dab78b6dcb
Every other architecture with permanent fixed addresses has FIX_HOLE as the first entry. This seems to be designed as a debugging aid but there are a couple of side effects of not having FIX_HOLE: - If the first fixed address is 0, fix_to_virt -> virt_to_fix triggers a BUG_ON for the virtual address being equal to FIXADDR_TOP - fix_to_virt may return a value outside of FIXADDR_START and FIXADDR_TOP which may look like a bug to a developer. Match up with other architectures and make everything clearer by adding FIX_HOLE. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
69 lines
1.8 KiB
C
69 lines
1.8 KiB
C
/*
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* fixmap.h: compile-time virtual memory allocation
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1998 Ingo Molnar
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* Copyright (C) 2013 Mark Salter <msalter@redhat.com>
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*
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* Adapted from arch/x86_64 version.
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*
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*/
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#ifndef _ASM_ARM64_FIXMAP_H
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#define _ASM_ARM64_FIXMAP_H
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#ifndef __ASSEMBLY__
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#include <linux/kernel.h>
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#include <asm/page.h>
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/*
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* Here we define all the compile-time 'special' virtual
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* addresses. The point is to have a constant address at
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* compile time, but to set the physical address only
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* in the boot process.
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*
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* These 'compile-time allocated' memory buffers are
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* page-sized. Use set_fixmap(idx,phys) to associate
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* physical memory with fixmap indices.
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*
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*/
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enum fixed_addresses {
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FIX_HOLE,
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FIX_EARLYCON_MEM_BASE,
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__end_of_permanent_fixed_addresses,
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/*
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* Temporary boot-time mappings, used by early_ioremap(),
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* before ioremap() is functional.
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*/
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#ifdef CONFIG_ARM64_64K_PAGES
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#define NR_FIX_BTMAPS 4
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#else
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#define NR_FIX_BTMAPS 64
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#endif
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#define FIX_BTMAPS_SLOTS 7
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#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
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FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
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FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
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__end_of_fixed_addresses
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};
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#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
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#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
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#define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
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void __init early_fixmap_init(void);
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#define __early_set_fixmap __set_fixmap
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extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
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#include <asm-generic/fixmap.h>
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_ARM64_FIXMAP_H */
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