[RFC PATCH 06/11] iommu/arm-smmu-v3: Scan leaf TTD to sync hardware dirty log

Keqian Zhu
2021-01-28T15:19:25Z

From: jiangkunkun <jiangkunkun@huawei.com>

During dirty log tracking, user will try to retrieve dirty log from
iommu if it supports hardware dirty log. This adds a new interface
named sync_dirty_log in iommu layer and arm smmuv3 implements it,
which scans leaf TTD and treats it's dirty if it's writable (As we
just enable HTTU for stage1, so check AP[2] is not set).

Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 27 +++++++
drivers/iommu/io-pgtable-arm.c | 90 +++++++++++++++++++++
drivers/iommu/iommu.c | 41 ++++++++++
include/linux/io-pgtable.h | 4 +
include/linux/iommu.h | 17 ++++
5 files changed, 179 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 2434519e4bb6..43d0536b429a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2548,6 +2548,32 @@ static size_t arm_smmu_merge_page(struct iommu_domain *domain, unsigned long iov
return ops->merge_page(ops, iova, paddr, size, prot);
}

+static int arm_smmu_sync_dirty_log(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ unsigned long *bitmap,
+ unsigned long base_iova,
+ unsigned long bitmap_pgshift)
+{
+ struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
+ struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu;
+
+ if (!(smmu->features & ARM_SMMU_FEAT_HTTU_HD)) {
+ dev_err(smmu->dev, "don't support HTTU_HD and sync dirty log\n");
+ return -EPERM;
+ }
+
+ if (!ops || !ops->sync_dirty_log) {
+ pr_err("don't support sync dirty log\n");
+ return -ENODEV;
+ }
+
+ /* To ensure all inflight transactions are completed */
+ arm_smmu_flush_iotlb_all(domain);
+
+ return ops->sync_dirty_log(ops, iova, size, bitmap,
+ base_iova, bitmap_pgshift);
+}
+
static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
{
return iommu_fwspec_add_ids(dev, args->args, 1);
@@ -2649,6 +2675,7 @@ static struct iommu_ops arm_smmu_ops = {
.domain_set_attr = arm_smmu_domain_set_attr,
.split_block = arm_smmu_split_block,
.merge_page = arm_smmu_merge_page,
+ .sync_dirty_log = arm_smmu_sync_dirty_log,
.of_xlate = arm_smmu_of_xlate,
.get_resv_regions = arm_smmu_get_resv_regions,
.put_resv_regions = generic_iommu_put_resv_regions,
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 17390f258eb1..6cfe1ef3fedd 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -877,6 +877,95 @@ static size_t arm_lpae_merge_page(struct io_pgtable_ops *ops, unsigned long iova
return __arm_lpae_merge_page(data, iova, paddr, size, lvl, ptep, prot);
}

+static int __arm_lpae_sync_dirty_log(struct arm_lpae_io_pgtable *data,
+ unsigned long iova, size_t size,
+ int lvl, arm_lpae_iopte *ptep,
+ unsigned long *bitmap,
+ unsigned long base_iova,
+ unsigned long bitmap_pgshift)
+{
+ arm_lpae_iopte pte;
+ struct io_pgtable *iop = &data->iop;
+ size_t base, next_size;
+ unsigned long offset;
+ int nbits, ret;
+
+ if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
+ return -EINVAL;
+
+ ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+ pte = READ_ONCE(*ptep);
+ if (WARN_ON(!pte))
+ return -EINVAL;
+
+ if (size == ARM_LPAE_BLOCK_SIZE(lvl, data)) {
+ if (iopte_leaf(pte, lvl, iop->fmt)) {
+ if (pte & ARM_LPAE_PTE_AP_RDONLY)
+ return 0;
+
+ /* It is writable, set the bitmap */
+ nbits = size >> bitmap_pgshift;
+ offset = (iova - base_iova) >> bitmap_pgshift;
+ bitmap_set(bitmap, offset, nbits);
+ return 0;
+ } else {
+ /* To traverse next level */
+ next_size = ARM_LPAE_BLOCK_SIZE(lvl + 1, data);
+ ptep = iopte_deref(pte, data);
+ for (base = 0; base < size; base += next_size) {
+ ret = __arm_lpae_sync_dirty_log(data,
+ iova + base, next_size, lvl + 1,
+ ptep, bitmap, base_iova, bitmap_pgshift);
+ if (ret)
+ return ret;
+ }
+ return 0;
+ }
+ } else if (iopte_leaf(pte, lvl, iop->fmt)) {
+ if (pte & ARM_LPAE_PTE_AP_RDONLY)
+ return 0;
+
+ /* Though the size is too small, also set bitmap */
+ nbits = size >> bitmap_pgshift;
+ offset = (iova - base_iova) >> bitmap_pgshift;
+ bitmap_set(bitmap, offset, nbits);
+ return 0;
+ }
+
+ /* Keep on walkin */
+ ptep = iopte_deref(pte, data);
+ return __arm_lpae_sync_dirty_log(data, iova, size, lvl + 1, ptep,
+ bitmap, base_iova, bitmap_pgshift);
+}
+
+static int arm_lpae_sync_dirty_log(struct io_pgtable_ops *ops,
+ unsigned long iova, size_t size,
+ unsigned long *bitmap,
+ unsigned long base_iova,
+ unsigned long bitmap_pgshift)
+{
+ struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+ arm_lpae_iopte *ptep = data->pgd;
+ int lvl = data->start_level;
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
+ long iaext = (s64)iova >> cfg->ias;
+
+ if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
+ return -EINVAL;
+
+ if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1)
+ iaext = ~iaext;
+ if (WARN_ON(iaext))
+ return -EINVAL;
+
+ if (data->iop.fmt != ARM_64_LPAE_S1 &&
+ data->iop.fmt != ARM_32_LPAE_S1)
+ return -EINVAL;
+
+ return __arm_lpae_sync_dirty_log(data, iova, size, lvl, ptep,
+ bitmap, base_iova, bitmap_pgshift);
+}
+
static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
{
unsigned long granule, page_sizes;
@@ -957,6 +1046,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
.iova_to_phys = arm_lpae_iova_to_phys,
.split_block = arm_lpae_split_block,
.merge_page = arm_lpae_merge_page,
+ .sync_dirty_log = arm_lpae_sync_dirty_log,
};

return data;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f1261da11ea8..69f268069282 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2822,6 +2822,47 @@ size_t iommu_merge_page(struct iommu_domain *domain, unsigned long iova,
}
EXPORT_SYMBOL_GPL(iommu_merge_page);

+int iommu_sync_dirty_log(struct iommu_domain *domain, unsigned long iova,
+ size_t size, unsigned long *bitmap,
+ unsigned long base_iova, unsigned long bitmap_pgshift)
+{
+ const struct iommu_ops *ops = domain->ops;
+ unsigned int min_pagesz;
+ size_t pgsize;
+ int ret;
+
+ min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
+
+ if (!IS_ALIGNED(iova | size, min_pagesz)) {
+ pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n",
+ iova, size, min_pagesz);
+ return -EINVAL;
+ }
+
+ if (!ops || !ops->sync_dirty_log) {
+ pr_err("don't support sync dirty log\n");
+ return -ENODEV;
+ }
+
+ while (size) {
+ pgsize = iommu_pgsize(domain, iova, size);
+
+ ret = ops->sync_dirty_log(domain, iova, pgsize,
+ bitmap, base_iova, bitmap_pgshift);
+ if (ret)
+ break;
+
+ pr_debug("dirty_log_sync: iova 0x%lx pagesz 0x%zx\n", iova,
+ pgsize);
+
+ iova += pgsize;
+ size -= pgsize;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_sync_dirty_log);
+
void iommu_get_resv_regions(struct device *dev, struct list_head *list)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 754b62a1bbaf..f44551e4a454 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -166,6 +166,10 @@ struct io_pgtable_ops {
size_t size);
size_t (*merge_page)(struct io_pgtable_ops *ops, unsigned long iova,
phys_addr_t phys, size_t size, int prot);
+ int (*sync_dirty_log)(struct io_pgtable_ops *ops,
+ unsigned long iova, size_t size,
+ unsigned long *bitmap, unsigned long base_iova,
+ unsigned long bitmap_pgshift);
};

/**
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ac2b0b1bce0f..8069c8375e63 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -262,6 +262,10 @@ struct iommu_ops {
size_t size);
size_t (*merge_page)(struct iommu_domain *domain, unsigned long iova,
phys_addr_t phys, size_t size, int prot);
+ int (*sync_dirty_log)(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ unsigned long *bitmap, unsigned long base_iova,
+ unsigned long bitmap_pgshift);

/* Request/Free a list of reserved regions for a device */
void (*get_resv_regions)(struct device *dev, struct list_head *list);
@@ -517,6 +521,10 @@ extern size_t iommu_split_block(struct iommu_domain *domain, unsigned long iova,
size_t size);
extern size_t iommu_merge_page(struct iommu_domain *domain, unsigned long iova,
size_t size, int prot);
+extern int iommu_sync_dirty_log(struct iommu_domain *domain, unsigned long iova,
+ size_t size, unsigned long *bitmap,
+ unsigned long base_iova,
+ unsigned long bitmap_pgshift);

/* Window handling function prototypes */
extern int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr,
@@ -923,6 +931,15 @@ static inline size_t iommu_merge_page(struct iommu_domain *domain,
return -EINVAL;
}

+static inline int iommu_sync_dirty_log(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ unsigned long *bitmap,
+ unsigned long base_iova,
+ unsigned long pgshift)
+{
+ return -EINVAL;
+}
+
static inline int iommu_device_register(struct iommu_device *iommu)
{
return -ENODEV;
--
2.19.1