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