diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 9d2cd0c36ec27645eb82aa53a5d39b04ae422778..475d1be391916e8dffffb0fc7c93c4df1d29b690 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -18,6 +18,7 @@ extern void destroy_context(struct mm_struct *mm); #ifdef CONFIG_SPAPR_TCE_IOMMU struct mm_iommu_table_group_mem_t; +extern int isolate_lru_page(struct page *page); /* from internal.h */ extern bool mm_iommu_preregistered(void); extern long mm_iommu_get(unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem); diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index da6a2168ae9e1dd64d755344e77463338c0a5906..e0f1c33601ddb1ab6bc3e780b1ed43f9f80a1e58 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -15,6 +15,9 @@ #include #include #include +#include +#include +#include #include static DEFINE_MUTEX(mem_list_mutex); @@ -72,6 +75,55 @@ bool mm_iommu_preregistered(void) } EXPORT_SYMBOL_GPL(mm_iommu_preregistered); +/* + * Taken from alloc_migrate_target with changes to remove CMA allocations + */ +struct page *new_iommu_non_cma_page(struct page *page, unsigned long private, + int **resultp) +{ + gfp_t gfp_mask = GFP_USER; + struct page *new_page; + + if (PageHuge(page) || PageTransHuge(page) || PageCompound(page)) + return NULL; + + if (PageHighMem(page)) + gfp_mask |= __GFP_HIGHMEM; + + /* + * We don't want the allocation to force an OOM if possibe + */ + new_page = alloc_page(gfp_mask | __GFP_NORETRY | __GFP_NOWARN); + return new_page; +} + +static int mm_iommu_move_page_from_cma(struct page *page) +{ + int ret = 0; + LIST_HEAD(cma_migrate_pages); + + /* Ignore huge pages for now */ + if (PageHuge(page) || PageTransHuge(page) || PageCompound(page)) + return -EBUSY; + + lru_add_drain(); + ret = isolate_lru_page(page); + if (ret) + return ret; + + list_add(&page->lru, &cma_migrate_pages); + put_page(page); /* Drop the gup reference */ + + ret = migrate_pages(&cma_migrate_pages, new_iommu_non_cma_page, + NULL, 0, MIGRATE_SYNC, MR_CMA); + if (ret) { + if (!list_empty(&cma_migrate_pages)) + putback_movable_pages(&cma_migrate_pages); + } + + return 0; +} + long mm_iommu_get(unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem) { @@ -124,15 +176,36 @@ long mm_iommu_get(unsigned long ua, unsigned long entries, for (i = 0; i < entries; ++i) { if (1 != get_user_pages_fast(ua + (i << PAGE_SHIFT), 1/* pages */, 1/* iswrite */, &page)) { + ret = -EFAULT; for (j = 0; j < i; ++j) - put_page(pfn_to_page( - mem->hpas[j] >> PAGE_SHIFT)); + put_page(pfn_to_page(mem->hpas[j] >> + PAGE_SHIFT)); vfree(mem->hpas); kfree(mem); - ret = -EFAULT; goto unlock_exit; } - + /* + * If we get a page from the CMA zone, since we are going to + * be pinning these entries, we might as well move them out + * of the CMA zone if possible. NOTE: faulting in + migration + * can be expensive. Batching can be considered later + */ + if (get_pageblock_migratetype(page) == MIGRATE_CMA) { + if (mm_iommu_move_page_from_cma(page)) + goto populate; + if (1 != get_user_pages_fast(ua + (i << PAGE_SHIFT), + 1/* pages */, 1/* iswrite */, + &page)) { + ret = -EFAULT; + for (j = 0; j < i; ++j) + put_page(pfn_to_page(mem->hpas[j] >> + PAGE_SHIFT)); + vfree(mem->hpas); + kfree(mem); + goto unlock_exit; + } + } +populate: mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT; }