| Message ID | 20181210011504.122604-3-drinkcat@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables | expand |
On Mon, Dec 10, 2018 at 09:15:03AM +0800, Nicolas Boichat wrote: > 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. > > Cc: stable@vger.kernel.org > Fixes: ad67f5a6545f ("arm64: replace ZONE_DMA with ZONE_DMA32") > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> > --- Acked-by: Will Deacon <will.deacon@arm.com> Will
On Mon, Dec 10, 2018 at 09:15:03AM +0800, Nicolas Boichat wrote: > 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. > > Cc: stable@vger.kernel.org > Fixes: ad67f5a6545f ("arm64: replace ZONE_DMA with ZONE_DMA32") > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Assuming you're routing all of this via akpm: Acked-by: Will Deacon <will.deacon@arm.com> Will
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index 445c3bde04800c..d2fdb192f7610f 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -161,6 +161,14 @@ #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; @@ -198,13 +206,16 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp, 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)) @@ -737,7 +748,7 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, 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;
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. Cc: stable@vger.kernel.org Fixes: ad67f5a6545f ("arm64: replace ZONE_DMA with ZONE_DMA32") Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> --- Changes since v2: - Commit message (v3 used the page_frag approach) Changes since v4: - Do not pass ARM_V7S_TABLE_GFP_DMA to kmem_cache_zalloc, as this is unnecessary, and would trigger a warning. Changes since v5: - Rename ARM_V7S_TABLE_SLAB_CACHE to ARM_V7S_TABLE_SLAB_FLAGS. drivers/iommu/io-pgtable-arm-v7s.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)