[Patch v6 0/9] Tegra234 Memory interconnect support

Sumit Gupta
2023-04-11T11:00:31Z

Hi All,

Thank you for the review. Have incorporated the changes suggested in
v5. Requesting for ACK on the remaining patches and please consider
for merging.

The patches are divided into below groups:

- Patch [7-8]: Memory Interconnect support in PCI (MC client)
-- Need ACK.

- Patch [3-6, 9]: Memory Interconnect support in CPUFREQ (MC client)
-- 'Patch 3, 4 & 5': have ACK from Krzysztof.
-- 'Patch 6 & 9': Need ACK.

- Patch [1-2]: Memory Interconnect base support
-- 'Patch 2': has ACK from Krzysztof.
-- 'Patch 1': Need ACK.

Both the MC client patches are dependent on the 'Patch [1-2]'.

Thank you,
Sumit Gupta
============

This patch series adds memory interconnect support for Tegra234 SoC.
It is used to dynamically scale DRAM Frequency as per the bandwidth
requests from different Memory Controller (MC) clients.
MC Clients use ICC Framework's icc_set_bw() api to dynamically request
for the DRAM bandwidth (BW). As per path, the request will be routed
from MC to the EMC driver. MC driver passes the request info like the
Client ID, type, and frequency request info to the BPMP-FW which will
set the final DRAM freq considering all exisiting requests.

MC and EMC are the ICC providers. Nodes in path for a request will be:
Client[1-n] -> MC -> EMC -> EMEM/DRAM

The patch series also adds interconnect support in below clients:
1) CPUFREQ driver for scaling bandwidth with CPU frequency. For that,
add per cluster OPP table which will be used in the CPUFREQ driver
by requesting the minimum BW respective to the given CPU frequency
in the OPP table of it's cluster.
2) PCIE driver to request BW required for different modes.

---
v5[5] -> v6:
- split PCI patch into two 'patch 7 & 8' as suggested by 'Lorenzo'.
- added more info into the commit description of PCI patches.

v4[4] -> v5:
- dropped 'patch 1 & 2' from v4 which added "nvidia,bpmp" in MC node.
- save BPMP ref from EMC node into 'mc->bpmp' and use it in MC driver.
- added check for array bounds violation in pci suggested by Bjorn.
- moved DT patch having OPP table to the last 'Patch 8'.
- did multiple small changes and cleanup suggested by Krzysztof in v4.

v3[3] -> v4:
- dropped 'patch 1' from v3 which returns 'struct tegra_bpmp *'.
- added 'patch 1 & 2' to get bpmp ref using 'nvidia,bpmp' property.
- dropped 'patch 10 & 11' from v3 and added those changes in 'patch 3'.
- added static to prototype of 'tegra_cpufreq_init_cpufreq_table()' to
fix the warning reported by 'kernel test robot'.

v2[2] -> v3:
- in 'patch 7', set 'icc_dram_bw_scaling' to false if set_opp call failed
to avoid flooding of uart with 'Failed to set bw' messages.
- added 'patch 10' to handle if the bpmp-fw is old and not support bwmgr mrq.
- added 'patch 11' to fix interconnect registration in tegra186-emc.
ref patch link in linux next:
[https://lore.kernel.org/all/20230306075651.2449-21-johan+linaro@kernel.org/]

v1[1] -> v2:
- moved BW setting to tegra234_mc_icc_set() from EMC driver.
- moved sw clients to the 'tegra_mc_clients' table.
- point 'node->data' to the entry within 'tegra_mc_clients'.
- removed 'struct tegra_icc_node' and get client info using 'node->data'.
- changed error handling in and around tegra_emc_interconnect_init().
- moved 'tegra-icc.h' from 'include/soc/tegra' to 'include/linux'.
- added interconnect support to PCIE driver in 'Patch 9'.
- merged 'Patch 9 & 10' from [1] to get num_channels and use.
- merged 'Patch 2 & 3' from [1] to add ISO and NISO clients.
- added 'Acked-by' of Krzysztof from 'Patch 05/10' of [1].
- Removed 'Patch 7' from [1] as that is merged now.

Sumit Gupta (9):
memory: tegra: add interconnect support for DRAM scaling in Tegra234
memory: tegra: add mc clients for Tegra234
memory: tegra: add software mc clients in Tegra234
dt-bindings: tegra: add icc ids for dummy MC clients
memory: tegra: make cpu cluster bw request a multiple of mc channels
cpufreq: tegra194: add OPP support and set bandwidth
PCI: tegra194: Fix possible array out of bounds access
PCI: tegra194: Add interconnect support in Tegra234
arm64: tegra: Add cpu OPP tables and interconnects property

arch/arm64/boot/dts/nvidia/tegra234.dtsi | 276 ++++++++++
drivers/cpufreq/tegra194-cpufreq.c | 156 +++++-
drivers/memory/tegra/mc.c | 24 +
drivers/memory/tegra/mc.h | 1 +
drivers/memory/tegra/tegra186-emc.c | 130 +++++
drivers/memory/tegra/tegra234.c | 595 ++++++++++++++++++++-
drivers/pci/controller/dwc/pcie-tegra194.c | 44 +-
include/dt-bindings/memory/tegra234-mc.h | 5 +
include/linux/tegra-icc.h | 65 +++
include/soc/tegra/mc.h | 8 +
10 files changed, 1282 insertions(+), 22 deletions(-)
create mode 100644 include/linux/tegra-icc.h

[1] https://lore.kernel.org/lkml/20221220160240.27494-1-sumitg@nvidia.com/
[2] https://lore.kernel.org/lkml/20230220140559.28289-1-sumitg@nvidia.com/
[3] https://lore.kernel.org/lkml/20230320182441.11904-1-sumitg@nvidia.com/
[4] https://lore.kernel.org/lkml/20230327161426.32639-1-sumitg@nvidia.com/
[5] https://lore.kernel.org/lkml/20230330133354.714-1-sumitg@nvidia.com/

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2.17.1