arch/xtensa/mm/cache.c - linux - Git at Google

 /*
  * 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/memblock.h>
 #include <linux/swap.h>
 #include <linux/pagemap.h>
 #include <linux/pgtable.h>

 #include <asm/bootparam.h>
 #include <asm/mmu_context.h>
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
 #include <asm/page.h>

 /*
  * 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);

 			preempt_disable();
 			__invalidate_dcache_page_alias(kvaddr,
 						       page_to_phys(page));
 			preempt_enable();
 		}
 	}
 }

 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_file(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;

 		preempt_disable();
 		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);
 		preempt_enable();
 	}

 	/* 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);

 	preempt_disable();
 	__flush_invalidate_dcache_page_alias(virt, phys);
 	__invalidate_icache_page_alias(virt, phys);
 	preempt_enable();
 }
 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;

 		preempt_disable();
 		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);
 		preempt_enable();

 		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);
 		preempt_disable();
 		__flush_invalidate_dcache_page_alias(t, phys);
 		preempt_enable();
 	}

 	/* 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);

 		preempt_disable();
 		__flush_invalidate_dcache_range((unsigned long) dst, len);
 		if ((vma->vm_flags & VM_EXEC) != 0)
 			__invalidate_icache_page_alias(t, phys);
 		preempt_enable();

 	} 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);
 		preempt_disable();
 		__flush_invalidate_dcache_page_alias(t, phys);
 		preempt_enable();
 	}

 	memcpy(dst, src, len);
 }

 #endif
	/*
	* 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/memblock.h>
	#include <linux/swap.h>
	#include <linux/pagemap.h>
	#include <linux/pgtable.h>

	#include <asm/bootparam.h>
	#include <asm/mmu_context.h>
	#include <asm/tlb.h>
	#include <asm/tlbflush.h>
	#include <asm/page.h>

	/*
	* 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);

	preempt_disable();
	__invalidate_dcache_page_alias(kvaddr,
	page_to_phys(page));
	preempt_enable();
	}
	}
	}

	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_file(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;

	preempt_disable();
	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);
	preempt_enable();
	}

	/* 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);

	preempt_disable();
	__flush_invalidate_dcache_page_alias(virt, phys);
	__invalidate_icache_page_alias(virt, phys);
	preempt_enable();
	}
	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;

	preempt_disable();
	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);
	preempt_enable();

	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);
	preempt_disable();
	__flush_invalidate_dcache_page_alias(t, phys);
	preempt_enable();
	}

	/* 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);

	preempt_disable();
	__flush_invalidate_dcache_range((unsigned long) dst, len);
	if ((vma->vm_flags & VM_EXEC) != 0)
	__invalidate_icache_page_alias(t, phys);
	preempt_enable();

	} 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);
	preempt_disable();
	__flush_invalidate_dcache_page_alias(t, phys);
	preempt_enable();
	}

	memcpy(dst, src, len);
	}

	#endif