Skip to content
Projects
Groups
Snippets
Help
Loading...
Help
Support
Keyboard shortcuts
?
Submit feedback
Contribute to GitLab
Sign in / Register
Toggle navigation
L
linux
Project overview
Project overview
Details
Activity
Releases
Repository
Repository
Files
Commits
Branches
Tags
Contributors
Graph
Compare
Issues
0
Issues
0
List
Boards
Labels
Milestones
Merge Requests
0
Merge Requests
0
Analytics
Analytics
Repository
Value Stream
Wiki
Wiki
Snippets
Snippets
Members
Members
Collapse sidebar
Close sidebar
Activity
Graph
Create a new issue
Commits
Issue Boards
Open sidebar
Kirill Smelkov
linux
Commits
fc34d1eb
Commit
fc34d1eb
authored
May 26, 2009
by
Michal Simek
Browse files
Options
Browse Files
Download
Email Patches
Plain Diff
microblaze_mmu_v2: Context handling - mmu_context.c/h
Signed-off-by:
Michal Simek
<
monstr@monstr.eu
>
parent
5de96121
Changes
4
Hide whitespace changes
Inline
Side-by-side
Showing
4 changed files
with
238 additions
and
21 deletions
+238
-21
arch/microblaze/include/asm/mmu_context.h
arch/microblaze/include/asm/mmu_context.h
+5
-21
arch/microblaze/include/asm/mmu_context_mm.h
arch/microblaze/include/asm/mmu_context_mm.h
+140
-0
arch/microblaze/include/asm/mmu_context_no.h
arch/microblaze/include/asm/mmu_context_no.h
+23
-0
arch/microblaze/mm/mmu_context.c
arch/microblaze/mm/mmu_context.c
+70
-0
No files found.
arch/microblaze/include/asm/mmu_context.h
View file @
fc34d1eb
/*
#ifdef CONFIG_MMU
* Copyright (C) 2006 Atmark Techno, Inc.
# include "mmu_context_mm.h"
*
#else
* This file is subject to the terms and conditions of the GNU General Public
# include "mmu_context_no.h"
* License. See the file "COPYING" in the main directory of this archive
#endif
* for more details.
*/
#ifndef _ASM_MICROBLAZE_MMU_CONTEXT_H
#define _ASM_MICROBLAZE_MMU_CONTEXT_H
# define init_new_context(tsk, mm) ({ 0; })
# define enter_lazy_tlb(mm, tsk) do {} while (0)
# define change_mm_context(old, ctx, _pml4) do {} while (0)
# define destroy_context(mm) do {} while (0)
# define deactivate_mm(tsk, mm) do {} while (0)
# define switch_mm(prev, next, tsk) do {} while (0)
# define activate_mm(prev, next) do {} while (0)
#endif
/* _ASM_MICROBLAZE_MMU_CONTEXT_H */
arch/microblaze/include/asm/mmu_context_mm.h
0 → 100644
View file @
fc34d1eb
/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* 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.
*/
#ifndef _ASM_MICROBLAZE_MMU_CONTEXT_H
#define _ASM_MICROBLAZE_MMU_CONTEXT_H
#include <asm/atomic.h>
#include <asm/bitops.h>
#include <asm/mmu.h>
#include <asm-generic/mm_hooks.h>
# ifdef __KERNEL__
/*
* This function defines the mapping from contexts to VSIDs (virtual
* segment IDs). We use a skew on both the context and the high 4 bits
* of the 32-bit virtual address (the "effective segment ID") in order
* to spread out the entries in the MMU hash table.
*/
# define CTX_TO_VSID(ctx, va) (((ctx) * (897 * 16) + ((va) >> 28) * 0x111) \
& 0xffffff)
/*
MicroBlaze has 256 contexts, so we can just rotate through these
as a way of "switching" contexts. If the TID of the TLB is zero,
the PID/TID comparison is disabled, so we can use a TID of zero
to represent all kernel pages as shared among all contexts.
*/
static
inline
void
enter_lazy_tlb
(
struct
mm_struct
*
mm
,
struct
task_struct
*
tsk
)
{
}
# define NO_CONTEXT 256
# define LAST_CONTEXT 255
# define FIRST_CONTEXT 1
/*
* Set the current MMU context.
* This is done byloading up the segment registers for the user part of the
* address space.
*
* Since the PGD is immediately available, it is much faster to simply
* pass this along as a second parameter, which is required for 8xx and
* can be used for debugging on all processors (if you happen to have
* an Abatron).
*/
extern
void
set_context
(
mm_context_t
context
,
pgd_t
*
pgd
);
/*
* Bitmap of contexts in use.
* The size of this bitmap is LAST_CONTEXT + 1 bits.
*/
extern
unsigned
long
context_map
[];
/*
* This caches the next context number that we expect to be free.
* Its use is an optimization only, we can't rely on this context
* number to be free, but it usually will be.
*/
extern
mm_context_t
next_mmu_context
;
/*
* Since we don't have sufficient contexts to give one to every task
* that could be in the system, we need to be able to steal contexts.
* These variables support that.
*/
extern
atomic_t
nr_free_contexts
;
extern
struct
mm_struct
*
context_mm
[
LAST_CONTEXT
+
1
];
extern
void
steal_context
(
void
);
/*
* Get a new mmu context for the address space described by `mm'.
*/
static
inline
void
get_mmu_context
(
struct
mm_struct
*
mm
)
{
mm_context_t
ctx
;
if
(
mm
->
context
!=
NO_CONTEXT
)
return
;
while
(
atomic_dec_if_positive
(
&
nr_free_contexts
)
<
0
)
steal_context
();
ctx
=
next_mmu_context
;
while
(
test_and_set_bit
(
ctx
,
context_map
))
{
ctx
=
find_next_zero_bit
(
context_map
,
LAST_CONTEXT
+
1
,
ctx
);
if
(
ctx
>
LAST_CONTEXT
)
ctx
=
0
;
}
next_mmu_context
=
(
ctx
+
1
)
&
LAST_CONTEXT
;
mm
->
context
=
ctx
;
context_mm
[
ctx
]
=
mm
;
}
/*
* Set up the context for a new address space.
*/
# define init_new_context(tsk, mm) (((mm)->context = NO_CONTEXT), 0)
/*
* We're finished using the context for an address space.
*/
static
inline
void
destroy_context
(
struct
mm_struct
*
mm
)
{
if
(
mm
->
context
!=
NO_CONTEXT
)
{
clear_bit
(
mm
->
context
,
context_map
);
mm
->
context
=
NO_CONTEXT
;
atomic_inc
(
&
nr_free_contexts
);
}
}
static
inline
void
switch_mm
(
struct
mm_struct
*
prev
,
struct
mm_struct
*
next
,
struct
task_struct
*
tsk
)
{
tsk
->
thread
.
pgdir
=
next
->
pgd
;
get_mmu_context
(
next
);
set_context
(
next
->
context
,
next
->
pgd
);
}
/*
* 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
*
active_mm
,
struct
mm_struct
*
mm
)
{
current
->
thread
.
pgdir
=
mm
->
pgd
;
get_mmu_context
(
mm
);
set_context
(
mm
->
context
,
mm
->
pgd
);
}
extern
void
mmu_context_init
(
void
);
# endif
/* __KERNEL__ */
#endif
/* _ASM_MICROBLAZE_MMU_CONTEXT_H */
arch/microblaze/include/asm/mmu_context_no.h
0 → 100644
View file @
fc34d1eb
/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* 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.
*/
#ifndef _ASM_MICROBLAZE_MMU_CONTEXT_H
#define _ASM_MICROBLAZE_MMU_CONTEXT_H
# define init_new_context(tsk, mm) ({ 0; })
# define enter_lazy_tlb(mm, tsk) do {} while (0)
# define change_mm_context(old, ctx, _pml4) do {} while (0)
# define destroy_context(mm) do {} while (0)
# define deactivate_mm(tsk, mm) do {} while (0)
# define switch_mm(prev, next, tsk) do {} while (0)
# define activate_mm(prev, next) do {} while (0)
#endif
/* _ASM_MICROBLAZE_MMU_CONTEXT_H */
arch/microblaze/mm/mmu_context.c
0 → 100644
View file @
fc34d1eb
/*
* This file contains the routines for handling the MMU.
*
* Copyright (C) 2007 Xilinx, Inc. All rights reserved.
*
* Derived from arch/ppc/mm/4xx_mmu.c:
* -- paulus
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* 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; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/mm.h>
#include <linux/init.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
mm_context_t
next_mmu_context
;
unsigned
long
context_map
[
LAST_CONTEXT
/
BITS_PER_LONG
+
1
];
atomic_t
nr_free_contexts
;
struct
mm_struct
*
context_mm
[
LAST_CONTEXT
+
1
];
/*
* Initialize the context management stuff.
*/
void
__init
mmu_context_init
(
void
)
{
/*
* The use of context zero is reserved for the kernel.
* This code assumes FIRST_CONTEXT < 32.
*/
context_map
[
0
]
=
(
1
<<
FIRST_CONTEXT
)
-
1
;
next_mmu_context
=
FIRST_CONTEXT
;
atomic_set
(
&
nr_free_contexts
,
LAST_CONTEXT
-
FIRST_CONTEXT
+
1
);
}
/*
* Steal a context from a task that has one at the moment.
*
* This isn't an LRU system, it just frees up each context in
* turn (sort-of pseudo-random replacement :). This would be the
* place to implement an LRU scheme if anyone were motivated to do it.
*/
void
steal_context
(
void
)
{
struct
mm_struct
*
mm
;
/* free up context `next_mmu_context' */
/* if we shouldn't free context 0, don't... */
if
(
next_mmu_context
<
FIRST_CONTEXT
)
next_mmu_context
=
FIRST_CONTEXT
;
mm
=
context_mm
[
next_mmu_context
];
flush_tlb_mm
(
mm
);
destroy_context
(
mm
);
}
Write
Preview
Markdown
is supported
0%
Try again
or
attach a new file
Attach a file
Cancel
You are about to add
0
people
to the discussion. Proceed with caution.
Finish editing this message first!
Cancel
Please
register
or
sign in
to comment