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Diffstat (limited to 'arch/powerpc/mm/mmu_context_iommu.c')
-rw-r--r--arch/powerpc/mm/mmu_context_iommu.c37
1 files changed, 35 insertions, 2 deletions
diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c
index abb43646927a..a4ca57612558 100644
--- a/arch/powerpc/mm/mmu_context_iommu.c
+++ b/arch/powerpc/mm/mmu_context_iommu.c
@@ -19,6 +19,7 @@
#include <linux/hugetlb.h>
#include <linux/swap.h>
#include <asm/mmu_context.h>
+#include <asm/pte-walk.h>
static DEFINE_MUTEX(mem_list_mutex);
@@ -27,6 +28,7 @@ struct mm_iommu_table_group_mem_t {
struct rcu_head rcu;
unsigned long used;
atomic64_t mapped;
+ unsigned int pageshift;
u64 ua; /* userspace address */
u64 entries; /* number of entries in hpas[] */
u64 *hpas; /* vmalloc'ed */
@@ -125,6 +127,8 @@ long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
{
struct mm_iommu_table_group_mem_t *mem;
long i, j, ret = 0, locked_entries = 0;
+ unsigned int pageshift;
+ unsigned long flags;
struct page *page = NULL;
mutex_lock(&mem_list_mutex);
@@ -159,6 +163,12 @@ long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
goto unlock_exit;
}
+ /*
+ * For a starting point for a maximum page size calculation
+ * we use @ua and @entries natural alignment to allow IOMMU pages
+ * smaller than huge pages but still bigger than PAGE_SIZE.
+ */
+ mem->pageshift = __ffs(ua | (entries << PAGE_SHIFT));
mem->hpas = vzalloc(array_size(entries, sizeof(mem->hpas[0])));
if (!mem->hpas) {
kfree(mem);
@@ -199,6 +209,23 @@ long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries,
}
}
populate:
+ pageshift = PAGE_SHIFT;
+ if (PageCompound(page)) {
+ pte_t *pte;
+ struct page *head = compound_head(page);
+ unsigned int compshift = compound_order(head);
+
+ local_irq_save(flags); /* disables as well */
+ pte = find_linux_pte(mm->pgd, ua, NULL, &pageshift);
+ local_irq_restore(flags);
+
+ /* Double check it is still the same pinned page */
+ if (pte && pte_page(*pte) == head &&
+ pageshift == compshift)
+ pageshift = max_t(unsigned int, pageshift,
+ PAGE_SHIFT);
+ }
+ mem->pageshift = min(mem->pageshift, pageshift);
mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT;
}
@@ -349,7 +376,7 @@ struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
EXPORT_SYMBOL_GPL(mm_iommu_find);
long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
- unsigned long ua, unsigned long *hpa)
+ unsigned long ua, unsigned int pageshift, unsigned long *hpa)
{
const long entry = (ua - mem->ua) >> PAGE_SHIFT;
u64 *va = &mem->hpas[entry];
@@ -357,6 +384,9 @@ long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
if (entry >= mem->entries)
return -EFAULT;
+ if (pageshift > mem->pageshift)
+ return -EFAULT;
+
*hpa = *va | (ua & ~PAGE_MASK);
return 0;
@@ -364,7 +394,7 @@ 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)
+ unsigned long ua, unsigned int pageshift, unsigned long *hpa)
{
const long entry = (ua - mem->ua) >> PAGE_SHIFT;
void *va = &mem->hpas[entry];
@@ -373,6 +403,9 @@ long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
if (entry >= mem->entries)
return -EFAULT;
+ if (pageshift > mem->pageshift)
+ return -EFAULT;
+
pa = (void *) vmalloc_to_phys(va);
if (!pa)
return -EFAULT;