arch/sh/mm/cache.c

/*
 * arch/sh/mm/cache.c
 *
 * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
 * Copyright (C) 2002 - 2009  Paul Mundt
 *
 * Released under the terms of the GNU GPL v2.0.
 */
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>

void (*local_flush_cache_all)(void *args) = cache_noop;
void (*local_flush_cache_mm)(void *args) = cache_noop;
void (*local_flush_cache_dup_mm)(void *args) = cache_noop;
void (*local_flush_cache_page)(void *args) = cache_noop;
void (*local_flush_cache_range)(void *args) = cache_noop;
void (*local_flush_dcache_page)(void *args) = cache_noop;
void (*local_flush_icache_range)(void *args) = cache_noop;
void (*local_flush_icache_page)(void *args) = cache_noop;
void (*local_flush_cache_sigtramp)(void *args) = cache_noop;

void (*__flush_wback_region)(void *start, int size);
EXPORT_SYMBOL(__flush_wback_region);
void (*__flush_purge_region)(void *start, int size);
EXPORT_SYMBOL(__flush_purge_region);
void (*__flush_invalidate_region)(void *start, int size);
EXPORT_SYMBOL(__flush_invalidate_region);

static inline void noop__flush_region(void *start, int size)
{
}

static inline void cacheop_on_each_cpu(void (*func) (void *info), void *info,
                                   int wait)
{
	preempt_disable();
	smp_call_function(func, info, wait);
	func(info);
	preempt_enable();
}

/*
 * copy_to_user_page
 * @vma: vm_area_struct holding the pages
 * @page: struct page
 * @vaddr: user space address
 * @dst: address of page in kernel space (possibly from kmap)
 * @src: source address in kernel logical memory
 * @len: length of data in bytes (may be less than PAGE_SIZE)
 *
 * Copy data into the address space of a process other than the current
 * process (eg for ptrace).
 */
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
		       unsigned long vaddr, void *dst, const void *src,
		       unsigned long len)
{
	if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
	    !test_bit(PG_dcache_dirty, &page->flags)) {
		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
		memcpy(vto, src, len);
		kunmap_coherent(vto);
	} else {
		memcpy(dst, src, len);
		if (boot_cpu_data.dcache.n_aliases)
			set_bit(PG_dcache_dirty, &page->flags);
	}

	if (vma->vm_flags & VM_EXEC)
		flush_cache_page(vma, vaddr, page_to_pfn(page));
}

void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
			 unsigned long vaddr, void *dst, const void *src,
			 unsigned long len)
{
	if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
	    !test_bit(PG_dcache_dirty, &page->flags)) {
		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
		memcpy(dst, vfrom, len);
		kunmap_coherent(vfrom);
	} else {
		memcpy(dst, src, len);
		if (boot_cpu_data.dcache.n_aliases)
			set_bit(PG_dcache_dirty, &page->flags);
	}
}

/*
 * copy_user_highpage
 * @to: destination page
 * @from: source page
 * @vaddr: address of pages in user address space
 * @vma: vm_area_struct holding the pages
 *
 * This is used in COW implementation to copy data from page @from to
 * page @to. @from was previousl mapped at @vaddr, and @to will be.
 * As this is used only in the COW implementation, this means that the
 * source is unmodified, and so we don't have to worry about cache
 * aliasing on that side.
 */
#ifdef CONFIG_HIGHMEM
/*
 * If we ever have a real highmem system, this code will need fixing
 * (as will clear_user/clear_user_highmem), because the kmap potentitally
 * creates another alias risk.
 */
#error This code is broken with real HIGHMEM
#endif
void copy_user_highpage(struct page *to, struct page *from,
			unsigned long vaddr, struct vm_area_struct *vma)
{
	void *vfrom, *vto;

	vto = kmap_atomic(to, KM_USER1);
	vfrom = kmap_atomic(from, KM_USER0);

	if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
		__flush_invalidate_region(vto, PAGE_SIZE);

	if (boot_cpu_data.dcache.n_aliases && page_mapped(from) &&
	    !test_bit(PG_dcache_dirty, &from->flags)) {
		void *vto_coloured = kmap_coherent(to, vaddr);
		copy_page(vto_coloured, vfrom);
		kunmap_coherent(vto_coloured);
	} else
		copy_page(vto, vfrom);

	kunmap_atomic(vfrom, KM_USER0);
	kunmap_atomic(vto, KM_USER1);

	/* Make sure this page is cleared on other CPU's too before using it */
	smp_wmb();
}
EXPORT_SYMBOL(copy_user_highpage);

void clear_user_highpage(struct page *page, unsigned long vaddr)
{
	void *kaddr = kmap_atomic(page, KM_USER0);

	if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK)) {
		void *vto;

		/* Kernel alias may have modified data in the cache. */
		__flush_invalidate_region(kaddr, PAGE_SIZE);

		vto = kmap_coherent(page, vaddr);
		clear_page(vto);
		kunmap_coherent(vto);
	} else
		clear_page(kaddr);

	kunmap_atomic(kaddr, KM_USER0);
}
EXPORT_SYMBOL(clear_user_highpage);

void __update_cache(struct vm_area_struct *vma,
		    unsigned long address, pte_t pte)
{
	struct page *page;
	unsigned long pfn = pte_pfn(pte);

	if (!boot_cpu_data.dcache.n_aliases)
		return;

	page = pfn_to_page(pfn);
	if (pfn_valid(pfn)) {
		int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags);
		if (dirty) {
			unsigned long addr = (unsigned long)page_address(page);

			if (pages_do_alias(addr, address & PAGE_MASK))
				__flush_purge_region((void *)addr, PAGE_SIZE);
		}
	}
}

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 (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
		    !test_bit(PG_dcache_dirty, &page->flags)) {
			void *kaddr;

			kaddr = kmap_coherent(page, vmaddr);
			/* XXX.. For now kunmap_coherent() does a purge */
			/* __flush_purge_region((void *)kaddr, PAGE_SIZE); */
			kunmap_coherent(kaddr);
		} else
			__flush_purge_region((void *)addr, PAGE_SIZE);
	}
}

void flush_cache_all(void)
{
	cacheop_on_each_cpu(local_flush_cache_all, NULL, 1);
}
EXPORT_SYMBOL(flush_cache_all);

void flush_cache_mm(struct mm_struct *mm)
{
	if (boot_cpu_data.dcache.n_aliases == 0)
		return;

	cacheop_on_each_cpu(local_flush_cache_mm, mm, 1);
}

void flush_cache_dup_mm(struct mm_struct *mm)
{
	if (boot_cpu_data.dcache.n_aliases == 0)
		return;

	cacheop_on_each_cpu(local_flush_cache_dup_mm, mm, 1);
}

void flush_cache_page(struct vm_area_struct *vma, unsigned long addr,
		      unsigned long pfn)
{
	struct flusher_data data;

	data.vma = vma;
	data.addr1 = addr;
	data.addr2 = pfn;

	cacheop_on_each_cpu(local_flush_cache_page, (void *)&data, 1);
}

void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
		       unsigned long end)
{
	struct flusher_data data;

	data.vma = vma;
	data.addr1 = start;
	data.addr2 = end;

	cacheop_on_each_cpu(local_flush_cache_range, (void *)&data, 1);
}
EXPORT_SYMBOL(flush_cache_range);

void flush_dcache_page(struct page *page)
{
	cacheop_on_each_cpu(local_flush_dcache_page, page, 1);
}
EXPORT_SYMBOL(flush_dcache_page);

void flush_icache_range(unsigned long start, unsigned long end)
{
	struct flusher_data data;

	data.vma = NULL;
	data.addr1 = start;
	data.addr2 = end;

	cacheop_on_each_cpu(local_flush_icache_range, (void *)&data, 1);
}

void flush_icache_page(struct vm_area_struct *vma, struct page *page)
{
	/* Nothing uses the VMA, so just pass the struct page along */
	cacheop_on_each_cpu(local_flush_icache_page, page, 1);
}

void flush_cache_sigtramp(unsigned long address)
{
	cacheop_on_each_cpu(local_flush_cache_sigtramp, (void *)address, 1);
}

static void compute_alias(struct cache_info *c)
{
	c->alias_mask = ((c->sets - 1) << c->entry_shift) & ~(PAGE_SIZE - 1);
	c->n_aliases = c->alias_mask ? (c->alias_mask >> PAGE_SHIFT) + 1 : 0;
}

static void __init emit_cache_params(void)
{
	printk(KERN_NOTICE "I-cache : n_ways=%d n_sets=%d way_incr=%d\n",
		boot_cpu_data.icache.ways,
		boot_cpu_data.icache.sets,
		boot_cpu_data.icache.way_incr);
	printk(KERN_NOTICE "I-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
		boot_cpu_data.icache.entry_mask,
		boot_cpu_data.icache.alias_mask,
		boot_cpu_data.icache.n_aliases);
	printk(KERN_NOTICE "D-cache : n_ways=%d n_sets=%d way_incr=%d\n",
		boot_cpu_data.dcache.ways,
		boot_cpu_data.dcache.sets,
		boot_cpu_data.dcache.way_incr);
	printk(KERN_NOTICE "D-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
		boot_cpu_data.dcache.entry_mask,
		boot_cpu_data.dcache.alias_mask,
		boot_cpu_data.dcache.n_aliases);

	/*
	 * Emit Secondary Cache parameters if the CPU has a probed L2.
	 */
	if (boot_cpu_data.flags & CPU_HAS_L2_CACHE) {
		printk(KERN_NOTICE "S-cache : n_ways=%d n_sets=%d way_incr=%d\n",
			boot_cpu_data.scache.ways,
			boot_cpu_data.scache.sets,
			boot_cpu_data.scache.way_incr);
		printk(KERN_NOTICE "S-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
			boot_cpu_data.scache.entry_mask,
			boot_cpu_data.scache.alias_mask,
			boot_cpu_data.scache.n_aliases);
	}
}

void __init cpu_cache_init(void)
{
	unsigned int cache_disabled = 0;

#ifdef CCR
	cache_disabled = !(__raw_readl(CCR) & CCR_CACHE_ENABLE);
#endif

	compute_alias(&boot_cpu_data.icache);
	compute_alias(&boot_cpu_data.dcache);
	compute_alias(&boot_cpu_data.scache);

	__flush_wback_region		= noop__flush_region;
	__flush_purge_region		= noop__flush_region;
	__flush_invalidate_region	= noop__flush_region;

	/*
	 * No flushing is necessary in the disabled cache case so we can
	 * just keep the noop functions in local_flush_..() and __flush_..()
	 */
	if (unlikely(cache_disabled))
		goto skip;

	if (boot_cpu_data.family == CPU_FAMILY_SH2) {
		extern void __weak sh2_cache_init(void);

		sh2_cache_init();
	}

	if (boot_cpu_data.family == CPU_FAMILY_SH2A) {
		extern void __weak sh2a_cache_init(void);

		sh2a_cache_init();
	}

	if (boot_cpu_data.family == CPU_FAMILY_SH3) {
		extern void __weak sh3_cache_init(void);

		sh3_cache_init();

		if ((boot_cpu_data.type == CPU_SH7705) &&
		    (boot_cpu_data.dcache.sets == 512)) {
			extern void __weak sh7705_cache_init(void);

			sh7705_cache_init();
		}
	}

	if ((boot_cpu_data.family == CPU_FAMILY_SH4) ||
	    (boot_cpu_data.family == CPU_FAMILY_SH4A) ||
	    (boot_cpu_data.family == CPU_FAMILY_SH4AL_DSP)) {
		extern void __weak sh4_cache_init(void);

		sh4_cache_init();
	}

	if (boot_cpu_data.family == CPU_FAMILY_SH5) {
		extern void __weak sh5_cache_init(void);

		sh5_cache_init();
	}

skip:
	emit_cache_params();
}