path: root/arch/arm64
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authorHuang Rui <ray.huang@amd.com>2016-12-12 07:28:26 -0500
committerJoerg Roedel <jroedel@suse.de>2017-01-04 15:22:22 +0100
commit432abf68a79332282329286d190e21fe3ac02a31 (patch)
tree2acb338f4341a7deae4fdf99579f4b7528cf55cc /arch/arm64
parent65ca7f5f7d1cdde6c25172fe6107cd16902f826f (diff)
iommu/amd: Fix the left value check of cmd buffer
The generic command buffer entry is 128 bits (16 bytes), so the offset of tail and head pointer should be 16 bytes aligned and increased with 0x10 per command. When cmd buf is full, head = (tail + 0x10) % CMD_BUFFER_SIZE. So when left space of cmd buf should be able to store only two command, we should be issued one COMPLETE_WAIT additionally to wait all older commands completed. Then the left space should be increased after IOMMU fetching from cmd buf. So left check value should be left <= 0x20 (two commands). Signed-off-by: Huang Rui <ray.huang@amd.com> Fixes: ac0ea6e92b222 ('x86/amd-iommu: Improve handling of full command buffer') Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'arch/arm64')
0 files changed, 0 insertions, 0 deletions