[PATCH v6 09/15] iommu/io-pgtable-arm: Prepare PTE methods for handling multiple entries

From: Georgi Djakov
Date: Tue Jun 15 2021 - 13:09:17 EST


From: "Isaac J. Manjarres" <isaacm@xxxxxxxxxxxxxx>

The PTE methods currently operate on a single entry. In preparation
for manipulating multiple PTEs in one map or unmap call, allow them
to handle multiple PTEs.

Signed-off-by: Isaac J. Manjarres <isaacm@xxxxxxxxxxxxxx>
Suggested-by: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Georgi Djakov <quic_c_gdjako@xxxxxxxxxxx>
---
drivers/iommu/io-pgtable-arm.c | 78 ++++++++++++++++++++++++------------------
1 file changed, 44 insertions(+), 34 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 87def58e79b5..ea66b10c04c4 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -232,20 +232,23 @@ static void __arm_lpae_free_pages(void *pages, size_t size,
free_pages((unsigned long)pages, get_order(size));
}

-static void __arm_lpae_sync_pte(arm_lpae_iopte *ptep,
+static void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries,
struct io_pgtable_cfg *cfg)
{
dma_sync_single_for_device(cfg->iommu_dev, __arm_lpae_dma_addr(ptep),
- sizeof(*ptep), DMA_TO_DEVICE);
+ sizeof(*ptep) * num_entries, DMA_TO_DEVICE);
}

static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
- struct io_pgtable_cfg *cfg)
+ int num_entries, struct io_pgtable_cfg *cfg)
{
- *ptep = pte;
+ int i;
+
+ for (i = 0; i < num_entries; i++)
+ ptep[i] = pte;

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

static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
@@ -255,47 +258,54 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,

static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
phys_addr_t paddr, arm_lpae_iopte prot,
- int lvl, arm_lpae_iopte *ptep)
+ int lvl, int num_entries, arm_lpae_iopte *ptep)
{
arm_lpae_iopte pte = prot;
+ struct io_pgtable_cfg *cfg = &data->iop.cfg;
+ size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data);
+ int i;

if (data->iop.fmt != ARM_MALI_LPAE && lvl == ARM_LPAE_MAX_LEVELS - 1)
pte |= ARM_LPAE_PTE_TYPE_PAGE;
else
pte |= ARM_LPAE_PTE_TYPE_BLOCK;

- pte |= paddr_to_iopte(paddr, data);
+ for (i = 0; i < num_entries; i++)
+ ptep[i] = pte | paddr_to_iopte(paddr + i * sz, data);

- __arm_lpae_set_pte(ptep, pte, &data->iop.cfg);
+ if (!cfg->coherent_walk)
+ __arm_lpae_sync_pte(ptep, num_entries, cfg);
}

static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
unsigned long iova, phys_addr_t paddr,
- arm_lpae_iopte prot, int lvl,
+ arm_lpae_iopte prot, int lvl, int num_entries,
arm_lpae_iopte *ptep)
{
- arm_lpae_iopte pte = *ptep;
-
- if (iopte_leaf(pte, lvl, data->iop.fmt)) {
- /* We require an unmap first */
- WARN_ON(!selftest_running);
- return -EEXIST;
- } else if (iopte_type(pte) == ARM_LPAE_PTE_TYPE_TABLE) {
- /*
- * We need to unmap and free the old table before
- * overwriting it with a block entry.
- */
- arm_lpae_iopte *tblp;
- 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, sz, lvl, tblp) != sz) {
- WARN_ON(1);
- return -EINVAL;
+ int i;
+
+ for (i = 0; i < num_entries; i++)
+ if (iopte_leaf(ptep[i], lvl, data->iop.fmt)) {
+ /* We require an unmap first */
+ WARN_ON(!selftest_running);
+ return -EEXIST;
+ } else if (iopte_type(ptep[i]) == ARM_LPAE_PTE_TYPE_TABLE) {
+ /*
+ * We need to unmap and free the old table before
+ * overwriting it with a block entry.
+ */
+ arm_lpae_iopte *tblp;
+ 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,
+ lvl, tblp) != sz) {
+ WARN_ON(1);
+ return -EINVAL;
+ }
}
- }

- __arm_lpae_init_pte(data, paddr, prot, lvl, ptep);
+ __arm_lpae_init_pte(data, paddr, prot, lvl, num_entries, ptep);
return 0;
}

@@ -323,7 +333,7 @@ static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table,
return old;

/* Even if it's not ours, there's no point waiting; just kick it */
- __arm_lpae_sync_pte(ptep, cfg);
+ __arm_lpae_sync_pte(ptep, 1, cfg);
if (old == curr)
WRITE_ONCE(*ptep, new | ARM_LPAE_PTE_SW_SYNC);

@@ -344,7 +354,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,

/* If we can install a leaf entry at this level, then do so */
if (size == block_size)
- return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
+ return arm_lpae_init_pte(data, iova, paddr, prot, lvl, 1, ptep);

/* We can't allocate tables at the final level */
if (WARN_ON(lvl >= ARM_LPAE_MAX_LEVELS - 1))
@@ -361,7 +371,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
if (pte)
__arm_lpae_free_pages(cptep, tblsz, cfg);
} else if (!cfg->coherent_walk && !(pte & ARM_LPAE_PTE_SW_SYNC)) {
- __arm_lpae_sync_pte(ptep, cfg);
+ __arm_lpae_sync_pte(ptep, 1, cfg);
}

if (pte && !iopte_leaf(pte, lvl, data->iop.fmt)) {
@@ -543,7 +553,7 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
if (i == unmap_idx)
continue;

- __arm_lpae_init_pte(data, blk_paddr, pte, lvl, &tablep[i]);
+ __arm_lpae_init_pte(data, blk_paddr, pte, lvl, 1, &tablep[i]);
}

pte = arm_lpae_install_table(tablep, ptep, blk_pte, cfg);
@@ -585,7 +595,7 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,

/* 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, &iop->cfg);
+ __arm_lpae_set_pte(ptep, 0, 1, &iop->cfg);

if (!iopte_leaf(pte, lvl, iop->fmt)) {
/* Also flush any partial walks */