[PATCH] iommu/io-pgtable-arm: Fix cfg reading in arm_lpae_concat_mandatory()

[PATCH] iommu/io-pgtable-arm: Fix cfg reading in arm_lpae_concat_mandatory()

[Mostafa Saleh]

I messed up the newly introduced function arm_lpae_concat_mandatory()
where ias/oas are read from the io_pgtable_cfg copy in arm_lpae_io_pgtable.

However, this copy is set later in alloc_io_pgtable_ops() after alloc()
function was called.

I didn’t catch that with my selftesting as arm_lpae_io_pgtable is
allocated from kmalloc, which was caching old configs.

While at it, fix a couple of spaces.

Signed-off-by: Mostafa Saleh <smostafa@google.com>
---
 drivers/iommu/io-pgtable-arm.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index c1b62c7d81ba..7e53ee51270b 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -232,12 +232,13 @@ static inline int arm_lpae_max_entries(int i, struct arm_lpae_io_pgtable *data)
  *   c) 42 bits PA size with 4K: use level 1 instead of level 0 (8 tables for ias = oas)
  *   d) 48 bits PA size with 16K: use level 1 instead of level 0 (2 tables for ias = oas)
  */
-static inline bool arm_lpae_concat_mandatory(struct arm_lpae_io_pgtable *data)
+static inline bool arm_lpae_concat_mandatory(struct io_pgtable_cfg *cfg,
+					     struct arm_lpae_io_pgtable *data)
 {
-	unsigned int ias = data->iop.cfg.ias;
-	unsigned int oas = data->iop.cfg.oas;
+	unsigned int ias = cfg->ias;
+	unsigned int oas = cfg->oas;
 
-	/* Covers 1  and 2.d */
+	/* Covers 1 and 2.d */
 	if ((ARM_LPAE_GRANULE(data) == SZ_16K) && (data->start_level == 0))
 		return (oas == 48) || (ias == 48);
 
@@ -1033,7 +1034,7 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
 	if (!data)
 		return NULL;
 
-	if (arm_lpae_concat_mandatory(data))  {
+	if (arm_lpae_concat_mandatory(cfg, data)) {
 		if (WARN_ON((ARM_LPAE_PGD_SIZE(data) / sizeof(arm_lpae_iopte)) >
 			    ARM_LPAE_S2_MAX_CONCAT_PAGES))
 			return NULL;
-- 
2.47.1.613.gc27f4b7a9f-goog

Re: [PATCH] iommu/io-pgtable-arm: Fix cfg reading in arm_lpae_concat_mandatory()

[Will Deacon]

On Sun, 15 Dec 2024 20:04:11 +0000, Mostafa Saleh wrote:
> I messed up the newly introduced function arm_lpae_concat_mandatory()
> where ias/oas are read from the io_pgtable_cfg copy in arm_lpae_io_pgtable.
> 
> However, this copy is set later in alloc_io_pgtable_ops() after alloc()
> function was called.
> 
> I didn’t catch that with my selftesting as arm_lpae_io_pgtable is
> allocated from kmalloc, which was caching old configs.
> 
> [...]

Applied to will (for-joerg/arm-smmu/updates), thanks!

[1/1] iommu/io-pgtable-arm: Fix cfg reading in arm_lpae_concat_mandatory()
      https://git.kernel.org/will/c/b7b8a6305557

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
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