From b8b572e1015f81b4e748417be2629dfe51ab99f9 Mon Sep 17 00:00:00 2001 From: Stephen Rothwell Date: Fri, 1 Aug 2008 15:20:30 +1000 Subject: powerpc: Move include files to arch/powerpc/include/asm from include/asm-powerpc. This is the result of a mkdir arch/powerpc/include/asm git mv include/asm-powerpc/* arch/powerpc/include/asm Followed by a few documentation/comment fixups and a couple of places where was being used explicitly. Of the latter only one was outside the arch code and it is a driver only built for powerpc. Signed-off-by: Stephen Rothwell Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/highmem.h | 138 +++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 arch/powerpc/include/asm/highmem.h (limited to 'arch/powerpc/include/asm/highmem.h') diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h new file mode 100644 index 00000000000..5d99b6489d5 --- /dev/null +++ b/arch/powerpc/include/asm/highmem.h @@ -0,0 +1,138 @@ +/* + * highmem.h: 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 + */ + +#ifndef _ASM_HIGHMEM_H +#define _ASM_HIGHMEM_H + +#ifdef __KERNEL__ + +#include +#include +#include +#include +#include +#include + +extern pte_t *kmap_pte; +extern pgprot_t kmap_prot; +extern pte_t *pkmap_page_table; + +/* + * Right now we initialize only a single pte table. It can be extended + * easily, subsequent pte tables have to be allocated in one physical + * chunk of RAM. + */ +#define LAST_PKMAP (1 << PTE_SHIFT) +#define LAST_PKMAP_MASK (LAST_PKMAP-1) +#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) +#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) +#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) + +extern void *kmap_high(struct page *page); +extern void kunmap_high(struct page *page); + +static inline void *kmap(struct page *page) +{ + might_sleep(); + if (!PageHighMem(page)) + return page_address(page); + return kmap_high(page); +} + +static inline void kunmap(struct page *page) +{ + BUG_ON(in_interrupt()); + if (!PageHighMem(page)) + return; + 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); + + 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)); + 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); + 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; + pte_t *pte; + + if (vaddr < FIXADDR_START) + return virt_to_page(ptr); + + idx = virt_to_fix(vaddr); + pte = kmap_pte - (idx - FIX_KMAP_BEGIN); + return pte_page(*pte); +} + +#define flush_cache_kmaps() flush_cache_all() + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ -- cgit v1.2.3