[PATCH v10 05/20] iommu/exynos: allocate lv2 page table from own slab

From: Cho KyongHo
Date: Sun Oct 06 2013 - 21:54:09 EST


Since kmalloc() does not guarantee that the allignment of 1KiB when it
allocates 1KiB, it is required to allocate lv2 page table from own
slab that guarantees alignment of 1KiB

Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 34 ++++++++++++++++++++++++++++------
1 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index cbe1e5a..191cb3f 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -100,6 +100,8 @@
#define REG_PB1_SADDR 0x054
#define REG_PB1_EADDR 0x058

+static struct kmem_cache *lv2table_kmem_cache;
+
static unsigned long *section_entry(unsigned long *pgtable, unsigned long iova)
{
return pgtable + lv1ent_offset(iova);
@@ -738,7 +740,8 @@ static void exynos_iommu_domain_destroy(struct iommu_domain *domain)

for (i = 0; i < NUM_LV1ENTRIES; i++)
if (lv1ent_page(priv->pgtable + i))
- kfree(__va(lv2table_base(priv->pgtable + i)));
+ kmem_cache_free(lv2table_kmem_cache,
+ __va(lv2table_base(priv->pgtable + i)));

free_pages((unsigned long)priv->pgtable, 2);
free_pages((unsigned long)priv->lv2entcnt, 1);
@@ -837,7 +840,7 @@ static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
if (lv1ent_fault(sent)) {
unsigned long *pent;

- pent = kzalloc(LV2TABLE_SIZE, GFP_ATOMIC);
+ pent = kmem_cache_zalloc(lv2table_kmem_cache, GFP_ATOMIC);
BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1));
if (!pent)
return ERR_PTR(-ENOMEM);
@@ -867,8 +870,7 @@ static int lv1set_section(unsigned long *sent, unsigned long iova,
return -EADDRINUSE;
}

- kfree(page_entry(sent, 0));
-
+ kmem_cache_free(lv2table_kmem_cache, page_entry(sent, 0));
*pgcnt = 0;
}

@@ -1073,11 +1075,31 @@ static int __init exynos_iommu_init(void)
{
int ret;

+ lv2table_kmem_cache = kmem_cache_create("exynos-iommu-lv2table",
+ LV2TABLE_SIZE, LV2TABLE_SIZE, 0, NULL);
+ if (!lv2table_kmem_cache) {
+ pr_err("%s: Failed to create kmem cache\n", __func__);
+ return -ENOMEM;
+ }
+
ret = platform_driver_register(&exynos_sysmmu_driver);
+ if (ret) {
+ pr_err("%s: Failed to register driver\n", __func__);
+ goto err_reg_driver;
+ }

- if (ret == 0)
- bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
+ ret = bus_set_iommu(&platform_bus_type, &exynos_iommu_ops);
+ if (ret) {
+ pr_err("%s: Failed to register exynos-iommu driver.\n",
+ __func__);
+ goto err_set_iommu;
+ }

+ return 0;
+err_set_iommu:
+ platform_driver_unregister(&exynos_sysmmu_driver);
+err_reg_driver:
+ kmem_cache_destroy(lv2table_kmem_cache);
return ret;
}
subsys_initcall(exynos_iommu_init);
--
1.7.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/