On 2026/08/05 04:39 PM, Mahesh Salgaonkar wrote: > Current Power system firmware caps the PVR list array size at 16 entries > during CAS (Client Architecture Support) negotiation. Passing more than > capped size to older firmware could cause an undefined behaviour and > breaks compatibility. > > Future Power system firmware releases will lift this restriction and > support greater than 16 array entries. > > Ensure that when running on Power11 or below hardware, the number > of PVR entries passed during CAS negotiation does not exceed the > firmware-imposed limit of 16. > > In prom_send_capabilities(), compute start_index to skip the oldest > leading pvrs[] entries when running on Power11 or below hardware, so > that the pointer passed to ibm,client-architecture-support points to > ibm_architecture_vec.pvrs[start_index], presenting exactly 16 entries to > firmware. > > Signed-off-by: Mahesh Salgaonkar <[email protected]> > Tested-by: Praveen K Pandey <[email protected]> > --- > Change in v3: > - Remove unintentional whitespace change. > > Change in v2: > - Define a named macro CAS_MAX_PVR_ENTRIES > --- > arch/powerpc/kernel/prom_init.c | 34 +++++++++++++++++++++++++++------ > 1 file changed, 28 insertions(+), 6 deletions(-)
Reviewed-by: Amit Machhiwal <[email protected]> ~Amit
