From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/asm-mips/highmem.h | 103 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 include/asm-mips/highmem.h (limited to 'include/asm-mips/highmem.h') diff --git a/include/asm-mips/highmem.h b/include/asm-mips/highmem.h new file mode 100644 index 00000000000..f49930d947d --- /dev/null +++ b/include/asm-mips/highmem.h @@ -0,0 +1,103 @@ +/* + * highmem.h: virtual kernel memory mappings for high memory + * + * 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 Terabyte 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 + +/* undef for production */ +#define HIGHMEM_DEBUG 1 + +/* declarations for highmem.c */ +extern unsigned long highstart_pfn, highend_pfn; + +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 (0xfe000000UL) +#define LAST_PKMAP 1024 +#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)) + +extern void * kmap_high(struct page *page); +extern void kunmap_high(struct page *page); + +/* + * CONFIG_LIMITED_DMA is for systems with DMA limitations such as Momentum's + * Jaguar ATX. This option exploits the highmem code in the kernel so is + * always enabled together with CONFIG_HIGHMEM but at this time doesn't + * actually add highmem functionality. + */ + +#ifdef CONFIG_LIMITED_DMA + +/* + * These are the default functions for the no-highmem case from + * + */ +static inline void *kmap(struct page *page) +{ + might_sleep(); + return page_address(page); +} + +#define kunmap(page) do { (void) (page); } while (0) + +static inline void *kmap_atomic(struct page *page, enum km_type type) +{ + return page_address(page); +} + +static inline void kunmap_atomic(void *kvaddr, enum km_type type) { } + +#define kmap_atomic_to_page(ptr) virt_to_page(ptr) + +#define flush_cache_kmaps() do { } while (0) + +#else /* LIMITED_DMA */ + +extern void *__kmap(struct page *page); +extern void __kunmap(struct page *page); +extern void *__kmap_atomic(struct page *page, enum km_type type); +extern void __kunmap_atomic(void *kvaddr, enum km_type type); +extern struct page *__kmap_atomic_to_page(void *ptr); + +#define kmap __kmap +#define kunmap __kunmap +#define kmap_atomic __kmap_atomic +#define kunmap_atomic __kunmap_atomic +#define kmap_atomic_to_page __kmap_atomic_to_page + +#define flush_cache_kmaps() flush_cache_all() + +#endif /* LIMITED_DMA */ + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ -- cgit v1.2.3-70-g09d2