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Subject[PATCH v8 03/12] iommu/exynos: fix page table maintenance
Date
This prevents allocating lv2 page table for the lv1 page table entry
that already has 1MB page mapping. In addition some BUG_ON() is
changed to WARN_ON().

Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
---
drivers/iommu/exynos-iommu.c | 52 +++++++++++++++++++++++++++++------------
1 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index e3be3e5..6c4ecce 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -52,11 +52,11 @@
#define lv2ent_large(pent) ((*(pent) & 3) == 1)

#define section_phys(sent) (*(sent) & SECT_MASK)
-#define section_offs(iova) ((iova) & 0xFFFFF)
+#define section_offs(iova) ((iova) & ~SECT_MASK)
#define lpage_phys(pent) (*(pent) & LPAGE_MASK)
-#define lpage_offs(iova) ((iova) & 0xFFFF)
+#define lpage_offs(iova) ((iova) & ~LPAGE_MASK)
#define spage_phys(pent) (*(pent) & SPAGE_MASK)
-#define spage_offs(iova) ((iova) & 0xFFF)
+#define spage_offs(iova) ((iova) & ~SPAGE_MASK)

#define lv1ent_offset(iova) ((iova) >> SECT_ORDER)
#define lv2ent_offset(iova) (((iova) & 0xFF000) >> SPAGE_ORDER)
@@ -862,12 +862,14 @@ static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
pent = kzalloc(LV2TABLE_SIZE, GFP_ATOMIC);
BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1));
if (!pent)
- return NULL;
+ return ERR_PTR(-ENOMEM);

*sent = mk_lv1ent_page(__pa(pent));
*pgcounter = NUM_LV2ENTRIES;
pgtable_flush(pent, pent + NUM_LV2ENTRIES);
pgtable_flush(sent, sent + 1);
+ } else if (lv1ent_section(sent)) {
+ return ERR_PTR(-EADDRINUSE);
}

return page_entry(sent, iova);
@@ -894,6 +896,12 @@ static int lv1set_section(unsigned long *sent, phys_addr_t paddr, short *pgcnt)
return 0;
}

+static void clear_page_table(unsigned long *ent, int n)
+{
+ if (n > 0)
+ memset(ent, 0, sizeof(*ent) * n);
+}
+
static int lv2set_page(unsigned long *pent, phys_addr_t paddr, size_t size,
short *pgcnt)
{
@@ -908,7 +916,7 @@ static int lv2set_page(unsigned long *pent, phys_addr_t paddr, size_t size,
int i;
for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) {
if (!lv2ent_fault(pent)) {
- memset(pent, 0, sizeof(*pent) * i);
+ clear_page_table(pent - i, i);
return -EADDRINUSE;
}

@@ -944,17 +952,16 @@ static int exynos_iommu_map(struct iommu_domain *domain, unsigned long iova,
pent = alloc_lv2entry(entry, iova,
&priv->lv2entcnt[lv1ent_offset(iova)]);

- if (!pent)
- ret = -ENOMEM;
+ if (IS_ERR(pent))
+ ret = PTR_ERR(pent);
else
ret = lv2set_page(pent, paddr, size,
&priv->lv2entcnt[lv1ent_offset(iova)]);
}

- if (ret) {
- pr_debug("%s: Failed to map iova 0x%lx/0x%x bytes\n",
- __func__, iova, size);
- }
+ if (ret)
+ pr_err("%s: Failed(%d) to map 0x%#x bytes @ %#lx\n",
+ __func__, ret, size, iova);

spin_unlock_irqrestore(&priv->pgtablelock, flags);

@@ -968,6 +975,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
struct sysmmu_drvdata *data;
unsigned long flags;
unsigned long *ent;
+ size_t err_pgsize;

BUG_ON(priv->pgtable == NULL);

@@ -976,7 +984,10 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
ent = section_entry(priv->pgtable, iova);

if (lv1ent_section(ent)) {
- BUG_ON(size < SECT_SIZE);
+ if (WARN_ON(size < SECT_SIZE)) {
+ err_pgsize = SECT_SIZE;
+ goto err;
+ }

*ent = 0;
pgtable_flush(ent, ent + 1);
@@ -1008,9 +1019,12 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
}

/* lv1ent_large(ent) == true here */
- BUG_ON(size < LPAGE_SIZE);
+ if (WARN_ON(size < LPAGE_SIZE)) {
+ err_pgsize = LPAGE_SIZE;
+ goto err;
+ }

- memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
+ clear_page_table(ent, SPAGES_PER_LPAGE);
pgtable_flush(ent, ent + SPAGES_PER_LPAGE);

size = LPAGE_SIZE;
@@ -1023,8 +1037,16 @@ done:
sysmmu_tlb_invalidate_entry(data->dev, iova);
spin_unlock_irqrestore(&priv->lock, flags);

-
return size;
+err:
+ spin_unlock_irqrestore(&priv->pgtablelock, flags);
+
+ pr_err("%s: Failed due to size(%#x) @ %#lx is"\
+ " smaller than page size %#x\n",
+ __func__, size, iova, err_pgsize);
+
+ return 0;
+
}

static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain,
--
1.7.2.5



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