[PATCH 3/5] iommu/arm-smmu-v3: Add read_and_clear_dirty() support
Shameer Kolothum
shameerali.kolothum.thodi at huawei.com
Tue Nov 28 01:49:38 PST 2023
From: Keqian Zhu <zhukeqian1 at huawei.com>
.read_and_clear_dirty() IOMMU domain op takes care of reading the dirty
bits (i.e. PTE has both DBM and AP[2] set) and marshalling into a bitmap of
a given page size.
While reading the dirty bits we also clear the PTE AP[2] bit to mark it as
writable-clean depending on read_and_clear_dirty() flags.
Structure it in a way that the IOPTE walker is generic, and so we pass a
function pointer over what to do on a per-PTE basis.
[Link below points to the original version that was based on]
Link: https://lore.kernel.org/lkml/20210413085457.25400-11-zhukeqian1@huawei.com/
Signed-off-by: Keqian Zhu <zhukeqian1 at huawei.com>
Co-developed-by: Kunkun Jiang <jiangkunkun at huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun at huawei.com>
[joaomart: Massage commit message and code to the new IOMMU op and logic]
Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
[Shameer: Changes to IOPTE walker function to handle size != iommu pgsize
blk sizes]
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 27 +++++
drivers/iommu/io-pgtable-arm.c | 114 ++++++++++++++++++++
2 files changed, 141 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 de4d07c4cc7f..8331a2c70a0c 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -43,6 +43,7 @@ MODULE_PARM_DESC(disable_msipolling,
"Disable MSI-based polling for CMD_SYNC completion.");
static struct iommu_ops arm_smmu_ops;
+static struct iommu_dirty_ops arm_smmu_dirty_ops;
enum arm_smmu_msi_index {
EVTQ_MSI_INDEX,
@@ -3379,6 +3380,28 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
return group;
}
+static int arm_smmu_read_and_clear_dirty(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ unsigned long flags,
+ struct iommu_dirty_bitmap *dirty)
+{
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+ struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
+ int ret;
+
+ if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
+ return -EINVAL;
+
+ if (!ops || !ops->read_and_clear_dirty) {
+ pr_err_once("io-pgtable don't support dirty tracking\n");
+ return -ENODEV;
+ }
+
+ ret = ops->read_and_clear_dirty(ops, iova, size, flags, dirty);
+
+ return ret;
+}
+
static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
{
return iommu_fwspec_add_ids(dev, args->args, 1);
@@ -3504,6 +3527,10 @@ static struct iommu_ops arm_smmu_ops = {
}
};
+static struct iommu_dirty_ops arm_smmu_dirty_ops = {
+ .read_and_clear_dirty = arm_smmu_read_and_clear_dirty,
+};
+
/* Probing and initialisation functions */
static int arm_smmu_init_one_queue(struct arm_smmu_device *smmu,
struct arm_smmu_queue *q,
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index b2f470529459..66b04c8ec693 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -717,6 +717,119 @@ static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
return iopte_to_paddr(pte, data) | iova;
}
+struct arm_lpae_iopte_read_dirty {
+ unsigned long flags;
+ struct iommu_dirty_bitmap *dirty;
+};
+
+static int __arm_lpae_read_and_clear_dirty(unsigned long iova, size_t size,
+ arm_lpae_iopte *ptep, void *opaque)
+{
+ struct arm_lpae_iopte_read_dirty *arg = opaque;
+ struct iommu_dirty_bitmap *dirty = arg->dirty;
+ arm_lpae_iopte pte;
+
+ pte = READ_ONCE(*ptep);
+ if (WARN_ON(!pte))
+ return -EINVAL;
+
+ if ((pte & ARM_LPAE_PTE_AP_WRITABLE) == ARM_LPAE_PTE_AP_WRITABLE)
+ return 0;
+
+ iommu_dirty_bitmap_record(dirty, iova, size);
+ if (!(arg->flags & IOMMU_DIRTY_NO_CLEAR))
+ set_bit(ARM_LPAE_PTE_AP_RDONLY_BIT, (unsigned long *)ptep);
+ return 0;
+}
+
+static int __arm_lpae_iopte_walk(struct arm_lpae_io_pgtable *data,
+ unsigned long iova, size_t size,
+ int lvl, arm_lpae_iopte *ptep,
+ int (*fn)(unsigned long iova, size_t size,
+ arm_lpae_iopte *pte, void *opaque),
+ void *opaque)
+{
+ struct io_pgtable *iop = &data->iop;
+ arm_lpae_iopte *base_ptep = ptep;
+ arm_lpae_iopte pte;
+ size_t base, next_size;
+ int ret;
+
+ if (WARN_ON_ONCE(!fn))
+ return -EINVAL;
+
+ 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))
+ return fn(iova, size, ptep, opaque);
+
+ /* Current level is table, 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_iopte_walk(data, iova + base,
+ next_size, lvl + 1, ptep,
+ fn, opaque);
+ if (ret)
+ return ret;
+ }
+ return 0;
+ } else if (iopte_leaf(pte, lvl, iop->fmt)) {
+ size_t blk_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
+
+ for (base = 0; base < size; base += blk_size) {
+ ret = __arm_lpae_iopte_walk(data, iova + base,
+ blk_size, lvl, base_ptep,
+ fn, opaque);
+ if (ret)
+ return ret;
+ }
+ return 0;
+ }
+
+ /* Keep on walkin */
+ ptep = iopte_deref(pte, data);
+ return __arm_lpae_iopte_walk(data, iova, size, lvl + 1, ptep,
+ fn, opaque);
+}
+
+static int arm_lpae_read_and_clear_dirty(struct io_pgtable_ops *ops,
+ unsigned long iova, size_t size,
+ unsigned long flags,
+ struct iommu_dirty_bitmap *dirty)
+{
+ struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
+ struct arm_lpae_iopte_read_dirty arg = {
+ .flags = flags, .dirty = dirty,
+ };
+ arm_lpae_iopte *ptep = data->pgd;
+ int lvl = data->start_level;
+ long iaext = (s64)iova >> cfg->ias;
+
+ if (WARN_ON(!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_iopte_walk(data, iova, size, lvl, ptep,
+ __arm_lpae_read_and_clear_dirty, &arg);
+}
+
static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
{
unsigned long granule, page_sizes;
@@ -795,6 +908,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
.map_pages = arm_lpae_map_pages,
.unmap_pages = arm_lpae_unmap_pages,
.iova_to_phys = arm_lpae_iova_to_phys,
+ .read_and_clear_dirty = arm_lpae_read_and_clear_dirty,
};
return data;
--
2.34.1
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