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Subject[PATCH v7 10/15] iommu/io-pgtable-arm: Implement arm_lpae_unmap_pages()
Date
From: "Isaac J. Manjarres" <isaacm@codeaurora.org>

Implement the unmap_pages() callback for the ARM LPAE io-pgtable
format.

Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
---
drivers/iommu/io-pgtable-arm.c | 120 +++++++++++++++++++++++++----------------
1 file changed, 74 insertions(+), 46 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index ea66b10c04c4..fe8fa0ee9c98 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -46,6 +46,9 @@
#define ARM_LPAE_PGD_SIZE(d) \
(sizeof(arm_lpae_iopte) << (d)->pgd_bits)

+#define ARM_LPAE_PTES_PER_TABLE(d) \
+ (ARM_LPAE_GRANULE(d) >> ilog2(sizeof(arm_lpae_iopte)))
+
/*
* Calculate the index at level l used to map virtual address a using the
* pagetable in d.
@@ -239,22 +242,19 @@ static void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries,
sizeof(*ptep) * num_entries, DMA_TO_DEVICE);
}

-static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
- int num_entries, struct io_pgtable_cfg *cfg)
+static void __arm_lpae_clear_pte(arm_lpae_iopte *ptep, struct io_pgtable_cfg *cfg)
{
- int i;

- for (i = 0; i < num_entries; i++)
- ptep[i] = pte;
+ *ptep = 0;

if (!cfg->coherent_walk)
- __arm_lpae_sync_pte(ptep, num_entries, cfg);
+ __arm_lpae_sync_pte(ptep, 1, cfg);
}

static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
struct iommu_iotlb_gather *gather,
- unsigned long iova, size_t size, int lvl,
- arm_lpae_iopte *ptep);
+ unsigned long iova, size_t size, size_t pgcount,
+ int lvl, arm_lpae_iopte *ptep);

static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
phys_addr_t paddr, arm_lpae_iopte prot,
@@ -298,7 +298,7 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data);

tblp = ptep - ARM_LPAE_LVL_IDX(iova, lvl, data);
- if (__arm_lpae_unmap(data, NULL, iova + i * sz, sz,
+ if (__arm_lpae_unmap(data, NULL, iova + i * sz, sz, 1,
lvl, tblp) != sz) {
WARN_ON(1);
return -EINVAL;
@@ -526,14 +526,15 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
struct iommu_iotlb_gather *gather,
unsigned long iova, size_t size,
arm_lpae_iopte blk_pte, int lvl,
- arm_lpae_iopte *ptep)
+ arm_lpae_iopte *ptep, size_t pgcount)
{
struct io_pgtable_cfg *cfg = &data->iop.cfg;
arm_lpae_iopte pte, *tablep;
phys_addr_t blk_paddr;
size_t tablesz = ARM_LPAE_GRANULE(data);
size_t split_sz = ARM_LPAE_BLOCK_SIZE(lvl, data);
- int i, unmap_idx = -1;
+ int ptes_per_table = ARM_LPAE_PTES_PER_TABLE(data);
+ int i, unmap_idx_start = -1, num_entries = 0, max_entries;

if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
return 0;
@@ -542,15 +543,18 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
if (!tablep)
return 0; /* Bytes unmapped */

- if (size == split_sz)
- unmap_idx = ARM_LPAE_LVL_IDX(iova, lvl, data);
+ if (size == split_sz) {
+ unmap_idx_start = ARM_LPAE_LVL_IDX(iova, lvl, data);
+ max_entries = ptes_per_table - unmap_idx_start;
+ num_entries = min_t(int, pgcount, max_entries);
+ }

blk_paddr = iopte_to_paddr(blk_pte, data);
pte = iopte_prot(blk_pte);

- for (i = 0; i < tablesz / sizeof(pte); i++, blk_paddr += split_sz) {
+ for (i = 0; i < ptes_per_table; i++, blk_paddr += split_sz) {
/* Unmap! */
- if (i == unmap_idx)
+ if (i >= unmap_idx_start && i < (unmap_idx_start + num_entries))
continue;

__arm_lpae_init_pte(data, blk_paddr, pte, lvl, 1, &tablep[i]);
@@ -568,76 +572,92 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
return 0;

tablep = iopte_deref(pte, data);
- } else if (unmap_idx >= 0) {
- io_pgtable_tlb_add_page(&data->iop, gather, iova, size);
- return size;
+ } else if (unmap_idx_start >= 0) {
+ for (i = 0; i < num_entries; i++)
+ io_pgtable_tlb_add_page(&data->iop, gather, iova + i * size, size);
+
+ return num_entries * size;
}

- return __arm_lpae_unmap(data, gather, iova, size, lvl, tablep);
+ return __arm_lpae_unmap(data, gather, iova, size, pgcount, lvl, tablep);
}

static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
struct iommu_iotlb_gather *gather,
- unsigned long iova, size_t size, int lvl,
- arm_lpae_iopte *ptep)
+ unsigned long iova, size_t size, size_t pgcount,
+ int lvl, arm_lpae_iopte *ptep)
{
arm_lpae_iopte pte;
struct io_pgtable *iop = &data->iop;
+ int i = 0, num_entries, max_entries, unmap_idx_start;

/* Something went horribly wrong and we ran out of page table */
if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
return 0;

- ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+ unmap_idx_start = ARM_LPAE_LVL_IDX(iova, lvl, data);
+ ptep += unmap_idx_start;
pte = READ_ONCE(*ptep);
if (WARN_ON(!pte))
return 0;

/* If the size matches this level, we're in the right place */
if (size == ARM_LPAE_BLOCK_SIZE(lvl, data)) {
- __arm_lpae_set_pte(ptep, 0, 1, &iop->cfg);
-
- if (!iopte_leaf(pte, lvl, iop->fmt)) {
- /* Also flush any partial walks */
- io_pgtable_tlb_flush_walk(iop, iova, size,
- ARM_LPAE_GRANULE(data));
- ptep = iopte_deref(pte, data);
- __arm_lpae_free_pgtable(data, lvl + 1, ptep);
- } else if (iop->cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT) {
- /*
- * Order the PTE update against queueing the IOVA, to
- * guarantee that a flush callback from a different CPU
- * has observed it before the TLBIALL can be issued.
- */
- smp_wmb();
- } else {
- io_pgtable_tlb_add_page(iop, gather, iova, size);
+ max_entries = ARM_LPAE_PTES_PER_TABLE(data) - unmap_idx_start;
+ num_entries = min_t(int, pgcount, max_entries);
+
+ while (i < num_entries) {
+ pte = READ_ONCE(*ptep);
+ if (WARN_ON(!pte))
+ break;
+
+ __arm_lpae_clear_pte(ptep, &iop->cfg);
+
+ if (!iopte_leaf(pte, lvl, iop->fmt)) {
+ /* Also flush any partial walks */
+ io_pgtable_tlb_flush_walk(iop, iova + i * size, size,
+ ARM_LPAE_GRANULE(data));
+ __arm_lpae_free_pgtable(data, lvl + 1, iopte_deref(pte, data));
+ } else if (iop->cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT) {
+ /*
+ * Order the PTE update against queueing the IOVA, to
+ * guarantee that a flush callback from a different CPU
+ * has observed it before the TLBIALL can be issued.
+ */
+ smp_wmb();
+ } else {
+ io_pgtable_tlb_add_page(iop, gather, iova + i * size, size);
+ }
+
+ ptep++;
+ i++;
}

- return size;
+ return i * size;
} else if (iopte_leaf(pte, lvl, iop->fmt)) {
/*
* Insert a table at the next level to map the old region,
* minus the part we want to unmap
*/
return arm_lpae_split_blk_unmap(data, gather, iova, size, pte,
- lvl + 1, ptep);
+ lvl + 1, ptep, pgcount);
}

/* Keep on walkin' */
ptep = iopte_deref(pte, data);
- return __arm_lpae_unmap(data, gather, iova, size, lvl + 1, ptep);
+ return __arm_lpae_unmap(data, gather, iova, size, pgcount, lvl + 1, ptep);
}

-static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
- size_t size, struct iommu_iotlb_gather *gather)
+static size_t arm_lpae_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova,
+ size_t pgsize, size_t pgcount,
+ struct iommu_iotlb_gather *gather)
{
struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
struct io_pgtable_cfg *cfg = &data->iop.cfg;
arm_lpae_iopte *ptep = data->pgd;
long iaext = (s64)iova >> cfg->ias;

- if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
+ if (WARN_ON(!pgsize || (pgsize & cfg->pgsize_bitmap) != pgsize || !pgcount))
return 0;

if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1)
@@ -645,7 +665,14 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
if (WARN_ON(iaext))
return 0;

- return __arm_lpae_unmap(data, gather, iova, size, data->start_level, ptep);
+ return __arm_lpae_unmap(data, gather, iova, pgsize, pgcount,
+ data->start_level, ptep);
+}
+
+static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
+ size_t size, struct iommu_iotlb_gather *gather)
+{
+ return arm_lpae_unmap_pages(ops, iova, size, 1, gather);
}

static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
@@ -761,6 +788,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
data->iop.ops = (struct io_pgtable_ops) {
.map = arm_lpae_map,
.unmap = arm_lpae_unmap,
+ .unmap_pages = arm_lpae_unmap_pages,
.iova_to_phys = arm_lpae_iova_to_phys,
};

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