1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * arch/arm/mm/highmem.c -- ARM highmem support
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Author: Nicolas Pitre
6*4882a593Smuzhiyun * Created: september 8, 2008
7*4882a593Smuzhiyun * Copyright: Marvell Semiconductors Inc.
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/highmem.h>
12*4882a593Smuzhiyun #include <linux/interrupt.h>
13*4882a593Smuzhiyun #include <asm/fixmap.h>
14*4882a593Smuzhiyun #include <asm/cacheflush.h>
15*4882a593Smuzhiyun #include <asm/tlbflush.h>
16*4882a593Smuzhiyun #include "mm.h"
17*4882a593Smuzhiyun
set_fixmap_pte(int idx,pte_t pte)18*4882a593Smuzhiyun static inline void set_fixmap_pte(int idx, pte_t pte)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun unsigned long vaddr = __fix_to_virt(idx);
21*4882a593Smuzhiyun pte_t *ptep = virt_to_kpte(vaddr);
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun set_pte_ext(ptep, pte, 0);
24*4882a593Smuzhiyun local_flush_tlb_kernel_page(vaddr);
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun
get_fixmap_pte(unsigned long vaddr)27*4882a593Smuzhiyun static inline pte_t get_fixmap_pte(unsigned long vaddr)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun pte_t *ptep = virt_to_kpte(vaddr);
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun return *ptep;
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
kmap_atomic_high_prot(struct page * page,pgprot_t prot)34*4882a593Smuzhiyun void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun unsigned int idx;
37*4882a593Smuzhiyun unsigned long vaddr;
38*4882a593Smuzhiyun void *kmap;
39*4882a593Smuzhiyun int type;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_HIGHMEM
42*4882a593Smuzhiyun /*
43*4882a593Smuzhiyun * There is no cache coherency issue when non VIVT, so force the
44*4882a593Smuzhiyun * dedicated kmap usage for better debugging purposes in that case.
45*4882a593Smuzhiyun */
46*4882a593Smuzhiyun if (!cache_is_vivt())
47*4882a593Smuzhiyun kmap = NULL;
48*4882a593Smuzhiyun else
49*4882a593Smuzhiyun #endif
50*4882a593Smuzhiyun kmap = kmap_high_get(page);
51*4882a593Smuzhiyun if (kmap)
52*4882a593Smuzhiyun return kmap;
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun type = kmap_atomic_idx_push();
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
57*4882a593Smuzhiyun vaddr = __fix_to_virt(idx);
58*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_HIGHMEM
59*4882a593Smuzhiyun /*
60*4882a593Smuzhiyun * With debugging enabled, kunmap_atomic forces that entry to 0.
61*4882a593Smuzhiyun * Make sure it was indeed properly unmapped.
62*4882a593Smuzhiyun */
63*4882a593Smuzhiyun BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
64*4882a593Smuzhiyun #endif
65*4882a593Smuzhiyun /*
66*4882a593Smuzhiyun * When debugging is off, kunmap_atomic leaves the previous mapping
67*4882a593Smuzhiyun * in place, so the contained TLB flush ensures the TLB is updated
68*4882a593Smuzhiyun * with the new mapping.
69*4882a593Smuzhiyun */
70*4882a593Smuzhiyun set_fixmap_pte(idx, mk_pte(page, prot));
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun return (void *)vaddr;
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun EXPORT_SYMBOL(kmap_atomic_high_prot);
75*4882a593Smuzhiyun
kunmap_atomic_high(void * kvaddr)76*4882a593Smuzhiyun void kunmap_atomic_high(void *kvaddr)
77*4882a593Smuzhiyun {
78*4882a593Smuzhiyun unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
79*4882a593Smuzhiyun int idx, type;
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun if (kvaddr >= (void *)FIXADDR_START) {
82*4882a593Smuzhiyun type = kmap_atomic_idx();
83*4882a593Smuzhiyun idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun if (cache_is_vivt())
86*4882a593Smuzhiyun __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
87*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_HIGHMEM
88*4882a593Smuzhiyun BUG_ON(vaddr != __fix_to_virt(idx));
89*4882a593Smuzhiyun set_fixmap_pte(idx, __pte(0));
90*4882a593Smuzhiyun #else
91*4882a593Smuzhiyun (void) idx; /* to kill a warning */
92*4882a593Smuzhiyun #endif
93*4882a593Smuzhiyun kmap_atomic_idx_pop();
94*4882a593Smuzhiyun } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
95*4882a593Smuzhiyun /* this address was obtained through kmap_high_get() */
96*4882a593Smuzhiyun kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
97*4882a593Smuzhiyun }
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun EXPORT_SYMBOL(kunmap_atomic_high);
100*4882a593Smuzhiyun
kmap_atomic_pfn(unsigned long pfn)101*4882a593Smuzhiyun void *kmap_atomic_pfn(unsigned long pfn)
102*4882a593Smuzhiyun {
103*4882a593Smuzhiyun unsigned long vaddr;
104*4882a593Smuzhiyun int idx, type;
105*4882a593Smuzhiyun struct page *page = pfn_to_page(pfn);
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun preempt_disable();
108*4882a593Smuzhiyun pagefault_disable();
109*4882a593Smuzhiyun if (!PageHighMem(page))
110*4882a593Smuzhiyun return page_address(page);
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun type = kmap_atomic_idx_push();
113*4882a593Smuzhiyun idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
114*4882a593Smuzhiyun vaddr = __fix_to_virt(idx);
115*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_HIGHMEM
116*4882a593Smuzhiyun BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
117*4882a593Smuzhiyun #endif
118*4882a593Smuzhiyun set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
119*4882a593Smuzhiyun
120*4882a593Smuzhiyun return (void *)vaddr;
121*4882a593Smuzhiyun }
122