From: Robin Murphy <robin.murphy@arm.com>
To: joro@8bytes.org, will.deacon@arm.com, thunder.leizhen@huawei.com,
iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: linuxarm@huawei.com, guohanjun@huawei.com,
huawei.libin@huawei.com, john.garry@huawei.com
Subject: [PATCH v7 3/6] iommu/io-pgtable-arm: Add support for non-strict mode
Date: Fri, 14 Sep 2018 15:30:21 +0100 [thread overview]
Message-ID: <75c1c1f9e8bc2fb9f199be5d3aef041a92d30160.1536935328.git.robin.murphy@arm.com> (raw)
In-Reply-To: <cover.1536935328.git.robin.murphy@arm.com>
From: Zhen Lei <thunder.leizhen@huawei.com>
To support non-strict mode, now we only TLBI and sync for strict mode,
except for non-leaf invalidations since page table updates themselves
must always be synchronous.
To save having to reason about it too much, make sure the invalidation
in arm_lpae_split_blk_unmap() just performs its own unconditional sync
to minimise the window in which we're technically violating the break-
before-make requirement on a live mapping. This might work out redundant
with an outer-level sync for strict unmaps, but we'll never be splitting
blocks on a DMA fastpath anyway.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
[rm: tweak comment, commit message, and split_blk_unmap logic]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/iommu/io-pgtable-arm.c | 9 ++++++---
drivers/iommu/io-pgtable.h | 5 +++++
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 2f79efd16a05..5b915aab7fd3 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -576,6 +576,7 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
tablep = iopte_deref(pte, data);
} else if (unmap_idx >= 0) {
io_pgtable_tlb_add_flush(&data->iop, iova, size, size, true);
+ io_pgtable_tlb_sync(&data->iop);
return size;
}
@@ -609,7 +610,7 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
io_pgtable_tlb_sync(iop);
ptep = iopte_deref(pte, data);
__arm_lpae_free_pgtable(data, lvl + 1, ptep);
- } else {
+ } else if (!(iop->cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT)) {
io_pgtable_tlb_add_flush(iop, iova, size, size, true);
}
@@ -771,7 +772,8 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
u64 reg;
struct arm_lpae_io_pgtable *data;
- if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA))
+ if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA |
+ IO_PGTABLE_QUIRK_NON_STRICT))
return NULL;
data = arm_lpae_alloc_pgtable(cfg);
@@ -863,7 +865,8 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
struct arm_lpae_io_pgtable *data;
/* The NS quirk doesn't apply at stage 2 */
- if (cfg->quirks & ~IO_PGTABLE_QUIRK_NO_DMA)
+ if (cfg->quirks & ~(IO_PGTABLE_QUIRK_NO_DMA |
+ IO_PGTABLE_QUIRK_NON_STRICT))
return NULL;
data = arm_lpae_alloc_pgtable(cfg);
diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h
index 2df79093cad9..47d5ae559329 100644
--- a/drivers/iommu/io-pgtable.h
+++ b/drivers/iommu/io-pgtable.h
@@ -71,12 +71,17 @@ struct io_pgtable_cfg {
* be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
* software-emulated IOMMU), such that pagetable updates need not
* be treated as explicit DMA data.
+ *
+ * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs
+ * on unmap, for DMA domains using the flush queue mechanism for
+ * delayed invalidation.
*/
#define IO_PGTABLE_QUIRK_ARM_NS BIT(0)
#define IO_PGTABLE_QUIRK_NO_PERMS BIT(1)
#define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2)
#define IO_PGTABLE_QUIRK_ARM_MTK_4GB BIT(3)
#define IO_PGTABLE_QUIRK_NO_DMA BIT(4)
+ #define IO_PGTABLE_QUIRK_NON_STRICT BIT(5)
unsigned long quirks;
unsigned long pgsize_bitmap;
unsigned int ias;
--
2.19.0.dirty
next prev parent reply other threads:[~2018-09-14 14:30 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-14 14:30 [PATCH v7 0/6] Add non-strict mode support for iommu-dma Robin Murphy
2018-09-14 14:30 ` [PATCH v7 1/6] iommu/arm-smmu-v3: Implement flush_iotlb_all hook Robin Murphy
2018-09-14 14:30 ` [PATCH v7 2/6] iommu/dma: Add support for non-strict mode Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 18:52 ` Robin Murphy
2018-09-14 14:30 ` Robin Murphy [this message]
2018-09-14 14:30 ` [PATCH v7 4/6] iommu: Add bootup option "iommu.non_strict" Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 19:01 ` Robin Murphy
2018-09-14 14:30 ` [PATCH v7 5/6] iommu/arm-smmu-v3: Add support for non-strict mode Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 19:09 ` Robin Murphy
2018-09-14 14:30 ` [PATCH v7 6/6] iommu/arm-smmu: Support " Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 19:22 ` Robin Murphy
2018-09-18 17:10 ` [PATCH v7 0/6] Add non-strict mode support for iommu-dma Will Deacon
2018-09-18 18:28 ` Robin Murphy
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