[PATCH v3 0/8] iommu/riscv: Add HPM support for RISC-V IOMMU

Lv Zheng
2026-02-04T09:09:18Z

Includes HPM support for RISC-V IOMMU. The HPM hardware mechanism can be
found in the recent announced SpacemiT SoCs (K3, V100), where T100
(SpacemiT distributed IOMMU) is shipped.

Revisions:
v1
Initial release.
v2 (sent as v1.1)
Split and cleanup DT-bindings.
v3
Refactor using vendor specific compatible.

The tested result can be found as follows:

root@sdfirm:~# perf stat --timeout 5000 -a -e spacemit_ioats_hpm_00/dd_walk,config1=0x20c0010000000000/ dmatest; sleep 1
[ 145.630224] dmatest: Started 1 threads using dma0chan0
[ 145.644896] dmatest: dma0chan0-copy0: summary 1 tests, 0 failures 123.60 iops 123 KB/s (0)

Performance counter stats for 'system wide':

3 spacemit_ioats_hpm_00/dd_walk,config1=0x20c0010000000000/

0.193108000 seconds time elapsed

root@sdfirm:~# echo dma0chan1 > /sys/module/dmatest/parameters/channel
[ 327.001820] dmatest: Added 1 threads using dma0chan1
root@sdfirm:~# perf stat --timeout 5000 -a -e spacemit_ioats_hpm_00/s_walk,config1=0x20c0011000000000/ dmatest; sleep 1
[ 484.037180] dmatest: Started 1 threads using dma0chan1
[ 484.048832] dmatest: dma0chan1-copy0: summary 1 tests, 0 failures 172.11 iops 172 KB/s (0)

Performance counter stats for 'system wide':

6 spacemit_ioats_hpm_00/s_walk,config1=0x20c0011000000000/

0.191970000 seconds time elapsed

root@sdfirm:~# perf stat --timeout 5000 -a -e spacemit_ioatc_hpm_0003/tlb_mis,config1=0x20c0011000000000/ dmatest; sleep 1
[ 546.332494] dmatest: No channels configured, continue with any
[ 546.363062] dmatest: Added 1 threads using dma0chan1
[ 546.377994] dmatest: Started 1 threads using dma0chan1
[ 546.388376] dmatest: dma0chan1-copy0: summary 1 tests, 0 failures 213.94 iops 213 KB/s (0)

Performance counter stats for 'system wide':

3 spacemit_ioatc_hpm_0003/tlb_mis,config1=0x20c0011000000000/

0.225062000 seconds time elapsed

Jingyu Li (3):
iommu/riscv: Enable IOMMU DMA mapping support
iommu/riscv: Fix WSI mode IRQ number handling
iommu/riscv: Add HPM support for performance monitoring

Lv Zheng (5):
dt-bindings: iommu: Add spacemit/t100 features
riscv/iommu: Add vendor event support for RISC-V IOMMU HPM
spacemit/t100: Add global filter awareness for RISC-V IOMMU HPM
spacemit/t100: Add SpacemiT T100 IOATC HPM support
perf vendor events riscv:: Add support for spacemit,riscv-iommu HPM
aliasing

.../bindings/iommu/riscv,iommu.yaml | 37 +
MAINTAINERS | 3 +
drivers/iommu/Kconfig | 2 +-
drivers/iommu/riscv/Kconfig | 9 +
drivers/iommu/riscv/Makefile | 1 +
drivers/iommu/riscv/iommu-bits.h | 18 +
drivers/iommu/riscv/iommu-hpm.c | 1122 +++++++++++++++++
drivers/iommu/riscv/iommu-pci.c | 13 +-
drivers/iommu/riscv/iommu-platform.c | 12 +-
drivers/iommu/riscv/iommu.c | 25 +-
drivers/iommu/riscv/iommu.h | 46 +-
.../arch/riscv/spacemit/iommu/sys/ioatc.json | 30 +
.../arch/riscv/spacemit/iommu/sys/ioats.json | 163 +++
13 files changed, 1469 insertions(+), 12 deletions(-)
create mode 100644 drivers/iommu/riscv/iommu-hpm.c
create mode 100644 tools/perf/pmu-events/arch/riscv/spacemit/iommu/sys/ioatc.json
create mode 100644 tools/perf/pmu-events/arch/riscv/spacemit/iommu/sys/ioats.json

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2.43.0