mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
154 lines
3.5 KiB
154 lines
3.5 KiB
/* |
|
* 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 */
|
|
|