[PATCH] iommu/io-pgtable-arm: Fix table descriptor paddr formatting

From: Hector Martin
Date: Wed Nov 17 2021 - 12:13:08 EST


Table descriptors were being installed without properly formatting the
address using paddr_to_iopte, which does not match up with the
iopte_deref in __arm_lpae_map. This is incorrect for the LPAE pte
format, as it does not handle the high bits properly.

This was found on Apple T6000 DARTs, which require a new pte format
(different shift); adding support for that to
paddr_to_iopte/iopte_to_paddr caused it to break badly, as even <48-bit
addresses would end up incorrect in that case.

Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
drivers/iommu/io-pgtable-arm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index dd9e47189d0d..b636e2737607 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -315,12 +315,12 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table,
arm_lpae_iopte *ptep,
arm_lpae_iopte curr,
- struct io_pgtable_cfg *cfg)
+ struct arm_lpae_io_pgtable *data)
{
arm_lpae_iopte old, new;

- new = __pa(table) | ARM_LPAE_PTE_TYPE_TABLE;
- if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
+ new = paddr_to_iopte(__pa(table), data) | ARM_LPAE_PTE_TYPE_TABLE;
+ if (data->iop.cfg.quirks & IO_PGTABLE_QUIRK_ARM_NS)
new |= ARM_LPAE_PTE_NSTABLE;

/*
@@ -332,11 +332,11 @@ static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table,

old = cmpxchg64_relaxed(ptep, curr, new);

- if (cfg->coherent_walk || (old & ARM_LPAE_PTE_SW_SYNC))
+ if (data->iop.cfg.coherent_walk || (old & ARM_LPAE_PTE_SW_SYNC))
return old;

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

@@ -380,7 +380,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
if (!cptep)
return -ENOMEM;

- pte = arm_lpae_install_table(cptep, ptep, 0, cfg);
+ pte = arm_lpae_install_table(cptep, ptep, 0, data);
if (pte)
__arm_lpae_free_pages(cptep, tblsz, cfg);
} else if (!cfg->coherent_walk && !(pte & ARM_LPAE_PTE_SW_SYNC)) {
@@ -592,7 +592,7 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
__arm_lpae_init_pte(data, blk_paddr, pte, lvl, 1, &tablep[i]);
}

- pte = arm_lpae_install_table(tablep, ptep, blk_pte, cfg);
+ pte = arm_lpae_install_table(tablep, ptep, blk_pte, data);
if (pte != blk_pte) {
__arm_lpae_free_pages(tablep, tablesz, cfg);
/*
--
2.33.0