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path: root/drivers/iommu/io-pgtable-dart.c
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Diffstat (limited to 'drivers/iommu/io-pgtable-dart.c')
-rw-r--r--drivers/iommu/io-pgtable-dart.c139
1 files changed, 86 insertions, 53 deletions
diff --git a/drivers/iommu/io-pgtable-dart.c b/drivers/iommu/io-pgtable-dart.c
index 679bda104797..54d287cc0dd1 100644
--- a/drivers/iommu/io-pgtable-dart.c
+++ b/drivers/iommu/io-pgtable-dart.c
@@ -27,8 +27,9 @@
#define DART1_MAX_ADDR_BITS 36
-#define DART_MAX_TABLES 4
-#define DART_LEVELS 2
+#define DART_MAX_TABLE_BITS 2
+#define DART_MAX_TABLES BIT(DART_MAX_TABLE_BITS)
+#define DART_MAX_LEVELS 4 /* Includes TTBR level */
/* Struct accessors */
#define io_pgtable_to_data(x) \
@@ -68,6 +69,7 @@
struct dart_io_pgtable {
struct io_pgtable iop;
+ int levels;
int tbl_bits;
int bits_per_level;
@@ -156,44 +158,45 @@ static dart_iopte dart_install_table(dart_iopte *table,
return old;
}
-static int dart_get_table(struct dart_io_pgtable *data, unsigned long iova)
+static int dart_get_index(struct dart_io_pgtable *data, unsigned long iova, int level)
{
- return (iova >> (3 * data->bits_per_level + ilog2(sizeof(dart_iopte)))) &
- ((1 << data->tbl_bits) - 1);
+ return (iova >> (level * data->bits_per_level + ilog2(sizeof(dart_iopte)))) &
+ ((1 << data->bits_per_level) - 1);
}
-static int dart_get_l1_index(struct dart_io_pgtable *data, unsigned long iova)
-{
-
- return (iova >> (2 * data->bits_per_level + ilog2(sizeof(dart_iopte)))) &
- ((1 << data->bits_per_level) - 1);
-}
-
-static int dart_get_l2_index(struct dart_io_pgtable *data, unsigned long iova)
+static int dart_get_last_index(struct dart_io_pgtable *data, unsigned long iova)
{
return (iova >> (data->bits_per_level + ilog2(sizeof(dart_iopte)))) &
((1 << data->bits_per_level) - 1);
}
-static dart_iopte *dart_get_l2(struct dart_io_pgtable *data, unsigned long iova)
+static dart_iopte *dart_get_last(struct dart_io_pgtable *data, unsigned long iova)
{
dart_iopte pte, *ptep;
- int tbl = dart_get_table(data, iova);
+ int level = data->levels;
+ int tbl = dart_get_index(data, iova, level);
+
+ if (tbl >= (1 << data->tbl_bits))
+ return NULL;
ptep = data->pgd[tbl];
if (!ptep)
return NULL;
- ptep += dart_get_l1_index(data, iova);
- pte = READ_ONCE(*ptep);
+ while (--level > 1) {
+ ptep += dart_get_index(data, iova, level);
+ pte = READ_ONCE(*ptep);
- /* Valid entry? */
- if (!pte)
- return NULL;
+ /* Valid entry? */
+ if (!pte)
+ return NULL;
- /* Deref to get level 2 table */
- return iopte_deref(pte, data);
+ /* Deref to get next level table */
+ ptep = iopte_deref(pte, data);
+ }
+
+ return ptep;
}
static dart_iopte dart_prot_to_pte(struct dart_io_pgtable *data,
@@ -230,6 +233,7 @@ static int dart_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
int ret = 0, tbl, num_entries, max_entries, map_idx_start;
dart_iopte pte, *cptep, *ptep;
dart_iopte prot;
+ int level = data->levels;
if (WARN_ON(pgsize != cfg->pgsize_bitmap))
return -EINVAL;
@@ -240,31 +244,36 @@ static int dart_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
return -EINVAL;
- tbl = dart_get_table(data, iova);
+ tbl = dart_get_index(data, iova, level);
+
+ if (tbl >= (1 << data->tbl_bits))
+ return -ENOMEM;
ptep = data->pgd[tbl];
- ptep += dart_get_l1_index(data, iova);
- pte = READ_ONCE(*ptep);
+ while (--level > 1) {
+ ptep += dart_get_index(data, iova, level);
+ pte = READ_ONCE(*ptep);
- /* no L2 table present */
- if (!pte) {
- cptep = iommu_alloc_pages_sz(gfp, tblsz);
- if (!cptep)
- return -ENOMEM;
+ /* no table present */
+ if (!pte) {
+ cptep = iommu_alloc_pages_sz(gfp, tblsz);
+ if (!cptep)
+ return -ENOMEM;
- pte = dart_install_table(cptep, ptep, 0, data);
- if (pte)
- iommu_free_pages(cptep);
+ pte = dart_install_table(cptep, ptep, 0, data);
+ if (pte)
+ iommu_free_pages(cptep);
- /* L2 table is present (now) */
- pte = READ_ONCE(*ptep);
- }
+ /* L2 table is present (now) */
+ pte = READ_ONCE(*ptep);
+ }
- ptep = iopte_deref(pte, data);
+ ptep = iopte_deref(pte, data);
+ }
/* install a leaf entries into L2 table */
prot = dart_prot_to_pte(data, iommu_prot);
- map_idx_start = dart_get_l2_index(data, iova);
+ map_idx_start = dart_get_last_index(data, iova);
max_entries = DART_PTES_PER_TABLE(data) - map_idx_start;
num_entries = min_t(int, pgcount, max_entries);
ptep += map_idx_start;
@@ -293,13 +302,13 @@ static size_t dart_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova,
if (WARN_ON(pgsize != cfg->pgsize_bitmap || !pgcount))
return 0;
- ptep = dart_get_l2(data, iova);
+ ptep = dart_get_last(data, iova);
/* Valid L2 IOPTE pointer? */
if (WARN_ON(!ptep))
return 0;
- unmap_idx_start = dart_get_l2_index(data, iova);
+ unmap_idx_start = dart_get_last_index(data, iova);
ptep += unmap_idx_start;
max_entries = DART_PTES_PER_TABLE(data) - unmap_idx_start;
@@ -330,13 +339,13 @@ static phys_addr_t dart_iova_to_phys(struct io_pgtable_ops *ops,
struct dart_io_pgtable *data = io_pgtable_ops_to_data(ops);
dart_iopte pte, *ptep;
- ptep = dart_get_l2(data, iova);
+ ptep = dart_get_last(data, iova);
/* Valid L2 IOPTE pointer? */
if (!ptep)
return 0;
- ptep += dart_get_l2_index(data, iova);
+ ptep += dart_get_last_index(data, iova);
pte = READ_ONCE(*ptep);
/* Found translation */
@@ -353,21 +362,37 @@ static struct dart_io_pgtable *
dart_alloc_pgtable(struct io_pgtable_cfg *cfg)
{
struct dart_io_pgtable *data;
- int tbl_bits, bits_per_level, va_bits, pg_shift;
+ int levels, max_tbl_bits, tbl_bits, bits_per_level, va_bits, pg_shift;
+
+ /*
+ * Old 4K page DARTs can use up to 4 top-level tables.
+ * Newer ones only ever use a maximum of 1.
+ */
+ if (cfg->pgsize_bitmap == SZ_4K)
+ max_tbl_bits = DART_MAX_TABLE_BITS;
+ else
+ max_tbl_bits = 0;
pg_shift = __ffs(cfg->pgsize_bitmap);
bits_per_level = pg_shift - ilog2(sizeof(dart_iopte));
va_bits = cfg->ias - pg_shift;
- tbl_bits = max_t(int, 0, va_bits - (bits_per_level * DART_LEVELS));
- if ((1 << tbl_bits) > DART_MAX_TABLES)
+ levels = max_t(int, 2, (va_bits - max_tbl_bits + bits_per_level - 1) / bits_per_level);
+
+ if (levels > (DART_MAX_LEVELS - 1))
+ return NULL;
+
+ tbl_bits = max_t(int, 0, va_bits - (bits_per_level * levels));
+
+ if (tbl_bits > max_tbl_bits)
return NULL;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return NULL;
+ data->levels = levels + 1; /* Table level counts as one level */
data->tbl_bits = tbl_bits;
data->bits_per_level = bits_per_level;
@@ -403,6 +428,7 @@ apple_dart_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
return NULL;
cfg->apple_dart_cfg.n_ttbrs = 1 << data->tbl_bits;
+ cfg->apple_dart_cfg.n_levels = data->levels;
for (i = 0; i < cfg->apple_dart_cfg.n_ttbrs; ++i) {
data->pgd[i] =
@@ -422,24 +448,31 @@ out_free_data:
return NULL;
}
-static void apple_dart_free_pgtable(struct io_pgtable *iop)
+static void apple_dart_free_pgtables(struct dart_io_pgtable *data, dart_iopte *ptep, int level)
{
- struct dart_io_pgtable *data = io_pgtable_to_data(iop);
- dart_iopte *ptep, *end;
- int i;
+ dart_iopte *end;
+ dart_iopte *start = ptep;
- for (i = 0; i < (1 << data->tbl_bits) && data->pgd[i]; ++i) {
- ptep = data->pgd[i];
+ if (level > 1) {
end = (void *)ptep + DART_GRANULE(data);
while (ptep != end) {
dart_iopte pte = *ptep++;
if (pte)
- iommu_free_pages(iopte_deref(pte, data));
+ apple_dart_free_pgtables(data, iopte_deref(pte, data), level - 1);
}
- iommu_free_pages(data->pgd[i]);
}
+ iommu_free_pages(start);
+}
+
+static void apple_dart_free_pgtable(struct io_pgtable *iop)
+{
+ struct dart_io_pgtable *data = io_pgtable_to_data(iop);
+ int i;
+
+ for (i = 0; i < (1 << data->tbl_bits) && data->pgd[i]; ++i)
+ apple_dart_free_pgtables(data, data->pgd[i], data->levels - 1);
kfree(data);
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-04 12:55:50 +0000