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authorAlexey Kardashevskiy <aik@ozlabs.ru>2019-04-03 15:12:33 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2019-04-17 21:36:51 +1000
commit7a3a4d763837d3aa654cd1059030950410c04d77 (patch)
tree7aac3da0f61a6d20c362b9dda93bdcb1d0be833f
parenteb9d7a62c38628ab0ba6e59d22d7cb7930e415d1 (diff)
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.c24
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;
}