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ubuntu-linux-kernel/arch/xtensa/mm/cache.c

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/*
* arch/xtensa/mm/cache.c
*
* 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) 2001-2006 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
* Joe Taylor
* Marc Gauthier
*
*/
#include <linux/init.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/bootmem.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
#include <asm/bootparam.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
//#define printd(x...) printk(x)
#define printd(x...) do { } while(0)
/*
* Note:
* The kernel provides one architecture bit PG_arch_1 in the page flags that
* can be used for cache coherency.
*
* I$-D$ coherency.
*
* The Xtensa architecture doesn't keep the instruction cache coherent with
* the data cache. We use the architecture bit to indicate if the caches
* are coherent. The kernel clears this bit whenever a page is added to the
* page cache. At that time, the caches might not be in sync. We, therefore,
* define this flag as 'clean' if set.
*
* D-cache aliasing.
*
* With cache aliasing, we have to always flush the cache when pages are
* unmapped (see tlb_start_vma(). So, we use this flag to indicate a dirty
* page.
*
*
*
*/
#if (DCACHE_WAY_SIZE > PAGE_SIZE)
static inline void kmap_invalidate_coherent(struct page *page,
unsigned long vaddr)
{
if (!DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
unsigned long kvaddr;
if (!PageHighMem(page)) {
kvaddr = (unsigned long)page_to_virt(page);
__invalidate_dcache_page(kvaddr);
} else {
kvaddr = TLBTEMP_BASE_1 +
(page_to_phys(page) & DCACHE_ALIAS_MASK);
__invalidate_dcache_page_alias(kvaddr,
page_to_phys(page));
}
}
}
static inline void *coherent_kvaddr(struct page *page, unsigned long base,
unsigned long vaddr, unsigned long *paddr)
{
if (PageHighMem(page) || !DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
*paddr = page_to_phys(page);
return (void *)(base + (vaddr & DCACHE_ALIAS_MASK));
} else {
*paddr = 0;
return page_to_virt(page);
}
}
void clear_user_highpage(struct page *page, unsigned long vaddr)
{
unsigned long paddr;
void *kvaddr = coherent_kvaddr(page, TLBTEMP_BASE_1, vaddr, &paddr);
preempt_disable();
kmap_invalidate_coherent(page, vaddr);
set_bit(PG_arch_1, &page->flags);
clear_page_alias(kvaddr, paddr);
preempt_enable();
}
EXPORT_SYMBOL(clear_user_highpage);
void copy_user_highpage(struct page *dst, struct page *src,
unsigned long vaddr, struct vm_area_struct *vma)
{
unsigned long dst_paddr, src_paddr;
void *dst_vaddr = coherent_kvaddr(dst, TLBTEMP_BASE_1, vaddr,
&dst_paddr);
void *src_vaddr = coherent_kvaddr(src, TLBTEMP_BASE_2, vaddr,
&src_paddr);
preempt_disable();
kmap_invalidate_coherent(dst, vaddr);
set_bit(PG_arch_1, &dst->flags);
copy_page_alias(dst_vaddr, src_vaddr, dst_paddr, src_paddr);
preempt_enable();
}
EXPORT_SYMBOL(copy_user_highpage);
/*
* Any time the kernel writes to a user page cache page, or it is about to
* read from a page cache page this routine is called.
*
*/
void flush_dcache_page(struct page *page)
{
struct address_space *mapping = page_mapping(page);
/*
* If we have a mapping but the page is not mapped to user-space
* yet, we simply mark this page dirty and defer flushing the
* caches until update_mmu().
*/
if (mapping && !mapping_mapped(mapping)) {
if (!test_bit(PG_arch_1, &page->flags))
set_bit(PG_arch_1, &page->flags);
return;
} else {
unsigned long phys = page_to_phys(page);
unsigned long temp = page->index << PAGE_SHIFT;
unsigned long alias = !(DCACHE_ALIAS_EQ(temp, phys));
unsigned long virt;
/*
* Flush the page in kernel space and user space.
* Note that we can omit that step if aliasing is not
* an issue, but we do have to synchronize I$ and D$
* if we have a mapping.
*/
if (!alias && !mapping)
return;
virt = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_page_alias(virt, phys);
virt = TLBTEMP_BASE_1 + (temp & DCACHE_ALIAS_MASK);
if (alias)
__flush_invalidate_dcache_page_alias(virt, phys);
if (mapping)
__invalidate_icache_page_alias(virt, phys);
}
/* There shouldn't be an entry in the cache for this page anymore. */
}
EXPORT_SYMBOL(flush_dcache_page);
/*
* For now, flush the whole cache. FIXME??
*/
void local_flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
__flush_invalidate_dcache_all();
__invalidate_icache_all();
}
EXPORT_SYMBOL(local_flush_cache_range);
/*
* Remove any entry in the cache for this page.
*
* Note that this function is only called for user pages, so use the
* alias versions of the cache flush functions.
*/
void local_flush_cache_page(struct vm_area_struct *vma, unsigned long address,
unsigned long pfn)
{
/* Note that we have to use the 'alias' address to avoid multi-hit */
unsigned long phys = page_to_phys(pfn_to_page(pfn));
unsigned long virt = TLBTEMP_BASE_1 + (address & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_page_alias(virt, phys);
__invalidate_icache_page_alias(virt, phys);
}
EXPORT_SYMBOL(local_flush_cache_page);
#endif /* DCACHE_WAY_SIZE > PAGE_SIZE */
void
update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t *ptep)
{
unsigned long pfn = pte_pfn(*ptep);
struct page *page;
if (!pfn_valid(pfn))
return;
page = pfn_to_page(pfn);
/* Invalidate old entry in TLBs */
flush_tlb_page(vma, addr);
#if (DCACHE_WAY_SIZE > PAGE_SIZE)
if (!PageReserved(page) && test_bit(PG_arch_1, &page->flags)) {
unsigned long phys = page_to_phys(page);
unsigned long tmp;
tmp = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_page_alias(tmp, phys);
tmp = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_page_alias(tmp, phys);
__invalidate_icache_page_alias(tmp, phys);
clear_bit(PG_arch_1, &page->flags);
}
#else
if (!PageReserved(page) && !test_bit(PG_arch_1, &page->flags)
&& (vma->vm_flags & VM_EXEC) != 0) {
unsigned long paddr = (unsigned long)kmap_atomic(page);
__flush_dcache_page(paddr);
__invalidate_icache_page(paddr);
set_bit(PG_arch_1, &page->flags);
kunmap_atomic((void *)paddr);
}
#endif
}
/*
* access_process_vm() has called get_user_pages(), which has done a
* flush_dcache_page() on the page.
*/
#if (DCACHE_WAY_SIZE > PAGE_SIZE)
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
unsigned long phys = page_to_phys(page);
unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
/* Flush and invalidate user page if aliased. */
if (alias) {
unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_page_alias(t, phys);
}
/* Copy data */
memcpy(dst, src, len);
/*
* Flush and invalidate kernel page if aliased and synchronize
* data and instruction caches for executable pages.
*/
if (alias) {
unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_range((unsigned long) dst, len);
if ((vma->vm_flags & VM_EXEC) != 0)
__invalidate_icache_page_alias(t, phys);
} else if ((vma->vm_flags & VM_EXEC) != 0) {
__flush_dcache_range((unsigned long)dst,len);
__invalidate_icache_range((unsigned long) dst, len);
}
}
extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
unsigned long phys = page_to_phys(page);
unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
/*
* Flush user page if aliased.
* (Note: a simply flush would be sufficient)
*/
if (alias) {
unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
__flush_invalidate_dcache_page_alias(t, phys);
}
memcpy(dst, src, len);
}
#endif
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