cregit-Linux how code gets into the kernel

Release 4.15 arch/riscv/include/asm/mmu_context.h

/*
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2017 SiFive
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 */

#ifndef _ASM_RISCV_MMU_CONTEXT_H

#define _ASM_RISCV_MMU_CONTEXT_H

#include <linux/mm_types.h>
#include <asm-generic/mm_hooks.h>

#include <linux/mm.h>
#include <linux/sched.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>


static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *task) { }

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Palmer Dabbelt16100.00%1100.00%
Total16100.00%1100.00%

/* Initialize context-related info for a new mm_struct */
static inline int init_new_context(struct task_struct *task, struct mm_struct *mm) { return 0; }

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Palmer Dabbelt20100.00%1100.00%
Total20100.00%1100.00%


static inline void destroy_context(struct mm_struct *mm) { }

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Palmer Dabbelt11100.00%1100.00%
Total11100.00%1100.00%


static inline pgd_t *current_pgdir(void) { return pfn_to_virt(csr_read(sptbr) & SPTBR_PPN); }

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Palmer Dabbelt21100.00%1100.00%
Total21100.00%1100.00%


static inline void set_pgdir(pgd_t *pgd) { csr_write(sptbr, virt_to_pfn(pgd) | SPTBR_MODE); }

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Palmer Dabbelt23100.00%1100.00%
Total23100.00%1100.00%

/* * When necessary, performs a deferred icache flush for the given MM context, * on the local CPU. RISC-V has no direct mechanism for instruction cache * shoot downs, so instead we send an IPI that informs the remote harts they * need to flush their local instruction caches. To avoid pathologically slow * behavior in a common case (a bunch of single-hart processes on a many-hart * machine, ie 'make -j') we avoid the IPIs for harts that are not currently * executing a MM context and instead schedule a deferred local instruction * cache flush to be performed before execution resumes on each hart. This * actually performs that local instruction cache flush, which implicitly only * refers to the current hart. */
static inline void flush_icache_deferred(struct mm_struct *mm) { #ifdef CONFIG_SMP unsigned int cpu = smp_processor_id(); cpumask_t *mask = &mm->context.icache_stale_mask; if (cpumask_test_cpu(cpu, mask)) { cpumask_clear_cpu(cpu, mask); /* * Ensure the remote hart's writes are visible to this hart. * This pairs with a barrier in flush_icache_mm. */ smp_mb(); local_flush_icache_all(); } #endif }

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Andrew Waterman60100.00%1100.00%
Total60100.00%1100.00%


static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *task) { if (likely(prev != next)) { /* * Mark the current MM context as inactive, and the next as * active. This is at least used by the icache flushing * routines in order to determine who should */ unsigned int cpu = smp_processor_id(); cpumask_clear_cpu(cpu, mm_cpumask(prev)); cpumask_set_cpu(cpu, mm_cpumask(next)); set_pgdir(next->pgd); local_flush_tlb_all(); flush_icache_deferred(next); } }

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Palmer Dabbelt4356.58%150.00%
Andrew Waterman3343.42%150.00%
Total76100.00%2100.00%


static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next) { switch_mm(prev, next, NULL); }

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Palmer Dabbelt26100.00%1100.00%
Total26100.00%1100.00%


static inline void deactivate_mm(struct task_struct *task, struct mm_struct *mm) { }

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Palmer Dabbelt16100.00%1100.00%
Total16100.00%1100.00%

#endif /* _ASM_RISCV_MMU_CONTEXT_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Palmer Dabbelt19866.22%133.33%
Andrew Waterman9832.78%133.33%
Olof Johansson31.00%133.33%
Total299100.00%3100.00%
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