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author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-11 21:55:47 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-11 21:55:47 -0700 |
commit | e86908614f2c7fec401827e5cefd7a6ea9407f85 (patch) | |
tree | fcb5d9e52422b37bdaf0e647126ebdfc1680f162 /include/asm-powerpc/highmem.h | |
parent | 547307420931344a868275bd7ea7a30f117a15a9 (diff) | |
parent | 9b4b8feb962f4b3e74768b7205f1f8f6cce87238 (diff) |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (408 commits)
[POWERPC] Add memchr() to the bootwrapper
[POWERPC] Implement logging of unhandled signals
[POWERPC] Add legacy serial support for OPB with flattened device tree
[POWERPC] Use 1TB segments
[POWERPC] XilinxFB: Allow fixed framebuffer base address
[POWERPC] XilinxFB: Add support for custom screen resolution
[POWERPC] XilinxFB: Use pdata to pass around framebuffer parameters
[POWERPC] PCI: Add 64-bit physical address support to setup_indirect_pci
[POWERPC] 4xx: Kilauea defconfig file
[POWERPC] 4xx: Kilauea DTS
[POWERPC] 4xx: Add AMCC Kilauea eval board support to platforms/40x
[POWERPC] 4xx: Add AMCC 405EX support to cputable.c
[POWERPC] Adjust TASK_SIZE on ppc32 systems to 3GB that are capable
[POWERPC] Use PAGE_OFFSET to tell if an address is user/kernel in SW TLB handlers
[POWERPC] 85xx: Enable FP emulation in MPC8560 ADS defconfig
[POWERPC] 85xx: Killed <asm/mpc85xx.h>
[POWERPC] 85xx: Add cpm nodes for 8541/8555 CDS
[POWERPC] 85xx: Convert mpc8560ads to the new CPM binding.
[POWERPC] mpc8272ads: Remove muram from the CPM reg property.
[POWERPC] Make clockevents work on PPC601 processors
...
Fixed up conflict in Documentation/powerpc/booting-without-of.txt manually.
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 00000000000..f7b21ee302b --- /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 */ |