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 /** 8 * Low level function to establish the page tables for an IO mapping 9 */ 10 void __iomem *__ioremap_at(phys_addr_t pa, void *ea, unsigned long size, pgprot_t prot) 11 { 12 int ret; 13 unsigned long va = (unsigned long)ea; 14 15 /* We don't support the 4K PFN hack with ioremap */ 16 if (pgprot_val(prot) & H_PAGE_4K_PFN) 17 return NULL; 18 19 if ((ea + size) >= (void *)IOREMAP_END) { 20 pr_warn("Outside the supported range\n"); 21 return NULL; 22 } 23 24 WARN_ON(pa & ~PAGE_MASK); 25 WARN_ON(((unsigned long)ea) & ~PAGE_MASK); 26 WARN_ON(size & ~PAGE_MASK); 27 28 if (slab_is_available()) { 29 ret = ioremap_page_range(va, va + size, pa, prot); 30 if (ret) 31 unmap_kernel_range(va, size); 32 } else { 33 ret = early_ioremap_range(va, pa, size, prot); 34 } 35 36 if (ret) 37 return NULL; 38 39 return (void __iomem *)ea; 40 } 41 EXPORT_SYMBOL(__ioremap_at); 42 43 /** 44 * Low level function to tear down the page tables for an IO mapping. This is 45 * used for mappings that are manipulated manually, like partial unmapping of 46 * PCI IOs or ISA space. 47 */ 48 void __iounmap_at(void *ea, unsigned long size) 49 { 50 WARN_ON(((unsigned long)ea) & ~PAGE_MASK); 51 WARN_ON(size & ~PAGE_MASK); 52 53 unmap_kernel_range((unsigned long)ea, size); 54 } 55 EXPORT_SYMBOL(__iounmap_at); 56 57 void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size, 58 pgprot_t prot, void *caller) 59 { 60 phys_addr_t paligned, offset; 61 void __iomem *ret; 62 int err; 63 64 /* We don't support the 4K PFN hack with ioremap */ 65 if (pgprot_val(prot) & H_PAGE_4K_PFN) 66 return NULL; 67 68 /* 69 * Choose an address to map it to. Once the vmalloc system is running, 70 * we use it. Before that, we map using addresses going up from 71 * ioremap_bot. vmalloc will use the addresses from IOREMAP_BASE 72 * through ioremap_bot. 73 */ 74 paligned = addr & PAGE_MASK; 75 offset = addr & ~PAGE_MASK; 76 size = PAGE_ALIGN(addr + size) - paligned; 77 78 if (size == 0 || paligned == 0) 79 return NULL; 80 81 if (slab_is_available()) 82 return do_ioremap(paligned, offset, size, prot, caller); 83 84 err = early_ioremap_range(ioremap_bot, paligned, size, prot); 85 if (err) 86 return NULL; 87 88 ret = (void __iomem *)ioremap_bot + offset; 89 ioremap_bot += size; 90 91 return ret; 92 } 93 94 /* 95 * Unmap an IO region and remove it from vmalloc'd list. 96 * Access to IO memory should be serialized by driver. 97 */ 98 void iounmap(volatile void __iomem *token) 99 { 100 void *addr; 101 102 if (!slab_is_available()) 103 return; 104 105 addr = (void *)((unsigned long __force)PCI_FIX_ADDR(token) & PAGE_MASK); 106 107 if ((unsigned long)addr < ioremap_bot) { 108 pr_warn("Attempt to iounmap early bolted mapping at 0x%p\n", addr); 109 return; 110 } 111 vunmap(addr); 112 } 113 EXPORT_SYMBOL(iounmap); 114