iommu/io-pgtable: Replace IO_PGTABLE_QUIRK_NO_DMA with specific flag

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@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 65de2458999fd63428005dcdd5bd2355dc6bde3a..8ff8f61d9e1cb646b0e70efa5c3bd6806f4dc963 100644 (file)
--- 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 5e54cc0a28b30516b65c2516c666ee3d9c398141..009156bb6d4297d555c644b8c19db94188089b64 100644 (file)
--- 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 9a8a8870e26727e7398afffd5286860b0e8581d9..8454de93e356fc3a91bd9a82372652a5074a8f6c 100644 (file)
--- 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 2454ac11aa97f848e447c434adc4b4971b145ac2..91d0a4228b587a8507447edad1219534d001df32 100644 (file)
--- 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 @@ out_free:
 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 9a380c10655e182d35d9f6c170336aeaa05030f6..12bcb95bdaa83fc486e50bb280daf6b844a11eef 100644 (file)
--- 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 76969a56483142a374469aca826fffa18a23c304..b5a450a3bb47a6f25beafa9510902af070f14dbd 100644 (file)
--- 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;