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

Signed-off-by: Isaac J. Manjarres <isa...@codeaurora.org>
Suggested-by: Will Deacon <w...@kernel.org>
---
 drivers/iommu/io-pgtable-arm.c | 124 +++++++++++++++++++++++++++------
 1 file changed, 104 insertions(+), 20 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 87def58e79b5..fc63d57b8037 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -60,6 +60,14 @@
 /* Calculate the block/page mapping size at level l for pagetable in d. */
 #define ARM_LPAE_BLOCK_SIZE(l,d)       (1ULL << ARM_LPAE_LVL_SHIFT(l,d))
 
+/*
+ * Calculate the level that corresponds to the block/page mapping for pagetable
+ * in d.
+ */
+#define ARM_LPAE_BLOCK_SIZE_LVL(s, d)                                  \
+       ((ARM_LPAE_MAX_LEVELS -                                         \
+         ((ilog2((s)) - ilog2(sizeof(arm_lpae_iopte))) / (d)->bits_per_level)))
+
 /* Page table bits */
 #define ARM_LPAE_PTE_TYPE_SHIFT                0
 #define ARM_LPAE_PTE_TYPE_MASK         0x3
@@ -248,10 +256,26 @@ static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, 
arm_lpae_iopte pte,
                __arm_lpae_sync_pte(ptep, cfg);
 }
 
+static void __arm_lpae_sync_ptes(arm_lpae_iopte *ptep, size_t num_ptes,
+                                struct io_pgtable_cfg *cfg)
+{
+       dma_sync_single_for_device(cfg->iommu_dev, __arm_lpae_dma_addr(ptep),
+                                  sizeof(*ptep) * num_ptes, DMA_TO_DEVICE);
+}
+
+static void __arm_lpae_clear_ptes(arm_lpae_iopte *ptep, size_t num_ptes,
+                                 struct io_pgtable_cfg *cfg)
+{
+       memset(ptep, 0, sizeof(*ptep) * num_ptes);
+
+       if (!cfg->coherent_walk)
+               __arm_lpae_sync_ptes(ptep, num_ptes, 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,
@@ -289,7 +313,7 @@ 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, sz, lvl, tblp) != sz) {
+               if (__arm_lpae_unmap(data, NULL, iova, sz, 1, lvl, tblp) != sz) 
{
                        WARN_ON(1);
                        return -EINVAL;
                }
@@ -516,14 +540,14 @@ 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 i, unmap_idx_start = -1;
 
        if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
                return 0;
@@ -533,14 +557,14 @@ static size_t arm_lpae_split_blk_unmap(struct 
arm_lpae_io_pgtable *data,
                return 0; /* Bytes unmapped */
 
        if (size == split_sz)
-               unmap_idx = ARM_LPAE_LVL_IDX(iova, lvl, data);
+               unmap_idx_start = ARM_LPAE_LVL_IDX(iova, lvl, data);
 
        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) {
                /* Unmap! */
-               if (i == unmap_idx)
+               if (i >= unmap_idx_start && i < (unmap_idx_start + pgcount))
                        continue;
 
                __arm_lpae_init_pte(data, blk_paddr, pte, lvl, &tablep[i]);
@@ -558,20 +582,24 @@ 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 < pgcount; i++) {
+                       io_pgtable_tlb_add_page(&data->iop, gather, iova, size);
+                       iova += size;
+               }
+               return pgcount * 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;
+       size_t i;
        struct io_pgtable *iop = &data->iop;
 
        /* Something went horribly wrong and we ran out of page table */
@@ -585,11 +613,11 @@ 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_clear_ptes(ptep, pgcount, &iop->cfg);
 
                if (!iopte_leaf(pte, lvl, iop->fmt)) {
                        /* Also flush any partial walks */
-                       io_pgtable_tlb_flush_walk(iop, iova, size,
+                       io_pgtable_tlb_flush_walk(iop, iova, pgcount * size,
                                                  ARM_LPAE_GRANULE(data));
                        ptep = iopte_deref(pte, data);
                        __arm_lpae_free_pgtable(data, lvl + 1, ptep);
@@ -601,22 +629,25 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable 
*data,
                         */
                        smp_wmb();
                } else {
-                       io_pgtable_tlb_add_page(iop, gather, iova, size);
+                       for (i = 0; i < pgcount; i++) {
+                               io_pgtable_tlb_add_page(iop, gather, iova, 
size);
+                               iova += size;
+                       }
                }
 
-               return size;
+               return pgcount * 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,
@@ -635,7 +666,59 @@ 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, size, 1, data->start_level, 
ptep);
+}
+
+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;
+       size_t unmapped = 0, unmapped_page;
+       int last_lvl;
+       size_t table_size, pages, tbl_offset, max_entries;
+
+       if (WARN_ON(!pgsize || (pgsize & cfg->pgsize_bitmap) != pgsize || 
!pgcount))
+               return 0;
+
+       if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1)
+               iaext = ~iaext;
+       if (WARN_ON(iaext))
+               return 0;
+
+       /*
+        * Calculating the page table size here helps avoid situations where
+        * a page range that is being unmapped may be mapped at the same level
+        * but not mapped by the same tables. Allowing such a scenario to
+        * occur can complicate the logic in arm_lpae_split_blk_unmap().
+        */
+       last_lvl = ARM_LPAE_BLOCK_SIZE_LVL(pgsize, data);
+
+       if (last_lvl == data->start_level)
+               table_size = ARM_LPAE_PGD_SIZE(data);
+       else
+               table_size = ARM_LPAE_GRANULE(data);
+
+       max_entries = table_size / sizeof(*ptep);
+
+       while (pgcount) {
+               tbl_offset = ARM_LPAE_LVL_IDX(iova, last_lvl, data);
+               pages = min_t(size_t, pgcount, max_entries - tbl_offset);
+               unmapped_page = __arm_lpae_unmap(data, gather, iova, pgsize,
+                                                pages, data->start_level,
+                                                ptep);
+               if (!unmapped_page)
+                       break;
+
+               unmapped += unmapped_page;
+               iova += unmapped_page;
+               pgcount -= pages;
+       }
+
+       return unmapped;
 }
 
 static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
@@ -751,6 +834,7 @@ 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,
        };
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to