a7f8de168a
This relaxes the kernel Image placement requirements, so that it may be placed at any 2 MB aligned offset in physical memory. This is accomplished by ignoring PHYS_OFFSET when installing memblocks, and accounting for the apparent virtual offset of the kernel Image. As a result, virtual address references below PAGE_OFFSET are correctly mapped onto physical references into the kernel Image regardless of where it sits in memory. Special care needs to be taken for dealing with memory limits passed via mem=, since the generic implementation clips memory top down, which may clip the kernel image itself if it is loaded high up in memory. To deal with this case, we simply add back the memory covering the kernel image, which may result in more memory to be retained than was passed as a mem= parameter. Since mem= should not be considered a production feature, a panic notifier handler is installed that dumps the memory limit at panic time if one was set. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
197 lines
5.7 KiB
C
197 lines
5.7 KiB
C
/*
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* Based on arch/arm/include/asm/memory.h
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*
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* Copyright (C) 2000-2002 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Note: this file should not be included by non-asm/.h files
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*/
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#ifndef __ASM_MEMORY_H
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#define __ASM_MEMORY_H
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#include <linux/compiler.h>
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#include <linux/const.h>
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#include <linux/types.h>
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#include <asm/bug.h>
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#include <asm/sizes.h>
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/*
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* Allow for constants defined here to be used from assembly code
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* by prepending the UL suffix only with actual C code compilation.
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*/
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#define UL(x) _AC(x, UL)
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/*
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* Size of the PCI I/O space. This must remain a power of two so that
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* IO_SPACE_LIMIT acts as a mask for the low bits of I/O addresses.
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*/
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#define PCI_IO_SIZE SZ_16M
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/*
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* PAGE_OFFSET - the virtual address of the start of the kernel image (top
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* (VA_BITS - 1))
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* VA_BITS - the maximum number of bits for virtual addresses.
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* VA_START - the first kernel virtual address.
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* TASK_SIZE - the maximum size of a user space task.
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* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
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*/
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#define VA_BITS (CONFIG_ARM64_VA_BITS)
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#define VA_START (UL(0xffffffffffffffff) << VA_BITS)
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#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
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#define KIMAGE_VADDR (MODULES_END)
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#define MODULES_END (MODULES_VADDR + MODULES_VSIZE)
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#define MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE)
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#define MODULES_VSIZE (SZ_64M)
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#define PCI_IO_END (PAGE_OFFSET - SZ_2M)
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#define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE)
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#define FIXADDR_TOP (PCI_IO_START - SZ_2M)
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#define TASK_SIZE_64 (UL(1) << VA_BITS)
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#ifdef CONFIG_COMPAT
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#define TASK_SIZE_32 UL(0x100000000)
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#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
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TASK_SIZE_32 : TASK_SIZE_64)
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#define TASK_SIZE_OF(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT) ? \
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TASK_SIZE_32 : TASK_SIZE_64)
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#else
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#define TASK_SIZE TASK_SIZE_64
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#endif /* CONFIG_COMPAT */
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#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
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/*
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* The size of the KASAN shadow region. This should be 1/8th of the
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* size of the entire kernel virtual address space.
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*/
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#ifdef CONFIG_KASAN
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#define KASAN_SHADOW_SIZE (UL(1) << (VA_BITS - 3))
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#else
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#define KASAN_SHADOW_SIZE (0)
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#endif
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/*
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* Physical vs virtual RAM address space conversion. These are
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* private definitions which should NOT be used outside memory.h
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* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
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*/
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#define __virt_to_phys(x) ({ \
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phys_addr_t __x = (phys_addr_t)(x); \
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__x >= PAGE_OFFSET ? (__x - PAGE_OFFSET + PHYS_OFFSET) : \
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(__x - kimage_voffset); })
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#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
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#define __phys_to_kimg(x) ((unsigned long)((x) + kimage_voffset))
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/*
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* Convert a page to/from a physical address
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*/
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#define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
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#define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys)))
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/*
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* Memory types available.
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*/
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#define MT_DEVICE_nGnRnE 0
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#define MT_DEVICE_nGnRE 1
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#define MT_DEVICE_GRE 2
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#define MT_NORMAL_NC 3
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#define MT_NORMAL 4
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#define MT_NORMAL_WT 5
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/*
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* Memory types for Stage-2 translation
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*/
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#define MT_S2_NORMAL 0xf
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#define MT_S2_DEVICE_nGnRE 0x1
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#ifdef CONFIG_ARM64_4K_PAGES
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#define IOREMAP_MAX_ORDER (PUD_SHIFT)
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#else
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#define IOREMAP_MAX_ORDER (PMD_SHIFT)
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#endif
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#ifdef CONFIG_BLK_DEV_INITRD
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#define __early_init_dt_declare_initrd(__start, __end) \
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do { \
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initrd_start = (__start); \
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initrd_end = (__end); \
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} while (0)
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#endif
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#ifndef __ASSEMBLY__
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extern phys_addr_t memstart_addr;
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/* PHYS_OFFSET - the physical address of the start of memory. */
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#define PHYS_OFFSET ({ BUG_ON(memstart_addr & 1); memstart_addr; })
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/* the offset between the kernel virtual and physical mappings */
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extern u64 kimage_voffset;
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/*
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* Allow all memory at the discovery stage. We will clip it later.
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*/
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#define MIN_MEMBLOCK_ADDR 0
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#define MAX_MEMBLOCK_ADDR U64_MAX
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/*
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* PFNs are used to describe any physical page; this means
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* PFN 0 == physical address 0.
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*
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* This is the PFN of the first RAM page in the kernel
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* direct-mapped view. We assume this is the first page
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* of RAM in the mem_map as well.
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*/
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#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
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/*
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* Note: Drivers should NOT use these. They are the wrong
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* translation for translating DMA addresses. Use the driver
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* DMA support - see dma-mapping.h.
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*/
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#define virt_to_phys virt_to_phys
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static inline phys_addr_t virt_to_phys(const volatile void *x)
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{
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return __virt_to_phys((unsigned long)(x));
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}
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#define phys_to_virt phys_to_virt
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static inline void *phys_to_virt(phys_addr_t x)
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{
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return (void *)(__phys_to_virt(x));
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}
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/*
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* Drivers should NOT use these either.
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*/
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#define __pa(x) __virt_to_phys((unsigned long)(x))
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#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
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#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
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#define virt_to_pfn(x) __phys_to_pfn(__virt_to_phys(x))
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/*
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* virt_to_page(k) convert a _valid_ virtual address to struct page *
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* virt_addr_valid(k) indicates whether a virtual address is valid
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*/
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#define ARCH_PFN_OFFSET ((unsigned long)PHYS_PFN_OFFSET)
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#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
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#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
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#endif
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#include <asm-generic/memory_model.h>
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#endif
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