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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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45890f6d34
Implement kmap* API for ARC. This enables - permanent kernel maps (pkmaps): :kmap() API - fixmap : kmap_atomic() We use a very simple/uniform approach for both (unlike some of the other arches). So fixmap doesn't use the customary compile time address stuff. The important semantic is sleep'ability (pkmap) vs. not (fixmap) which the API guarantees. Note that this patch only enables highmem for subsequent PAE40 support as there is no real highmem for ARC in pure 32-bit paradigm as explained below. ARC has 2:2 address split of the 32-bit address space with lower half being translated (virtual) while upper half unstranslated (0x8000_0000 to 0xFFFF_FFFF). kernel itself is linked at base of unstranslated space (i.e. 0x8000_0000 onwards), which is mapped to say DDR 0x0 by external Bus Glue logic (outside the core). So kernel can potentially access 1.75G worth of memory directly w/o need for highmem. (the top 256M is taken by uncached peripheral space from 0xF000_0000 to 0xFFFF_FFFF) In PAE40, hardware can address memory beyond 4G (0x1_0000_0000) while the logical/virtual addresses remain 32-bits. Thus highmem is required for kernel proper to be able to access these pages for it's own purposes (user space is agnostic to this anyways). Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
138 lines
3.9 KiB
C
138 lines
3.9 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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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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* vineetg: March 2009
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* -Implemented task_pt_regs( )
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*
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* Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
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*/
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#ifndef __ASM_ARC_PROCESSOR_H
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#define __ASM_ARC_PROCESSOR_H
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#ifndef __ASSEMBLY__
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#include <asm/ptrace.h>
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#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
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/* These DPFP regs need to be saved/restored across ctx-sw */
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struct arc_fpu {
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struct {
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unsigned int l, h;
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} aux_dpfp[2];
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};
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#endif
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/* Arch specific stuff which needs to be saved per task.
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* However these items are not so important so as to earn a place in
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* struct thread_info
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*/
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struct thread_struct {
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unsigned long ksp; /* kernel mode stack pointer */
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unsigned long callee_reg; /* pointer to callee regs */
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unsigned long fault_address; /* dbls as brkpt holder as well */
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#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
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struct arc_fpu fpu;
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#endif
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};
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#define INIT_THREAD { \
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.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
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}
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/* Forward declaration, a strange C thing */
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struct task_struct;
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#define task_pt_regs(p) \
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((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
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/* Free all resources held by a thread */
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#define release_thread(thread) do { } while (0)
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/*
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* A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
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* get optimised away by gcc
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*/
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#ifdef CONFIG_SMP
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#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
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#else
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#define cpu_relax() do { } while (0)
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#endif
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#define cpu_relax_lowlatency() cpu_relax()
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#define copy_segments(tsk, mm) do { } while (0)
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#define release_segments(mm) do { } while (0)
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#define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret)
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#define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
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/*
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* Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
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* Look in process.c for details of kernel stack layout
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*/
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#define TSK_K_ESP(tsk) (tsk->thread.ksp)
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#define TSK_K_REG(tsk, off) (*((unsigned long *)(TSK_K_ESP(tsk) + \
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sizeof(struct callee_regs) + off)))
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#define TSK_K_BLINK(tsk) TSK_K_REG(tsk, 4)
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#define TSK_K_FP(tsk) TSK_K_REG(tsk, 0)
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#define thread_saved_pc(tsk) TSK_K_BLINK(tsk)
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extern void start_thread(struct pt_regs * regs, unsigned long pc,
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unsigned long usp);
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extern unsigned int get_wchan(struct task_struct *p);
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/*
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* Default implementation of macro that returns current
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* instruction pointer ("program counter").
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* Should the PC register be read instead ? This macro does not seem to
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* be used in many places so this wont be all that bad.
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*/
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#define current_text_addr() ({ __label__ _l; _l: &&_l; })
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#endif /* !__ASSEMBLY__ */
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/*
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* System Memory Map on ARC
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*
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* ---------------------------- (lower 2G, Translated) -------------------------
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* 0x0000_0000 0x5FFF_FFFF (user vaddr: TASK_SIZE)
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* 0x6000_0000 0x6FFF_FFFF (reserved gutter between U/K)
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* 0x7000_0000 0x7FFF_FFFF (kvaddr: vmalloc/modules/pkmap..)
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*
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* PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
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* 0x8000_0000 0xBFFF_FFFF (kernel direct mapped)
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* 0xC000_0000 0xFFFF_FFFF (peripheral uncached space)
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* -----------------------------------------------------------------------------
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*/
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#define VMALLOC_START 0x70000000
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/*
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* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter
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* See asm/highmem.h for details
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*/
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#define VMALLOC_SIZE (PAGE_OFFSET - VMALLOC_START - PGDIR_SIZE * 4)
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#define VMALLOC_END (VMALLOC_START + VMALLOC_SIZE)
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#define USER_KERNEL_GUTTER 0x10000000
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#define TASK_SIZE (VMALLOC_START - USER_KERNEL_GUTTER)
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#define STACK_TOP TASK_SIZE
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#define STACK_TOP_MAX STACK_TOP
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/* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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*/
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#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
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#endif /* __ASM_ARC_PROCESSOR_H */
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