projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 65559100 MF |
1 | /* |
| 2 | * High memory support for Xtensa architecture | |
| 3 | * | |
| 4 | * This file is subject to the terms and conditions of the GNU General | |
| 5 | * Public License. See the file "COPYING" in the main directory of | |
| 6 | * this archive for more details. | |
| 7 | * | |
| 8 | * Copyright (C) 2014 Cadence Design Systems Inc. | |
| 9 | */ | |
| 10 | ||
| 11 | #include <linux/export.h> | |
| 12 | #include <linux/highmem.h> | |
| 13 | #include <asm/tlbflush.h> | |
| 14 | ||
| 15 | static pte_t *kmap_pte; | |
| 16 | ||
| 8504b503 MF |
17 | #if DCACHE_WAY_SIZE > PAGE_SIZE |
| 18 | unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS]; | |
| 19 | wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS]; | |
| 20 | ||
| 21 | static void __init kmap_waitqueues_init(void) | |
| 22 | { | |
| 23 | unsigned int i; | |
| 24 | ||
| 25 | for (i = 0; i < ARRAY_SIZE(pkmap_map_wait_arr); ++i) | |
| 26 | init_waitqueue_head(pkmap_map_wait_arr + i); | |
| 27 | } | |
| 28 | #else | |
| 29 | static inline void kmap_waitqueues_init(void) | |
| 30 | { | |
| 31 | } | |
| 32 | #endif | |
| 33 | ||
| 32544d9c MF |
34 | static inline enum fixed_addresses kmap_idx(int type, unsigned long color) |
| 35 | { | |
| 36 | return (type + KM_TYPE_NR * smp_processor_id()) * DCACHE_N_COLORS + | |
| 37 | color; | |
| 38 | } | |
| 39 | ||
| 65559100 MF |
40 | void *kmap_atomic(struct page *page) |
| 41 | { | |
| 42 | enum fixed_addresses idx; | |
| 43 | unsigned long vaddr; | |
| 65559100 MF |
44 | |
| 45 | pagefault_disable(); | |
| 46 | if (!PageHighMem(page)) | |
| 47 | return page_address(page); | |
| 48 | ||
| 32544d9c MF |
49 | idx = kmap_idx(kmap_atomic_idx_push(), |
| 50 | DCACHE_ALIAS(page_to_phys(page))); | |
| 65559100 MF |
51 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); |
| 52 | #ifdef CONFIG_DEBUG_HIGHMEM | |
| 22def768 | 53 | BUG_ON(!pte_none(*(kmap_pte + idx))); |
| 65559100 | 54 | #endif |
| 22def768 | 55 | set_pte(kmap_pte + idx, mk_pte(page, PAGE_KERNEL_EXEC)); |
| 65559100 MF |
56 | |
| 57 | return (void *)vaddr; | |
| 58 | } | |
| 59 | EXPORT_SYMBOL(kmap_atomic); | |
| 60 | ||
| 61 | void __kunmap_atomic(void *kvaddr) | |
| 62 | { | |
| 65559100 MF |
63 | if (kvaddr >= (void *)FIXADDR_START && |
| 64 | kvaddr < (void *)FIXADDR_TOP) { | |
| 32544d9c MF |
65 | int idx = kmap_idx(kmap_atomic_idx(), |
| 66 | DCACHE_ALIAS((unsigned long)kvaddr)); | |
| 65559100 MF |
67 | |
| 68 | /* | |
| 69 | * Force other mappings to Oops if they'll try to access this | |
| 70 | * pte without first remap it. Keeping stale mappings around | |
| 71 | * is a bad idea also, in case the page changes cacheability | |
| 72 | * attributes or becomes a protected page in a hypervisor. | |
| 73 | */ | |
| 22def768 | 74 | pte_clear(&init_mm, kvaddr, kmap_pte + idx); |
| 65559100 MF |
75 | local_flush_tlb_kernel_range((unsigned long)kvaddr, |
| 76 | (unsigned long)kvaddr + PAGE_SIZE); | |
| 77 | ||
| 78 | kmap_atomic_idx_pop(); | |
| 79 | } | |
| 80 | ||
| 81 | pagefault_enable(); | |
| 82 | } | |
| 83 | EXPORT_SYMBOL(__kunmap_atomic); | |
| 84 | ||
| 85 | void __init kmap_init(void) | |
| 86 | { | |
| 87 | unsigned long kmap_vstart; | |
| 88 | ||
| 89 | /* cache the first kmap pte */ | |
| 90 | kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); | |
| 91 | kmap_pte = kmap_get_fixmap_pte(kmap_vstart); | |
| 8504b503 | 92 | kmap_waitqueues_init(); |
| 65559100 | 93 | } |