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![Michael Ellerman](/assets/img/avatar_default.png)
We added checks to __pa() / __va() to ensure they're only called with
appropriate addresses. But using BUG_ON() is too strong, it means
virt_addr_valid() will BUG when DEBUG_VIRTUAL is enabled.
Instead switch them to warnings, arm64 does the same.
Fixes: 4dd7554a64
("powerpc/64: Add VIRTUAL_BUG_ON checks for __va and __pa addresses")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220406145802.538416-5-mpe@ellerman.id.au
340 lines
10 KiB
C
340 lines
10 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#ifndef _ASM_POWERPC_PAGE_H
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#define _ASM_POWERPC_PAGE_H
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/*
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* Copyright (C) 2001,2005 IBM Corporation.
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*/
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <linux/kernel.h>
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#else
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#include <asm/types.h>
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#endif
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#include <asm/asm-const.h>
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/*
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* On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
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* on PPC44x and 4K/16K on 8xx). For PPC64 we support either 4K or 64K software
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* page size. When using 64K pages however, whether we are really supporting
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* 64K pages in HW or not is irrelevant to those definitions.
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*/
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#define PAGE_SHIFT CONFIG_PPC_PAGE_SHIFT
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#define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
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#ifndef __ASSEMBLY__
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#ifndef CONFIG_HUGETLB_PAGE
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#define HPAGE_SHIFT PAGE_SHIFT
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#elif defined(CONFIG_PPC_BOOK3S_64)
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extern unsigned int hpage_shift;
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#define HPAGE_SHIFT hpage_shift
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#elif defined(CONFIG_PPC_8xx)
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#define HPAGE_SHIFT 19 /* 512k pages */
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#elif defined(CONFIG_PPC_FSL_BOOK3E)
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#define HPAGE_SHIFT 22 /* 4M pages */
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#endif
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#define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
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#define HPAGE_MASK (~(HPAGE_SIZE - 1))
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#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
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#define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1)
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#endif
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/*
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* Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
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* assign PAGE_MASK to a larger type it gets extended the way we want
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* (i.e. with 1s in the high bits)
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*/
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#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
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/*
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* KERNELBASE is the virtual address of the start of the kernel, it's often
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* the same as PAGE_OFFSET, but _might not be_.
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*
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* The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
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*
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* PAGE_OFFSET is the virtual address of the start of lowmem.
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*
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* PHYSICAL_START is the physical address of the start of the kernel.
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*
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* MEMORY_START is the physical address of the start of lowmem.
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*
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* KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
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* ppc32 and based on how they are set we determine MEMORY_START.
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*
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* For the linear mapping the following equation should be true:
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* KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
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*
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* Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
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*
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* There are two ways to determine a physical address from a virtual one:
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* va = pa + PAGE_OFFSET - MEMORY_START
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* va = pa + KERNELBASE - PHYSICAL_START
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*
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* If you want to know something's offset from the start of the kernel you
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* should subtract KERNELBASE.
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*
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* If you want to test if something's a kernel address, use is_kernel_addr().
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*/
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#define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
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#define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
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#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
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#if defined(CONFIG_NONSTATIC_KERNEL)
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#ifndef __ASSEMBLY__
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extern phys_addr_t memstart_addr;
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extern phys_addr_t kernstart_addr;
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#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC32)
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extern long long virt_phys_offset;
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#endif
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#endif /* __ASSEMBLY__ */
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#define PHYSICAL_START kernstart_addr
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#else /* !CONFIG_NONSTATIC_KERNEL */
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#define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
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#endif
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/* See Description below for VIRT_PHYS_OFFSET */
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#if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
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#ifdef CONFIG_RELOCATABLE
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#define VIRT_PHYS_OFFSET virt_phys_offset
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#else
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#define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
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#endif
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#endif
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#ifdef CONFIG_PPC64
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#define MEMORY_START 0UL
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#elif defined(CONFIG_NONSTATIC_KERNEL)
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#define MEMORY_START memstart_addr
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#else
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#define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
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#endif
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#ifdef CONFIG_FLATMEM
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#define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
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#ifndef __ASSEMBLY__
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extern unsigned long max_mapnr;
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static inline bool pfn_valid(unsigned long pfn)
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{
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unsigned long min_pfn = ARCH_PFN_OFFSET;
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return pfn >= min_pfn && pfn < max_mapnr;
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}
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#endif
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#endif
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#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
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#define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
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#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
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#define virt_addr_valid(vaddr) ({ \
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unsigned long _addr = (unsigned long)vaddr; \
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_addr >= PAGE_OFFSET && _addr < (unsigned long)high_memory && \
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pfn_valid(virt_to_pfn(_addr)); \
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})
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/*
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* On Book-E parts we need __va to parse the device tree and we can't
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* determine MEMORY_START until then. However we can determine PHYSICAL_START
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* from information at hand (program counter, TLB lookup).
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*
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* On BookE with RELOCATABLE && PPC32
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*
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* With RELOCATABLE && PPC32, we support loading the kernel at any physical
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* address without any restriction on the page alignment.
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*
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* We find the runtime address of _stext and relocate ourselves based on
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* the following calculation:
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*
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* virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
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* MODULO(_stext.run,256M)
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* and create the following mapping:
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*
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* ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
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*
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* When we process relocations, we cannot depend on the
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* existing equation for the __va()/__pa() translations:
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*
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* __va(x) = (x) - PHYSICAL_START + KERNELBASE
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*
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* Where:
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* PHYSICAL_START = kernstart_addr = Physical address of _stext
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* KERNELBASE = Compiled virtual address of _stext.
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*
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* This formula holds true iff, kernel load address is TLB page aligned.
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*
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* In our case, we need to also account for the shift in the kernel Virtual
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* address.
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*
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* E.g.,
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*
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* Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
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* In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
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*
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* Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
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* = 0xbc100000 , which is wrong.
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*
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* Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
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* according to our mapping.
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*
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* Hence we use the following formula to get the translations right:
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*
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* __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
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*
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* Where :
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* PHYSICAL_START = dynamic load address.(kernstart_addr variable)
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* Effective KERNELBASE = virtual_base =
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* = ALIGN_DOWN(KERNELBASE,256M) +
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* MODULO(PHYSICAL_START,256M)
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*
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* To make the cost of __va() / __pa() more light weight, we introduce
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* a new variable virt_phys_offset, which will hold :
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*
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* virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
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* = ALIGN_DOWN(KERNELBASE,256M) -
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* ALIGN_DOWN(PHYSICALSTART,256M)
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*
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* Hence :
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*
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* __va(x) = x - PHYSICAL_START + Effective KERNELBASE
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* = x + virt_phys_offset
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*
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* and
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* __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
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* = x - virt_phys_offset
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*
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* On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
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* the other definitions for __va & __pa.
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*/
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#if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
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#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
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#define __pa(x) ((phys_addr_t)(unsigned long)(x) - VIRT_PHYS_OFFSET)
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#else
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#ifdef CONFIG_PPC64
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#define VIRTUAL_WARN_ON(x) WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x))
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/*
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* gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
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* with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
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* This also results in better code generation.
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*/
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#define __va(x) \
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({ \
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VIRTUAL_WARN_ON((unsigned long)(x) >= PAGE_OFFSET); \
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(void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET); \
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})
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#define __pa(x) \
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({ \
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VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET); \
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(unsigned long)(x) & 0x0fffffffffffffffUL; \
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})
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#else /* 32-bit, non book E */
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#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
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#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
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#endif
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#endif
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/*
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* Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
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* and needs to be executable. This means the whole heap ends
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* up being executable.
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*/
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#define VM_DATA_DEFAULT_FLAGS32 VM_DATA_FLAGS_TSK_EXEC
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#define VM_DATA_DEFAULT_FLAGS64 VM_DATA_FLAGS_NON_EXEC
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#ifdef __powerpc64__
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#include <asm/page_64.h>
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#else
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#include <asm/page_32.h>
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#endif
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/*
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* Don't compare things with KERNELBASE or PAGE_OFFSET to test for
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* "kernelness", use is_kernel_addr() - it should do what you want.
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*/
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#ifdef CONFIG_PPC_BOOK3E_64
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#define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
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#elif defined(CONFIG_PPC_BOOK3S_64)
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#define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
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#else
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#define is_kernel_addr(x) ((x) >= TASK_SIZE)
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#endif
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#ifndef CONFIG_PPC_BOOK3S_64
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/*
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* Use the top bit of the higher-level page table entries to indicate whether
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* the entries we point to contain hugepages. This works because we know that
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* the page tables live in kernel space. If we ever decide to support having
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* page tables at arbitrary addresses, this breaks and will have to change.
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*/
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#ifdef CONFIG_PPC64
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#define PD_HUGE 0x8000000000000000UL
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#else
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#define PD_HUGE 0x80000000
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#endif
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#else /* CONFIG_PPC_BOOK3S_64 */
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/*
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* Book3S 64 stores real addresses in the hugepd entries to
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* avoid overlaps with _PAGE_PRESENT and _PAGE_PTE.
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*/
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#define HUGEPD_ADDR_MASK (0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK)
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#endif /* CONFIG_PPC_BOOK3S_64 */
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/*
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* Some number of bits at the level of the page table that points to
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* a hugepte are used to encode the size. This masks those bits.
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* On 8xx, HW assistance requires 4k alignment for the hugepte.
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*/
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#ifdef CONFIG_PPC_8xx
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#define HUGEPD_SHIFT_MASK 0xfff
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#else
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#define HUGEPD_SHIFT_MASK 0x3f
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#endif
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_PPC_BOOK3S_64
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#include <asm/pgtable-be-types.h>
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#else
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#include <asm/pgtable-types.h>
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#endif
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#ifndef CONFIG_HUGETLB_PAGE
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#define is_hugepd(pdep) (0)
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#define pgd_huge(pgd) (0)
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#endif /* CONFIG_HUGETLB_PAGE */
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struct page;
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extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
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extern void copy_user_page(void *to, void *from, unsigned long vaddr,
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struct page *p);
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extern int devmem_is_allowed(unsigned long pfn);
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#ifdef CONFIG_PPC_SMLPAR
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void arch_free_page(struct page *page, int order);
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#define HAVE_ARCH_FREE_PAGE
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#endif
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struct vm_area_struct;
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extern unsigned long kernstart_virt_addr;
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static inline unsigned long kaslr_offset(void)
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{
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return kernstart_virt_addr - KERNELBASE;
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}
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#include <asm-generic/memory_model.h>
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_POWERPC_PAGE_H */
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