155 lines
3.5 KiB
C
155 lines
3.5 KiB
C
/*
|
|
* Switch an MMU context.
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* Copyright (C) 2001 - 2013 Tensilica Inc.
|
|
*/
|
|
|
|
#ifndef _XTENSA_MMU_CONTEXT_H
|
|
#define _XTENSA_MMU_CONTEXT_H
|
|
|
|
#ifndef CONFIG_MMU
|
|
#include <asm/nommu_context.h>
|
|
#else
|
|
|
|
#include <linux/stringify.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/mm_types.h>
|
|
#include <linux/pgtable.h>
|
|
|
|
#include <asm/vectors.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm-generic/mm_hooks.h>
|
|
#include <asm-generic/percpu.h>
|
|
|
|
#if (XCHAL_HAVE_TLBS != 1)
|
|
# error "Linux must have an MMU!"
|
|
#endif
|
|
|
|
DECLARE_PER_CPU(unsigned long, asid_cache);
|
|
#define cpu_asid_cache(cpu) per_cpu(asid_cache, cpu)
|
|
|
|
/*
|
|
* NO_CONTEXT is the invalid ASID value that we don't ever assign to
|
|
* any user or kernel context. We use the reserved values in the
|
|
* ASID_INSERT macro below.
|
|
*
|
|
* 0 invalid
|
|
* 1 kernel
|
|
* 2 reserved
|
|
* 3 reserved
|
|
* 4...255 available
|
|
*/
|
|
|
|
#define NO_CONTEXT 0
|
|
#define ASID_USER_FIRST 4
|
|
#define ASID_MASK ((1 << XCHAL_MMU_ASID_BITS) - 1)
|
|
#define ASID_INSERT(x) (0x03020001 | (((x) & ASID_MASK) << 8))
|
|
|
|
void init_mmu(void);
|
|
void init_kio(void);
|
|
|
|
static inline void set_rasid_register (unsigned long val)
|
|
{
|
|
__asm__ __volatile__ (" wsr %0, rasid\n\t"
|
|
" isync\n" : : "a" (val));
|
|
}
|
|
|
|
static inline unsigned long get_rasid_register (void)
|
|
{
|
|
unsigned long tmp;
|
|
__asm__ __volatile__ (" rsr %0, rasid\n\t" : "=a" (tmp));
|
|
return tmp;
|
|
}
|
|
|
|
static inline void get_new_mmu_context(struct mm_struct *mm, unsigned int cpu)
|
|
{
|
|
unsigned long asid = cpu_asid_cache(cpu);
|
|
if ((++asid & ASID_MASK) == 0) {
|
|
/*
|
|
* Start new asid cycle; continue counting with next
|
|
* incarnation bits; skipping over 0, 1, 2, 3.
|
|
*/
|
|
local_flush_tlb_all();
|
|
asid += ASID_USER_FIRST;
|
|
}
|
|
cpu_asid_cache(cpu) = asid;
|
|
mm->context.asid[cpu] = asid;
|
|
mm->context.cpu = cpu;
|
|
}
|
|
|
|
static inline void get_mmu_context(struct mm_struct *mm, unsigned int cpu)
|
|
{
|
|
/*
|
|
* Check if our ASID is of an older version and thus invalid.
|
|
*/
|
|
|
|
if (mm) {
|
|
unsigned long asid = mm->context.asid[cpu];
|
|
|
|
if (asid == NO_CONTEXT ||
|
|
((asid ^ cpu_asid_cache(cpu)) & ~ASID_MASK))
|
|
get_new_mmu_context(mm, cpu);
|
|
}
|
|
}
|
|
|
|
static inline void activate_context(struct mm_struct *mm, unsigned int cpu)
|
|
{
|
|
get_mmu_context(mm, cpu);
|
|
set_rasid_register(ASID_INSERT(mm->context.asid[cpu]));
|
|
invalidate_page_directory();
|
|
}
|
|
|
|
/*
|
|
* Initialize the context related info for a new mm_struct
|
|
* instance. Valid cpu values are 0..(NR_CPUS-1), so initializing
|
|
* to -1 says the process has never run on any core.
|
|
*/
|
|
|
|
#define init_new_context init_new_context
|
|
static inline int init_new_context(struct task_struct *tsk,
|
|
struct mm_struct *mm)
|
|
{
|
|
int cpu;
|
|
for_each_possible_cpu(cpu) {
|
|
mm->context.asid[cpu] = NO_CONTEXT;
|
|
}
|
|
mm->context.cpu = -1;
|
|
return 0;
|
|
}
|
|
|
|
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
|
|
struct task_struct *tsk)
|
|
{
|
|
unsigned int cpu = smp_processor_id();
|
|
int migrated = next->context.cpu != cpu;
|
|
/* Flush the icache if we migrated to a new core. */
|
|
if (migrated) {
|
|
__invalidate_icache_all();
|
|
next->context.cpu = cpu;
|
|
}
|
|
if (migrated || prev != next)
|
|
activate_context(next, cpu);
|
|
}
|
|
|
|
/*
|
|
* Destroy context related info for an mm_struct that is about
|
|
* to be put to rest.
|
|
*/
|
|
#define destroy_context destroy_context
|
|
static inline void destroy_context(struct mm_struct *mm)
|
|
{
|
|
invalidate_page_directory();
|
|
}
|
|
|
|
|
|
#include <asm-generic/mmu_context.h>
|
|
|
|
#endif /* CONFIG_MMU */
|
|
#endif /* _XTENSA_MMU_CONTEXT_H */
|