DynamicTablesPkg/RiscV: Support IMSICs without guest interrupt files

ACPI 6.6 Table 5.57 requires NumGuestIds to be zero when no guest
interrupt files are implemented. The FDT parser currently defaults
the count to NumIds even when no guest index bits are present,
and the MADT generator asserts on a zero count.

Parse and validate the guest index width before deriving NumGuestIds.
An absent riscv,guest-index-bits property defaults to zero, so emit
zero guest identities for an absent or zero width without reading
the unused riscv,num-guest-ids property. For a nonzero width,
preserve the explicit guest identity count or its default from
riscv,num-ids. Validate explicit counts before narrowing, including
rejecting zero as required by the DT binding.

Allow zero in the MADT generator while preserving the bounds and
granularity checks for nonzero counts. The existing RINTC size
calculation already yields one supervisor page for zero guest index
bits and remains bounded by the DT reg extent.

Signed-off-by: Djordje Nedic <djordje.nedic@nextsilicon.com>

0 files changed, 0 insertions, 0 deletions