1/*
2 * Copyright IBM Corp. 2011
3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
4 */
5#include <linux/hugetlb.h>
6#include <linux/module.h>
7#include <linux/mm.h>
8#include <asm/cacheflush.h>
9#include <asm/facility.h>
10#include <asm/pgtable.h>
11#include <asm/page.h>
12
13#if PAGE_DEFAULT_KEY
14static inline unsigned long sske_frame(unsigned long addr, unsigned char skey)
15{
16	asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0"
17		     : [addr] "+a" (addr) : [skey] "d" (skey));
18	return addr;
19}
20
21void __storage_key_init_range(unsigned long start, unsigned long end)
22{
23	unsigned long boundary, size;
24
25	while (start < end) {
26		if (MACHINE_HAS_EDAT1) {
27			/* set storage keys for a 1MB frame */
28			size = 1UL << 20;
29			boundary = (start + size) & ~(size - 1);
30			if (boundary <= end) {
31				do {
32					start = sske_frame(start, PAGE_DEFAULT_KEY);
33				} while (start < boundary);
34				continue;
35			}
36		}
37		page_set_storage_key(start, PAGE_DEFAULT_KEY, 0);
38		start += PAGE_SIZE;
39	}
40}
41#endif
42
43static pte_t *walk_page_table(unsigned long addr)
44{
45	pgd_t *pgdp;
46	pud_t *pudp;
47	pmd_t *pmdp;
48	pte_t *ptep;
49
50	pgdp = pgd_offset_k(addr);
51	if (pgd_none(*pgdp))
52		return NULL;
53	pudp = pud_offset(pgdp, addr);
54	if (pud_none(*pudp) || pud_large(*pudp))
55		return NULL;
56	pmdp = pmd_offset(pudp, addr);
57	if (pmd_none(*pmdp) || pmd_large(*pmdp))
58		return NULL;
59	ptep = pte_offset_kernel(pmdp, addr);
60	if (pte_none(*ptep))
61		return NULL;
62	return ptep;
63}
64
65static void change_page_attr(unsigned long addr, int numpages,
66			     pte_t (*set) (pte_t))
67{
68	pte_t *ptep, pte;
69	int i;
70
71	for (i = 0; i < numpages; i++) {
72		ptep = walk_page_table(addr);
73		if (WARN_ON_ONCE(!ptep))
74			break;
75		pte = *ptep;
76		pte = set(pte);
77		__ptep_ipte(addr, ptep);
78		*ptep = pte;
79		addr += PAGE_SIZE;
80	}
81}
82
83int set_memory_ro(unsigned long addr, int numpages)
84{
85	change_page_attr(addr, numpages, pte_wrprotect);
86	return 0;
87}
88
89int set_memory_rw(unsigned long addr, int numpages)
90{
91	change_page_attr(addr, numpages, pte_mkwrite);
92	return 0;
93}
94
95/* not possible */
96int set_memory_nx(unsigned long addr, int numpages)
97{
98	return 0;
99}
100
101int set_memory_x(unsigned long addr, int numpages)
102{
103	return 0;
104}
105
106#ifdef CONFIG_DEBUG_PAGEALLOC
107
108static void ipte_range(pte_t *pte, unsigned long address, int nr)
109{
110	int i;
111
112	if (test_facility(13)) {
113		__ptep_ipte_range(address, nr - 1, pte);
114		return;
115	}
116	for (i = 0; i < nr; i++) {
117		__ptep_ipte(address, pte);
118		address += PAGE_SIZE;
119		pte++;
120	}
121}
122
123void __kernel_map_pages(struct page *page, int numpages, int enable)
124{
125	unsigned long address;
126	int nr, i, j;
127	pgd_t *pgd;
128	pud_t *pud;
129	pmd_t *pmd;
130	pte_t *pte;
131
132	for (i = 0; i < numpages;) {
133		address = page_to_phys(page + i);
134		pgd = pgd_offset_k(address);
135		pud = pud_offset(pgd, address);
136		pmd = pmd_offset(pud, address);
137		pte = pte_offset_kernel(pmd, address);
138		nr = (unsigned long)pte >> ilog2(sizeof(long));
139		nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1));
140		nr = min(numpages - i, nr);
141		if (enable) {
142			for (j = 0; j < nr; j++) {
143				pte_val(*pte) = __pa(address);
144				address += PAGE_SIZE;
145				pte++;
146			}
147		} else {
148			ipte_range(pte, address, nr);
149		}
150		i += nr;
151	}
152}
153
154#ifdef CONFIG_HIBERNATION
155bool kernel_page_present(struct page *page)
156{
157	unsigned long addr;
158	int cc;
159
160	addr = page_to_phys(page);
161	asm volatile(
162		"	lra	%1,0(%1)\n"
163		"	ipm	%0\n"
164		"	srl	%0,28"
165		: "=d" (cc), "+a" (addr) : : "cc");
166	return cc == 0;
167}
168#endif /* CONFIG_HIBERNATION */
169
170#endif /* CONFIG_DEBUG_PAGEALLOC */
171