1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/module.h> 5 #include <linux/highmem.h> 6 #include <linux/smp.h> 7 #include <linux/memblock.h> 8 #include <asm/fixmap.h> 9 #include <asm/tlbflush.h> 10 #include <asm/cacheflush.h> 11 12 static pte_t *kmap_pte; 13 14 unsigned long highstart_pfn, highend_pfn; 15 16 void kmap_flush_tlb(unsigned long addr) 17 { 18 flush_tlb_one(addr); 19 } 20 EXPORT_SYMBOL(kmap_flush_tlb); 21 22 EXPORT_SYMBOL(kmap); 23 24 void *kmap_atomic_high(struct page *page) 25 { 26 unsigned long vaddr; 27 int idx, type; 28 29 type = kmap_atomic_idx_push(); 30 idx = type + KM_TYPE_NR*smp_processor_id(); 31 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); 32 #ifdef CONFIG_DEBUG_HIGHMEM 33 BUG_ON(!pte_none(*(kmap_pte - idx))); 34 #endif 35 set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL)); 36 flush_tlb_one((unsigned long)vaddr); 37 38 return (void *)vaddr; 39 } 40 EXPORT_SYMBOL(kmap_atomic_high); 41 42 void __kunmap_atomic(void *kvaddr) 43 { 44 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; 45 int idx; 46 47 if (vaddr < FIXADDR_START) 48 goto out; 49 50 #ifdef CONFIG_DEBUG_HIGHMEM 51 idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx(); 52 53 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); 54 55 pte_clear(&init_mm, vaddr, kmap_pte - idx); 56 flush_tlb_one(vaddr); 57 #else 58 (void) idx; /* to kill a warning */ 59 #endif 60 kmap_atomic_idx_pop(); 61 out: 62 pagefault_enable(); 63 preempt_enable(); 64 } 65 EXPORT_SYMBOL(__kunmap_atomic); 66 67 /* 68 * This is the same as kmap_atomic() but can map memory that doesn't 69 * have a struct page associated with it. 70 */ 71 void *kmap_atomic_pfn(unsigned long pfn) 72 { 73 unsigned long vaddr; 74 int idx, type; 75 76 pagefault_disable(); 77 78 type = kmap_atomic_idx_push(); 79 idx = type + KM_TYPE_NR*smp_processor_id(); 80 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); 81 set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL)); 82 flush_tlb_one(vaddr); 83 84 return (void *) vaddr; 85 } 86 87 struct page *kmap_atomic_to_page(void *ptr) 88 { 89 unsigned long idx, vaddr = (unsigned long)ptr; 90 pte_t *pte; 91 92 if (vaddr < FIXADDR_START) 93 return virt_to_page(ptr); 94 95 idx = virt_to_fix(vaddr); 96 pte = kmap_pte - (idx - FIX_KMAP_BEGIN); 97 return pte_page(*pte); 98 } 99 100 static void __init kmap_pages_init(void) 101 { 102 unsigned long vaddr; 103 pgd_t *pgd; 104 pmd_t *pmd; 105 pud_t *pud; 106 pte_t *pte; 107 108 vaddr = PKMAP_BASE; 109 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); 110 111 pgd = swapper_pg_dir + __pgd_offset(vaddr); 112 pud = (pud_t *)pgd; 113 pmd = pmd_offset(pud, vaddr); 114 pte = pte_offset_kernel(pmd, vaddr); 115 pkmap_page_table = pte; 116 } 117 118 void __init kmap_init(void) 119 { 120 unsigned long vaddr; 121 122 kmap_pages_init(); 123 124 vaddr = __fix_to_virt(FIX_KMAP_BEGIN); 125 126 kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr); 127 } 128