From 6b5c19c55266f6efd10ffac0e9f9f2b7aa420a58 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 22 Mar 2017 15:21:47 +1100 Subject: [PATCH] powerpc/mmu: Add real mode support for IOMMU preregistered memory 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_ua_to_hpa_rm() 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 Reviewed-by: David Gibson Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/mmu_context.h | 4 +++ arch/powerpc/mm/mmu_context_iommu.c | 39 ++++++++++++++++++++++++++ 2 files changed, 43 insertions(+) diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index b9e3f0aca261..c70c8272523d 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -29,10 +29,14 @@ extern void mm_iommu_init(struct mm_struct *mm); extern void mm_iommu_cleanup(struct mm_struct *mm); extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm, unsigned long ua, unsigned long size); +extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm( + struct mm_struct *mm, unsigned long ua, unsigned long size); extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm, 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_ua_to_hpa_rm(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 497130c5c742..fc67bd766eaf 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -314,6 +314,25 @@ struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm, } EXPORT_SYMBOL_GPL(mm_iommu_lookup); +struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(struct mm_struct *mm, + unsigned long ua, unsigned long size) +{ + struct mm_iommu_table_group_mem_t *mem, *ret = NULL; + + list_for_each_entry_lockless(mem, &mm->context.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_find(struct mm_struct *mm, unsigned long ua, unsigned long entries) { @@ -345,6 +364,26 @@ 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_ua_to_hpa_rm(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 *pa; + + if (entry >= mem->entries) + return -EFAULT; + + pa = (void *) vmalloc_to_phys(va); + if (!pa) + return -EFAULT; + + *hpa = *pa | (ua & ~PAGE_MASK); + + return 0; +} +EXPORT_SYMBOL_GPL(mm_iommu_ua_to_hpa_rm); + long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem) { if (atomic64_inc_not_zero(&mem->mapped)) -- 2.20.1