diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 11:56:29 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 11:56:29 -0800 |
commit | 52fefcec97c25b15887e6a9a885ca54e7f7c0928 (patch) | |
tree | 4898112a7fb30c20a9da3aefe9fdc7fdebda57a6 /arch/xtensa/include/asm/mmu_context.h | |
parent | a0e280e0f33f6c859a235fb69a875ed8f3420388 (diff) | |
parent | 5fee325e7d2bcbebf1cb38b4ff3a7aa3744c43e3 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-2.6:
xtensa: Update platform files to reflect new location of the header files.
xtensa: switch to packed struct unaligned access implementation
xtensa: Add xt2000 support files.
xtensa: move headers files to arch/xtensa/include
xtensa: use the new byteorder headers
Diffstat (limited to 'arch/xtensa/include/asm/mmu_context.h')
-rw-r--r-- | arch/xtensa/include/asm/mmu_context.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/mmu_context.h b/arch/xtensa/include/asm/mmu_context.h new file mode 100644 index 00000000000..c0fd8e5b451 --- /dev/null +++ b/arch/xtensa/include/asm/mmu_context.h @@ -0,0 +1,136 @@ +/* + * include/asm-xtensa/mmu_context.h + * + * 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 - 2005 Tensilica Inc. + */ + +#ifndef _XTENSA_MMU_CONTEXT_H +#define _XTENSA_MMU_CONTEXT_H + +#include <linux/stringify.h> +#include <linux/sched.h> + +#include <asm/pgtable.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm-generic/mm_hooks.h> + +#define XCHAL_MMU_ASID_BITS 8 + +#if (XCHAL_HAVE_TLBS != 1) +# error "Linux must have an MMU!" +#endif + +extern unsigned long asid_cache; + +/* + * NO_CONTEXT is the invalid ASID value that we don't ever assign to + * any user or kernel context. + * + * 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)) + +static inline void set_rasid_register (unsigned long val) +{ + __asm__ __volatile__ (" wsr %0, "__stringify(RASID)"\n\t" + " isync\n" : : "a" (val)); +} + +static inline unsigned long get_rasid_register (void) +{ + unsigned long tmp; + __asm__ __volatile__ (" rsr %0,"__stringify(RASID)"\n\t" : "=a" (tmp)); + return tmp; +} + +static inline void +__get_new_mmu_context(struct mm_struct *mm) +{ + extern void flush_tlb_all(void); + if (! (++asid_cache & ASID_MASK) ) { + flush_tlb_all(); /* start new asid cycle */ + asid_cache += ASID_USER_FIRST; + } + mm->context = asid_cache; +} + +static inline void +__load_mmu_context(struct mm_struct *mm) +{ + set_rasid_register(ASID_INSERT(mm->context)); + invalidate_page_directory(); +} + +/* + * 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 = NO_CONTEXT; + return 0; +} + +/* + * 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) +{ + /* Unconditionally get a new ASID. */ + + __get_new_mmu_context(next); + __load_mmu_context(next); +} + + +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + unsigned long asid = asid_cache; + + /* Check if our ASID is of an older version and thus invalid */ + + if (next->context == NO_CONTEXT || ((next->context^asid) & ~ASID_MASK)) + __get_new_mmu_context(next); + + __load_mmu_context(next); +} + +#define deactivate_mm(tsk, mm) do { } while(0) + +/* + * 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) +{ + invalidate_page_directory(); +} + + +static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) +{ + /* Nothing to do. */ + +} + +#endif /* _XTENSA_MMU_CONTEXT_H */ |