cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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mmu_context.h (2430B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef __PARISC_MMU_CONTEXT_H
      3#define __PARISC_MMU_CONTEXT_H
      4
      5#include <linux/mm.h>
      6#include <linux/sched.h>
      7#include <linux/atomic.h>
      8#include <linux/spinlock.h>
      9#include <asm-generic/mm_hooks.h>
     10
     11/* on PA-RISC, we actually have enough contexts to justify an allocator
     12 * for them.  prumpf */
     13
     14extern unsigned long alloc_sid(void);
     15extern void free_sid(unsigned long);
     16
     17#define init_new_context init_new_context
     18static inline int
     19init_new_context(struct task_struct *tsk, struct mm_struct *mm)
     20{
     21	BUG_ON(atomic_read(&mm->mm_users) != 1);
     22
     23	mm->context.space_id = alloc_sid();
     24	return 0;
     25}
     26
     27#define destroy_context destroy_context
     28static inline void
     29destroy_context(struct mm_struct *mm)
     30{
     31	free_sid(mm->context.space_id);
     32	mm->context.space_id = 0;
     33}
     34
     35static inline unsigned long __space_to_prot(mm_context_t context)
     36{
     37#if SPACEID_SHIFT == 0
     38	return context.space_id << 1;
     39#else
     40	return context.space_id >> (SPACEID_SHIFT - 1);
     41#endif
     42}
     43
     44static inline void load_context(mm_context_t context)
     45{
     46	mtsp(context.space_id, SR_USER);
     47	mtctl(__space_to_prot(context), 8);
     48}
     49
     50static inline void switch_mm_irqs_off(struct mm_struct *prev,
     51		struct mm_struct *next, struct task_struct *tsk)
     52{
     53	if (prev != next) {
     54#ifdef CONFIG_TLB_PTLOCK
     55		/* put physical address of page_table_lock in cr28 (tr4)
     56		   for TLB faults */
     57		spinlock_t *pgd_lock = &next->page_table_lock;
     58		mtctl(__pa(__ldcw_align(&pgd_lock->rlock.raw_lock)), 28);
     59#endif
     60		mtctl(__pa(next->pgd), 25);
     61		load_context(next->context);
     62	}
     63}
     64
     65static inline void switch_mm(struct mm_struct *prev,
     66		struct mm_struct *next, struct task_struct *tsk)
     67{
     68	unsigned long flags;
     69
     70	if (prev == next)
     71		return;
     72
     73	local_irq_save(flags);
     74	switch_mm_irqs_off(prev, next, tsk);
     75	local_irq_restore(flags);
     76}
     77#define switch_mm_irqs_off switch_mm_irqs_off
     78
     79#define activate_mm activate_mm
     80static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
     81{
     82	/*
     83	 * Activate_mm is our one chance to allocate a space id
     84	 * for a new mm created in the exec path. There's also
     85	 * some lazy tlb stuff, which is currently dead code, but
     86	 * we only allocate a space id if one hasn't been allocated
     87	 * already, so we should be OK.
     88	 */
     89
     90	BUG_ON(next == &init_mm); /* Should never happen */
     91
     92	if (next->context.space_id == 0)
     93		next->context.space_id = alloc_sid();
     94
     95	switch_mm(prev,next,current);
     96}
     97
     98#include <asm-generic/mmu_context.h>
     99
    100#endif