[PATCH v3 0/2] iommu: rockchip: Fix directory table address encoding

Jonas Karlman jonas at kwiboo.se
Sat Jun 17 11:25:44 PDT 2023


The address to the directory table is currently encoded using an
incorrect bit layout when configured into the DTE_ADDR reg on IOMMU v2.

This currently do not cause any issue because the directory and page
tables is allocated in memory below 4GB thanks to the use of the
GFP_DMA32 flag.

Testing has shown that the directory table address should be encoded
using the same bit layout as the page table and memory page addresses.

Only removing the GFP_DMA32 on a RK3568 device with 8GB of memory will
result in a page fault similar to:

[    0.907236] rk_iommu fe043e00.iommu: Page fault at 0x00000000ff801000 of type read
[    0.907264] rk_iommu fe043e00.iommu: iova = 0x00000000ff801000: dte_index: 0x3fe pte_index: 0x1 page_offset: 0x0
[    0.907281] rk_iommu fe043e00.iommu: mmu_dte_addr: 0x000000010189a000 dte at 0x000000010189aff8: 0x1722101 valid: 1 pte at 0x0000000101722004: 0x2c01107 valid: 1 page at 0x0000000102c01000 flags: 0x106

This series fixes this by using the existing mk_dtentries instead of the
dma_addr_dte ops to encode the directory table address, removes unused
ops and finally removes the GFP_DMA32 flag to allow for directory and
page tables to be allocated in memory above 4GB on IOMMU v2.

Changes in v3:
- merge patch 1 and 2
- only remove GFP_DMA32 flag for IOMMU v2

Changes in v2:
- no changes, rebased on next-20230615

This series can also be found at [1].

[1] https://github.com/Kwiboo/linux-rockchip/commits/next-20230616-iommu

Jonas Karlman (2):
  iommu: rockchip: Fix directory table address encoding
  iommu: rockchip: Allocate tables from all available memory for IOMMU
    v2

 drivers/iommu/rockchip-iommu.c | 50 +++++++---------------------------
 1 file changed, 10 insertions(+), 40 deletions(-)

-- 
2.40.1




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