cache.c

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/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 2003, 06, 07 by Ralf Baechle ([email protected])
 * Copyright (C) 2007 MIPS Technologies, Inc.
 */
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/mm.h>

#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/cpu.h>
#include <asm/cpu-features.h>

/* Cache operations. */
void (*flush_cache_all)(void);
void (*__flush_cache_all)(void);
void (*flush_cache_mm)(struct mm_struct *mm);
void (*flush_cache_range)(struct vm_area_struct *vma, unsigned long start,
    unsigned long end);
void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
    unsigned long pfn);
void (*flush_icache_range)(unsigned long start, unsigned long end);
void (*local_flush_icache_range)(unsigned long start, unsigned long end);

void (*__flush_cache_vmap)(void);
void (*__flush_cache_vunmap)(void);

void (*__flush_kernel_vmap_range)(unsigned long vaddr, int size);
void (*__invalidate_kernel_vmap_range)(unsigned long vaddr, int size);

EXPORT_SYMBOL_GPL(__flush_kernel_vmap_range);

/* MIPS specific cache operations */
void (*flush_cache_sigtramp)(unsigned long addr);
void (*local_flush_data_cache_page)(void * addr);
void (*flush_data_cache_page)(unsigned long addr);
void (*flush_icache_all)(void);

EXPORT_SYMBOL_GPL(local_flush_data_cache_page);
EXPORT_SYMBOL(flush_data_cache_page);

#ifdef CONFIG_DMA_NONCOHERENT

/* DMA cache operations. */
void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
void (*_dma_cache_wback)(unsigned long start, unsigned long size);
void (*_dma_cache_inv)(unsigned long start, unsigned long size);

EXPORT_SYMBOL(_dma_cache_wback_inv);

#endif /* CONFIG_DMA_NONCOHERENT */

/*
 * We could optimize the case where the cache argument is not BCACHE but
 * that seems very atypical use ...
 */
SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, bytes,
    unsigned int, cache)
{
    if (bytes == 0)
        return 0;
    if (!access_ok(VERIFY_WRITE, (void __user *) addr, bytes))
        return -EFAULT;

    flush_icache_range(addr, addr + bytes);

    return 0;
}

void __flush_dcache_page(struct page *page)
{
    struct address_space *mapping = page_mapping(page);
    unsigned long addr;

    if (PageHighMem(page))
        return;
    if (mapping && !mapping_mapped(mapping)) {
        SetPageDcacheDirty(page);
        return;
    }

    /*
     * We could delay the flush for the !page_mapping case too.  But that
     * case is for exec env/arg pages and those are %99 certainly going to
     * get faulted into the tlb (and thus flushed) anyways.
     */
    addr = (unsigned long) page_address(page);
    flush_data_cache_page(addr);
}

EXPORT_SYMBOL(__flush_dcache_page);

void __flush_anon_page(struct page *page, unsigned long vmaddr)
{
    unsigned long addr = (unsigned long) page_address(page);

    if (pages_do_alias(addr, vmaddr)) {
        if (page_mapped(page) && !Page_dcache_dirty(page)) {
            void *kaddr;

            kaddr = kmap_coherent(page, vmaddr);
            flush_data_cache_page((unsigned long)kaddr);
            kunmap_coherent();
        } else
            flush_data_cache_page(addr);
    }
}

EXPORT_SYMBOL(__flush_anon_page);

void __update_cache(struct vm_area_struct *vma, unsigned long address,
    pte_t pte)
{
    struct page *page;
    unsigned long pfn, addr;
    int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;

    pfn = pte_pfn(pte);
    if (unlikely(!pfn_valid(pfn)))
        return;
    page = pfn_to_page(pfn);
    if (page_mapping(page) && Page_dcache_dirty(page)) {
        addr = (unsigned long) page_address(page);
        if (exec || pages_do_alias(addr, address & PAGE_MASK))
            flush_data_cache_page(addr);
        ClearPageDcacheDirty(page);
    }
}

unsigned long _page_cachable_default;
EXPORT_SYMBOL(_page_cachable_default);

static inline void setup_protection_map(void)
{
    if (cpu_has_rixi) {
        protection_map[0]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
        protection_map[1]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
        protection_map[2]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
        protection_map[3]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
        protection_map[4]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_READ);
        protection_map[5]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
        protection_map[6]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_READ);
        protection_map[7]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);

        protection_map[8]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
        protection_map[9]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
        protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
        protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
        protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_READ);
        protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
        protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE  | _PAGE_NO_READ);
        protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);

    } else {
        protection_map[0] = PAGE_NONE;
        protection_map[1] = PAGE_READONLY;
        protection_map[2] = PAGE_COPY;
        protection_map[3] = PAGE_COPY;
        protection_map[4] = PAGE_READONLY;
        protection_map[5] = PAGE_READONLY;
        protection_map[6] = PAGE_COPY;
        protection_map[7] = PAGE_COPY;
        protection_map[8] = PAGE_NONE;
        protection_map[9] = PAGE_READONLY;
        protection_map[10] = PAGE_SHARED;
        protection_map[11] = PAGE_SHARED;
        protection_map[12] = PAGE_READONLY;
        protection_map[13] = PAGE_READONLY;
        protection_map[14] = PAGE_SHARED;
        protection_map[15] = PAGE_SHARED;
    }
}

void __cpuinit cpu_cache_init(void)
{
    if (cpu_has_3k_cache) {
        extern void __weak r3k_cache_init(void);

        r3k_cache_init();
    }
    if (cpu_has_6k_cache) {
        extern void __weak r6k_cache_init(void);

        r6k_cache_init();
    }
    if (cpu_has_4k_cache) {
        extern void __weak r4k_cache_init(void);

        r4k_cache_init();
    }
    if (cpu_has_8k_cache) {
        extern void __weak r8k_cache_init(void);

        r8k_cache_init();
    }
    if (cpu_has_tx39_cache) {
        extern void __weak tx39_cache_init(void);

        tx39_cache_init();
    }

    if (cpu_has_octeon_cache) {
        extern void __weak octeon_cache_init(void);

        octeon_cache_init();
    }

    setup_protection_map();
}

int __weak __uncached_access(struct file *file, unsigned long addr)
{
    if (file->f_flags & O_DSYNC)
        return 1;

    return addr >= __pa(high_memory);
}