1 // SPDX-License-Identifier: GPL-2.0-or-later 2 3 #include <linux/io.h> 4 #include <linux/slab.h> 5 #include <linux/vmalloc.h> 6 7 #include <mm/mmu_decl.h> 8 9 void __iomem *ioremap_wt(phys_addr_t addr, unsigned long size) 10 { 11 pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL); 12 13 return __ioremap_caller(addr, size, prot, __builtin_return_address(0)); 14 } 15 EXPORT_SYMBOL(ioremap_wt); 16 17 void __iomem * 18 __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller) 19 { 20 unsigned long v; 21 phys_addr_t p, offset; 22 int err; 23 24 /* 25 * Choose an address to map it to. 26 * Once the vmalloc system is running, we use it. 27 * Before then, we use space going down from IOREMAP_TOP 28 * (ioremap_bot records where we're up to). 29 */ 30 p = addr & PAGE_MASK; 31 offset = addr & ~PAGE_MASK; 32 size = PAGE_ALIGN(addr + size) - p; 33 34 /* 35 * If the address lies within the first 16 MB, assume it's in ISA 36 * memory space 37 */ 38 if (p < 16 * 1024 * 1024) 39 p += _ISA_MEM_BASE; 40 41 #ifndef CONFIG_CRASH_DUMP 42 /* 43 * Don't allow anybody to remap normal RAM that we're using. 44 * mem_init() sets high_memory so only do the check after that. 45 */ 46 if (slab_is_available() && p <= virt_to_phys(high_memory - 1) && 47 page_is_ram(__phys_to_pfn(p))) { 48 pr_warn("%s(): phys addr 0x%llx is RAM lr %ps\n", __func__, 49 (unsigned long long)p, __builtin_return_address(0)); 50 return NULL; 51 } 52 #endif 53 54 if (size == 0) 55 return NULL; 56 57 /* 58 * Is it already mapped? Perhaps overlapped by a previous 59 * mapping. 60 */ 61 v = p_block_mapped(p); 62 if (v) 63 return (void __iomem *)v + offset; 64 65 if (slab_is_available()) 66 return do_ioremap(p, offset, size, prot, caller); 67 68 /* 69 * Should check if it is a candidate for a BAT mapping 70 */ 71 pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller); 72 73 err = early_ioremap_range(ioremap_bot - size - PAGE_SIZE, p, size, prot); 74 if (err) 75 return NULL; 76 ioremap_bot -= size + PAGE_SIZE; 77 78 return (void __iomem *)ioremap_bot + offset; 79 } 80 81 void iounmap(volatile void __iomem *addr) 82 { 83 /* 84 * If mapped by BATs then there is nothing to do. 85 * Calling vfree() generates a benign warning. 86 */ 87 if (v_block_mapped((unsigned long)addr)) 88 return; 89 90 if (addr > high_memory && (unsigned long)addr < ioremap_bot) 91 vunmap((void *)(PAGE_MASK & (unsigned long)addr)); 92 } 93 EXPORT_SYMBOL(iounmap); 94