@@ -79,6 +79,8 @@
#define ARM_LPAE_PTE_SH_IS (((arm_lpae_iopte)3) << 8)
#define ARM_LPAE_PTE_NS (((arm_lpae_iopte)1) << 5)
#define ARM_LPAE_PTE_VALID (((arm_lpae_iopte)1) << 0)
+/* Block descriptor bits */
+#define ARM_LPAE_PTE_NT (((arm_lpae_iopte)1) << 16)
#define ARM_LPAE_PTE_ATTR_LO_MASK (((arm_lpae_iopte)0x3ff) << 2)
/* Ignore the contiguous bit for block splitting */
@@ -679,6 +681,125 @@ static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
return iopte_to_paddr(pte, data) | iova;
}
+static size_t __arm_lpae_split_block(struct arm_lpae_io_pgtable *data,
+ unsigned long iova, size_t size, int lvl,
+ arm_lpae_iopte *ptep);
+
+static size_t arm_lpae_do_split_blk(struct arm_lpae_io_pgtable *data,
+ unsigned long iova, size_t size,
+ arm_lpae_iopte blk_pte, int lvl,
+ arm_lpae_iopte *ptep)
+{
+ 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;
+
+ if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
+ return 0;
+
+ tablep = __arm_lpae_alloc_pages(tablesz, GFP_ATOMIC, cfg);
+ if (!tablep)
+ return 0;
+
+ 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)
+ __arm_lpae_init_pte(data, blk_paddr, pte, lvl, &tablep[i]);
+
+ if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_BBML1) {
+ /* Race does not exist */
+ blk_pte |= ARM_LPAE_PTE_NT;
+ __arm_lpae_set_pte(ptep, blk_pte, cfg);
+ io_pgtable_tlb_flush_walk(&data->iop, iova, size, size);
+ }
+ /* Race does not exist */
+ pte = arm_lpae_install_table(tablep, ptep, blk_pte, cfg);
+
+ /* Have splited it into page? */
+ if (lvl == (ARM_LPAE_MAX_LEVELS - 1))
+ return size;
+
+ /* Go back to lvl - 1 */
+ ptep -= ARM_LPAE_LVL_IDX(iova, lvl - 1, data);
+ return __arm_lpae_split_block(data, iova, size, lvl - 1, ptep);
+}
+
+static size_t __arm_lpae_split_block(struct arm_lpae_io_pgtable *data,
+ unsigned long iova, size_t size, int lvl,
+ arm_lpae_iopte *ptep)
+{
+ arm_lpae_iopte pte;
+ struct io_pgtable *iop = &data->iop;
+ size_t base, next_size, total_size;
+
+ if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
+ return 0;
+
+ ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+ pte = READ_ONCE(*ptep);
+ if (WARN_ON(!pte))
+ return 0;
+
+ if (size == ARM_LPAE_BLOCK_SIZE(lvl, data)) {
+ if (iopte_leaf(pte, lvl, iop->fmt)) {
+ if (lvl == (ARM_LPAE_MAX_LEVELS - 1) ||
+ (pte & ARM_LPAE_PTE_AP_RDONLY))
+ return size;
+
+ /* We find a writable block, split it. */
+ return arm_lpae_do_split_blk(data, iova, size, pte,
+ lvl + 1, ptep);
+ } else {
+ /* If it is the last table level, then nothing to do */
+ if (lvl == (ARM_LPAE_MAX_LEVELS - 2))
+ return size;
+
+ total_size = 0;
+ next_size = ARM_LPAE_BLOCK_SIZE(lvl + 1, data);
+ ptep = iopte_deref(pte, data);
+ for (base = 0; base < size; base += next_size)
+ total_size += __arm_lpae_split_block(data,
+ iova + base, next_size, lvl + 1,
+ ptep);
+ return total_size;
+ }
+ } else if (iopte_leaf(pte, lvl, iop->fmt)) {
+ WARN(1, "Can't split behind a block.\n");
+ return 0;
+ }
+
+ /* Keep on walkin */
+ ptep = iopte_deref(pte, data);
+ return __arm_lpae_split_block(data, iova, size, lvl + 1, ptep);
+}
+
+static size_t arm_lpae_split_block(struct io_pgtable_ops *ops,
+ unsigned long iova, size_t size)
+{
+ 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;
+ int lvl = data->start_level;
+ long iaext = (s64)iova >> cfg->ias;
+
+ if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
+ return 0;
+
+ if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1)
+ iaext = ~iaext;
+ if (WARN_ON(iaext))
+ return 0;
+
+ /* If it is smallest granule, then nothing to do */
+ if (size == ARM_LPAE_BLOCK_SIZE(ARM_LPAE_MAX_LEVELS - 1, data))
+ return size;
+
+ return __arm_lpae_split_block(data, iova, size, lvl, ptep);
+}
+
static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
{
unsigned long granule, page_sizes;
@@ -757,6 +878,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
.map = arm_lpae_map,
.unmap = arm_lpae_unmap,
.iova_to_phys = arm_lpae_iova_to_phys,
+ .split_block = arm_lpae_split_block,
};
return data;
@@ -167,6 +167,8 @@ struct io_pgtable_ops {
size_t size, struct iommu_iotlb_gather *gather);
phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
unsigned long iova);
+ size_t (*split_block)(struct io_pgtable_ops *ops, unsigned long iova,
+ size_t size);
};
/**