[PATCH] iommu/io-pgtable: Replace IO_PGTABLE_QUIRK_NO_DMA with specific flag

From: Will Deacon
Date: Tue Jun 25 2019 - 07:51:25 EST

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IO_PGTABLE_QUIRK_NO_DMA is a bit of a misnomer, since it's really just
an indication of whether or not the page-table walker for the IOMMU is
coherent with the CPU caches. Since cache coherency is more than just a
quirk, replace the flag with its own field in the io_pgtable_cfg
structure.

Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
---
drivers/iommu/arm-smmu-v3.c | 4 +---
drivers/iommu/arm-smmu.c | 4 +---
drivers/iommu/io-pgtable-arm-v7s.c | 10 +++++-----
drivers/iommu/io-pgtable-arm.c | 19 ++++++++-----------
drivers/iommu/ipmmu-vmsa.c | 1 +
include/linux/io-pgtable.h | 11 ++++-------
6 files changed, 20 insertions(+), 29 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 65de2458999f..8ff8f61d9e1c 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1789,13 +1789,11 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
.pgsize_bitmap = smmu->pgsize_bitmap,
.ias = ias,
.oas = oas,
+ .coherent_walk = smmu->features & ARM_SMMU_FEAT_COHERENCY,
.tlb = &arm_smmu_gather_ops,
.iommu_dev = smmu->dev,
};

- if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
- pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
-
if (smmu_domain->non_strict)
pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 5e54cc0a28b3..009156bb6d42 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -895,13 +895,11 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
.pgsize_bitmap = smmu->pgsize_bitmap,
.ias = ias,
.oas = oas,
+ .coherent_walk = smmu->features & ARM_SMMU_FEAT_COHERENT_WALK,
.tlb = smmu_domain->tlb_ops,
.iommu_dev = smmu->dev,
};

- if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
- pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
-
if (smmu_domain->non_strict)
pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 9a8a8870e267..8454de93e356 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -215,7 +215,7 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
dev_err(dev, "Page table does not fit in PTE: %pa", &phys);
goto out_free;
}
- if (table && !(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) {
+ if (table && !cfg->coherent_walk) {
dma = dma_map_single(dev, table, size, DMA_TO_DEVICE);
if (dma_mapping_error(dev, dma))
goto out_free;
@@ -249,7 +249,7 @@ static void __arm_v7s_free_table(void *table, int lvl,
struct device *dev = cfg->iommu_dev;
size_t size = ARM_V7S_TABLE_SIZE(lvl);

- if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA))
+ if (!cfg->coherent_walk)
dma_unmap_single(dev, __arm_v7s_dma_addr(table), size,
DMA_TO_DEVICE);
if (lvl == 1)
@@ -261,7 +261,7 @@ static void __arm_v7s_free_table(void *table, int lvl,
static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries,
struct io_pgtable_cfg *cfg)
{
- if (cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)
+ if (cfg->coherent_walk)
return;

dma_sync_single_for_device(cfg->iommu_dev, __arm_v7s_dma_addr(ptep),
@@ -727,7 +727,6 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
IO_PGTABLE_QUIRK_NO_PERMS |
IO_PGTABLE_QUIRK_TLBI_ON_MAP |
IO_PGTABLE_QUIRK_ARM_MTK_4GB |
- IO_PGTABLE_QUIRK_NO_DMA |
IO_PGTABLE_QUIRK_NON_STRICT))
return NULL;

@@ -846,7 +845,8 @@ static int __init arm_v7s_do_selftests(void)
.tlb = &dummy_tlb_ops,
.oas = 32,
.ias = 32,
- .quirks = IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA,
+ .coherent_walk = true,
+ .quirks = IO_PGTABLE_QUIRK_ARM_NS,
.pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M,
};
unsigned int iova, size, iova_start;
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 2454ac11aa97..91d0a4228b58 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -252,7 +252,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
return NULL;

pages = page_address(p);
- if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) {
+ if (!cfg->coherent_walk) {
dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE);
if (dma_mapping_error(dev, dma))
goto out_free;
@@ -278,7 +278,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
static void __arm_lpae_free_pages(void *pages, size_t size,
struct io_pgtable_cfg *cfg)
{
- if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA))
+ if (!cfg->coherent_walk)
dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages),
size, DMA_TO_DEVICE);
free_pages((unsigned long)pages, get_order(size));
@@ -296,7 +296,7 @@ static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
{
*ptep = pte;

- if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA))
+ if (!cfg->coherent_walk)
__arm_lpae_sync_pte(ptep, cfg);
}

@@ -374,8 +374,7 @@ static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table,

old = cmpxchg64_relaxed(ptep, curr, new);

- if ((cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA) ||
- (old & ARM_LPAE_PTE_SW_SYNC))
+ if (cfg->coherent_walk || (old & ARM_LPAE_PTE_SW_SYNC))
return old;

/* Even if it's not ours, there's no point waiting; just kick it */
@@ -416,8 +415,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
pte = arm_lpae_install_table(cptep, ptep, 0, cfg);
if (pte)
__arm_lpae_free_pages(cptep, tblsz, cfg);
- } else if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA) &&
- !(pte & ARM_LPAE_PTE_SW_SYNC)) {
+ } else if (!cfg->coherent_walk && !(pte & ARM_LPAE_PTE_SW_SYNC)) {
__arm_lpae_sync_pte(ptep, cfg);
}

@@ -799,7 +797,7 @@ 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_NON_STRICT))
return NULL;

@@ -894,8 +892,7 @@ 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 |
- IO_PGTABLE_QUIRK_NON_STRICT))
+ if (cfg->quirks & ~(IO_PGTABLE_QUIRK_NON_STRICT))
return NULL;

data = arm_lpae_alloc_pgtable(cfg);
@@ -1230,7 +1227,7 @@ static int __init arm_lpae_do_selftests(void)
struct io_pgtable_cfg cfg = {
.tlb = &dummy_tlb_ops,
.oas = 48,
- .quirks = IO_PGTABLE_QUIRK_NO_DMA,
+ .coherent_walk = true,
};

for (i = 0; i < ARRAY_SIZE(pgsize); ++i) {
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 9a380c10655e..12bcb95bdaa8 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -431,6 +431,7 @@ static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
* TODO: Add support for coherent walk through CCI with DVM and remove
* cache handling. For now, delegate it to the io-pgtable code.
*/
+ domain->cfg.coherent_walk = false;
domain->cfg.iommu_dev = domain->mmu->root->dev;

/*
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 76969a564831..b5a450a3bb47 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -44,6 +44,8 @@ struct iommu_gather_ops {
* tables.
* @ias: Input address (iova) size, in bits.
* @oas: Output address (paddr) size, in bits.
+ * @coherent_walk A flag to indicate whether or not page table walks made
+ * by the IOMMU are coherent with the CPU caches.
* @tlb: TLB management callbacks for this set of tables.
* @iommu_dev: The device representing the DMA configuration for the
* page table walker.
@@ -68,11 +70,6 @@ struct io_pgtable_cfg {
* when the SoC is in "4GB mode" and they can only access the high
* remap of DRAM (0x1_00000000 to 0x1_ffffffff).
*
- * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
- * 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.
@@ -81,12 +78,12 @@ struct io_pgtable_cfg {
#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)
+ #define IO_PGTABLE_QUIRK_NON_STRICT BIT(4)
unsigned long quirks;
unsigned long pgsize_bitmap;
unsigned int ias;
unsigned int oas;
+ bool coherent_walk;
const struct iommu_gather_ops *tlb;
struct device *iommu_dev;

--
2.11.0

Next message: Dan Carpenter: "Re: [PATCH 1/8] staging: kpc2000: add line breaks"
Previous message: Mika Westerberg: "Re: [PATCH v6 4/7] i2c: core: Make i2c_acpi_get_irq available to the rest of the I2C core"
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