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author | Kumar Gala <galak@kernel.crashing.org> | 2007-08-20 08:50:28 -0500 |
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committer | Kumar Gala <galak@kernel.crashing.org> | 2007-08-22 22:43:29 -0500 |
commit | 33d71d26ba982f99b8cb76b86b2e1e0a0964a8ac (patch) | |
tree | 20826dc9252a265438c23f6e755a285d6c2508ba /include/asm-powerpc/highmem.h | |
parent | ed16c20da6f500bc2dfad933078d2987636a7b60 (diff) | |
download | kernel_samsung_smdk4412-33d71d26ba982f99b8cb76b86b2e1e0a0964a8ac.zip kernel_samsung_smdk4412-33d71d26ba982f99b8cb76b86b2e1e0a0964a8ac.tar.gz kernel_samsung_smdk4412-33d71d26ba982f99b8cb76b86b2e1e0a0964a8ac.tar.bz2 |
[POWERPC] Copy over headers from arch/ppc to arch/powerpc that we need
To build arch/powerpc without including asm-ppc/ we need these files
in asm-powerpc/
Moved some headers under arch/powerpc/platforms if they were only used by
platform or driver files and fixed up the source file includes to match
the new locations
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'include/asm-powerpc/highmem.h')
-rw-r--r-- | include/asm-powerpc/highmem.h | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/include/asm-powerpc/highmem.h b/include/asm-powerpc/highmem.h new file mode 100644 index 0000000..f7b21ee --- /dev/null +++ b/include/asm-powerpc/highmem.h @@ -0,0 +1,135 @@ +/* + * 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 <mingo@redhat.com> + */ + +#ifndef _ASM_HIGHMEM_H +#define _ASM_HIGHMEM_H + +#ifdef __KERNEL__ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <asm/kmap_types.h> +#include <asm/tlbflush.h> +#include <asm/page.h> + +/* undef for production */ +#define HIGHMEM_DEBUG 1 + +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 PKMAP_BASE CONFIG_HIGHMEM_START +#define LAST_PKMAP (1 << PTE_SHIFT) +#define LAST_PKMAP_MASK (LAST_PKMAP-1) +#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) +#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) + +#define KMAP_FIX_BEGIN (PKMAP_BASE + 0x00400000UL) + +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(struct page *page, enum km_type type) +{ + 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 = KMAP_FIX_BEGIN + idx * PAGE_SIZE; +#ifdef HIGHMEM_DEBUG + BUG_ON(!pte_none(*(kmap_pte+idx))); +#endif + set_pte_at(&init_mm, vaddr, kmap_pte+idx, mk_pte(page, kmap_prot)); + flush_tlb_page(NULL, vaddr); + + return (void*) vaddr; +} + +static inline void kunmap_atomic(void *kvaddr, enum km_type type) +{ +#ifdef HIGHMEM_DEBUG + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + unsigned int idx = type + KM_TYPE_NR*smp_processor_id(); + + if (vaddr < KMAP_FIX_BEGIN) { // FIXME + pagefault_enable(); + return; + } + + BUG_ON(vaddr != KMAP_FIX_BEGIN + idx * PAGE_SIZE); + + /* + * 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; + + if (vaddr < KMAP_FIX_BEGIN) + return virt_to_page(ptr); + + idx = (vaddr - KMAP_FIX_BEGIN) >> PAGE_SHIFT; + return pte_page(kmap_pte[idx]); +} + +#define flush_cache_kmaps() flush_cache_all() + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ |