The patch titled
Subject: iommu/io-pgtable-arm-v7s: request DMA32 memory, and improve debugging
has been added to the -mm tree. Its filename is
iommu-io-pgtable-arm-v7s-request-dma32-memory-and-improve-debugging.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/iommu-io-pgtable-arm-v7s-request-dma32-memory-and-improve-debugging.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/iommu-io-pgtable-arm-v7s-request-dma32-memory-and-improve-debugging.patch
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From: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
Subject: iommu/io-pgtable-arm-v7s: request DMA32 memory, and improve debugging
IOMMUs using ARMv7 short-descriptor format require page tables (level 1
and 2) to be allocated within the first 4GB of RAM, even on 64-bit
systems.
For level 1/2 pages, ensure GFP_DMA32 is used if CONFIG_ZONE_DMA32 is
defined (e.g. on arm64 platforms).
For level 2 pages, allocate a slab cache in SLAB_CACHE_DMA32. Note that
we do not explicitly pass GFP_DMA[32] to kmem_cache_zalloc, as this is not
strictly necessary, and would cause a warning in mm/sl*b.c, as we did not
update GFP_SLAB_BUG_MASK.
Also, print an error when the physical address does not fit in
32-bit, to make debugging easier in the future.
Link: http://lkml.kernel.org/r/20181210011504.122604-3-drinkcat@xxxxxxxxxxxx
Fixes: ad67f5a6545f ("arm64: replace ZONE_DMA with ZONE_DMA32")
Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Cc: Huaisheng Ye <yehs1@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Sasha Levin <Alexander.Levin@xxxxxxxxxxxxx>
Cc: Tomasz Figa <tfiga@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx>
Cc: Yong Wu <yong.wu@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/io-pgtable-arm-v7s.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
--- a/drivers/iommu/io-pgtable-arm-v7s.c~iommu-io-pgtable-arm-v7s-request-dma32-memory-and-improve-debugging
+++ a/drivers/iommu/io-pgtable-arm-v7s.c
@@ -160,6 +160,14 @@
#define ARM_V7S_TCR_PD1 BIT(5)
+#ifdef CONFIG_ZONE_DMA32
+#define ARM_V7S_TABLE_GFP_DMA GFP_DMA32
+#define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA32
+#else
+#define ARM_V7S_TABLE_GFP_DMA GFP_DMA
+#define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA
+#endif
+
typedef u32 arm_v7s_iopte;
static bool selftest_running;
@@ -197,13 +205,16 @@ static void *__arm_v7s_alloc_table(int l
void *table = NULL;
if (lvl == 1)
- table = (void *)__get_dma_pages(__GFP_ZERO, get_order(size));
+ table = (void *)__get_free_pages(
+ __GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size));
else if (lvl == 2)
- table = kmem_cache_zalloc(data->l2_tables, gfp | GFP_DMA);
+ table = kmem_cache_zalloc(data->l2_tables, gfp);
phys = virt_to_phys(table);
- if (phys != (arm_v7s_iopte)phys)
+ if (phys != (arm_v7s_iopte)phys) {
/* Doesn't fit in PTE */
+ dev_err(dev, "Page table does not fit in PTE: %pa", &phys);
goto out_free;
+ }
if (table && !(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) {
dma = dma_map_single(dev, table, size, DMA_TO_DEVICE);
if (dma_mapping_error(dev, dma))
@@ -733,7 +744,7 @@ static struct io_pgtable *arm_v7s_alloc_
data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2",
ARM_V7S_TABLE_SIZE(2),
ARM_V7S_TABLE_SIZE(2),
- SLAB_CACHE_DMA, NULL);
+ ARM_V7S_TABLE_SLAB_FLAGS, NULL);
if (!data->l2_tables)
goto out_free_data;
_
Patches currently in -mm which might be from drinkcat@xxxxxxxxxxxx are
mm-add-support-for-kmem-caches-in-dma32-zone.patch
iommu-io-pgtable-arm-v7s-request-dma32-memory-and-improve-debugging.patch
mm-add-sys-kernel-slab-cache-cache_dma32.patch
