx = type + KM_TYPE_NR*smp_processor_id();
> -	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
> -#ifdef CONFIG_DEBUG_HIGHMEM
> -	BUG_ON(!pte_none(*(kmap_pte-idx)));
> -#endif
> -	__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
> -	local_flush_tlb_page(NULL, vaddr);
> -
> -	return (void*) vaddr;
> -}
> -
>  static inline void *kmap_atomic(struct page *page, enum km_type type)
>  {
>  	return kmap_atomic_prot(page, type, kmap_prot);
>  }
>  
> -static inline void kunmap_atomic(void *kvaddr, enum km_type type)
> -{
> -#ifdef CONFIG_DEBUG_HIGHMEM
> -	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
> -	enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
> -
> -	if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
> -		pagefault_enable();
> -		return;
> -	}
> -
> -	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
> -
> -	/*
> -	 * force other mappings to Oops if they'll try to access
> -	 * this pte without first remap it
> -	 */
> -	pte_clear(&init_mm, vaddr, kmap_pte-idx);
> -	local_flush_tlb_page(NULL, vaddr);
> -#endif
> -	pagefault_enable();
> -}
> -
>  static inline struct page *kmap_atomic_to_page(void *ptr)
>  {
>  	unsigned long idx, vaddr = (unsigned long) ptr;
> @@ -148,6 +100,7 @@ static inline struct page *kmap_atomic_t
>  	return pte_page(*pte);
>  }
>  
> +
>  #define flush_cache_kmaps()	flush_cache_all()
>  
>  #endif /* __KERNEL__ */
> Index: linux-work/arch/powerpc/mm/Makefile
> ===================================================================
> --- linux-work.orig/arch/powerpc/mm/Makefile	2009-06-18 11:34:42.000000000 +1000
> +++ linux-work/arch/powerpc/mm/Makefile	2009-06-18 11:34:45.000000000 +1000
> @@ -30,3 +30,4 @@ obj-$(CONFIG_PPC_MM_SLICES)	+= slice.o
>  obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
>  obj-$(CONFIG_PPC_SUBPAGE_PROT)	+= subpage-prot.o
>  obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
> +obj-$(CONFIG_HIGHMEM)		+= highmem.o
> Index: linux-work/arch/powerpc/mm/highmem.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-work/arch/powerpc/mm/highmem.c	2009-06-18 11:35:51.000000000 +1000
> @@ -0,0 +1,75 @@
> +/*
> + * highmem.c: virtual kernel memory mappings for high memory
> + *
> + * PowerPC version, stolen from the i386 version.
> + *
> + * Used in CONFIG_HIGHMEM systems for memory pages which
> + * are not addressable by direct kernel virtual addresses.
> + *
> + * Copyright (C) 1999 Gerhard Wichert, Siemens AG
> + *		      Gerhard.Wichert@pdb.siemens.de
> + *
> + *
> + * Redesigned the x86 32-bit VM architecture to deal with
> + * up to 16 Terrabyte physical memory. With current x86 CPUs
> + * we now support up to 64 Gigabytes physical RAM.
> + *
> + * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
> + *
> + * Reworked for PowerPC by various contributors. Moved from
> + * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
> + */
> +
> +
> +/*
> + * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
> + * gives a more generic (and caching) interface. But kmap_atomic can
> + * be used in IRQ contexts, so in some (very limited) cases we need
> + * it.
> + */
> +void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
> +{
> +	unsigned int idx;
> +	unsigned long vaddr;
> +
> +	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
> +	pagefault_disable();
> +	if (!PageHighMem(page))
> +		return page_address(page);
> +
> +	debug_kmap_atomic(type);
> +	idx = type + KM_TYPE_NR*smp_processor_id();
> +	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
> +#ifdef CONFIG_DEBUG_HIGHMEM
> +	BUG_ON(!pte_none(*(kmap_pte-idx)));
> +#endif
> +	__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
> +	local_flush_tlb_page(NULL, vaddr);
> +
> +	return (void*) vaddr;
> +}
> +EXPORT_SYMBOL(kmap_atomic_prot);
> +
> +void kunmap_atomic(void *kvaddr, enum km_type type)
> +{
> +#ifdef CONFIG_DEBUG_HIGHMEM
> +	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
> +	enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
> +
> +	if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
> +		pagefault_enable();
> +		return;
> +	}
> +
> +	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
> +
> +	/*
> +	 * force other mappings to Oops if they'll try to access
> +	 * this pte without first remap it
> +	 */
> +	pte_clear(&init_mm, vaddr, kmap_pte-idx);
> +	local_flush_tlb_page(NULL, vaddr);
> +#endif
> +	pagefault_enable();
> +}
> +EXPORT_SYMBOL(kunmap_atomic);
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