2005-04-16 22:20:36 +00:00
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/* $Id: mmu_context.h,v 1.54 2002/02/09 19:49:31 davem Exp $ */
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#ifndef __SPARC64_MMU_CONTEXT_H
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#define __SPARC64_MMU_CONTEXT_H
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/* Derived heavily from Linus's Alpha/AXP ASN code... */
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#ifndef __ASSEMBLY__
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#include <linux/spinlock.h>
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#include <asm/system.h>
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#include <asm/spitfire.h>
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static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
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{
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}
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extern spinlock_t ctx_alloc_lock;
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extern unsigned long tlb_context_cache;
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extern unsigned long mmu_context_bmap[];
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extern void get_new_mmu_context(struct mm_struct *mm);
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/* Initialize a new mmu context. This is invoked when a new
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* address space instance (unique or shared) is instantiated.
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* This just needs to set mm->context to an invalid context.
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*/
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#define init_new_context(__tsk, __mm) \
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2006-02-01 02:29:18 +00:00
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({ unsigned long __pg = get_zeroed_page(GFP_KERNEL); \
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(__mm)->context.sparc64_ctx_val = 0UL; \
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(__mm)->context.sparc64_tsb = \
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(unsigned long *) __pg; \
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(__pg ? 0 : -ENOMEM); \
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})
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2005-04-16 22:20:36 +00:00
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/* Destroy a dead context. This occurs when mmput drops the
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* mm_users count to zero, the mmaps have been released, and
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* all the page tables have been flushed. Our job is to destroy
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* any remaining processor-specific state, and in the sparc64
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* case this just means freeing up the mmu context ID held by
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* this task if valid.
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*/
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#define destroy_context(__mm) \
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2006-02-01 02:29:18 +00:00
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do { free_page((unsigned long)(__mm)->context.sparc64_tsb); \
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spin_lock(&ctx_alloc_lock); \
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2005-04-16 22:20:36 +00:00
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if (CTX_VALID((__mm)->context)) { \
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unsigned long nr = CTX_NRBITS((__mm)->context); \
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mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63)); \
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} \
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spin_unlock(&ctx_alloc_lock); \
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} while(0)
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2006-02-01 02:29:18 +00:00
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extern unsigned long tsb_context_switch(unsigned long pgd_pa, unsigned long *tsb);
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2005-04-16 22:20:36 +00:00
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/* Set MMU context in the actual hardware. */
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#define load_secondary_context(__mm) \
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__asm__ __volatile__("stxa %0, [%1] %2\n\t" \
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"flush %%g6" \
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: /* No outputs */ \
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: "r" (CTX_HWBITS((__mm)->context)), \
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"r" (SECONDARY_CONTEXT), "i" (ASI_DMMU))
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extern void __flush_tlb_mm(unsigned long, unsigned long);
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/* Switch the current MM context. */
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static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk)
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{
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unsigned long ctx_valid;
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[SPARC64] mm: context switch ptlock
sparc64 is unique among architectures in taking the page_table_lock in
its context switch (well, cris does too, but erroneously, and it's not
yet SMP anyway).
This seems to be a private affair between switch_mm and activate_mm,
using page_table_lock as a per-mm lock, without any relation to its uses
elsewhere. That's fine, but comment it as such; and unlock sooner in
switch_mm, more like in activate_mm (preemption is disabled here).
There is a block of "if (0)"ed code in smp_flush_tlb_pending which would
have liked to rely on the page_table_lock, in switch_mm and elsewhere;
but its comment explains how dup_mmap's flush_tlb_mm defeated it. And
though that could have been changed at any time over the past few years,
now the chance vanishes as we push the page_table_lock downwards, and
perhaps split it per page table page. Just delete that block of code.
Which leaves the mysterious spin_unlock_wait(&oldmm->page_table_lock)
in kernel/fork.c copy_mm. Textual analysis (supported by Nick Piggin)
suggests that the comment was written by DaveM, and that it relates to
the defeated approach in the sparc64 smp_flush_tlb_pending. Just delete
this block too.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 22:09:01 +00:00
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int cpu;
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2005-04-16 22:20:36 +00:00
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[SPARC64] mm: context switch ptlock
sparc64 is unique among architectures in taking the page_table_lock in
its context switch (well, cris does too, but erroneously, and it's not
yet SMP anyway).
This seems to be a private affair between switch_mm and activate_mm,
using page_table_lock as a per-mm lock, without any relation to its uses
elsewhere. That's fine, but comment it as such; and unlock sooner in
switch_mm, more like in activate_mm (preemption is disabled here).
There is a block of "if (0)"ed code in smp_flush_tlb_pending which would
have liked to rely on the page_table_lock, in switch_mm and elsewhere;
but its comment explains how dup_mmap's flush_tlb_mm defeated it. And
though that could have been changed at any time over the past few years,
now the chance vanishes as we push the page_table_lock downwards, and
perhaps split it per page table page. Just delete that block of code.
Which leaves the mysterious spin_unlock_wait(&oldmm->page_table_lock)
in kernel/fork.c copy_mm. Textual analysis (supported by Nick Piggin)
suggests that the comment was written by DaveM, and that it relates to
the defeated approach in the sparc64 smp_flush_tlb_pending. Just delete
this block too.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 22:09:01 +00:00
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/* Note: page_table_lock is used here to serialize switch_mm
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* and activate_mm, and their calls to get_new_mmu_context.
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* This use of page_table_lock is unrelated to its other uses.
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*/
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2005-04-16 22:20:36 +00:00
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spin_lock(&mm->page_table_lock);
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[SPARC64] mm: context switch ptlock
sparc64 is unique among architectures in taking the page_table_lock in
its context switch (well, cris does too, but erroneously, and it's not
yet SMP anyway).
This seems to be a private affair between switch_mm and activate_mm,
using page_table_lock as a per-mm lock, without any relation to its uses
elsewhere. That's fine, but comment it as such; and unlock sooner in
switch_mm, more like in activate_mm (preemption is disabled here).
There is a block of "if (0)"ed code in smp_flush_tlb_pending which would
have liked to rely on the page_table_lock, in switch_mm and elsewhere;
but its comment explains how dup_mmap's flush_tlb_mm defeated it. And
though that could have been changed at any time over the past few years,
now the chance vanishes as we push the page_table_lock downwards, and
perhaps split it per page table page. Just delete that block of code.
Which leaves the mysterious spin_unlock_wait(&oldmm->page_table_lock)
in kernel/fork.c copy_mm. Textual analysis (supported by Nick Piggin)
suggests that the comment was written by DaveM, and that it relates to
the defeated approach in the sparc64 smp_flush_tlb_pending. Just delete
this block too.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 22:09:01 +00:00
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ctx_valid = CTX_VALID(mm->context);
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if (!ctx_valid)
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get_new_mmu_context(mm);
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spin_unlock(&mm->page_table_lock);
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2005-04-16 22:20:36 +00:00
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if (!ctx_valid || (old_mm != mm)) {
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load_secondary_context(mm);
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2006-02-01 02:29:18 +00:00
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tsb_context_switch(__pa(mm->pgd),
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mm->context.sparc64_tsb);
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2005-04-16 22:20:36 +00:00
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}
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[SPARC64] mm: context switch ptlock
sparc64 is unique among architectures in taking the page_table_lock in
its context switch (well, cris does too, but erroneously, and it's not
yet SMP anyway).
This seems to be a private affair between switch_mm and activate_mm,
using page_table_lock as a per-mm lock, without any relation to its uses
elsewhere. That's fine, but comment it as such; and unlock sooner in
switch_mm, more like in activate_mm (preemption is disabled here).
There is a block of "if (0)"ed code in smp_flush_tlb_pending which would
have liked to rely on the page_table_lock, in switch_mm and elsewhere;
but its comment explains how dup_mmap's flush_tlb_mm defeated it. And
though that could have been changed at any time over the past few years,
now the chance vanishes as we push the page_table_lock downwards, and
perhaps split it per page table page. Just delete that block of code.
Which leaves the mysterious spin_unlock_wait(&oldmm->page_table_lock)
in kernel/fork.c copy_mm. Textual analysis (supported by Nick Piggin)
suggests that the comment was written by DaveM, and that it relates to
the defeated approach in the sparc64 smp_flush_tlb_pending. Just delete
this block too.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 22:09:01 +00:00
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/* Even if (mm == old_mm) we _must_ check
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* the cpu_vm_mask. If we do not we could
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* corrupt the TLB state because of how
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* smp_flush_tlb_{page,range,mm} on sparc64
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* and lazy tlb switches work. -DaveM
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*/
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cpu = smp_processor_id();
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if (!ctx_valid || !cpu_isset(cpu, mm->cpu_vm_mask)) {
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cpu_set(cpu, mm->cpu_vm_mask);
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__flush_tlb_mm(CTX_HWBITS(mm->context),
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SECONDARY_CONTEXT);
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2005-04-16 22:20:36 +00:00
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}
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}
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#define deactivate_mm(tsk,mm) do { } while (0)
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/* Activate a new MM instance for the current task. */
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static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm)
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{
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int cpu;
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[SPARC64] mm: context switch ptlock
sparc64 is unique among architectures in taking the page_table_lock in
its context switch (well, cris does too, but erroneously, and it's not
yet SMP anyway).
This seems to be a private affair between switch_mm and activate_mm,
using page_table_lock as a per-mm lock, without any relation to its uses
elsewhere. That's fine, but comment it as such; and unlock sooner in
switch_mm, more like in activate_mm (preemption is disabled here).
There is a block of "if (0)"ed code in smp_flush_tlb_pending which would
have liked to rely on the page_table_lock, in switch_mm and elsewhere;
but its comment explains how dup_mmap's flush_tlb_mm defeated it. And
though that could have been changed at any time over the past few years,
now the chance vanishes as we push the page_table_lock downwards, and
perhaps split it per page table page. Just delete that block of code.
Which leaves the mysterious spin_unlock_wait(&oldmm->page_table_lock)
in kernel/fork.c copy_mm. Textual analysis (supported by Nick Piggin)
suggests that the comment was written by DaveM, and that it relates to
the defeated approach in the sparc64 smp_flush_tlb_pending. Just delete
this block too.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-07 22:09:01 +00:00
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/* Note: page_table_lock is used here to serialize switch_mm
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* and activate_mm, and their calls to get_new_mmu_context.
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* This use of page_table_lock is unrelated to its other uses.
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*/
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2005-04-16 22:20:36 +00:00
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spin_lock(&mm->page_table_lock);
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if (!CTX_VALID(mm->context))
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get_new_mmu_context(mm);
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cpu = smp_processor_id();
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if (!cpu_isset(cpu, mm->cpu_vm_mask))
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cpu_set(cpu, mm->cpu_vm_mask);
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spin_unlock(&mm->page_table_lock);
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load_secondary_context(mm);
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__flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT);
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2006-02-01 02:29:18 +00:00
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tsb_context_switch(__pa(mm->pgd), mm->context.sparc64_tsb);
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2005-04-16 22:20:36 +00:00
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}
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#endif /* !(__ASSEMBLY__) */
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#endif /* !(__SPARC64_MMU_CONTEXT_H) */
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