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Diffstat (limited to 'Documentation/virtual/kvm/devices/mpic.txt')
| -rw-r--r-- | Documentation/virtual/kvm/devices/mpic.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/mpic.txt b/Documentation/virtual/kvm/devices/mpic.txt index ce98e3264fa8..ad0ac778f20a 100644 --- a/Documentation/virtual/kvm/devices/mpic.txt +++ b/Documentation/virtual/kvm/devices/mpic.txt @@ -35,3 +35,22 @@ Groups: "attr" is the IRQ number. IRQ numbers for standard sources are the byte offset of the relevant IVPR from EIVPR0, divided by 32. + +IRQ Routing: + + The MPIC emulation supports IRQ routing. Only a single MPIC device can + be instantiated. Once that device has been created, it's available as + irqchip id 0. + + This irqchip 0 has 256 interrupt pins, which expose the interrupts in + the main array of interrupt sources (a.k.a. "SRC" interrupts). + + The numbering is the same as the MPIC device tree binding -- based on + the register offset from the beginning of the sources array, without + regard to any subdivisions in chip documentation such as "internal" + or "external" interrupts. + + Default routes are established for these pins, with the GSI being equal + to the pin number. + + Access to non-SRC interrupts is not implemented through IRQ routing mechanisms. |