cregit-Linux how code gets into the kernel

Release 4.14 arch/score/include/asm/mmu_context.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_SCORE_MMU_CONTEXT_H

#define _ASM_SCORE_MMU_CONTEXT_H

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm_types.h>
#include <linux/slab.h>

#include <asm-generic/mm_hooks.h>

#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/scoreregs.h>

/*
 * For the fast tlb miss handlers, we keep a per cpu array of pointers
 * to the current pgd for each processor. Also, the proc. id is stuffed
 * into the context register.
 */
extern unsigned long asid_cache;
extern unsigned long pgd_current;


#define TLBMISS_HANDLER_SETUP_PGD(pgd) (pgd_current = (unsigned long)(pgd))


#define TLBMISS_HANDLER_SETUP()				\
do {                                                    \
        write_c0_context(0);                            \
        TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)       \
} while (0)

/*
 * All unused by hardware upper bits will be considered
 * as a software asid extension.
 */

#define ASID_VERSION_MASK	0xfffff000

#define ASID_FIRST_VERSION	0x1000

/* PEVN    --------- VPN ---------- --ASID--- -NA- */
/* binary: 0000 0000 0000 0000 0000 0000 0001 0000 */
/* binary: 0000 0000 0000 0000 0000 1111 1111 0000 */

#define ASID_INC	0x10

#define ASID_MASK	0xff0


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

Contributors

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Chen Liqin16100.00%1100.00%
Total16100.00%1100.00%


static inline void get_new_mmu_context(struct mm_struct *mm) { unsigned long asid = asid_cache + ASID_INC; if (!(asid & ASID_MASK)) { local_flush_tlb_all(); /* start new asid cycle */ if (!asid) /* fix version if needed */ asid = ASID_FIRST_VERSION; } mm->context = asid; asid_cache = asid; }

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Chen Liqin55100.00%1100.00%
Total55100.00%1100.00%

/* * Initialize the context related info for a new mm_struct * instance. */
static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { mm->context = 0; return 0; }

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Chen Liqin26100.00%1100.00%
Total26100.00%1100.00%


static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { unsigned long flags; local_irq_save(flags); if ((next->context ^ asid_cache) & ASID_VERSION_MASK) get_new_mmu_context(next); pevn_set(next->context); TLBMISS_HANDLER_SETUP_PGD(next->pgd); local_irq_restore(flags); }

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Chen Liqin67100.00%1100.00%
Total67100.00%1100.00%

/* * Destroy context related info for an mm_struct that is about * to be put to rest. */
static inline void destroy_context(struct mm_struct *mm) {}

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Chen Liqin11100.00%1100.00%
Total11100.00%1100.00%


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

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Chen Liqin16100.00%1100.00%
Total16100.00%1100.00%

/* * After we have set current->mm to a new value, this activates * the context for the new mm so we see the new mappings. */
static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next) { unsigned long flags; local_irq_save(flags); get_new_mmu_context(next); pevn_set(next->context); TLBMISS_HANDLER_SETUP_PGD(next->pgd); local_irq_restore(flags); }

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Chen Liqin50100.00%1100.00%
Total50100.00%1100.00%

#endif /* _ASM_SCORE_MMU_CONTEXT_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Chen Liqin31898.76%133.33%
Ingo Molnar30.93%133.33%
Greg Kroah-Hartman10.31%133.33%
Total322100.00%3100.00%
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