Message ID | 1457322077-26640-3-git-send-email-aik@ozlabs.ru |
---|---|
State | Changes Requested |
Headers | show |
On Mon, Mar 07, 2016 at 02:41:10PM +1100, Alexey Kardashevskiy wrote: > This makes mm_iommu_lookup() able to work in realmode by replacing > list_for_each_entry_rcu() (which can do debug stuff which can fail in > real mode) with list_for_each_entry_lockless(). > > This adds realmode version of mm_iommu_ua_to_hpa() which adds > explicit vmalloc'd-to-linear address conversion. > Unlike mm_iommu_ua_to_hpa(), mm_iommu_rm_ua_to_hpa() can fail. > > This changes mm_iommu_preregistered() to receive @mm as in real mode > @current does not always have a correct pointer. So, I'd generally expect a parameter called @mm to be an mm_struct *, not a mm_context_t. > > This adds realmode version of mm_iommu_lookup() which receives @mm > (for the same reason as for mm_iommu_preregistered()) and uses > lockless version of list_for_each_entry_rcu(). > > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > arch/powerpc/include/asm/mmu_context.h | 6 ++++- > arch/powerpc/mm/mmu_context_iommu.c | 45 ++++++++++++++++++++++++++++++---- > 2 files changed, 45 insertions(+), 6 deletions(-) > > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h > index 878c277..3ba652a 100644 > --- a/arch/powerpc/include/asm/mmu_context.h > +++ b/arch/powerpc/include/asm/mmu_context.h > @@ -18,7 +18,7 @@ extern void destroy_context(struct mm_struct *mm); > #ifdef CONFIG_SPAPR_TCE_IOMMU > struct mm_iommu_table_group_mem_t; > > -extern bool mm_iommu_preregistered(void); > +extern bool mm_iommu_preregistered(mm_context_t *mm); > extern long mm_iommu_get(unsigned long ua, unsigned long entries, > struct mm_iommu_table_group_mem_t **pmem); > extern long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem); > @@ -26,10 +26,14 @@ extern void mm_iommu_init(mm_context_t *ctx); > extern void mm_iommu_cleanup(mm_context_t *ctx); > extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, > unsigned long size); > +extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(mm_context_t *mm, > + unsigned long ua, unsigned long size); > extern struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua, > unsigned long entries); > extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, > unsigned long ua, unsigned long *hpa); > +extern long mm_iommu_rm_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, > + unsigned long ua, unsigned long *hpa); > extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem); > extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem); > #endif > diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c > index da6a216..aa1565d 100644 > --- a/arch/powerpc/mm/mmu_context_iommu.c > +++ b/arch/powerpc/mm/mmu_context_iommu.c > @@ -63,12 +63,9 @@ static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, > return ret; > } > > -bool mm_iommu_preregistered(void) > +bool mm_iommu_preregistered(mm_context_t *mm) > { > - if (!current || !current->mm) > - return false; > - > - return !list_empty(¤t->mm->context.iommu_group_mem_list); > + return !list_empty(&mm->iommu_group_mem_list); > } > EXPORT_SYMBOL_GPL(mm_iommu_preregistered); > > @@ -231,6 +228,24 @@ unlock_exit: > } > EXPORT_SYMBOL_GPL(mm_iommu_put); > > +struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(mm_context_t *mm, > + unsigned long ua, unsigned long size) > +{ > + struct mm_iommu_table_group_mem_t *mem, *ret = NULL; I think you could do with a comment here explaining why the lockless traversal is safe. > + list_for_each_entry_lockless(mem, &mm->iommu_group_mem_list, next) { > + if ((mem->ua <= ua) && > + (ua + size <= mem->ua + > + (mem->entries << PAGE_SHIFT))) { > + ret = mem; > + break; > + } > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(mm_iommu_lookup_rm); > + > struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, > unsigned long size) > { > @@ -284,6 +299,26 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, > } > EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa); > > +long mm_iommu_rm_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, > + unsigned long ua, unsigned long *hpa) > +{ > + const long entry = (ua - mem->ua) >> PAGE_SHIFT; > + void *va = &mem->hpas[entry]; > + unsigned long *ra; > + > + if (entry >= mem->entries) > + return -EFAULT; > + > + ra = (void *) vmalloc_to_phys(va); > + if (!ra) > + return -EFAULT; > + > + *hpa = *ra | (ua & ~PAGE_MASK); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(mm_iommu_rm_ua_to_hpa); > + > long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem) > { > if (atomic64_inc_not_zero(&mem->mapped))
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 878c277..3ba652a 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -18,7 +18,7 @@ extern void destroy_context(struct mm_struct *mm); #ifdef CONFIG_SPAPR_TCE_IOMMU struct mm_iommu_table_group_mem_t; -extern bool mm_iommu_preregistered(void); +extern bool mm_iommu_preregistered(mm_context_t *mm); extern long mm_iommu_get(unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem); extern long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem); @@ -26,10 +26,14 @@ extern void mm_iommu_init(mm_context_t *ctx); extern void mm_iommu_cleanup(mm_context_t *ctx); extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, unsigned long size); +extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(mm_context_t *mm, + unsigned long ua, unsigned long size); extern struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua, unsigned long entries); extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, unsigned long ua, unsigned long *hpa); +extern long mm_iommu_rm_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, + unsigned long ua, unsigned long *hpa); extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem); extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem); #endif diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index da6a216..aa1565d 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -63,12 +63,9 @@ static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, return ret; } -bool mm_iommu_preregistered(void) +bool mm_iommu_preregistered(mm_context_t *mm) { - if (!current || !current->mm) - return false; - - return !list_empty(¤t->mm->context.iommu_group_mem_list); + return !list_empty(&mm->iommu_group_mem_list); } EXPORT_SYMBOL_GPL(mm_iommu_preregistered); @@ -231,6 +228,24 @@ unlock_exit: } EXPORT_SYMBOL_GPL(mm_iommu_put); +struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(mm_context_t *mm, + unsigned long ua, unsigned long size) +{ + struct mm_iommu_table_group_mem_t *mem, *ret = NULL; + + list_for_each_entry_lockless(mem, &mm->iommu_group_mem_list, next) { + if ((mem->ua <= ua) && + (ua + size <= mem->ua + + (mem->entries << PAGE_SHIFT))) { + ret = mem; + break; + } + } + + return ret; +} +EXPORT_SYMBOL_GPL(mm_iommu_lookup_rm); + struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, unsigned long size) { @@ -284,6 +299,26 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, } EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa); +long mm_iommu_rm_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, + unsigned long ua, unsigned long *hpa) +{ + const long entry = (ua - mem->ua) >> PAGE_SHIFT; + void *va = &mem->hpas[entry]; + unsigned long *ra; + + if (entry >= mem->entries) + return -EFAULT; + + ra = (void *) vmalloc_to_phys(va); + if (!ra) + return -EFAULT; + + *hpa = *ra | (ua & ~PAGE_MASK); + + return 0; +} +EXPORT_SYMBOL_GPL(mm_iommu_rm_ua_to_hpa); + long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem) { if (atomic64_inc_not_zero(&mem->mapped))
This makes mm_iommu_lookup() able to work in realmode by replacing list_for_each_entry_rcu() (which can do debug stuff which can fail in real mode) with list_for_each_entry_lockless(). This adds realmode version of mm_iommu_ua_to_hpa() which adds explicit vmalloc'd-to-linear address conversion. Unlike mm_iommu_ua_to_hpa(), mm_iommu_rm_ua_to_hpa() can fail. This changes mm_iommu_preregistered() to receive @mm as in real mode @current does not always have a correct pointer. This adds realmode version of mm_iommu_lookup() which receives @mm (for the same reason as for mm_iommu_preregistered()) and uses lockless version of list_for_each_entry_rcu(). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> --- arch/powerpc/include/asm/mmu_context.h | 6 ++++- arch/powerpc/mm/mmu_context_iommu.c | 45 ++++++++++++++++++++++++++++++---- 2 files changed, 45 insertions(+), 6 deletions(-)