[PATCH 1/3] iommu/io-pgtable-arm: Add nents_per_pgtable in struct io_pgtable_cfg

[Nicolin Chen]

Add a new nents_per_pgtable in struct io_pgtable_cfg to store the number
of entries per IO pagetable, so it can be passed back to an IOMMU driver.
It will be used by one of the following changes to set the maximum number
of TLBI operations in the arm-smmu-v3 driver.

Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
 drivers/iommu/io-pgtable-arm.c | 3 +++
 include/linux/io-pgtable.h     | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 72dcdd468cf3..7583d9ecca2b 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -891,6 +891,7 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
 
 	/* TTBR */
 	cfg->arm_lpae_s1_cfg.ttbr = virt_to_phys(data->pgd);
+	cfg->nents_per_pgtable = 1 << data->bits_per_level;
 	return &data->iop;
 
 out_free_data:
@@ -993,6 +994,7 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
 
 	/* VTTBR */
 	cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd);
+	cfg->nents_per_pgtable = 1 << data->bits_per_level;
 	return &data->iop;
 
 out_free_data:
@@ -1071,6 +1073,7 @@ arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie)
 					  ARM_MALI_LPAE_TTBR_ADRMODE_TABLE;
 	if (cfg->coherent_walk)
 		cfg->arm_mali_lpae_cfg.transtab |= ARM_MALI_LPAE_TTBR_SHARE_OUTER;
+	cfg->nents_per_pgtable = 1 << data->bits_per_level;
 
 	return &data->iop;
 
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 1b7a44b35616..4b55a327abc1 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -55,6 +55,7 @@ struct iommu_flush_ops {
  *                 tables.
  * @ias:           Input address (iova) size, in bits.
  * @oas:           Output address (paddr) size, in bits.
+ * @nents_per_pgtable: Number of entries per page table.
  * @coherent_walk  A flag to indicate whether or not page table walks made
  *                 by the IOMMU are coherent with the CPU caches.
  * @tlb:           TLB management callbacks for this set of tables.
@@ -96,6 +97,7 @@ struct io_pgtable_cfg {
 	unsigned long			pgsize_bitmap;
 	unsigned int			ias;
 	unsigned int			oas;
+	unsigned int			nents_per_pgtable;
 	bool				coherent_walk;
 	const struct iommu_flush_ops	*tlb;
 	struct device			*iommu_dev;
-- 
2.41.0