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