diff options
| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2019-04-03 06:12:33 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-04-17 13:36:51 +0200 |
| commit | 7a3a4d763837d3aa654cd1059030950410c04d77 (patch) | |
| tree | 7aac3da0f61a6d20c362b9dda93bdcb1d0be833f | |
| parent | powerpc/mm_iommu: Fix potential deadlock (diff) | |
| download | linux-7a3a4d763837d3aa654cd1059030950410c04d77.tar.xz linux-7a3a4d763837d3aa654cd1059030950410c04d77.zip | |
powerpc/mm_iommu: Allow pinning large regions
When called with vmas_arg==NULL, get_user_pages_longterm() allocates
an array of nr_pages*8 which can easily get greater that the max order,
for example, registering memory for a 256GB guest does this and fails
in __alloc_pages_nodemask().
This adds a loop over chunks of entries to fit the max order limit.
Fixes: 678e174c4c16 ("powerpc/mm/iommu: allow migration of cma allocated pages during mm_iommu_do_alloc", 2019-03-05)
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/mm/mmu_context_iommu.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index 9d9be850f8c2..8330f135294f 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -98,6 +98,7 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, struct mm_iommu_table_group_mem_t *mem, *mem2; long i, ret, locked_entries = 0, pinned = 0; unsigned int pageshift; + unsigned long entry, chunk; if (dev_hpa == MM_IOMMU_TABLE_INVALID_HPA) { ret = mm_iommu_adjust_locked_vm(mm, entries, true); @@ -134,11 +135,26 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, } down_read(&mm->mmap_sem); - ret = get_user_pages_longterm(ua, entries, FOLL_WRITE, mem->hpages, NULL); + chunk = (1UL << (PAGE_SHIFT + MAX_ORDER - 1)) / + sizeof(struct vm_area_struct *); + chunk = min(chunk, entries); + for (entry = 0; entry < entries; entry += chunk) { + unsigned long n = min(entries - entry, chunk); + + ret = get_user_pages_longterm(ua + (entry << PAGE_SHIFT), n, + FOLL_WRITE, mem->hpages + entry, NULL); + if (ret == n) { + pinned += n; + continue; + } + if (ret > 0) + pinned += ret; + break; + } up_read(&mm->mmap_sem); - pinned = ret > 0 ? ret : 0; - if (ret != entries) { - ret = -EFAULT; + if (pinned != entries) { + if (!ret) + ret = -EFAULT; goto free_exit; } |