 127c1fefff
			
		
	
	
	127c1fefff
	
	
	
		
			
			With dirty and referenced bits implemented in software it is unnecessary to initialize the storage key for every page. With this patch not a single storage key operation is done for a system that does not use KVM. For KVM set_pte_at/pgste_set_key will do the initialization for the guest view of the storage key when the mapping for the page is established in the host. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
		
			
				
	
	
		
			146 lines
		
	
	
	
		
			2.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			146 lines
		
	
	
	
		
			2.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright IBM Corp. 2011
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|  * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
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|  */
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| #include <linux/hugetlb.h>
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| #include <linux/module.h>
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| #include <linux/mm.h>
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| #include <asm/cacheflush.h>
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| #include <asm/pgtable.h>
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| #include <asm/page.h>
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| 
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| #if PAGE_DEFAULT_KEY
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| static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
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| {
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| 	asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
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| 		     : [addr] "+a" (addr) : [skey] "d" (skey));
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| 	return addr;
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| }
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| 
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| void __storage_key_init_range(unsigned long start, unsigned long end)
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| {
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| 	unsigned long boundary, size;
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| 
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| 	while (start < end) {
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| 		if (MACHINE_HAS_EDAT1) {
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| 			/* set storage keys for a 1MB frame */
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| 			size = 1UL << 20;
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| 			boundary = (start + size) & ~(size - 1);
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| 			if (boundary <= end) {
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| 				do {
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| 					start = sske_frame(start, PAGE_DEFAULT_KEY);
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| 				} while (start < boundary);
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| 				continue;
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| 			}
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| 		}
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| 		page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
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| 		start += PAGE_SIZE;
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| 	}
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| }
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| #endif
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| 
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| static pte_t *walk_page_table(unsigned long addr)
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| {
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| 	pgd_t *pgdp;
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| 	pud_t *pudp;
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| 	pmd_t *pmdp;
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| 	pte_t *ptep;
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| 
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| 	pgdp = pgd_offset_k(addr);
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| 	if (pgd_none(*pgdp))
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| 		return NULL;
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| 	pudp = pud_offset(pgdp, addr);
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| 	if (pud_none(*pudp) || pud_large(*pudp))
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| 		return NULL;
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| 	pmdp = pmd_offset(pudp, addr);
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| 	if (pmd_none(*pmdp) || pmd_large(*pmdp))
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| 		return NULL;
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| 	ptep = pte_offset_kernel(pmdp, addr);
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| 	if (pte_none(*ptep))
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| 		return NULL;
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| 	return ptep;
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| }
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| 
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| static void change_page_attr(unsigned long addr, int numpages,
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| 			     pte_t (*set) (pte_t))
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| {
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| 	pte_t *ptep, pte;
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| 	int i;
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| 
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| 	for (i = 0; i < numpages; i++) {
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| 		ptep = walk_page_table(addr);
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| 		if (WARN_ON_ONCE(!ptep))
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| 			break;
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| 		pte = *ptep;
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| 		pte = set(pte);
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| 		__ptep_ipte(addr, ptep);
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| 		*ptep = pte;
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| 		addr += PAGE_SIZE;
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| 	}
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| }
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| 
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| int set_memory_ro(unsigned long addr, int numpages)
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| {
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| 	change_page_attr(addr, numpages, pte_wrprotect);
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| 	return 0;
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| }
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| 
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| int set_memory_rw(unsigned long addr, int numpages)
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| {
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| 	change_page_attr(addr, numpages, pte_mkwrite);
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| 	return 0;
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| }
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| 
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| /* not possible */
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| int set_memory_nx(unsigned long addr, int numpages)
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| {
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| 	return 0;
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| }
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| 
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| int set_memory_x(unsigned long addr, int numpages)
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| {
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| 	return 0;
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| }
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| 
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| #ifdef CONFIG_DEBUG_PAGEALLOC
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| void kernel_map_pages(struct page *page, int numpages, int enable)
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| {
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| 	unsigned long address;
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| 	pgd_t *pgd;
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| 	pud_t *pud;
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| 	pmd_t *pmd;
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| 	pte_t *pte;
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| 	int i;
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| 
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| 	for (i = 0; i < numpages; i++) {
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| 		address = page_to_phys(page + i);
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| 		pgd = pgd_offset_k(address);
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| 		pud = pud_offset(pgd, address);
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| 		pmd = pmd_offset(pud, address);
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| 		pte = pte_offset_kernel(pmd, address);
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| 		if (!enable) {
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| 			__ptep_ipte(address, pte);
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| 			pte_val(*pte) = _PAGE_INVALID;
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| 			continue;
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| 		}
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| 		pte_val(*pte) = __pa(address);
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| 	}
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| }
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| 
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| #ifdef CONFIG_HIBERNATION
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| bool kernel_page_present(struct page *page)
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| {
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| 	unsigned long addr;
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| 	int cc;
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| 
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| 	addr = page_to_phys(page);
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| 	asm volatile(
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| 		"	lra	%1,0(%1)\n"
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| 		"	ipm	%0\n"
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| 		"	srl	%0,28"
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| 		: "=d" (cc), "+a" (addr) : : "cc");
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| 	return cc == 0;
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| }
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| #endif /* CONFIG_HIBERNATION */
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| 
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| #endif /* CONFIG_DEBUG_PAGEALLOC */
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