1 /* 2 * arch/sh/mm/ioremap.c 3 * 4 * (C) Copyright 1995 1996 Linus Torvalds 5 * (C) Copyright 2005 - 2010 Paul Mundt 6 * 7 * Re-map IO memory to kernel address space so that we can access it. 8 * This is needed for high PCI addresses that aren't mapped in the 9 * 640k-1MB IO memory area on PC's 10 * 11 * This file is subject to the terms and conditions of the GNU General 12 * Public License. See the file "COPYING" in the main directory of this 13 * archive for more details. 14 */ 15 #include <linux/vmalloc.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/mm.h> 19 #include <linux/pci.h> 20 #include <linux/io.h> 21 #include <asm/io_trapped.h> 22 #include <asm/page.h> 23 #include <asm/pgalloc.h> 24 #include <asm/addrspace.h> 25 #include <asm/cacheflush.h> 26 #include <asm/tlbflush.h> 27 #include <asm/mmu.h> 28 #include "ioremap.h" 29 30 /* 31 * On 32-bit SH, we traditionally have the whole physical address space mapped 32 * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do 33 * anything but place the address in the proper segment. This is true for P1 34 * and P2 addresses, as well as some P3 ones. However, most of the P3 addresses 35 * and newer cores using extended addressing need to map through page tables, so 36 * the ioremap() implementation becomes a bit more complicated. 37 */ 38 #ifdef CONFIG_29BIT 39 static void __iomem * 40 __ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot) 41 { 42 phys_addr_t last_addr = offset + size - 1; 43 44 /* 45 * For P1 and P2 space this is trivial, as everything is already 46 * mapped. Uncached access for P1 addresses are done through P2. 47 * In the P3 case or for addresses outside of the 29-bit space, 48 * mapping must be done by the PMB or by using page tables. 49 */ 50 if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) { 51 u64 flags = pgprot_val(prot); 52 53 /* 54 * Anything using the legacy PTEA space attributes needs 55 * to be kicked down to page table mappings. 56 */ 57 if (unlikely(flags & _PAGE_PCC_MASK)) 58 return NULL; 59 if (unlikely(flags & _PAGE_CACHABLE)) 60 return (void __iomem *)P1SEGADDR(offset); 61 62 return (void __iomem *)P2SEGADDR(offset); 63 } 64 65 /* P4 above the store queues are always mapped. */ 66 if (unlikely(offset >= P3_ADDR_MAX)) 67 return (void __iomem *)P4SEGADDR(offset); 68 69 return NULL; 70 } 71 #else 72 #define __ioremap_29bit(offset, size, prot) NULL 73 #endif /* CONFIG_29BIT */ 74 75 void __iomem __ref *ioremap_prot(phys_addr_t phys_addr, size_t size, 76 unsigned long prot) 77 { 78 void __iomem *mapped; 79 pgprot_t pgprot = __pgprot(prot); 80 81 mapped = __ioremap_trapped(phys_addr, size); 82 if (mapped) 83 return mapped; 84 85 mapped = __ioremap_29bit(phys_addr, size, pgprot); 86 if (mapped) 87 return mapped; 88 89 /* 90 * If we can't yet use the regular approach, go the fixmap route. 91 */ 92 if (!mem_init_done) 93 return ioremap_fixed(phys_addr, size, pgprot); 94 95 /* 96 * First try to remap through the PMB. 97 * PMB entries are all pre-faulted. 98 */ 99 mapped = pmb_remap_caller(phys_addr, size, pgprot, 100 __builtin_return_address(0)); 101 if (mapped && !IS_ERR(mapped)) 102 return mapped; 103 104 return generic_ioremap_prot(phys_addr, size, pgprot); 105 } 106 EXPORT_SYMBOL(ioremap_prot); 107 108 /* 109 * Simple checks for non-translatable mappings. 110 */ 111 static inline int iomapping_nontranslatable(unsigned long offset) 112 { 113 #ifdef CONFIG_29BIT 114 /* 115 * In 29-bit mode this includes the fixed P1/P2 areas, as well as 116 * parts of P3. 117 */ 118 if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX) 119 return 1; 120 #endif 121 122 return 0; 123 } 124 125 void iounmap(volatile void __iomem *addr) 126 { 127 unsigned long vaddr = (unsigned long __force)addr; 128 129 /* 130 * Nothing to do if there is no translatable mapping. 131 */ 132 if (iomapping_nontranslatable(vaddr)) 133 return; 134 135 /* 136 * There's no VMA if it's from an early fixed mapping. 137 */ 138 if (iounmap_fixed((void __iomem *)addr) == 0) 139 return; 140 141 /* 142 * If the PMB handled it, there's nothing else to do. 143 */ 144 if (pmb_unmap((void __iomem *)addr) == 0) 145 return; 146 147 generic_iounmap(addr); 148 } 149 EXPORT_SYMBOL(iounmap); 150