1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 4 */ 5 6 #include <linux/vmalloc.h> 7 #include <linux/init.h> 8 #include <linux/module.h> 9 #include <linux/io.h> 10 #include <linux/mm.h> 11 #include <linux/cache.h> 12 13 static inline bool arc_uncached_addr_space(phys_addr_t paddr) 14 { 15 if (is_isa_arcompact()) { 16 if (paddr >= ARC_UNCACHED_ADDR_SPACE) 17 return true; 18 } else if (paddr >= perip_base && paddr <= perip_end) { 19 return true; 20 } 21 22 return false; 23 } 24 25 void __iomem *ioremap(phys_addr_t paddr, unsigned long size) 26 { 27 /* 28 * If the region is h/w uncached, MMU mapping can be elided as optim 29 * The cast to u32 is fine as this region can only be inside 4GB 30 */ 31 if (arc_uncached_addr_space(paddr)) 32 return (void __iomem *)(u32)paddr; 33 34 return ioremap_prot(paddr, size, 35 pgprot_val(pgprot_noncached(PAGE_KERNEL))); 36 } 37 EXPORT_SYMBOL(ioremap); 38 39 /* 40 * ioremap with access flags 41 * Cache semantics wise it is same as ioremap - "forced" uncached. 42 * However unlike vanilla ioremap which bypasses ARC MMU for addresses in 43 * ARC hardware uncached region, this one still goes thru the MMU as caller 44 * might need finer access control (R/W/X) 45 */ 46 void __iomem *ioremap_prot(phys_addr_t paddr, size_t size, 47 unsigned long flags) 48 { 49 pgprot_t prot = __pgprot(flags); 50 51 /* force uncached */ 52 return generic_ioremap_prot(paddr, size, pgprot_noncached(prot)); 53 } 54 EXPORT_SYMBOL(ioremap_prot); 55 56 void iounmap(volatile void __iomem *addr) 57 { 58 /* weird double cast to handle phys_addr_t > 32 bits */ 59 if (arc_uncached_addr_space((phys_addr_t)(u32)addr)) 60 return; 61 62 generic_iounmap(addr); 63 } 64 EXPORT_SYMBOL(iounmap); 65