
So far all arm64 devices have supported 32 bit DMA masks for their peripherals. This is not true anymore for the Raspberry Pi 4 as most of it's peripherals can only address the first GB of memory on a total of up to 4 GB. This goes against ZONE_DMA32's intent, as it's expected for ZONE_DMA32 to be addressable with a 32 bit mask. So it was decided to re-introduce ZONE_DMA in arm64. ZONE_DMA will contain the lower 1G of memory, which is currently the memory area addressable by any peripheral on an arm64 device. ZONE_DMA32 will contain the rest of the 32 bit addressable memory. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
44 lines
1.1 KiB
C
44 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Based on arch/arm/include/asm/page.h
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*
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* Copyright (C) 1995-2003 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*/
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#ifndef __ASM_PAGE_H
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#define __ASM_PAGE_H
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#include <asm/page-def.h>
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#ifndef __ASSEMBLY__
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#include <linux/personality.h> /* for READ_IMPLIES_EXEC */
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#include <asm/pgtable-types.h>
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extern void __cpu_clear_user_page(void *p, unsigned long user);
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extern void __cpu_copy_user_page(void *to, const void *from,
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unsigned long user);
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extern void copy_page(void *to, const void *from);
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extern void clear_page(void *to);
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#define clear_user_page(addr,vaddr,pg) __cpu_clear_user_page(addr, vaddr)
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#define copy_user_page(to,from,vaddr,pg) __cpu_copy_user_page(to, from, vaddr)
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typedef struct page *pgtable_t;
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extern int pfn_valid(unsigned long);
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#include <asm/memory.h>
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#endif /* !__ASSEMBLY__ */
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#define VM_DATA_DEFAULT_FLAGS \
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(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
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VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
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#include <asm-generic/getorder.h>
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#define ARCH_ZONE_DMA_BITS 30
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#endif
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