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Differential D43452

riscv: Introduce support for Incoming MSI Controller (IMSIC)
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Authored by himanshu_thechauhan.dev on Jan 14 2024, 6:40 AM.
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imp
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Details

Reviewers
mhorne
jrtc27
br
Summary

This patch adds support for IMSIC on RISCV architecture.
The following features are supported:

  • Interrupt delivery with aplic-imsic
  • Sending IPIs between HARTS without ecall
  • IPIs are sent IMSIC-to-IMSIC

Whats not supported:

  • MSI interrupts from devices.

MSI chosen for IPI is 1 as it has the highest priority.

IPIs over IMSIC can be disabled by "aia.imsic.ipi_disabled=1" kernel parameter.

Test Plan
  • Tested SMP boot with aplic-imsic and aplic-only.
  • Tested from 1 CPU to 16 CPUs

Diff Detail

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rG FreeBSD src repository
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Event Timeline

himanshu_thechauhan.dev created this revision.Jan 14 2024, 6:40 AM
Herald added subscribers: riscv, imp. · View Herald TranscriptJan 14 2024, 6:40 AM
himanshu_thechauhan.dev requested review of this revision.Jan 14 2024, 6:40 AM
himanshu_thechauhan.dev edited the test plan for this revision. (Show Details)Jan 14 2024, 8:35 AM
mhorne mentioned this in D35899: intrng: Allow alternative IPI PICs to be registered and used.Jan 22 2024, 4:51 PM
mmel mentioned this in D40474: intrng: call pic_init_secondary on all registered PICs.Jan 23 2024, 8:17 AM
br added a comment.Aug 13 2024, 1:29 PM

Hi Himanshu what is status of this? could you regenerate for the latest HEAD ?

himanshu_thechauhan.dev added a comment.Aug 14 2024, 6:39 AM
In D43452#1055467, @br wrote:

Hi Himanshu what is status of this? could you regenerate for the latest HEAD ?

Hi Ruslan,

This patch (and the latest one I have) depend on D40474 for the correct ordering of initialisation. Do we have any idea on how to close D40474?
I can generate the patch on current HEAD, no problem.

himanshu_thechauhan.dev retitled this revision from [RFC] riscv: Introduce support for Incoming MSI Controller (IMSIC) to riscv: Introduce support for Incoming MSI Controller (IMSIC).Dec 23 2024, 5:50 PM
himanshu_thechauhan.dev edited the summary of this revision. (Show Details)
himanshu_thechauhan.dev edited the test plan for this revision. (Show Details)
himanshu_thechauhan.dev updated this revision to Diff 148351.Dec 23 2024, 5:52 PM
  • Refactor aplic code into common init and aplic/imsic specific code.
  • Add support for IMSIC.
himanshu_thechauhan.dev added a comment.Jun 12 2025, 4:53 PM

Shall I send a new patch? No comments on this one.

br added a comment.Jan 30 2026, 4:38 PM

how hard it would be to implement MSI interface here? to support MSI interrupts from devices, which is a crucial functionality

sys/riscv/include/cpufunc.h
60

looks like these macroses used just once in entire code, so we can remove them?

sys/riscv/riscv/aplic.c
646

look like magic numbers all around

Revision Contents
Changeset List

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sys/
conf/
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riscv/
include/
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32 lines
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riscv/
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Diff 148351

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sys/conf/files.riscv

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sys/riscv/include/cpufunc.h

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sys/riscv/include/imsic.h

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sys/riscv/include/intr.h

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sys/riscv/riscv/aplic.c

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sys/riscv/riscv/imsic.c

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